Invasion History

First Non-native North American Tidal Record: 1902
First Non-native West Coast Tidal Record: 1902
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

Magallana angulata gigas is native to the northwest Pacific including Russia, China, and Korea. Its native range may extend south and west into the Philippines and Indonesia, to Borneo and Sumatra, and west to Pakistan (Carriker and Gaffney 1996). However, the presence of several closely related species and the morphological variation of M. gigas make the boundaries of its range difficult to assess. It is the most widely transplanted shellfish in the world, introduced to at least 52 countries (Food and Agricultural Organization 1998; Ruesink et al. 2005). It is now the world's most widely cultivated oyster. It has established breeding populations in the northeast Pacific (US-Canada), southwest Pacific (Australia-New Zealand), northeast Atlantic-Mediterranean (Europe), southwest Atlantic (Argentina-Brazil), and Indian Ocean (South Africa). It is also successfully cultured using hatcheries and imported spat in many places where conditions are unsuitable for breeding, and has been introduced unsuccessfully to many regions (Food and Agricultural Organization 1998; Ruesink et al. 2005). A repeated pattern in different regions has been for M. gigas to go from being largely confined to culture areas, with only sporadic and limited reproduction, to becoming a major biomass component and ecosystem engineer. This process, which has taken 3-10 decades, has occurred in British Columbia and Washington State (Quayle 1969; Klinger et al. 2006; Kelly et al. 2008; Padilla 2010), the North Sea in Europe (Diederich 2005; Beukema and Dekker 2011), the Atlantic coast of Patagonia (Escapa 2004), Hawaii (Carlton and Eldredge 2009), and Australia (Krassoi et al. 2008). The transition from cultured hatchery-dependent populations, to feral self-sustaining populations complicates the assignment of dates of invasion.

North American Invasion History:

Invasion History on the West Coast:

In North America, Magallana gigas was first introduced to Puget Sound, Washington (WA) in 1902, following overfishing of the native Olympic Oyster (Ostrea lurida) and unsuccessful stocking of M. virginica (Eastern Oyster). Early transplants were unsuccessful due to mortality in shipping, but after numerous subsequent imports, large-scale cultivation was underway in Washington State by 1928 (Chew 1979). In British Columbia, imports began in 1912, but large-scale natural spawning was not seen until 1932 (Quayle 1969). Fairly regular settlement of M. gigas spat, outside areas of cultivation, now occurs from Pendrell Sound, British Columbia, to Willapa Bay, WA (Quayle 1969; Ruesink et al. 2005). This species is now the basis of the West Coast oyster industry, with commercial culture taking place from southern British Columbia to Morro Bay, California (CA) (Chew 1979; Quayle 1969; Conte 1996). However, these operations were largely dependent on imported seed from Japan, and later (1970s onward) on hatchery-reared spat (Barrett 1963; Quayle 1969; Carlton 1979; Conte 1996). South of Willapa Bay, natural spawnings of M. gigas were rare (Span 1978; Carlton 1979; Boyd et al. 2000; Coan et al. 2000), but hatchery-based oyster aquaculture operations occur in several Oregon bays and south to Morro Bay, CA (Carlton 1979; Conte 1996), the Pacific Coast of Baja California (Rodriguez and Ibarra-Obando 2008), and the Gulf of California (Arizpe 1996).

In California, since 2000, there have been collections of 'wild' M. gigas in San Francisco Bay and southern California estuaries (Andy Chang, personal communication; Ruiz et al. unpublished data; Cohen et al. 2002; de Rivera et al. 2005; Burnaford et al. 2011; Goodwin et al. 2011). At least some of the San Francisco Bay occurrences have resulted from the breeding of illegally planted M. gigas (Andy Chang, personal communication). Transport of oysters in ship fouling or larvae in ballast water are also possible vectors. There is some evidence for multiple cohorts of oysters in San Francisco Bay, but at this time we consider the establishment of M. gigas to be uncertain.

Invasion History on the East Coast:

Magallana gigas attracted some attention in the mid-20th century because of its large size and rapid growth. A bushel of Pacific Oysters was planted in Barnegat Bay, New Jersey, but failed to grow, and died within two years. A number of illegal and government plantings were made in estuaries from Delaware to Maine from the 1930s to the 1980s, but settlement of larvae and establishment of Pacific Oysters was not observed (Dean 1979; Hickey 1979; Andrews 1980). There was particular interest in Maine, because of the limited existing Eastern Oyster (M. virginica) stocks there. Plantings were made in 1949 in Blue Hill Bay and in the 1970s in Damariscotta River and Goose Pond, a lagoon of Penobscot Bay (Dean 1979; Shatkin et al. 1997). However, we are not aware of more recent introduction attempts.

Around Chesapeake Bay, interest in M. gigas intensified as the native M. virginica  declined due to overfishing and disease (MSX- Haplosporidium nelsoni, Dermo- Perkinsus marinus). Magallana gigas was considered to be more disease-resistant than the Eastern Oyster, and was considered as a potential replacement, especially in Virginia, where oyster losses were greatest (Andrews 1980; DuPaul 1992). Numerous culture experiments were undertaken with diploid and triploid (sterile) M. gigas in order to assess the disease resistance of the Pacific Oyster and its adaptability to the Chesapeake Bay environment. Experiments in quarantined flumes indicated that M. gigas had lower prevalence and intensity of P. marinus and H. nelsoni infections (Barber 1996; Barber and Mann 1994; Chu et al. 1996; Krantz 1992). Plantings of sterile triploid M. gigas in Chesapeake Bay, Virginia, and North Carolina indicated that this oyster grew well at high salinities, but performed poorly at low salinities (Calvo et al. 1999; Grabowski et al. 2004). Benefits of a disease-resistant oyster would include restoration of the oyster-reef environment and of a filter-feeding biomass in at least part of Chesapeake Bay, as well as revival of oystering (Gottlieb and Schweighofer 1996; Lipton et al. 1992; Mann et al. 1991). Although M. gigas showed strong disease resistance, trials in Chesapeake Bay suggested that this oyster was not well-adapted to the local environment. In quarantined flumes, M. gigas had high non-disease mortality in summer (Barber and Mann 1994), and heavy Polydora spp. infestations (Mann and Burreson 1994; DeBrosse and Allen 1996). By 1998-2000, research interests in Virginia and North Carolina had shifted to M. ariakensis, which demonstrated better growth and survival under Chesapeake Bay conditions (Hallerman et al. 2001; National Research Council 2003).

Invasion History on the Gulf Coast:

At least one unsuccessful attempt was made to introduce M. gigas to the Gulf Coast. Kavanaugh (1941) reported very briefly that 'Japanese oysters' in Louisiana, showed 'amazingly serious infestation' by spionid polychaetes (Polydora spp.), and that native oysters were not seriously affected. This is the only report that we have of this oyster in the Gulf of Mexico.

Invasion History in Hawaii:

A small shipment of M. gigas was planted at Mokapu, Oahu on Kaneohe Bay in 1926, but did not become established. Larger plantings were made at Pearl Harbor in 1938, and in Kaneohe Bay (2 million spat planted) in 1939. Pacific Oysters are now established in Pearl Harbor and abundant in Kaneohe Bay (Coles et al. 1999; Coles et al. 2002; Carlton and Eldredge 2009 - 2000 oysters planted, established).

Invasion History Elsewhere in the World:

In the northeastern Atlantic, Magallana gigas was imported to Marennes, France in small quantities in 1966. This was followed by a disease epizootic in M. angulata (Portuguese Oyster), which was then the predominant commercial species (itself imported to supplant the overfished Ostrea edulis or the European Flat Oyster). Consequently, large imports of M. gigas were made to replace the lost M. angulata stocks (Grizel and Héral 1991). In the United Kingdom, laboratory stocks were imported in 1965 and 1972, and the experimental field plantings of lab-reared spat, in 1967 and 1973. Spawning and recruitment were rare in British waters, owing to low water temperatures (Walne and Helm 1979). Extensive plantings of M. gigas were made in the Atlantic waters of Europe in the 1970s, from Spain to Ireland, and east to Germany and Denmark (Ruesink et al. 2005; Minchin 2007; Troost 2010; Wrange et al. 2010). This culture was largely hatchery-based, but natural spawning and settlement were seen in the 1970s and 1980s in many locations, particularly the Wadden Sea area of the Netherlands, Germany and Denmark (Reise 1998; Gittenberger et al. 2010; Troost 2010; Wrange et al. 2010), where extensive oyster beds were replacing mussel beds by the year 2000. The occurrence of successful spawning and massive recruitment in northern Europe in recent decades has been attributed in part to climate change (Troost 2010; Wrange et al. 2010; Thomas et al. 2016). Successful spawning and apparent establishment took place by 2007 in Espevik, Norway (60⁰N). Established populations also occur in Denmark and Sweden, along the Kattegatt, at the mouth of the Baltic (Wrange et al. 2010) and along the Atlantic coast of France, Portugal and Spain (Grizel and Héral 1991, Ruesink et al. 2005). Hatchery and wild M. gigas populations along the Atlantic coasts of Europe, from Germany (Sylt) to southern France (Arcachon), show little genetic differentiation, being strongly determined by hatchery and aquaculture practices (Meistertzheim et al. 2013).

Magallana gigas, imported from Japan, was first introduced to the Mediterranean Sea by 1964, in the Thau Lagoon, near Sete, France, again as a replacement for declining stocks of Ostrea edulis and M. angulata. It soon was widely cultured in the Mediterranean from Morocco to Israel (Ruesink et al. 2005). This oyster appears to be, at least locally, established in coastal lagoons and estuaries in Tunisia, France, Italy, Greece, and Turkey (Zenetos et al. 2003; Ruesink et al. 2005; Zenetos et al. 2005; Albayrak 2011; Antit et al. 2011). The status of M. gigas in the Black Sea is uncertain - it is known mostly as single individuals near ports and oyster farms (Skarlato and Sarobogov 1972, cited by Zoloterev 1996; Gomiou et al. 2002; Skolka and Preda 2010).

Magallana gigas has been widely cultured in the Southern Hemisphere, beginning in 1947 in Tasmania, Australia (Nell 2001), in 1950 in South Africa (Robinson et al. 2005), and in 1977 in Chile (Castilla et al. 2005). In Chile, Pacific Oysters remain confined to aquaculture facilities, possibly because of low water temperatures (Castilla et al. 2005). However, breeding populations quickly developed in Tasmania and by the 1960s in mainland Australia (Nell 2001), and locally by 2001 on the southern coast of South Africa (Robinson et al. 2005). In Argentina, a failed aquaculture operation led to established populations on the Patagonian coast (Orensanz et al. 2002; Escapa 2004). Surprisingly, spat and adults of M. gigas were identified by molecular means in cultures of native oysters (M. brasiliana and M. rhizophorae) in Brazil, at latitudes between 27 and 29⁰S (Melo et al. 2010). Some populations of M. gigas in New Zealand (1st record 1961, Cranfield et al. 1998) are believed to have resulted in transport by shipping, and are not associated with known aquaculture operations (Krassoi et al. 2008). Pacific Oysters have been widely introduced to tropical and subtropical regions and islands (e.g., Puerto Rico, Virgin Islands, Madeira, Guam, Tonga, Fiji, Belize, Malaysia), but with the exception of Hawaii, these introductions have not resulted in established populations or successful hatchery-based aquaculture (Ruesink et al. 2005). Carrasco and Baron (2010) concluded that M. gigas could establish populations in regions with mean sea surface temperature ranging from 14 to 28.9⁰C for the warmest month and from -1.9 to 19.8⁰C for the coldest month of the year. The Pacific Oyster's occurrence in slightly warmer water in Brazil may have been due to unintentional selection of oysters in Brazilian shellfish laboratories (Melo et al. 2010).


Description

Magallana gigas resembles other oysters in having unequal valves and an irregular shape. The shape of the shell varies greatly with the growth environment. For instance, on hard substrate the shell can be rounded, domed and fluted; on soft substrate it can be flatter and less ridged; and when crowded the shell is often narrower (Quayle 1969). The right (lower) valve may be deeply cupped. Both valves are covered with concentric growth layers (lamellae) on the outer surface, but with fewer and stronger ridges on the left (upper) side. The edges of the lamellae are strongly rippled into spines and ridges (Coan and Valentich-Scott 2007; Langdon and Robinson 1996). Shells can be white to off-white to gray, sometimes with brown or purple on the ridges. The interior of the shell is smooth and white, with a purple muscle scar (Quayle 1969; Coan et al. 2000). Magallana gigas matures at about 80 mm, but is reported to occasionally grow to 400-450 mm (Carriker and Gaffney 1996). The larvae are illustrated by Quayle (1969). Early veligers are nearly circular, but late larvae of this and other oysters are distinguished by the asymmetrical umbo. They settle at a length of about 300 µm (Quayle 1969).

Magallana gigas is a genetically diverse species. In different parts of Japan, different strains are cultivated with different growth patterns and ecological preferences. The most widely planted form is the Miyagi strain, from the central Pacific coast of Japan which is large and fast-growing (Quayle 1969). In addition, many closely related species are found in the Northwest and Indo-West Pacific regions. Magallana angulata (Portuguese Oyster), introduced to Europe in the 16th century, is very closely related (Ó'Foighil et al. 1998; Huvet et al. 2004; Lapegue et al. 2004; Reece et al. 2008).

The genus name Magallana has been proposed for Pacific members of the genus Crassostrea, based on genetic divergence between Pacific and Atlantic oysters of the genus (Salvi et al. 2014; Salvi and Mariottini 2020). Bayne and 23 co-authors disagreed with the proposed name changes, based on the limited scope of the genetic analysis, the absence of morphological differentiation, and the inconveninece of changing thename of an economically important species (Bayne et al. 2017). A further genetic analysis by Salvi and Mariottini (2020) owed that the Indo-Pacific and western Atlantic 'Crassotrea' clustered in two separate groups, justifying the use of the name Magallana for the Indo-Pacific species (James T. Carlton, personal communication).


Taxonomy

Taxonomic Tree

Kingdom:   Animalia
Phylum:   Mollusca
Class:   Bivalvia
Subclass:   Pteriomorphia
Order:   Ostreoida
Family:   Ostreidae
Species:   gigas

Synonyms

Crassostrea angulata (Lamarck, 1819)
Ostrea gigas (Thunberg, 1793)
Magallana gigas (Salvi & Marriotini, 2016)

Potentially Misidentified Species

Alectryonella plicatula
Plicate Kitten's Paw Oyster, Large Indo-Paciifc oyster, cultivated in China (Carriker and Gaffney 1996)

Crassostrea virginica
Eastern Oyster

Magallana angulata
Portuguese Oyster, closely related, native to the northwest Pacific (Japan and China), introduced to Europe in the 16th-17th centuries, and described from the Tagus River, Portugal in 1817 (Wolff and Reise 2002). Genetic barcoding indicates that the two species have been separate for 2.7 million years. Crassostrea anuglata is dominant cupped oyster species in Taiwan and southern China (Hsiao et al. 2016).

Magallana ariakensis
Suminoe Oyster, Chinese River Oyster, native to China, cultured, with unsuccessful introductions in Yaquina Bay, Oregon, and Puget Sound (Carriker and Gaffney 1996)

Magallana hongkongensis
Closely related, cutivated in the Pearl River Delta, China.

Magallana sikamea
The Kumamoto Oyster is under limited cultivation in US waters. It does not spawn in Puget Sound, because of low water temperatures, and so is available in summer, when other oysters are out of season (Washington Sea Grant 2002, http://wsg.washington.edu/oysterstew/cool/oystervarieties.html)

Ostrea lurida
Olympic Oyster, northeast Pacific native

Ecology

General:

Magallana gigas like other oysters, is a protandric hermaphrodite, maturing first as a male, and then often becoming female in subsequent seasons. Females release eggs and males release sperm into the water column, where fertilization occurs. The fertilized egg develops first into a ciliated trochophore larva, and then into a shelled veliger larva. The larva feeds on phytoplankton, and grows, eventually developing a foot and becoming a pediveliger, competent for settlement. In laboratory culture, larval settlement occurred at about 11-30 days at 16 to 30⁰C (Quayle 1969; His et al. 1989). Gonads can develop in M. gigas at 80 mm (National Research Council 2003). Adult M. gigas feed on phytoplankton of 6-32 um with ~100% retention efficiency, but are less efficient with smaller organisms (Nielsen et al. 2016). Adult oysters are reported to grow to 450 mm, although 300 mm in length is a more typical maximum (Quayle 1969; Carriker and Gaffney 1996).

Magallana gigas is characteristic of protected coastal waters in China and Japan. This oyster normally grows at salinities of 23-28 PSU, and can tolerate brief exposures to salinities as low as 5-10 PSU (Nell and Holliday 1988; Carriker and Gaffney 1996; Gray and Langdon 2018). It tolerates a very wide temperature range, from -1.8 to 35⁰C, although temperatures over 30⁰C are stressful (Shpigel et al. 1992; Carrasco and Barón 2010). Settlement and survival are best at sites at sites portected from wave exposure (Teschke et al. 2020).

Food:

Phytoplankton

Consumers:

Crabs, Fishes, Starfish, Humans

Trophic Status:

Suspension Feeder

SusFed

Habitats

General HabitatOyster ReefNone
General HabitatCoarse Woody DebrisNone
General HabitatMarinas & DocksNone
General HabitatRockyNone
General HabitatVessel HullNone
General HabitatMangrovesNone
Salinity RangeMesohaline5-18 PSU
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Tidal RangeLow IntertidalNone
Vertical HabitatEpibenthicNone


Tolerances and Life History Parameters

Minimum Temperature (ºC)-1.8Based on geographical range (Carrasco and Baron 2010).
Maximum Temperature (ºC)35<i>Crassostrea gigas</i> (Pacific Oysters) shows signs of metabolic stress at 30 C (Shpigel et al. 1992; Gray and Langdon 2018).
Minimum Salinity (‰)5Substantial growth and reproduction occurs only above 20 ppt. (His et al. 1989; Mann et al. 1991; Nell and Holliday 1988; Gray and Langdon 2018).
Maximum Salinity (‰)41Successful aquaculture, Nell and Holliday 1988
Minimum Reproductive Temperature16Field and experimental data (His 1991; Mann et al. 1991)
Maximum Reproductive Temperature30Field and experimental data (His 1991; Mann et al. 1991)
Minimum Reproductive Salinity15Experimental conditions for larval growth (Nell and Holliday 1988). Optimum salinities for reproduction and larval growth are 20-30 ppt (His et al. 1989; Mann et al. 1991; Nell and Holliday 1988).
Maximum Reproductive Salinity40Experimental conditions for larval growth (Nell and Holliday 1988). Optimum salinities for reproduction and larval growth are 20-30 ppt (His et al. 1989; Mann et al. 1991; Nell and Holliday 1988).
Minimum Duration11Larval Period (His et al. 1989)
Maximum Duration30Larval Period (His et al. 1989)
Minimum Length (mm)80Carriker and Gaffney (1996)
Maximum Length (mm)450Carriker and Gaffney (1996)
Broad Temperature RangeNoneCold temperate-Warm temperate
Broad Salinity RangeNoneMesohaline-Euhaline

General Impacts

Magallana gigas is the world's most widely cultivated and eaten shellfish (Carriker and Gaffney 1996; Ruesink et al. 2005), but it is also a highly successful invader, and a powerful ecosystem engineer, creating complex reefs, replacing native shellfish, and altering estuarine foodwebs through suspension-feeding (Herbert et al. 2016).

Economic Impacts

Fisheries - Magallana gigas is the most widely cultivated and harvested shellfish species in the world, introduced to at least 52 countries (Carriker and Gaffney 1996; Ruesink et al. 2005). Among the more notable introductions have been those to the west coast of North America (Chew 1979; Quayle 1969), European waters (Grizel and Héral 1991; Walne and Helm 1979), and Australia (Nell 2001). The disease resistance of this oyster, its adaptability to a wide range of environments, the long development of culture techniques, and its large size are among the reasons for its widespread introduction (Quayle 1969; Andrews 1980; Mann et al. 1991; Ruesink et al. 2005). Profitable culture in natural waters is possible, using hatcheries or imported seed, even in regions where M. gigas cannot breed successfully in the wild, such as California and Pacific Mexico (Arizpe 1996; Conte 1996; Ruesink et al. 2005).

Disadvantages include bland flavor compared to other species, including Ostrea eduis and M. virginica (DuPaul 1992), and risks to native oyster populations, including competition, hybridization, and introductions of associated organisms (parasites, fouling species and oyster predators) (Galtsoff 1932; Grizel and Héral 1991; Mann et al. 1991; Ruesink et al. 2005). In the Wadden Sea area of northern Europe, settlement of M. gigas has covered valuable beds of mussels (Mytilus edulis) and cockles (Cerastoderma edule), and interfered with the use of fishnets (Troost 2010). In Willapa Bay and Grays Harbor, Washington (WA), the pesticide Carbaryl is used to kill mud shrimps which burrow in oyster beds, creating general environmental concerns, as well as killing other fisheries species, such as Dungeness Crabs (Metacarcinus magister) and English Sole (Parophrys vetulus).

Ecological Impacts

Competition - Introductions of new oyster species are often motivated by the decline of the previously dominant oyster due to overfishing or disease, but in some cases they have led to further damage to the remaining populations. Introductions of M. angulata (Portuguese Oyster) in France coincided with the decline of the native Ostrea edulis (European Flat Oyster) in the 19th century (Galtsoff 1932); the replacement of M. angulata by M. gigas in the 1970's seems to have largely been a consequence of a disease of unknown origin (Grizel and Héral 1991). In Australia, competition with M. gigas is considered a threat to the native Saccostrea commercialis (Sydney Rock Oyster) (Mann et al. 1991; Nell 2001). On the West Coast of North America, competition between M. gigas and the native Olympia Oyster (Ostrea lurida) is limited since M. gigas tends to settle, and is cultivated in intertidal areas, while the native oyster tends to grow in lower intertidal and subtidal areas. However, where they do overlap, M. gigas grows much faster, and has a higher filtration rate (Ruesink et al. 2005).

Magallana gigas also competes for space and food with bivalves other than oysters, such as Mytilus edulis (Blue Mussel) and Cerastoderma edule (Common Cockle). In the Wadden Sea (southern North Sea) of Netherlands-Germany-Denmark, M. gigas has been settling on intertidal mussel and cockle beds (Reise 1998; Diederich 2005).

Habitat Change - Both cultivated populations of M. gigas and naturally settled reefs can make large structural changes in littoral communities. These changes are greatest in soft-bottom habitats, such as Willapa Bay, WA; Bahia Anagada, Argentina; and the Wadden Sea (southern North Sea) of Netherlands-Germany-Denmark, which include vast intertidal mudflats. Cultivation takes place on man-made structures, while natural beds result from settlement on mussel beds, logs, or other isolated hard substrates (Escapa 2004; Ruesink et al. 2005; Ruesink et al. 2006; Troost 2010). Cultivated and natural beds create large, complex structures, with extensive hard substrate for organisms to settle on, and lots of nooks and crannies providing shelter for native and introduced mobile organisms (Escapa 2004; Diederich 2005; Hosack et al. 2006; Ruesink et al. 2006; Gittenberger et al. 2010; Markert et al. 2010; LeJart and Hily 2011). While Pacific Oysters settle on and cover mussel beds, they also provide substrate for mussel settlement, and can result in increased biodiversity in their invaded habitats (Markert et al. 2010; LeJart and Hily 2011). On hard substrates, such as rocky shores, impacts of M. gigas are less dramatic (Ruesink et al. 2005). However, intertidal oysters provide a light-colored substrate, cooler than exposed dark rocks, and favoring the survival of limpets (Lottia sp.) at high tide (Padilla 2010), and also increase habitat for barnacle settlement (Bourne 1979, cited by Ruesink et al. 2005). The deposits of pseudofeces can also increase the diversity and abundance of deposit feeders (LeJart and Hily 2011).

Invasions by M. gigas do have negative impacts on habitats. Their high filtration rates result in the deposition of partially digested pseudofeces, which can accumulate around the oyster beds, creating anoxic zones in the sediment, limiting infauna and adversely affecting eelgrass beds (Kelly et al. 2008; Troost 2010). The large accumulations of shell which M. gigas creates in the intertidal zone have a negative effect on the native oyster (O. lurida) by attracting large numbers of settling larvae to the intertidal zone, where their survival is poor, acting as a recruitment sink (Ruesink et al. 2005).

Parasite-Predator vector - In many regions of the world, parasites, epifauna, and predators have been imported with shipments of M. gigas. Known parasites of M. gigas which are now established on the Pacific coast of North America, or in France, include three viruses, three bacterial diseases, three protistans (other than haplosporidians) (Marteilia refringens, Marteilioides chungmuensis and Mikrocytos mackini), the copepod Mytilicola orientalis, and at least one disease of unknown etiology (Mann et al. 1991). The first imports of M. gigas to France coincided with a viral epizootic which largely wiped out the then-dominant commercial oyster M. angulata (Portuguese Oyster), but the origin of this disease is unknown (Grizel and Héral 1991). Many species of macro-organisms have been introduced to, or transferred locally in European and West Coast waters with M. gigas, these include macroalgae (eg. Sargassum muticum), flatworms (Pseudostylochus ostreophagus), snails (e.g. Pteropurpura inornata, Japanese Oyster Drill), clams, bryozoans (Schizoporella japonica), and tunicates (Perophora japonica, Styela clava). Some of these species have had negative impacts on oysters and surrounding communities (Cohen and Carlton 1995; Grizel and Héral 1991; Mann et al. 1991; Cohen et al. 1998; Reise et al. 1999; Goulletquer et al. 2002).

However, the associate of M. gigas which has had the largest ecological and economic impact is probably the protist Haplosporidium nelsoni, which infects the Pacific Oyster with minimal symptoms, but produces the symptoms of the MSX disease, with high mortality, in the Eastern Oyster (M. virginica) (Friedman 1996; Burreson et al. 2000). From 1958 to the present, outbreaks of this disease have caused high mortality in Chesapeake and Delaware Bays, and elsewhere on the East Coast of North America. It seems likely that one of the many early unofficial introductions of M. gigas to the East Coast may have introduced H. nelsoni, although transport of oysters in fouling or spores in ballast water cannot be excluded (Burreson et al. 2000).

In a sort of reverse-parasite vector role, Magallana gigas, together with the Common Atlantic Slipper Shell Crepidula fornicata and other filter feeders, such as the Softshell Clam (Mya arenaria) were found to affect transmission of native parasites (the trematode Himasthla elongata) of the Common Cockle (Cerastoderma edule) and the Blue Mussel (Mytilus edulis), by filtering out the metacercariae, without becoming infected themselves. The effect of these invaders was to reduce the parasite load of the native bivalves (Thieltges et al. 2008; Thieltges et al. 2009).

While it is a highly desired seafood item, Magallana gigas is also an ecosystem engineer and poses a challenge to managers of marine protected areas. This oyster can interfere with native mussel fisheries, create reefs which can obstruct navigation, litter beaches with 'razor-sharp' shells, and drastically effect native marine communities. Regional planning and risk assessment is desirable for oyster culture operations in new areas. Environmental measurements can be used to determine the risk of reproduction of cultured oysters. One option is to require use of triploid oysters in culture, to limit reproduction, but reversion of triploids can occur. Heavy settlement of 'wild' oysters can interfere with culture operations by fouling equipment and cultured oysters. Dredging has been used to eliminate 'wild' oysters, but the habitat damage is considerable. In some areas, hand collection is sufficient to maintain oyster-free zones (Herbert et al. 2016).

Regional Impacts

NEP-IIIAlaskan panhandle to N. of Puget SoundEcological ImpactHabitat Change
On San Juan Island, Washington, intertidal M. gigas altered rocky shore communities by providing a light-colored substrate, decreasing substrate temperatures from a maximum of 56°C to 41°C. On average, oysters were 3.3°C cooler than surrounding rocks, and supported higher densities of limpets (4 species, Lottia strigatella, L. pelta, L. scutum, and L. digitalis). The most abundant limpet, L. strigatella was 3X more abundant on oysters than on surrounding rocks (Padilla 2010; Herbert et al. 2016). On rocky shores of British Columbia, where M. gigas primarily recruits in the upper intertidal zone, it increases the amount of habitat available for barnacle settlement (Bourne 1979, cited by Ruesink et al. 2005). Expanding cultivated and feral oyster beds of M. gigas have resulted in the reduction of Eelgrass (Zosters marina) beds on Cortes Island, in Georgia Strait, British Columbia. Eelgrass tends to disappear in areas seaward of the beds as well. These areas had reduced abundance of epifaunal invertebrates, but increased abundance of infauna (Kelly et al. 2008). The large accumulations of shells which M. gigas creates in the intertidal zone has a negative effect on the native oyster by attracting large numbers of settling larvae of O. lurida, in the intertdal zone, where their survival is poor, acting as a recruitment sink (Ruesink et al. 2005).
P292_CDA_P292 (San Juan Islands)Ecological ImpactHabitat Change
On San Juan Island, Washington, intertidal M. gigas altered rocky shore communities by providing a light-colored substrate, decreasing substrate temperatures from a maximum of 56°C to 41°C. On average, oysters were 3.3°C cooler than surrounding rocks, and supported higher densities of limpets (4 species, Lottia strigatella, L. pelta, L. scutum, and L. digitalis). The most abundant limpet, L. strigatella was 3X more abundant on oysters than on surrounding rocks (Padilla 2010).
NEA-IINoneEcological ImpactHabitat Change
On the Wadden Sea Coast of Germany and the Netherlands, M. gigas has been settling on mussel (Mytilus edulis) beds growing on mudflats, since at least 1991, resulting in overgrowth of mussels and attached barnacles, converting mussel beds to extensive oyster beds (Reise 1998; Diederich 2005; Gittenberger et al. 2010; Walles et al. 2015; Herbert et al. 2016). Oysterbeds provide potential habitat for attached algae, but native forms are outcompeted by the introduced Sargassum muticum (Lang and Buschbaum 2010). Overall, C. gigas beds supported greater abundance and diversity of native epi-and infauna than mussel beds (Markert et al. 2010). Oyster reefs are stablilizing the sediment, but also increasing the deposition of organic material (as pseudofeces), forming anoxic layers (Troost 2010). In experimental plantings, the polychaete Lanice conchilega was more abundant on oyster rings and the oligochaete Tubificoides benedeni on mussel rings (Kochman et al. 2013). Settling of spat of C. gigas on shells of Littorina littorea (Common Periwinkle) had adverse impacts on the movement, growth, and reproduction of this snail in the Wadden Sea (Germany) (Eschweiler and Buschbaum 2011). While invasion of mudflat and mussel bed habitats altered the density and diversity of epifauna, benthic assemlages were similar between C. gigas and native Ostrea edulis communities in Strangford Lough, Northern Ireland (Zwerschke et al. 2016; Zwerschke et al. 2018). However, a later study in Strangford Lough found that epibiota were more diverse on O. edulis than M. gigas, possibly because of the flakier nature of the M. gigas shell (Guy et al. 2018).

The development and consolidation of Pacific Oyster beds in the Wadden Sea has had mixed effects on shorebirds. Eurasian Oystercatchers (Haematopus ostralegus) fed more easily when oysters successfully recruited, while as young oysters grew, and the reef consolidated, feeding was more difficult, but birds were able to maintain a steady intake. Eurasian Curlews (Numenius arquata) were favored by increased density of Green Crabs (Carcinus maenas), while the feeding of Herring Gulls (Larus argentatus) was hampered by the replacement of mussel beds with oysterbeds (Markert et al. 2013). Waser et al. (2016) found that 46 of 50 species of shore- and waterbirds were not affected by the replacement of mussels with oysters. However, the abundances of 4 birds, Common Gulls (Larus canus), Common Eiders (Somateria mollissima), Eurasian Oystercatchers (Haematopus ostralegus), and Red Knots (Calidris canutus) was reduced when oysters were dominant. On the whole, the authors considered that negative impacts from oyster removal exceeded the oysters' negative impacts on bird populations (Waser et al. 2016). On a mudfalt in southeast England, areas colonized by oysters were ustilized by greater numbers of Eurasion Oystercatchers and Curlews, but smaller numbers of smaller shorebiurds (Herbert et al. 2018).

Markert (2020) has published a detailed study of the structure of oyster reefs in the Wadden Sea, and comparisons with native reefs of the Blue Mussel (Mytilus edulis), as habitats for nstive and non-indigenousspecies.
B-IINoneEcological ImpactCompetition
Moderate level of community impacts (Kattegatt and Belt Seas) (Zaiko et al. 2011)
B-IINoneEcological ImpactHabitat Change
Moderate level of habitat impacts (Kattegatt and Belt Seas) (Zaiko et al. 2011).
P110Tomales BayEconomic ImpactFisheries
Commercial oyster operations, using M. gigas began in Tomales Bay in 1928, and continue to the present. Oyster culture here was intially dependent on seed imported from Japan, but now uses seed produced in US hatcheries (Barrett 1963; Conte 1996).
NEP-VNorthern California to Mid Channel IslandsEconomic ImpactFisheries
Commercial oyster operations, using M. gigas began in Tomales Bay in 1928, and continue to the present. Major locations of oyster rearing included Morro Bay, Elkhorn Slough, Drakes Estero, and Tomales Bay (Barrett 1963; Carlton 1979; Conte 1996). Culture of M. gigas continues in Morro Bay, Drakes Estero and Tomales Bay (Conte 1996). In San Francisco Bay, commercial Pacfiic Oyster rearing occurred form 1932 to 1939. Oyster culture here was intially dependent on seed imported from Japan, but now uses seed produced in US hatcheries (Barrett 1963, Conte 1996). California Pacific Oyster growers produced 1.5 million pounds of shucked meat in 1995. About 90% of Calfornia's production occurred in Drakes Estero and Humboldt Bays (Conte 1996).
P100Drakes EsteroEconomic ImpactFisheries
Commercial culture of M. gigas began in Drakes Estero in 1932 and continues to the present. Oyster culture here was intially dependent on seed imported from Japan, but now uses seed produced in US hatcheries (Barrett 1963, Conte 1996). Drakes Estero is one of the two most important oyster-growing sites in California About 90% of production occurred in Drakes Estero and Humboldt Bays (Conte 1996).
P080Monterey BayEconomic ImpactFisheries
Culture of M. gigas continued in Elkhorn Slough from 1929 to the 1980s (Barrett 1963; Conte 1996; Wasson et al. 2001)
P070Morro BayEconomic ImpactFisheries
Culture of M. gigas in Morro Bay started in 1932 and continues to the present (Barrett 1963; Conte 1996; Morro Bay National Estuary Program 2005 http://www.mbnep.org/index.php).
P090San Francisco BayEconomic ImpactFisheries
Commercial rearing of M. gigas took place in San Francisco Bay from 1932 to 1939, when the company involved went out of business (Barrett 1963).
P112_CDA_P112 (Bodega Bay)Economic ImpactFisheries
Commercial rearing of M. gigas occurred in San Francisco Bay from 1932 to 1938 (Barrett 1963, cited by Carlton 1979)
NEP-VIINoneEconomic ImpactFisheries
Crassostrea gigas has been reared in oyster farms in the Gulf of California since 1973. This oyster does not reproduce successfully here, so the operations are dependent on hatcheries (Arizpe 1996; Caceras-Martinez et al. 2007).
NEP-VIPt. Conception to Southern Baja CaliforniaEconomic ImpactFisheries
Substantial aquaculture operations for M. gigas occur in Bahia San Quitin, Baja California, Mexico (Rodriguez and Ibarra-Obando 2008).
P130Humboldt BayEconomic ImpactFisheries
Magallana gigas is reared in extensive aquaculture operations in Humboldt Bay. These began in 1953 and continue to the present. About 90% of Calfornia's production occurred in Drakes Estero and Humboldt Bays (Conte 1996).
P170Coos BayEconomic ImpactFisheries
Culture of M. gigas continues in Coos Bay to the present (Oregon Department of Fish and Wildlife http://www.dfw.state.or.us/mrp/shellfish/bayclams/about_oysters.asp)
P180Umpqua RiverEconomic ImpactFisheries
Culture of M. gigas continues in Winchester Bay (a subestuary) to the present day (Oregon Department of State Lands 2011, http://www.oregon.gov/DSL/SSNERR/docs/EFS/EFS34aquaculture.pdf?ga=t)
NEP-IVPuget Sound to Northern CaliforniaEconomic ImpactFisheries
Willapa Bay and Grays Harbor are major oyster-growing areas, producing more than 10% of the US oyster crop, through intensively managed culture (Feldman et al. 2000; Ruesink et al. 2006). A negative impact of this aquaculture operation is the use of the pesticide carbaryl to kill the mud shrimps Neotrypaea californiensis and Upogebia pugettensis, which interfere with oyster culture by burrowing and suspending sediment. The pesticide also kills juvenile Dungeness Crabs (Metacarcinus magister), English sole (Parophrys vetulus), and other commerical and sport fishery species, as well as raising general environmental concerns (Feldman et al. 2000).

In Oregon, aquaculture of M. gigas began in 1906 in Yaquina Bay, and 1940-1948 in Netarts, Tillamook, Winchester, and Coos Bays (Carlton 1979), and continues to the present day (Oregon Department of Fish and Wildlife 2011, http://www.dfw.state.or.us/mrp/shellfish/bayclams/about_oysters.asp; Oregon Department of State Lands 2011, http://www.oregon.gov/DSL/SSNERR/docs/EFS/EFS34aquaculture.pdf?ga=t).
P230Netarts BayEconomic ImpactFisheries
None
P240Tillamook BayEconomic ImpactFisheries
Magallana gigas (Pacific Oyster) are currently cultured in Tillamook Bay (Oregon Department of Fish and Wildlife 2011; http://www.dfw.state.or.us/mrp/shellfish/bayclams/about_oysters.asp).
P270Willapa BayEconomic ImpactFisheries
Willapa Bay is a major oyster-growing area, producing 10% of the US oyster crop, through intensively managed culture (Ruesink et all. 2006). A negative impact of this aquaculture operation is the use of the pesticide carbaryl to kill the mud shrimps Neotrypaea californiensis and Upogebia pugettensis, which interfere with oyster culture by burrowing and suspending sediment. The pesticide also kills juvenile Dungeness Crabs (Metacarcinus magister), English sole (Parophrys vetulus), and other commerical and sport fishery species, as well as raising general environmental concerns (Feldman et al. 2000).
NEP-IVPuget Sound to Northern CaliforniaEcological ImpactHabitat Change
Intensive oyster production has greatly altered Willapa Bay. Most of the production takes place in the intertidal zone, which was formerly mudflat. The native Olympic Oyster, O. lurida, now rare, was primarily subtidal. Oyster growth in the interitdal zone has created large areas of hard, stuctured habitat, which supports greatly increased densities of epibenthic invertebrates, incluiding mussels, scaleworms, and tube-dwelling amphipods (Ruesink et al. 2005; Ruesink et al. 2006; Hosack et al. 2006). However, the large accumulations of shell which M. gigas creates in the intertidal zone has a negetive effect on the native oyster by attracting large numbers of settling larvae of O. lurida, in the interitdal zone, where their survival is poor, acting as a recuriment sink (Ruesink et al. 2005)
P270Willapa BayEcological ImpactHabitat Change
Intensive oyster production has greatly altered Willapa Bay. Most of the production takes place in the intertidal zone, which was formerly mudflat. The native Olympic Oyster, O. lurida, now rare, was primarily subtidal. Oyster growth in the intertidal zone has created large areas of hard, stuctured habitat, which supports greatly increased densities of epibenthic invertebrates, including mussels, scaleworms, and tube-dwelling amphipods (Ruesink et al. 2005; Ruesink et al. 2006; Hosack et al. 2006). However, the large accumulations of shell which M. gigas creates in the intertidal zone has a negative effect on the native oyster by attracting large numbers of settling larvae of O. lurida, to the interitdal zone, where their survival is poor, acting as a recuriment sink (Ruesink et al. 2005).
P270Willapa BayEcological ImpactHerbivory
The greatly increased oyster biomass has resulted in an increase in filtration rate of about 25%, from 0.8 to 1.3% of the bay's volume. This is an underestimate, since it is based on harvested biomass, and excludes feral populations of M. gigas. However, oyster-rearing habitat consitutes only a small portion of Willapa Bays area (Ferraro and Cole 2007).
NEP-IVPuget Sound to Northern CaliforniaEcological ImpactHerbivory
The greatly increased oyster biomass has resulted in an increase in filtration rate of about 25%, from 0.8 to 1.3% of the bay's volume (Ruesink et al. 2006). This is an underestimate, since it is based on harvested biomass, and excludes feral populations of M. gigas.
P280Grays HarborEconomic ImpactFisheries
Grays Harbor is a major oyster-growing area, producing 10% of the US oyster crop, through intensively managed culture. A negative impact of this aquaculture operation is the use of the pesticide carbaryl to kill the mud shrimps Neotrypaea californiensis and Upogebia pugettensis, which interfere with oyster culture by burrowing and suspending sediment. The pesticide also kills juvenile Dungeness Crabs (Metacarcinus magister), English sole (Parophrys vetulus), and other commerical and sport fishery species, as well as raising general environmental concerns (Feldman et al. 2000).
P290Puget SoundEconomic ImpactFisheries
Magallana gigas has been reared in Puget Sound since 1902 in commercial operations (Carlton 1979). Commercial rearing includes bottom and raft culture in many of the Bay's inlets. However, pollution limits the extent of oyster culture. The fishery is largely dependent on hatcheries for reproduction, but some natural settlement occurs (Carlton 1979; Quayle 1969; Pauley et al. 1988; Cohen et al. 2001).
NEP-IIIAlaskan panhandle to N. of Puget SoundEconomic ImpactFisheries
Magallana gigas has been reared in Puget Sound since 1902 in commercial operations (Carlton 1979). Commercial rearing includes bottom and raft culture in many of the Sound's inlets. However, pollution limits the extent of oyster culture. The fishery is largely dependent on hatcheries for reproduction, but some natural settlement occurs (Pauley et al. 1998; Cohen et al. 2001). In British Columbia, plantings began around 1912. Fisheries gradually expanded, especially with a mass spawning in 1958, but closures due to sewage pollution in the 1960s began to limit harvests in developed areas (Quayle 1969). Since the 1990s, most culture in British Columbia has primarily used raft culture on suspended ropes (BC Shellfish Grower's Association 2011; http://bcsga.ca/about/industry-encyclopedia/oysters/). In 2005, 7,638 tonnes of Pacific oysters were produced in British Columbia at a value of $8 million CAN (Canadian department of Fisheries and Oceans 2006; http://www.dfo-mpo.gc.ca/aquaculture/shellfish-mollusque/pac_oyster-huitre-eng.htm).
NEP-IIAlaska south of Aluetians to the Alaskan panhandleEconomic ImpactFisheries
Crassostrea gigas (Pacific Oyster) is cultured in Alaska waters, but does not reproduce. Culture is dependent on hatcheries (Hines et al. 2000; Hines et al. 2001).
NEA-IINoneEcological ImpactCompetition
On the Wadden Sea Coast of Germany, M. gigas has been settling on mussel (Mytilus edulis) beds growing on mudflats, since at least 1991, resulting in overgrowth of mussels and attached barnacles, converting mussel beds to oyster beds (Reise 1998; Baird 2012). However, year to year variation in oyster spawning and settlement, the steadier recruitment of mussels, and the poor settlement of oysters on mussels covered with the seaweed Fucus vesiculosus allow for the co-occurrence of oysters and mussels (Diederich 2005).
SA-INoneEcological ImpactHabitat Change
Oyster beds of M. gigas in Bahia Anagada in Argentina supported higher concentrations of benthic invertebrates than adjacent marsh zones. However, the overall effect of the oyster beds was small, owing to the limited amount of hard substrate for oyster settlement (Escapa 2004; Herbert et al. 2016). Tide pools on the reefs provide a new habitat for a variety of native seaweeds (Croce and Parodi 2012). In surveys at El Condor, settlement of invertebrates in oyster beds did not consistently differ from control plots (36-41 S, Mendez et al. 2015)
AUS-XNoneEconomic ImpactFisheries
Magallana gigas has ben cultured in New South Wales since 1967 (Nell 2001), although it has been regarded as a pest for competition with the native Sydney Rock Oyster (Saccostrea glomerata) (Nell et al. 2001; Krassoi et al. 2008). In the Port Jackson estuary, M. gigas outnumbered S. glomerata in the upper reaches fo the estuary (Scanes et al. 2016).
AUS-XNoneEcological ImpactCompetition
Magallana gigas overgrows and smothers the native Sydney Rock Oyster (Saccostrea glomerata) in subtidal to mid-intertidal zones, but has 80% mortality in the high intertidal zone, where S. glomerata dominates. Magallana gigas has superior growth rates to S. glomerata, but is less tolerant of abiotic stress (Krassoi et al. 2008). The larger recruits of M. gigas have greater survival than S. glomerata under various condtions of density and predation reduction (Hedge and Johnston 2014).
NZ-IVNoneEconomic ImpactFisheries
Magallana gigas is actively fished and cultured in New Zealand (Ruesink et al. 2005).
NZ-IVNoneEcological ImpactCompetition
'Following the first observation of M. gigas in Mahurangi Harbour, New Zealand in 1971, the ratio of oyster recruits rapidly changed from 1000 native Saccostrea glomerata to every M. gigas in 1972, to four exotic oyster recruits to every native recruit in 1978' (Dinamani 1991, cited by Krassoi et al. 2008). Magallana gigas has much higher growth rates and fecuundity than the native S. glomerata (Sydney Rock Oyster) (Krassoi et al. 2008).
AUS-IXNoneEconomic ImpactFisheries
Oyster culture continues in southern Tasmania, using intertidal baskets (Nell 2001).
AUS-VIINoneEconomic ImpactFisheries
Extensive oyster culture (M. gigas), using hatcheries and spat imported from Tasmania, continues in South Australia (Nell 2001).
NEP-IVPuget Sound to Northern CaliforniaEcological ImpactCompetition
Competition between the introduced Pacific Oyster (Magallana gigas) and the native Olympia Oyster (Ostrea lurida) is expected to be minimal, since M. gigas tends to settle, and is cultivated in intertidal areas, while the native oyster tends to grow in the lower intertidal and subtidal areas. However, where they do overlap, M. gigas grows much faster, and has a higher filtration rate (Ruesink et al. 2005). Competition for space occurs when M. gigas displaces native Eelgrass (Zostera marina), in culture operations (Wagner et al. 2012).
P270Willapa BayEcological ImpactCompetition
Competition between the introduced Pacific Oyster (Magallana gigas) and the native Olympia Oyster (Ostrea lurida) is expected to be minimal, since M. gigas tends to settle, and is cultivated in intertidal areas, while the native oyster tends to grow in lower intertidal and subtidal areas. However, where they do overlap, M. gigas grows much faster, and has a higher filtration rate (Ruesink et al. 2005). Competition for space occurs when M. gigas displaces native Eelgrass (Zostera marina), in culture operations (Wagner et al. 2012).
P270Willapa BayEcological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators in Willapa Bay, including Pteropurpura (=Ocinebrellus) inornata (Japanese Oyster Drill), the parasitic copepod Mytilicola orientalis (widespread), the bryozoan Schizoporella japonica, and the tunicate Botrylloides violaceus (Carlton 1979; Cohen et al. 2001).
NEA-IINoneEconomic ImpactFisheries
In northern Europe, overfishing and pollution led to a great decline in stocks of the native Flat Oyster (Ostrea edulis). The native oyster was partially replaced by cultured seed of the Portuguese Oyster (M. angulata), imported from Portugal or Spain. However, diseases in the 1960s and 70s ended this trade, and led to searches for a new oyster. Magallana gigas was introduced into waters of the United Kingdom in 1965 (Walne and Helm 1979; Utting and Spencer 1992). Similar introductions took place in the Netherlands (in 1965), Belgium (in 1969, Kerckhof et al. 2007), Ireland (in 1969, Minchin 2007), Germany (in 1986, Reise 1998), Denmark (in 1972, Wrange et al. 2010). Initially, aquaculture was dependent on hatcheries, but natural spawning and recruitment was seen at some locations in the late 1980s to the present, with extensive oyster beds forming in the Wadden Sea (Netherlands-Germany-Denmark) (Reise 1998; Gittenberger et al. 2010; Troost 2010).

Negative impacts of fisheries include reduction of areas where fishnets can be used, declines in biomass of Blue Mussels (Mytilus edulis) and Common Cockles (Cerastoderma edule) (Troost 2010).

The expansion of Pacific Oyster aquaculture in the Netherlands, as well as the expansion of wild beds, and increasing populations of the American razor clam Ensis leei, has been associated with a decrease in yeilds of cultured mussels (Mytilus edulis) and Edible Cockles (Cerastoderma edule) (Smaal et al. 2013).
AR-VNoneEconomic ImpactFisheries
Oyster aquaculture, began in 1979, and was dependent on imported seed, and later on seed from hatcheries (Hopkins 2002; Wrange et al. 2010).
NEA-IVNoneEconomic ImpactFisheries
Magallana gigas (Pacific Oyster) was introduced after the decline of M. angulata (Potuguese Oyster) due to disease. It is intensively reared along the Atlantic coast of France (Grizel and Hèral 1993; Goulletquer et al. 2002).
NEA-VNoneEconomic ImpactFisheries
Magallana gigas (Pacific Oyster) is reared extensively in the Bay of Biscay (France-Spain) (Grizel and Héral 1991; de Montaudouin et al. 1999) and on the Atlantic coast of Spain and Portugal (Ruiz et al. 1992; Ruesink et al. 2005).
MED-IINoneEconomic ImpactFisheries
Magallanaa gigas (Pacific Oyster) is intensively cultivated in lagoons on the Languedoc coast of France, particularly the Thau lagoon (Grizel and Hèral 1991). Aquaculture is also reported on the coasts of Algeria, Spain, and Italy (Ruesink et al. 2005).
MED-INoneEconomic ImpactFisheries
Magallana gigas (Pacific Oyster) is cultivated in Morocco, and probably on the Atlantic Coast of Spain, although natural reproduction is not documented (Ruesink et al. 2005).
MED-IIINoneEconomic ImpactFisheries
Magallana gigas (Pacific Oyster) is cultivated in Italy and Tunisia (Ruesink et al. 2005; Antit et al. 2011)
MED-VIINoneEconomic ImpactFisheries
Magallana gigas (Pacific Oyster) is cultivated in Italy (Cesari and Pellizzato 1985; Ruesink et al. 2005).
WA-IVNoneEconomic ImpactFisheries
Crassostrea gigas (Pacific Oyster) is currently cultivated in several farms in Namibia and along the Atlantic coast of South Africa (Robinson et al. 2005; Ruesink et al. 2005; Haupt et al. 2010).
WA-VNoneEconomic ImpactFisheries
Magallana gigas (Pacific Oyster) is currently cultivated in several farms in Namibia and along the Atlantic coast of South Africa (Robinson et al. 2005; Ruesink et al. 2005; Haupt et al. 2010).
EA-VNoneEconomic ImpactFisheries
Mgallana gigas (Pacific Oyster) is currently cultivated in Mauritius (Ruesink et al. 2005)
MED-VNoneEconomic ImpactFisheries
Magallana gigas (Pacific Oyster) is cultivated in Israel (Ruesink et al. 2005)
SA-IINoneEconomic ImpactFisheries
Magallana gigas (Pacific Oyster) was reared in hatcheries, beginning in 1974, and farmed in southern Brazilian waters. Oysters were bred selectively for tolerance to higher temperatures (Melo et al. 2010).
P210Yaquina BayEconomic ImpactFisheries
Magallana gigas (Pacific Oyster) are currently cultured in Yaquina Bay (Oregon Department of Fish and Wildlife 2011 http://www.dfw.state.or.us/mrp/shellfish/bayclams/about_oysters.asp).
NEA-IIINoneEconomic ImpactFisheries
Magallana gigas is extensively cultured on the coast of southwestern England and Ireland (Utting and Spencer 1992; Minchin 2007)
SEP-BNoneEconomic ImpactFisheries
Crassostrea gigas is extensively reared in Chile. In 1999, 5441 tons were harvested, but reproduction is dependent on hatcheries (Castilla et al. 2005).
NEP-VNorthern California to Mid Channel IslandsEcological ImpactParasite/Predator Vector
Parasite-Predator vector- Although M. gigas has not become definitely established in central California, its introduction has been a possible/probable vector for a number of oyster foulers or predators, including Pteropurpura (=Ocinebrellus) inornata (Japanese Oyster Drill) in Tomales Bay, the parasitc copepod Mytilicola orientalis (widespread), the mussel Musculista senhousia, the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus, Didemnum vexillum and Styela clava (Carlton 1979; Cohen and Carlton 1995; Wasson et al. 2001; de Rivera et al. 2005).
P090San Francisco BayEcological ImpactParasite/Predator Vector
Parasite-Predator vector- Although M. gigas has not become definitely established in San Francisco Bay, its introduction has been a possible/probable vector for a number of oyster foulers or predators, including, the parasitc copepod Mytilicola orientalis (widespread), the mussel Musculista senhousia, the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus and Styela clava (Carlton 1979; Cohen and Carlton 1995).
P110Tomales BayEcological ImpactParasite/Predator Vector
Parasite-Predator vector- Although M. gigas has not become definitely established in Tomales Bay, its introduction has been a possible/probable vector for a number of oyster foulers or predators, including Pteropurpura (=Ocinebrellus) inornata (Japanese Oyster Drill), the parasitc copepod Mytilicola orientalis (widespread), the mussel Musculista senhousia, the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus, Didemnum vexillum, and Styela clava (Carlton 1979; Cohen and Carlton 1995).
P080Monterey BayEcological ImpactParasite/Predator Vector
Parasite-Predator vector- Although M. gigas has not become definitely established in Elkhorn Slough, its introduction has been a possible/probable vector for a number of oyster foulers or predators, including the parasitc copepod Mytilicola orientalis (widespread), the mussel Musculista senhousia, the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus and Styela clava (Carlton 1979; Wasson et al. 2001; de Rivera et al. 2005)
P070Morro BayEcological ImpactParasite/Predator Vector
Parasite-Predator vector- Although M. gigas has not become definitely established in Morro Bay, its introduction has been a possible/probable vector for a number of oyster foulers or predators, including the parasitc copepod Mytilicola orientalis (widespread), the mussel Musculista senhousia, the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus, Didemnum vexillum, and Styela clava (Carlton 1979; Needles 2007)
NEP-IVPuget Sound to Northern CaliforniaEcological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators on the Washington-Oregon-northern California Coast, including Pteropurpura (=Ocinebrellus) inornata (Japanese Oyster Drill) in Willapa Bay, the parasitic copepod Mytilicola orientalis (widespread), the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus, Didemnum vexillum and Styela clava (Carlton 1979; Cohen and Carlton 1995; Boyd et al. 2002; Wonham and Carlton 2005).
P130Humboldt BayEcological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators in Humboldt Bay, including the parasitc copepod Mytilicola orientalis (widespread), the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus, Didemnum vexillum and Styela clava (Carlton 1979; Boyd et al. 2002).
P170Coos BayEcological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators in Coos Bay including the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus, Didemnum vexillum and Styela clava (Carlton 1979; Cohen and Carlton 1995; USGS Nonindigenous Aquatic Species Program 2010).
P180Umpqua RiverEcological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators in Umpqua Bay including the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus, Didemnum vexillum and Styela clava (Carlton 1979; Cohen and Carlton 1995; USGS Nonindigenous Aquatic Species Program 2010).
P210Yaquina BayEcological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators in Yaquina Bay including the parasitic copepod Mytilicola orientalis, the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus, and Styela clava (Carlton 1979; Cohen and Carlton 1995; USGS Nonindigenous Aquatic Species Program 2010).
NEP-IIIAlaskan panhandle to N. of Puget SoundEcological ImpactParasite/Predator Vector
Parasite-Predator vector: The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators on the Washington-British Columbia coast, including the seaweed Sargassum muticum, Pteropurpura (=Ocinebrellus) inornata (Japanese Oyster Drill), the flatworm Pseudostylochus ostreophagus, the parasitic copepod Mytilicola orientalis, the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus, Didemnum vexillum, and Styela clava (Carlton 1979; Cohen et al. 1998; Cohen et al. 2002; Gillespie et al. 2007).
P290Puget SoundEcological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators in Puget Sound, including Pteropurpura (=Ocinebrellus) inornata (Japanese Oyster Drill), the flatworm Pseudostylochus ostreophagus, the parasitic copepod Mytilicola orientalis (widespread), the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus, Didemnum vexillum and Styela clava (Carlton 1979; Cohen et al. 1998; Cohen et al. 2001).
P293_CDA_P293 (Strait of Georgia)Economic ImpactFisheries
Bellingham, Padilla and Samish Bays are areas of long-standing oyster culture and harvesting (Carlton 1979; http://www.taylorshellfishfarms.com/ourStore-oysters-samish-bay).
P293_CDA_P293 (Strait of Georgia)Ecological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators in northern Puget Sound, including Pteropurpura (=Ocinebrellus) inornata (Japanese Oyster Drill), the flatworm Pseudostylochus ostreophagus, the parasitic copepod Mytilicola orientalis (widespread), the bryozoan Schizoporella japonica, and the tunicates Botrylloides violaceus, Didemnum vexillum and Styela clava (Carlton 1979; Cohen et al. 1998; Cohen et al. 2002).
NA-ET3Cape Cod to Cape HatterasEcological ImpactParasite/Predator Vector
Parasite-Predator vector- Although C. gigas has never become established in the northwest Atlantic, the many failed introductions of C. gigas comprise a likely vector for the introduction of Haplosporidium nelsoni, the cause of the MSX disease which has severely affected the native Eastern Oyster, C. virdinica (Andrews 1980; Burreson and Ford 2004).
NEA-IINoneEcological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators in northern European coastal waters, including the seaweed Sargassum muticum, many other macroalgal species, Pteropurpura (=Ocinebrellus) inornata (Japanese Oyster Drill), the parasitic copepod Mytilicola orientalis, and the tunicates Botrylloides violaceus, Didemnum vexillum and Perophora japonica (Eno et al. 1997; Reise et al. 1999; Wolff and Resie 2002; Gittenberger 2010). Mytilicola orientalis, on the coast of the Netherlands, infected Pacific Oysters (Magallana gigas at 2-43% frequency, but also were found in Blue Mussels (Mytilus edulis, 3-63%), Common Cockles (Cerastoderma edule, 2-13%), and Baltic Tellins (Macoma balthica, 6-7%) (Goedknegt et al. 2016).
NEA-IVNoneEcological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators in Atlantic French waters, including the seaweed Sargassum muticum, many other macroalgal species, Pteropurpura (=Ocinebrellus) inornata, Japanese Oyster Drill, the parasitic copepod Mytilicola orientalis, and the tunicates Botrylloides violaceus, Didemnum vexillum and Perophora japonica (Eno et al. 1999; Goulletquer et al. 2002).
NEA-VNoneEcological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction of M. gigas has been a possible/probable vector for a number of oyster foulers or predators in the Bay of Biscay and the Atlantic waters of Spain and Portugal, including the seaweed Sargassum muticum, many other macroalgal species, Pteropurpura (=Ocinebrellus) inornata (Japanese Oyster Drill), the parasitic copepod Mytilicola orientalis, and the tunicates Botrylloides violaceus, Didemnum vexillum and Perophora japonica (Goulletquer et al. 2002; El Nagar et al. 2010; Afonso 2011)
MED-IINoneEcological ImpactParasite/Predator Vector
Parasite-Predator vector- The introduction and transfer of M. gigas has been a possible/probable vector for a number of oyster foulers or predators in lagoons of the western Mediterranean, including the seaweed Sargassum muticum, many other macroalgal species, the parasitic copepod Mytilicola orientalis, and the tunicate Styela clava. The culture of M. gigas has introduced 45+ species of macoalgae to the Thau lagoon (Galil 2000; Verlaque 2001; Davis and Davis 2008).
P100Drakes EsteroEcological ImpactParasite/Predator Vector
None
WA-IVNoneEcological ImpactParasite/Predator Vector
The East Pacific sea urchin Tetrapygus niger, native to Chile, was introduced with cultures of C. gigas in Alexander Bay, South Africa. Breeding populations are present, but no impacts are reported. Howver, in Chile, this species is a major grazer of kelp beds (Haupt et al. 2010).
NEA-IINoneEcological ImpactFood/Prey
Conversion of mussel (Mytilus edulis) beds in the Wadden Sea to Pacific Oyster beds may have adverse effects on some bird species which have difficulty detaching and opening oysters, particularly Common Eiders (Somateria mollissima). Other species such as European Oystercatchers (Haematopus ostralegus) and Herring Gulls (Larus argentatus) may be able to adjust feeding habits to the new prey (Scheiffarth et al. 2007; Baird 2012). Pacific oysters showed different patterns in the concentration of trace metals (lead, copper, cadmium, zinc), compared to native Blue Mussels (Mytilus edulis, potentially affecting the accumulation of these metals in the foodweb. However, shell thickness and predation rates may have a greater effect than metal concentrations on how these metals enter the food web, as C. gigas replaces M. edulus (Bray et al. 2015). Predation by the native Green Crab (Carcinus maenas dod not provide biotic resistance to M. gigas invasion, since the crabs preferred the native Blue Mussel (Mytilus edulis (Joyce et al. 2020).
NEA-IVNoneEcological ImpactHabitat Change
The formation of extensive M. gigas reefs has created a new habitat on the rocky coasts and mud habitats of Brittany. Reef formation on mud bottoms resulted in a shift from suspension feeders to carnivores among the fauna. Reefs on rock led to an increase in deposit feeders (LeJart and Hily 2011; Herbert et al. 2016). In the Bay of Mont-St.-Michel, colonization by M. gigas has damaged polychaete reefs of Sabellaria laveolata (Cognie et al. 2006; Dubois et al. 2006; Desroy et al. 2011, all cited by Herbert et al. 2011). While invasion of mudflat and mussel bed habitats altered the density and diversity of epifauna, benthic assemlages were similar between M. gigas and native Ostrea edulis communities in Brittany (Zwerschke et al. 2016; Zwerschke et al. 2018).
AUS-XNoneEcological ImpactHabitat Change
Magallana gigas on experimental plates in oysterbeds at Wanda Wanda Head, Port Stephens, grew larger than the native Saccostrea glomerata, and supported higher abundances of epibiotic organisms, but the identity of the biota on the two oyster species did not differ (Wilkie et al. 2012).
NEP-IIIAlaskan panhandle to N. of Puget SoundEcological ImpactFood/Prey
Juvenile M. gigas were a preferred food of the native Red Rock Crab (Cancer productus) in Puget Sound. Impacts on oyster populations were complicated by the fact that the crabs also fed on introduced predatory snails (Japanese and Atlantic Oyster Drills - Pteropurpurea inornata and Urosalpinx cinerea) (Grason and Miner 2012).
P290Puget SoundEcological ImpactFood/Prey
Juvenile M. gigas were a preferred food of the native Red Rock Crab (Cancer productus) in Puget Sound. Impacts on oyster populations were complicated by the fact that the crabs also fed on introduced predatory snails Japanese and Atlantic Oyster Drills (Pteropurpurea inornata and Urosalpinx cinerea) (Grason and Miner 2012).
NEA-IIINoneEcological ImpactHabitat Change
Magallana gigas, settling on an intertidal boulder field in Lough Swilly, Ireland, had complex effects on the epibenthic community. Some organisms, such as early settling stages of the polychaete Sabellaria alveolata, the gastropods Gibbula umbilicalis and Nucella lapillus, and the seaweed Fucus vesiculosus were favored on rocks with live oysters. Both living and dead oysters increased habitat complexity, but the filtration and biodepostion of oysters may have favored Fucus, adversely affecting a tunicate Ascidia conchilega through competition. While settlement of the reef-building polychaete Sabellaria was favored by oysters, long-term survival and colony formation did not occur on boulders with live or dead oysters. Habitat effects on several species appeared to be complex and unpredictable (Green and Crowe 2013a; Green and Crowe 2013b). Oysters on fouling plates reduced the settlement of the introduced barnacle Austrominius modestus, but not the native barnacle Semibalanus balanoides (Vye et al. 2017). In natural and artificial habitats, Pacific Oysters received more settlement of the inva.sive barnacle Austrominus modestus, comparted to the native limpet Patella vulgata (Firth et al. 2020). When Pacific Oysters were planted on mudflats, biodiversity increased, but when oysters were added to mussel beds, biodiversity decreased. Ammonium fluxes and benthic respiration increased with addition of oysters to both habitats, but silicate fluxes showed opposing reponses, increasing in mudflats, but decreasing in mudflats (Green and Crowe 2013a; Green and Crowe 2013b; Herbert et al. 2016). While invasion of mudflat and mussel bed habitats altered the density and diversity of epifauna, benthic assemlages were similar between M. gigas and native Ostrea edulis communities in southwest England (Zwerschke et al. 2016; Zwerschke et al. 2018).
NEA-IINoneEcological ImpactHerbivory
The expansion of Pacific Oyster aquaculture in the Netherlands, as well as the expansion of wild beds, and increasing populations of the American razor clam Ensis leei, has resulted in an increase of filtering biomass, and a decrease in phytoplanktion concentrations, and a shift towards an increassing proportion of picoplankton (very small, poorly grazed cells) (Smaal et al. 2013).
B-INoneEcological ImpactHabitat Change
Oyster reefs in Swedish west coast waters support higher species richness and biomass of benthic invertebrates than mussel beds or bare sediment (Hollander et al. 2015; Norling 2015; Herbert et al. 2016)
NEA-IINoneEcological ImpactTrophic Cascade
The expansion of Pacific Oyster aquaculture in the Netherlands has had indirect impacts on the predation of the Green Crab (Carcinus maenas on the Blue Mussel (Mytilus edulis, reducing predation on juvenile mussels, by providing refuges in the interspaces ibetween the oysters (Waser et al. 2015). Another indirect effect of M. gigas involves the effect of its parasite Mytilicola orientalis, which also infects the native Blue Mussel Mytiulus edulis. The longeer-lived planktonic larvae of this copepod are more likely to infect mussels at the top of the bed, more exposed to current, while a native trematode, with a short lived larva is more likely to infect mussels at the bottom of the reef, less exposed to current (Goeknecht et al. 2020).
MED-IINoneEcological ImpactHabitat Change
Increased filtration by Magallana gigas has improved water quality, enabling Zostera marina to grow in deeper water (Deslous-Paoli et al. 1998. cited by Herbert et al. 2016).
AUS-XINoneEcological ImpactFood/Prey
Magallana gigas is a food source for the naitve Mulberry Whelk Mulberry whelk) (Tenguella marginalba), which shows no preference between M. gigas and the native Sydney Rock Oyster (Saccostrea glomerata) (Wright et al. 2018).
MED-VIINoneEcological ImpactCompetition
Ezget-Balic et al. (2021) found significant overlap in feeding between M. gigas, and native Ostrea edulisand recommeded agianst the introduction of M. gigas to Lim Bay, Croatia.
MED-VIINoneEcological ImpactPredation
Ezget-Balic et al. (2021) found that n M. gigas had significant predaiton on and native Ostrea edilis larvare, and recommeded agianst the introduction of M. gigas to Lim Bay, Croatia.

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
NWP-4a None 0 Native Estab
NWP-3a None 0 Native Estab
NWP-3b None 0 Native Estab
NWP-4b None 0 Native Estab
NWP-2 None 0 Native Estab
NA-ET2 Bay of Fundy to Cape Cod 1949 Def Failed
NA-ET3 Cape Cod to Cape Hatteras 1935 Def Failed
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 1941 Def Failed
NEP-III Alaskan panhandle to N. of Puget Sound 1902 Def Estab
NEP-II Alaska south of Aluetians to the Alaskan panhandle 1998 Def Failed
NEP-IV Puget Sound to Northern California 1928 Def Estab
NEP-V Northern California to Mid Channel Islands 2000 Def Unk
NEP-VI Pt. Conception to Southern Baja California 2000 Def Estab
MED-II None 1964 Def Estab
MED-III None 1988 Def Estab
MED-VII None 1966 Def Estab
MED-IV None 1978 Def Estab
MED-IX None 1972 Def Estab
NEA-V None 1971 Def Estab
NEA-IV None 1966 Def Estab
NEA-II None 1965 Def Estab
NEA-III None 1989 Def Estab
SA-I None 1982 Def Estab
WA-IV None 1990 Def Unk
WA-V None 1955 Def Estab
SP-XXI None 1938 Def Estab
AUS-IX None 1947 Def Estab
AUS-VIII None 1960 Def Estab
AUS-X None 1967 Def Estab
AUS-XI None 1984 Def Estab
AUS-VII None 1985 Def Unk
AUS-IV None 1947 Def Unk
NZ-IV None 1961 Def Estab
SEP-B None 1997 Def Unk
AR-V None 2007 Def Estab
NEP-VII None 1973 Def Unk
P130 Humboldt Bay 1953 Def Unk
M130 Chesapeake Bay 1980 Def Failed
M040 Long Island Sound 1979 Def Failed
M010 Buzzards Bay 1976 Def Failed
P170 Coos Bay 1948 Def Failed
P090 San Francisco Bay 2000 Def Unk
P010 Tijuana Estuary 2005 Def Estab
P030 Mission Bay 2005 Def Estab
P023 _CDA_P023 (San Louis Rey-Escondido) 2000 Def Estab
P040 Newport Bay 1932 Def Estab
P070 Morro Bay 1932 Def Failed
P080 Monterey Bay 1929 Def Failed
P100 Drakes Estero 1932 Def Failed
P110 Tomales Bay 1928 Def Failed
P112 _CDA_P112 (Bodega Bay) 1932 Def Failed
P210 Yaquina Bay 1906 Def Estab
P230 Netarts Bay 1948 Def Unk
P240 Tillamook Bay 1940 Def Unk
P270 Willapa Bay 1928 Def Estab
P290 Puget Sound 1902 Def Estab
P293 _CDA_P293 (Strait of Georgia) 1905 Def Estab
P284 _CDA_P284 (Hoh-Quillayute) 2002 Def Estab
P286 _CDA_P286 (Crescent-Hoko) 2001 Def Estab
P050 San Pedro Bay 2000 Def Estab
P061 _CDA_P061 (Los Angeles) 1932 Def Failed
P095 _CDA_P095 (Tomales-Drakes Bay) 1955 Def Failed
N180 Cape Cod Bay 1949 Def Failed
M100 Delaware Inland Bays 1962 Def Failed
M070 Barnegat Bay 1935 Def Failed
M128 _CDA_M128 (Eastern Lower Delmarva) 1997 Def Failed
M120 Chincoteague Bay 1997 Def Failed
N040 Blue Hill Bay 1949 Def Failed
N050 Penobscot Bay 1975 Def Failed
N070 Damariscotta River 1975 Def Failed
NZ-VI None 2001 Def Unk
SA-II None 2006 Def Estab
P180 Umpqua River 1948 Def Failed
SP-XII None 1975 Def Failed
B-II None 2000 Def Estab
B-I None 2005 Def Estab
P292 _CDA_P292 (San Juan Islands) 1942 Def Estab
MED-VIII None 1989 Def Estab
MED-VI None 2007 Def Estab
MED-V None 2001 Def Estab
WA-I None 1991 Def Failed
EA-V None 1971 Def Unk
SP-VII None 1969 Def Failed
SP-XVI None 1972 Def Failed
SP-IV None 1967 Def Failed
SP-XIII None 1972 Def Failed
SP-VIII None 0 Def Failed
SP-V None 1972 Def Failed
CAR-II None 1980 Def Failed
SEP-H None 1979 Def Failed
EAS-I None 1980 Def Failed
MED-I None 1966 Def Unk
SEP-C None 1997 Def Unk
CAR-IV None 1980 Def Failed
SP-IX None 1980 Def Failed
EAS-VI None 2003 Def Unk
P280 Grays Harbor 1930 Def Estab
P297 _CDA_P297 (Strait of Georgia) 1926 Def Estab
P296 _CDA_P296 (Strait of Georgia) 1926 Def Estab
SEP-I None 1980 Def Failed
CAR-VII Cape Hatteras to Mid-East Florida 1999 Def Failed
S010 Albemarle Sound 2001 Def Failed
S020 Pamlico Sound 2001 Def Failed
S030 Bogue Sound 2001 Def Failed
S040 New River 1999 Def Failed
S045 _CDA_S045 (New) 2001 Def Failed
NEP-VIII None 0 Def Unk
P022 _CDA_P022 (San Diego) 2014 Def Estab
SA-III None 0 Def Failed
P020 San Diego Bay 2013 Def Estab
B-III None 2017 Def Unk
SA-I None 1981 Def Estab
B-IV None 2019 Def Unk

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude
27873 Fairey et al. 2002 2001 2001-10-10 Mission Bay Epifaunal 03 Def 32.7619 -117.2357
27956 Fairey et al. 2002 2001 2001-07-11 Los Angeles Epifaunal 03 Def 33.7684 -118.2782
32191 Introduced Species Study 2011 2011-04-20 Los Angeles-Long Beach Coast Guard Pier Def 33.7233 -118.2685
32401 California Department of Fish and Wildlife 2011 2011 2011-04-21 Long Beach Downtown Marina - ISS Def 33.7594 -118.1866

References

Dick, Matthew H.; Tilbrook, Kevin J. Shunsuke F. Mawatari (2006) Diversity and taxonomy of rocky-intertidal Bryozoa on the island of Hawaii, USA, Journal of Natural History 40(38-40): 2197-2257

Abbott, R. Tucker (1974) <missing title>, Van Nostrand Reinhold, New York. Pp. <missing location>

Afonso, Carlos M. L. (2011) Non-indigenous Japanese oyster drill Pteropurpura (Ocinebrellus) inornata (Récluz, 1851) (Gastropoda: Muricidae) on the South-west coast of Portugal, Aquatic Invasions 6(S1): S85-S88

Agius, C.; Schembri, P. J.; Jaccarini, V. (1977) A preliminary report on organsims fouling oyster cultures in Malta., Memorie di Biologia Marina e di Oceanographia 7(3-4): 51-59

Agudo-Padrón, A. Ignacio (2011) Exotic molluscs (Mollusca, Gastropoda et Bivalvia) in Santa Catarina State, Southern Brazil region: check list and regional spatial distribution, Biodiversity Journal 2: 53-58

Albayrak, Serhat (2011) Alien marine bivalve species reported from Turkish seas, Cahiers de Biologie Marine 52: 107-118

Allen, Standish K., Jr., Gaffney, Patrick M. (1993) Genetic confirmation of hybridization between Crassostrea gigas (Thunberg) and Crassostrea rivularis (Gould), Aquaculture 113: 291-300

Allen, Standish K., Jr., Gaffney, Patrick M., Scarpa, John, Bushek, David (1993) Inviable hybrids of Crassostrea virginica (Gmelin) with C. rivularis (Gould) and C. gigas (Thunberg), Aquaculture 113: 269-289

Amor, Kounofi-Ben; Rifi, M.; Ghanem, R.; Draief, I.; Zouali, J.; Souissi, J. Ben (2016) Update of alien fauna and new records of Tunisian marine fauna, Mediterranean Marine Science 17(1): 124-143

Andrews, Jay D. (1979) Scenario for introduction of Crassostrea gigas to the Atlantic coast of North America, In: Mann, Roger(Eds.) Symposium on Exotic Species in Mariculture. , Cambridge. Pp. 225-231

Andrews, Jay D. (1980) A review of introductions of exotic oysters and biological planning for new importations, Marine Fisheries Review 42(12): 1-11

Antit, M.; Gofas, S.; Salas, C.; Azzouna, A. (2011) One hundred years after Pinctada: an update on alien Mollusca in Tunisia, Mediterranean Marine Science 12(1): 53-73

Araya, Juan Francisco (2015) Current status of the non-indigenous molluscs in Chile, with the first record of Otala punctata (Müller, 1774) (Gastropoda: Helicidae) in the country and new records for Cornu aspersum (Müller, 1774) and Deroceras laeve (Müller,, Journal of Natural History 49(29-30): 1731-1761

Arizpe, Oscar C. (1996) Secondary production, growth and survival of the Pacific Oyster Crassostrea gigas in tropical waters, Bahia de la Paz, Mexico, Journal of Shellfish Research 15(3): 601-607

Aydin, Mehmet; Biltekin, Demet; Breugelmans, Karin; Backeljau, Thierry (2021) irst record, DNA identification and morphometric characterization of Pacific oyster, Crassostrea gigas (Thunberg, 1793) in the southern Black Sea, BioInvasiob=ns Records 10: In press

Baird, Dan (2012) Assessment of observed and perceived changes in ecosystems over time, with special reference to the Sylt-Rømø Bight, German Wadden Sea, Estuarine, Coastal and Shelf Science 108: 144-154

Baker, Beth (1992) Botcher of the bay or economic boon?, BioScience 42(10): 744-747

Baldwin, Andy; Leason, Diane (2016) Potential Ecological impacts of Emerald Ash Borer on Maryland's Eastern Shore, In: None(Eds.) None. , <missing place>. Pp. <missing location>

Bancila. Raluca I.; Skolka, Marius; Ivanova, Petya; Surugiu, Victor; Stefanova, Kremena; Todorova. Valentina; Zenetos, Argyro (2022) Alien species of the Romanian and Bulgarian Black Sea coast: state of knowledge, uncertainties, and needs for future research, Aquatic Invasions 17: Published online

Barber, Bruce J. (1996) Gametogenesis of Eastern oysters, Crassostrea virginica (Gmelin, 1791), and Pacific oysters, Crassostrea gigas (Thunberg, 1793) in disease-endemic lower Chesapeake Bay, Journal of Shellfish Research 15(2): 285-290

Barber, Bruce J.; Mann, Roger (1994) Growth and mortality of Eastern oysters Crassostrea virginica (Gmelin 1871) and Pacific oysters Crassostrea gigas (Thunberg 1793) under challenge from the parasite Perkinsus marinus, Journal of Shellfish Research 13(1): 109-114

Barrett, Elinore M. (1963) The California Oyster Industry., California Department of Fish and Game Fish Bulletin 123: 1-103

Bazterrica, María Cielo; Hidalgo, Fernando J. ; Rumbold, Carlos Casariego, Agustina Mendez; Jaubet , María Lourdes; Merlo, Matías; Cesar, Ines , Pro (2022) Macrofaunal assemblages structure three decades after the first report of the invasive Crassostrea gigas reefs in a soft-intertidal of Argentina, Estuarine, Coastal and Shelf Science 270(107832): Published online

Bergström, Per; Thorngren, Linnea; Strand, Lisa; Lindegarth, Mats (2021) Identifying high-density areas of oysters using species distribution modeling: Lessons for conservation of the native Ostrea edulis and management of the invasive Magallana (Crassostrea) gigas in Sweden, Ecology and Evolution Published online: 1-21

Bernard, I.; Massabuau, J.-C.; Ciret, P.; Sow, M.; Sottolichio, A.; Pouvreau, S.; Tran, D. (2016) In situ spawning in a marine broadcast spawner, the Pacific oyster Crassostrea gigas: Timing and environmental trigger, Limnology and Oceanography 61: 635-647

Besterman, Alice F.; Pace, Michael L. (2022) Do macroalgal mats impact microphytobenthos on mudflats? evidence from a meta-analysis, comparative survey, and large-scale manipulation, Estuarine and Coasts 41: 2304–2316

Beukema, J. J.; Dekker, R. (2011) Increasing species richness of the macrozoobenthic fauna on tidal flats of the Wadden Sea by local range expansion and invasion of exotic species, Helgoland Marine Research 65: 155-164

Bishop, John D. D.; Wood, Christine A.; Lévêque, Laurent; Yunnie, Anna L. E.; Viard, Frédérique (2015b) Repeated rapid assessment surveys reveal contrasting trends in occupancy of marinas by non-indigenous species on opposite sides of the western English Channel, Marine Pollution Bulletin 95: 699-706

Blanchard, Michel; Pechenik, Jan A.; Giudicelli, Emilie; Connan, Jean-Paul ; Robert, René (2008) Competition for food in the larvae of two marine molluscs, Crepidula fornicata and Crassostrea gigas, Aquatic Living Resources 21: 197-205

Boisset, Fernando; Ferrer-Gallego, P.. Pablo , (2015) Typification of the marine siphonous green algae Caulerpa prolifera (Bryopsidales, Chlorophyta), Phytotaxa 221(2): 148–156

Boudry, P.; Barre, M.; Gerard, A. (1998) Genetic improvement and selection in shellfish: a review based on oyster research and production., Cahiers de Centre international de Hautes Estudes Agronomigues Mediterranean 34: 61-75

Boyd, Milton J.; Mulligan, Tim J; Shaughnessy, Frank J. (2002) <missing title>, California Department of Fish and Game, Sacramento. Pp. 1-118

Boyd, S. (1999) Introduced Mollusca of Port Phillip Bay, In: (Eds.) Marine Biological Invasions of Port Phillip Bay, Victoria. , Hobart, Tasmania. Pp. 129-149

Brandt, G.; Wehrmann, A.; Wirtz, K.W. (2008) Rapid invasion of Crassostrea gigas into the German Wadden Sea dominated by larval supply., Journal of Sea Research 59: 279-296

Bray, D. J.; Green, I.; Golicher, D.; Herbert, R. J. H. (2015) Spatial variation of trace metals within intertidal beds of native mussels (Mytilus edulis) and non-native Pacific oysters (Crassostrea gigas): implications for the food web?, Hydrobiologia 757: 235-249

Bright, Donald B. (1966) The Land Cloabs of Costa Rica, Revista Biologia Tropica 14(2): 182-203

Buhle, Eric R.; Ruesink, Jennifer L. (2009) Impacts of invasive oyster drills on Olympia oyster (Ostrea lurida Carpenter 1864) recovery in Willapa Bay, Washington, United States, Journal of Shellfish Research 28(1): 87-96

Burnaford, Jennifer L.; Henderson, Scottie Y. Pernet, Bruno (2011) Assemblage shift following population collapse of a non-indigenous bivalve in an urban lagoon, Marine Biology 158: 1915-1927

Burreson, E.M.; Stokes, N.A.; Friedman, C.S. (2000) Increased virulence in an introduced pathogen: Haplosporidium nelsoni (MSX) in the Eastern Oyster Crassostrea virginica., Journal of Aquatic Animal Health 12: 1-8

Burreson, Eugene M.; Ford, Susan E. (2004) A review of recent information on the Haplosporidia, with special reference to Haplosporidium nelsoni (MSX disease), Aquatic Living Resources 17: 499-517

Calder, Dale R. (2019) On a collection of hydroids (Cnidaria, Hydrozoa) from the southwest coast of Florida, USA, Zootaxa 4689(1): 1-141

California Department of Fish and Game (2001) California’s Living Marine Resources: A Status Report, California Department of Fish and Game, Sacramento CA. Pp. 450-451

California Department of Fish and Wildlife (2014) Introduced Aquatic Species in California Bays and Harbors, 2011 Survey, California Department of Fish and Wildlife, Sacramento CA. Pp. 1-36

California Department of Health Services (2007) <missing title>, California Department of Health Services, Sacramento CA. Pp. <missing location>

Calvo, G.W.; Luckenbach, M.W.; Burreson, E.M. (1999) Evaluating the performance of non-native oyster species in Virginia, Journal of Shellfish Research 18: 303

Calvo, Gustavo; Luckenbach, Mark W.; Allen, Standish K.; Burreson, Eugene M. (1999) Comparative field study of Crassostrea gigas (Thunberg, 1793) and Crassostrea virginica (Gmelin 1791) in relation to salinity in Virginia., Journal of Shellfish Research 18(2): 465-473

Cardoso, Joana F. M. F.; Peralta, Nelson R. E.; Machado, Jorge P.; van der Veer, Henk W. (2013) Growth and reproductive investment of introduced Pacific oysters Crassostrea gigas in southern European waters, Estuarine, Coastal and Shelf Science 118: 24-30

Cardoso, Joana F.M.F. And 6 authors (2007) Spatial variability in growth and reproduction of the Pacific oyster Crassostrea gigas (Thunberg, 1793) along the west European coast., Journal of Sea Research 57: 303-315

Carlton, James T. (1979) History, biogeography, and ecology of the introduced marine and estuarine invertebrates of the Pacific Coast of North America., Ph.D. dissertation, University of California, Davis. Pp. 1-904

Carlton, James T. (1992) Introduced marine and estuarine mollusks of North America: An end-of-the-20th-century perspective., Journal of Shellfish Research 11(2): 489-505

Carlton, James T. (1996) Marine bioinvasions: the alteration of marine ecosystems by nonindigenous species., Oceanography 9(1): 36-43

Carlton, James T. (1999) Molluscan invasions in marine and estuarine communities., Malacologia 41(2): 439-454

Carlton, James T. (Ed.) (2007) <missing title>, University of California Press, Berkeley. Pp. <missing location>

Carlton, James T.; Eldredge, Lucius (2009) Marine bioinvasions of Hawaii: The introduced and cryptogenic marine and estuarine animals and plants of the Hawaiian archipelago., Bishop Museum Bulletin in Cultural and Environmental Studies 4: 1-202

Carrasco, Mauro F.; Baron, Pedro J. (2010) Analysis of the potential geographic range of the Pacific oyster Crassostrea gigas (Thunberg, 1793) based on surface seawater temperature satellite data and climate charts: the coast of South America as a study case., Biological Invasions 12: 2597-2607

Carriker, Melbourne R.; Gaffney, Patrick M. (1996) The Eastern Oyster Crassostrea virginica, Maryland Sea Grant, College Park MD. Pp. <missing location>

Castanos, Cecilia; Pascual, Marcela; Camacho, Alejandro Perez (2009) Reproductive biology of the nonnative oyster,Crassostrea gigas Tthunberg, 1793), as a key factor for its successful spread along the rocky shores of northern Patagonia, Argentina, Journal of Shellfish Research 28(4): 837-847

Castilla, Juan C. and 10 authors (2005) Down under the southeastern Pacific: marine non-indigenous species in Chile., Biological Invasions 7: 213-232

Cesari, P.; Pellizzato, M. (1985) Insediamento nella laguna di Venezia e distribuzione adriatica Rapana venosa, Bollettino Malacologico 21(10-12): 237-274

Cesari, Paolo; Mizzan, Luca (1991) Osservazioni su Rapana venosa (Valenciennes, 1846) in cattività, Bollettino del Museo Civico di Storia Naturale di Venezia 42: 9-21

Chainho, Paula and 20 additional authors (2015) Non-indigenous species in Portuguese coastal areas, lagoons, estuaries, and islands, Estuarine, Coastal and Shelf Science <missing volume>: <missing location>

Chávez-Villalba, Mazón-Suástegui, José M.;; Maeda-Martínez, Alfonso N. ,García-Morales, Ricardo; Lodeiros, César (2021) Tropical and subtropical Ostreidae of the American Pacific: fisheries, aquaculture, management, and conservation, Journal of Shellfish Research 40(2): 239-253

Chávez-Villalba, Jorge; Arreola-Lizárraga, Alfredo; Burrola-Sánchez, Sara; Hoyos-Chairez, Francisco (2009) Growth, condition, and survival of the Pacific oyster Crassostrea gigas cultivated within and outside a subtropical lagoon, Aquaculture 300: 128-136

2019 Emerald Ash Borer <em>Agrilus planipennis</em>. https://www.chesapeakebay.net/S=0/fieldguide/critter/emerald_ash_borer

Chew, K. K.; Sparks, A. K.; Katkansky, S. C. (1965) Preliminary results on the seasonal size distribution of Mytilicola orientalis and the effects of theis parasite on the condition of the Pacific Oyster Crassostrea gigas, Journal of the Fisheries Research Board of Canada 22(4): 1099-1101

Chew, Kenneth K. (1979) Pacific oyster (Crassostrea gigas) in the west coast of the United States, In: Mann, Roger(Eds.) Symposium on Exotic Species in Mariculture. , Cambridge. Pp. 54-79

Chew, Kenneth K. (1990) Global bivalve shellfish introductions, World Aquaculture 21(3): 9-22

Chu, Fu-Lin E. (1996) Laboratory investigations of susceptibilty, infectivity, and transmission of Perkinsus marinus in oysters, Journal of Shellfish Research 15(1): 57-66

Chu, Fu-Lin E.; Volety, Aswani K.; Constantin, Gegorgeta (1996) A comparison of Crassostrea gigas and Crassostrea virginica: Effects of temperature and salinity on susceptibility to the protozoan parasite, Perkinsus marinus, Journal of Shellfish Research 15(2): 375-380

Cinar, Melih Ertan and 7 authors (2021) Current status (as of end of 2020) of marine alien species in Turkey, PLOS ONE 16: Published online

Coan, Eugene V.; Valentich-Scott, Paul (2007) The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon, University of California Press, Berkeley CA. Pp. 807-859

Coan, Eugene V.; Valentich-Scott, Paul; Bernard, Frank R. (2000) <missing title>, Santa Barbara Museum of Natural history, Santa Barbara CA. Pp. <missing location>

Coen, Loren D.; Bishop, Melanie J. (2015) The ecology, evolution, impacts and management of host-parasite interactions of marine molluscs, Journal of Invertebrate Pathology 131: 177-211

Cohen, Andrew N. and 12 authors (2002) Project report for the Southern California exotics expedition 2000: a rapid assessment survey of exotic species in sheltered coastal waters., In: (Eds.) . , Sacramento CA. Pp. 1-23

Cohen, Andrew N. and 22 authors (2001) <missing title>, Washington State Department of Natural Resources, Olympia. Pp. <missing location>

Cohen, Andrew N.; Carlton, James T. (1995) Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and Delta., U.S. Fish and Wildlife Service and National Sea Grant College Program (Connecticut Sea Grant), Washington DC, Silver Spring MD.. Pp. <missing location>

Cohen, Andrew N.; Zabin, Chela J. (2009) Oyster shells as vectors for exotic organisms, Journal of Shellfish Research 28(1): 163-167

Cohen, Andrew; and 16 authors. (1998) <missing title>, Washington State Department of Natural Resources, Olympia, Washington. Pp. 1-37

Coles, S. L.; DeFelice, R. C. : Eldredge, L. G. (2002a) Nonindigenous marine species in Kaneohe Bay, Oahu, Hawai`i, Bishop Museum Technical Report 24: 1-364

Coles, S. L.; DeFelice, R. C.; Eldredge, L. G.; Carlton, J. T. (1999b) Historical and recent introductions of non-indigenous marine species into Pearl Harbor, Oahu, Hawaiian Islands., Marine Biology 135(1): 147-158

Common Wadden Sea Secretariat (CWSS) (2007) Conclusions and recommendations from the trilateral workshop on Pacific Oyster Invasion in the Wadden Sea: Consequences for ecology, monitoring and management 22 March 2007, Wilhelmshaven, Wadden Sea Newsletter 2007(1): 6-9

Conte, Fred S. (1996) California oyster culture., California Aquaculture A-7: 1-7

Coon, Steven L., Bonar, Dale B., Weiner, Ronald M. (1985) Induction of settlement and metamorphosis of the Pacific oyster, Crassostrea gigas (Thunberg), by l-DOPA and catecholamines, Journal of Experimental Marine Biology and Ecology 94: 211-221

Cordone,,Georgina; and 7 authors (2021) Metabarcoding, direct stomach observation and stable isotope analysis reveal a highly diverse diet or the invasive green crab in Atlantic Patagonia, Biological Invasions Published online: <missing location>

Cranfield, H.J.; Gordon, D.P.; Willan, R.C.; Marshall, B.A; Battershill, C.N.; Francis, M.P.; Nelson, W.A.; Glasby, C.J.; Read, G.B. (1998) <missing title>, The National Institute of Water and Atmospheric Research, New Zealand. Pp. <missing location>

Croce, M. Emilia; Parodi, Elisa R. (2012) Seasonal dynamic of macroalgae in intertidal pools formed by beds of Crassostrea gigas (Mollusca, Bivalvia) on the north Patagonian Atlantic coast, Botanica Marina 55: 49-58

Crocetta, Fabio (2011) Marine alien Mollusca in the Gulf of Trieste and neighbouring areas: a critical review and state of knowledge (updated in 2011), Acta Adriatica 52(2): 247 - 260,

Crocetta, Fabio (2012) Marine alien Mollusca in Italy: a critical review and state of the knowledge, Journal of the Marine Biological Association of the United Kingdom 92(6): 1357-1365

Crooks, Jeffrey A.; Crooks, Kai R.; Crooks, Aiden J. (2016) Observations of the non-native Pacific oyster (Crassostrea gigas) in San Diego County, California, California Fish and Game 101(2): 101-107

DAISIE (Delivering Alien Invasive Species Inventories to Europe) (2009) Handbook of alien species in Europe, Springer, Dordrecht, Netherlands. Pp. 269-374

Davis, Martin H.; Davis, Mary E. (2008) First record of Styela clava (Tunicata, Ascidiacea) in the Mediterranean region, Aquatic Invasions 3(1): 125-132

De Mesel, Ilse; Kerckhof, Francis; Norro, Alain; Rumes, Bob; Degraer, Steven (2015) Succession and seasonal dynamics of the epifauna community on offshore wind farm foundations and their role as stepping stones for non-indigenous species, Hydrobiologia 756: 37-50

de Montaudouin, Xavier; Audemard, Corinne; Labourg, Pierre-Jean (1999) Does the slipper limpet (Crepidula fornicata, L.) impair oyster growth and zoobenthos biodiversity? A revisited hypothesis, Journal of Experimental Marine Biology and Ecology 235: 105-124

de Montaudouin, Xavier; Sauriau, Pierre-Guy (2000) Contributions to a synopsis of marine species richness in the Pertuis-Charentais Sea with new insights into the soft-bottom macrofauna of the Marennes-Oleron Bay, Cahiers de Biologie Marine 41: 181-222

de Rivera, Catherine, and 27 authors (2005a) <missing title>, National Fish and Wildlife Foundation, Washington, D.C.. Pp. <missing location>

Dean, David (1979) Introduced species and the Maine situation., In: Mann, Roger(Eds.) Symposium on Exotic Species in Mariculture. , Cambridge. Pp. 149-164

Debrosse, Gregory A.; Allen, Standish K., Jr. (1996) Suitability of land-based evaluations of Crassostrea gigas (Thunberg, 1793) as an indicator of performance in the field, Journal of Shellfish Research 15(2): 291-295

Decottignies, Priscilla; Beninger, Peter G.; Rincé, Yves; Robins, Richard J.; Riera, Pascal (2007a) Exploitation of natural food sources by two sympatric, invasive suspension-feeders: Crassostrea gigas and Crepidula fornicata., Marine Ecology Progress Series 334: 179-192,

Dew, Jodie R.; Berkson, Jim; Hallerman, Eric M. (2003) A model for assessing the likelihood of self-sustaining populations resulting from commercial production of triploid Suminoe oysters Crassostrea ariakensis, in Chesapeake Bay., Fisheries Bulletin 101: 758-768

Diederich, Susanne (2005) Differential recruitment of intorduced Pacific oysters and native mussels at the North Sea Coast: coexistence possible?, Journal of Sea Research 53: 269-781

Dijkstra, Jennifer; Harris, Larry G.; Westerman, Erica (2007) Distribution and long-term temporal patterns of four invasive colonial ascidians in the Gulf of Maine, Journal of Experimental Marine Biology and Ecology 342: 61-68

Dineen, J. F. Jr.; Hines, A. H. (1994) Effects of salinity and adult extract on settlement of the oligohaline barnacle Balanussubalbidus, Marine Biology 119: 423-430

do Amaral, Vanessa Simao; Simone, Luiz Ricardo L. (2014) Revision of genus Crassostrea (Bivalvia: Ostreidae) of Brazil, Journal of the Marine Biological Association of the United Kingdom 94(4): 811-836

dos Santos, Eder P.; Fiori, Sandra M. (2010) [First record of the presence of Crassostrea gigas in the estuary oif Bahia Blanca (Argentina), Comunicaciones de la Sociedad Malacológica del Uruguay 9(93): 245-253

Douillet, Philippe; Langdon, Christopher J. (1993) Effects of marine bacteria on the culture of axenic oyster Crassostrea gigas (Thunberg) larvae, Biological Bulletin 184: 36-54

Dumbauld, Brett R.; Chapman, John W.; Torchin, Mark E.; Kuris, Armand M. (2011) Is the collapse of mud shrimp (Upogebia pugettensis) populations along the Pacific coast of North America caused by outbreaks of a previously unknown bopyrid isopod parasite (Orthione griffenis)?, Estuaries and Coasts 34: 336-350

DuPaul, William (1992) History of the proposal to introduce Crassostrea gigas to Chesapeake Bay., In: DeVoe, M. Richard .(Eds.) Introductions and Transfers of Marine Species. , Charleston. Pp. 103-105

Dutertre, Mickaël (2009) <missing title>, University of Nantes (Ph.D. Thesis), Nantes, France. Pp. <missing location>

El Nagar, Aliya; Huys, Rony; Bishop, John D. D. (2010) Widespread occurrence of the Southern Hemisphere ascidian Corella eumyota Traustedt, 1882 on the Atlantic coast of Iberia, Aquatic Invasions 5(2): 169-173

Eldredge, L.G. (1994) Perspectives in aquatic exotic species management in the Pacific Islands Vol. I. Introductions of commercially significant aquatic organisms to the Pacific islands, South Pacific Commission. Inshore Fisheries Research Project, Technical Document 7: 1-127

Elton, Charles S. (1958) <missing title>, Methuen & Co. Ltd., London. Pp. <missing location>

English, L. J.; Maguire, G. B.; Ward, R. D. (2000) Genetic variation of wild and hatchery populations of the Pacific oyster, Crassostrea gigas Thunberg, in Australia, Aquaculture 187: 283-298

Eno, N. Clare (1996) Non-native marine species in British waters: effects and controls, Aquatic Conservation: Marine and Freshwater Ecosystems 6: 215-228

Eno, N. Clare; Clark, Robin A.; Sanderson, William G. (1997) <missing title>, Joint Nature Conservation Committee, Peterborough. Pp. <missing location>

1997-2012 Directory of Non-Native Marine Species in British waters. http://jncc.defra.gov.uk/page-1532

Environment Canada (1994) Fraser River Benthic Invertebrate Catalogue, In: None(Eds.) None. , <missing place>. Pp. <missing location>

Escapa, Mauricio (2004) The distribution and ecological effects of the introduced Pacific Oyster Crassostrea gigas in Patagonia., Journal of Shellfish Research 23(3): 765-772

Eschweiler, Nina; Buschbaum, Christian (2011) Alien epibiont (Crassostrea gigas) impacts on native periwinkles (Littorina littorea), Aquatic Invasions 6: corrected proof

Everett, Richard; Sherfy, Mark H. (2001) The Chesapeake Bay: A model for regional approaches to the prevention and control of aquatic non-indigenous species, Transactions of the North American Wildlife and Natural Resource Conference 66: 611-624

Ezgeta-Balic, Daria and 12 authors (2021) Competitive feeding interactions between native Ostrea edulis and non-native Crassostrea gigas with implications of introducing C. gigas into commercial aquaculture in the eastern Adriatic Sea, Marine Environmental Research 1060(105051): Published online

Fairey, Russell; Dunn, Roslyn; Sigala, Marco; Oliver, John (2002) <missing title>, California Department of Fish and Game, Sacramento. Pp. <missing location>

Feldman, Kristine L.; Armstrong, David A.; Dumbauld, Brett R; DeWitt, Theodore H.; Doty, Daniel C. (2000) Oysters, crabs, and burrowing shrimp: review of an environmental conflict over aquatic resources and pesticide use in washington state's (usa) coastal estuaries, Estuaries 23(2): 141-176

Ferraro, Steven P.; Cole, Faith A. (2007) Benthic macrofauna-habitat associations in Willapa Bay, Washington, USA, Estuarine, Coastal and Shelf Science 71: 491-507

Fischer, W.; Schneider, M.; Bauchot, M.-L. (1987) <missing title>, FAO-CEE, Rome. Pp. <missing location>

Fitzgerald, William J.; Nelson, Stephen G. (1979) Development of aquaculture in an island community (Guam, Marianas Islands), Proceedings of the World Mariculture Society 10: 39-50

Flowerdew, M. W. (1985) Indices of genetic identity and distance in three taxa within the Balanus amphitrite Darwin complex (Cirripedia, Thoracica)., Crustaceana 49(1): 7-15

1998-2012 Database on Introductions of Aquatic Species. Web address http://www.fao.org/fishery/introsp/search/en

Friedman, Carolyn S. (1996) Haplosporidian infections of the Pacific oyster, Crassostrea gigas (Thunberg), in California and Japan, Journal of Shellfish Research 15(3): 597-600

Fritts, Anthony L; Pearson, Todd N. (2006) Effects of predation by nonnative smallmouth bass on native salmonid prey: The role of predator and prey size., Transactions of the American Fisheries Society 135: 853-860

Furlani, Dianne M. (1996) A guide to the introduced marine species in Australian waters., In: (Eds.) . , Hobart, Australia. Pp. <missing location>

Gaffney, Patrick M.; Allen, Standish K., Jr. (1992) Genetic aspects of introduction and transfer of molluscs, Journal of Shellfish Research 11(2): 535-538

Galil, Bela S. (2000) A sea under siege: alien species in the Mediterranean., Biological Invasions 2: 177-186

Galtsoff, Paul S. (1932) Introduction of Japanese Oysters into the United States, United States Department of Commerce, Bureau of Fisheries, Fisheries Circular 12: 1-16

Gerdes, D. (1983) Pacific oyster Crassostrea gigas Part I. Feeding behaviour of larvae and adults, Aquaculture 31: 195-219

Gillespie, Graham E. (2007) Distribution of non-indigenous intertidal species on the Pacific Coast of Canada, Nippon Suisan Gakkaishi 73(6): 1133-1137

Gillespie, Graham E.; Bower, Susan M.; Marcus, Kerry L.; Kieser, Dorothee (2012) <missing title>, Canadian Science Advisory Secretariat, Fisheries and Oceans Canada, Ottawa, Ontario. Pp. 1-97

2007 Distribution of nonindigenous intertidal species on the Pacific Coast of Canada. http://www.pices.int/publications/presentations/PICES_15/Ann15_S8/S8_Gillespie.pdf

Gittenberger, Adriaan; Rensing, Marjolein; Stegenga, Herre; Hoeksema, Bert (2010) Native and non-native species of hard substrata in the Dutch Wadden Sea, Nederlandse Faunistiche Mededelingen 33: 20-76

Gollasch, Stephan (2006) Overview on introduced aquatic species in European navigational and adjacent waters., Helgoland Journal of Marine Research 60: 84-89

Gomiou, Marian-Traian; Alexandrov, Boris; Shadrin, Nikolai; Zaitsev, Yuvenaly (2002) The Black Sea- a recipient, donor, and transit area for alien species., In: Leppakoski, E.; Gollasch, S.; Olenin, S.(Eds.) Invasive aquatic species of Europe: Distribution, impacts, and management.. , Dordrecht. Pp. 341-350

Goodwin, David H.; Cohen, Andrew N.; Roopnarine, Peter D. (2011) Forensics on the half shell: A sclerochronological investigation of a modern biological invasion in San Francisco Bay, United States, Palaios 25: published online

Gottlieb, Sara J.; Schweighofer, Mona E. (1996) Oysters and the Chesapeake Bay ecosystem: a case for exotic species introduction to improve environmental quality?, Estuaries 19(3): 639-650

Goulletquer, Philippe; Bachelet, Guy; Sauriau, Pierre; Noel, Pierre (2002) Invasive aquatic species of Europe: Distribution, impacts, and management., Kluwer Academic Publishers, Dordrecht. Pp. 276-290

Grabowski, Jonathan H.; Petterson, Charles H.; Powers, Sean P.; Gaskill, David; Summerson, Henry C. (2004) Growth and survivorship of non-native (Crassostrea gigas and Crassostrea ariakensis) versus native eastern oysters (Crassostrea virginica)., Journal of Shellfish Research 23(3): 781-793.

Grabowski, Jonathan H.; Powers, Sean P.; Peterson, Charles H.; Powers, Monica J. (2003) Consumer ratings of non-native (Crassostrea gigas and Crassostrea ariakensis) vs. native (Crassostrea virginica) oysters., Journal of Shellfish Research 22(1): 21-30

Green, Dannielle S.; Crowe, Tasman P. (2013) Physical and biological effects of introduced oysters on biodiversity in an intertidal boulder field, Marine Ecology Progress Series 482: 119-132

Green, Dannielle S.; Crowe, Tasman P. (2013) Context- and density-dependent effects of introduced oysters on biodiversity, Biological Invasions 116(5): 1145-1163

Green, Dannielle S.; Rocha, Carlos; Crowe, Tasman P. (2013) Effects of non-indigenous oysters on ecosystem processes vary with abundance and context, Ecosystems 16: 881-893

Grey, Erin K. (2009) Scale-dependent relationships between native richness, resource stability and exotic cover in dock fouling communities of Washington, USA, Diversity and Distributions 15: 1073-1080

Griffiths, Charles L.; Robinson, Tamara B.; Mead, Angela (2009) Biological Invasions in Marine Ecosystems., Springer-Verlag, Berlin Heidelberg. Pp. <missing location>

Grizel, H; Héral, M (1991) Introduction into France of the Japanese oyster Crassostrea gigas)., Journal Conseil Internationale d' Exploration de la Mer 47(3): 399-403

Grizel, Henri (1994) Reflexions sur les problemes d'introduction de mollusques., In: Boudouresque, C. F., Briand, F., and Nolan, C.(Eds.) Introduced Species in European Coastal Waters.. , Brussels. Pp. 50-55

Groslier, Tilde and 6 authors (2014) Status of the Pacific Oyster Crassostrea gigas (Thunberg, 1793) in the western Limfjord, Denmark – Five years of population development, Aquatic Invasions 9: in press

Guy, Claire; Roberts, Dai (2010) Can the spread of non-native oysters (Crassostrea gigas) at the early stages of population expansion be managed?, Marine Pollution Bulletin 60: 1059-1064

Hallerman, Eric; Leffler, Merrill; Mills, Sally; Allen, Satandish, Jr. (2001) <missing title>, Maryland Sea Grant, College Park MD. Pp. <missing location>

Haupt, T. M.; Griffiths, C. L.; Robinson, T. B.;Tonin, A. F. G. (2010) Oysters as vectors of marine aliens, with notes on four introduced species associated with oyster farming in South Africa, African Zoology 45: 52-62

Haupt, Tanya M.; Griffiths, Charles L.; Robinson, Tamara B.; Tonin, Antonio F. G.; De Bruyn, Paul A. (2010) The history and status of oyster exploitation and culture in South Africa, Journal of Shellfish Research 29(1): 151-159

Haydar, Deniz; Wolff, Wim J. (2011) Predicting invasion patterns in coastal ecosystems: relationship between vector strength and vector tempo, Marine Ecology Progress Series 431: 1-10

Hedge, Luke H.; Johnston, Emma L. (2014) Colonisation of the non-indigenous Pacific Oyster Crassostrea gigas determined by predation, size and initial settlement densities, PLOS ONE 9(3): e90621

Hegazi, Muhammad Mosaad (2006) Distribution of the invasive species Caulerpa prolifera along the coasts of the suez canal, egyp, Catrina 1(2): 31-35

Hickey, John M. (1979) Culture of the Pacific oyster, Crassostrea gigas, in Massachusetts waters., In: Mann, Roger.(Eds.) Symposium on Exotic Species in Mariculture. , Cambridge. Pp. 129-148

Hilling,Corbin D.; Bunch, Aaron J.; Emmel, Jason A.; Schmitt, Joseph D.; Orth, Donald J. (2020) Growth and mortality of invasive Flathead Catfish in the tidalJames River, Virginia, Journal of Fish and Wildlife Management 10(2): Published online

Hines, Anson H.; Ruiz, Gregory M. (2000) Biological invasions of cold-water coastal ecosystems: ballast-mediated introductions in Port Valdez/Prince William Sound (Final Report), In: (Eds.) . , Valdez, Alaska. Pp. <missing location>

Hines, Anson H.; Ruiz, Gregory M. (2001) <missing title>, Prince William Sound Regional Citizen's Council, Valdez. Pp. <missing location>

His, E.; Robert, R.; Dinet, A. (1989) Combined effects of temperature and salinity on fed and starved larvae of the Mediterranean mussel Mytilus galloprovincialis and the Japanese oyster Crassostrea gigas, Marine Biology 100: 455-463

Hollander, Johan; Blomfeldt, Johan; Carlsson, Per; Strand, Åsa (2015) Effects of the alien Pacific oyster (Crassostrea gigas) on subtidal macrozoobenthos communities, Marine Biology 162: 547-555

Holm, Mark Wejlemann; Davids, Jens Kristian; Dolmer, Per; Vismann, Bent; Hansen, Benni Winding; (2015) Moderate establishment success of Pacific oyster, Crassostrea gigas, on a sheltered intertidal mussel bed, Journal of Sea Research 104: 1-8

Hommersand, M. H.; Freshwater, D. W. (2009) Gracilaria hummii sp. nov. (Gracilariales, Rhodophyta), a new name for the agarophyte ‘‘Fracilaria confervoides’’ harvested in North Carolina during World War I!, Journal of Phycology 45: 503-516

Hopkins, C.C.E. (2002) Invasive aquatic species of Europe: Distribution, impacts, and management., Kluwer Academic Publishers, <missing place>. Pp. 240-253

Hosack, Geoffrey R.; Dumbauld, Brett R.; Ruesink, Jennifer L.; Armstrong,, David A. (2006) Habitat associations of estuarine species: Comparisons of intertidal mudflat, seagrass (Zostera marina), and Oyster (Crassostrea gigas) habitats., Estuaries and Coasts 29(6B): 1150-1160

Huvet, A.; Fabioux, C.; McCombie, H.; Lapegue, S.; Boudry, P. (2004) Natural hybridization between genetically differentiated populations of Crassostrea gigas and C. angulata highlighted by sequence variation in flanktng regions of a microsatellite locus., Marine Ecology Progress Series 272: 141-152

Inglis, Graeme and 6 authors (2005a) Dunedin Harbour (Port Otago and Port Chalmers): Baseline survey for non-indigenous marine species, Biosecurity New Zealand Technical Paper 2005/10: 1-49

Inglis, Graeme and 6 authors (2006e) Whangarei Harbour (Whangarei Port and Marsden Point: Baseline survey for non-indigenous species, Biosecurity New Zealand Technical Paper 2005(16): 1-52

Itani, Gyo (2004) Distribution of intertidal upogebiid shrimp (Crustacea:Decapoda: Thalassinidea) in Japan, Contributions of the Biological Laboratory of Kyoto University 29: 383-399

Joyce, Patrick W. S.; Smyth, David M.; Dick . Jaimie T. A. ; Kregting, Louise T. (2021) Coexistence of the native mussel, Mytilus edulis, and the invasive Pacific oyster,Crassostrea (Magallana) gigas, does not affect their growth or mortality, but reduces condition of both species, Hydrobiolgia 848: 1859-1871

Kamenev, Gennady M.; Nekrasov, Dmitry A. (2012) Bivalve fauna and distribution in the Amur River estuary: A warm-water ecosystem in the cold-water Pacific region, Marine Ecology Progress Series 455: 195-210

Katkansky, Stanley C.; Warner, Ronald W. (1970) Sporulation of a haplosporidan in a Pacific oyster (Crassostrea gigas) in Humboldt Bay, California, Journal of the Fisheries Research Board of Canada 27(7): 1320-1321

Kavanaugh, L. D. (1941) Reactions of American and imported oysters to an annelid worm, Journal of the Tennessee Academy of Science 16(4): 354

Keller, Abigail G.; Grason, Emily W.; McDonald, P. Sean; Ramón-Laca, Ana; Kelly, Ryan P. (2021) Tracking an invasion front with environmental DNA, Ecological Applications <missing volume>: https://esajournals.

Kelly, Jennifer R.; Proctor, Heather; Volpe, John P. (2008) Intertidal community structure differs significantly between substrates dominated by native eelgrass (Zostera marina L.) and adjacent to the introduced oyster Crassostrea gigas (Thunberg) in British Columbia, Canada., Hydrobiologia 596: 57-66

Kerckhof, Francis; Haelters, Jan; Gollasch, Stephan G. (2007) Alien species in the marine and brackish ecosystem: the situation in Belgian waters., Aquatic Invasions 2(3): 243-257

Kern, Frederick G. (1976) Sporulation of Minchinia sp. (Haplosporida, Haplosporidiidae) in the Pacific oyster Crassostrea gigas (Thunberg) from the Republic of Korea, Journal of Protozoology 23(4): 478-500

Kil, Hyun Jong; Yoon, Sook Hee; Kim, Won; Choe, Byung Lae; Sohn, Hyun Joon; Park, Joong-Kee (2005) Faunistic investigation for marine mollusks in Jindo Island., Korean Journal of Systematic Zoology Special Issue 5: 29-46

Klinger, Terrie; Padilla, Diana; Britton-Simmons, Kevin (2006) Two invaders achieve higher densities in reserves., Aquatic Conservation: Marine and Freshwater Ecosystems 16: 301-311

Koçak, Ferah; Aydin Önen, Sinem (2014) Checklist of Bryozoa on the coasts of Turkey, Turkish Journal of Zoology 38: 880-891

Kochmann, Judith; O’Beirn, Francis; Yearsley, Jon; Crowe, Tasman P. (2013) Environmental factors associated with invasion: modelling occurrence data from a coordinated sampling programme for Pacific oysters, Biological Invasions published online: <missing location>

Kochmann, Judith; Carlsson, Jens; Crowe, Tasman P.; Mariani, Stefano (2012) Genetic evidence for the uncoupling of local aquaculture activities and a population of an invasive species—a case study of Pacific Oysters (Crassostrea gigas), Journal of Heredity 103: 661-671

Kochmann, Judith; Crowe, Tasman P. (2014) Effects of native macroalgae and predators on survival, condition and growth of non-indigenous Pacific oysters (Crassostrea gigas), Journal of Experimental Marine Biology and Ecology 451: 122-129

Kornbluth, Aaron; Perog. Bryce D.; Crippen, Samantha; Zacherl. Danielle; Quintana, Brandon; Grosholz, Edwin D.; WassonI, Kerstin (2022) Mapping oysters on the Pacific coast of North America: A coast-wide collaboration to inform enhanced conservation, PLOS Biology 17(3): Published online

Krakau, M.; Thieltges, D.W.; Reise, K. (2006) Native parasites adopt introduced bivalves of the North Sea., Biological Invasions 8: 919-925

Krantz, George E. (1992) Present management position on Crassostrea virginica in Maryland with comments on the possible introduction of an exotic oyster, Crassostra gigas., In: DeVoe, M. Richard(Eds.) Introductions and Transfers of Marine Species.. , Charleston. Pp. 121-126

Krassoi; Frederick R.; Brown, Kenneth R.; Bishop, Melanie J.; Kelaher, Brendan P.; Summerhayes, Stephen (2008) Condition-specific competition allows coexistence of competitively superior exotic oysters with native oysters., Journal of Animal Ecology 77: 5-15

Krueger-Hadfield, Stacy A. and 10 authors (2017) Genetic identification of source and likely vector of a widespread marine invader, Ecology and Evolution 7: 4432-4447

Lacy, Jessica R.; Foster-Martinez, Madeline R..; Allen, Rachel M.; Drexler, Judith Z. (2021) Influence of invasive submerged aquatic vegetation (E. densa) on currents and sediment transport in a freshwater tidal system, Water Resources Research 57: e2020WR028789

Lallias, Delphine; Boudry, Pierre; Batista, Frederico M.; Beaumont, Andy; King, Jonathan W.; Turner, John R.; Lapegue, Sylvie (2015) Invasion genetics of the Pacific oyster Crassostrea gigas in the British Isles inferred from microsatellite and mitochondrial markers, Biological Invasions 17: 2581-2595

Lam, Katherine; Morton, Brian (2009) Oysters (Bivalvia: Ostrreidae and Gryphaeidae) from Malaysia and Singapore, Raffles Bulletin of Zoology 57(2): 481-494

Lang, Anne C.; Buschbaum, Christian (2010) Facilitative effects of introduced Pacific oysters on native macroalgae are limited by a secondary invader, the seaweed Sargassum muticum, Journal of Sea Research 63: 119-128

Langdon, Christopher J.; Robinson, Anja M. (1996) Aquaculture potential of the Suminoe oyster (Crassostrea ariakensisFugita 1913), Aquaculture 144: 321-338

Lapegue, Sylvie; Batista,Frederico M.; Heurtebise, Serge; Yu, Ziniu; Boudry, Pierre (2004) Evidence for the presence of the Portuguese oyster, Crassostrea angulata, in Northern China., Journal of Shellfish Research 23(3): 759-763

Laugen, Ane T.; Hollander, Johan; Obst, Matthias; Strand, Åsa (2015) Biological Invasions in Changing Ecosystems: Vectors, Ecological Impacts, Management and Predictions, de Gruyter de Gruyter, Berlin, Germany. Pp. 230-252

Laverty, Ciaran; Nentwig, Wolfgang; Dick, Jaimie T.A.; Lucy, Frances E. (2015) Alien aquatics in Europe: assessing the relative environmental and socioeconomic impacts of invasive aquatic macroinvertebrates and other taxa, Management of Biological Invasions 6: In Press

Lavigne, Andrea S. Sunesen, Ines Sar, Eugenia A. (2015) Morphological, taxonomic and nomenclatural analysis of species of Odontella, Trieres and Zygoceros (Triceratiaceae, Bacillariophyta) from Anegada Bay (Province of Buenos Aires, Argentina), Diatom Research 30: 307-331

Leidenberger, Sonja; Obst, Matthias; Kulawik, Robert; Stelzer, Kerstin; Heyer, Karin; Hardisty, Alex; Bourlat, Sarah J. (2015) Evaluating the potential of ecological niche modelling as a component in marine non-indigenous species risk assessments, Marine Pollution Bulletin 97: 470-487

Lejart, Morgane; Clavier, Jacques; Chauvaud, Laurent; Hily, Christian (2012) Respiration and calcification of Crassostrea gigas: contribution of an intertidal invasive species to coastal ecosystem CO2 fluxes, Estuaries and Coasts 35: 622-632

LeJart, Morgane; Hily, Christian (2011) Differental response of macrobenthos to formation of novel oyster reefs (Crassostrea gigas Thunberg) on soft and rocky substrate in theinteridal of the Bay of Brest, France, Journal of Sea Research 65: 84-93

Lemasson, Anaëlle J. , Knights, Antony M. (2021) Differential responses in anti-predation traits of the native oyster Ostrea edulis and invasive Magallana gigas to ocean acidification and warming, Marine Ecology Progress Series 665: 87-102,

Lenz, Mark and 11 authors (2011) Non-native marine invertebrates are more tolerant towards environmental stress than taxonomically related native species: Results from a globally replicated study, Environmental Research 111: 943-952

Lester, L. James (1992) Marine species introductions and native species vitality: Genetic consequences of marine introductions., In: DeVoe, M. Richard(Eds.) Introductions and Transfers of Marine Species: Achieving a Balance Between Economic Development and Resources Protection.. , Charleston. Pp. 79-89

Lewis, Thomas B., Power, Garrett (1979) Chesapeake Bay oysters: legal theses on exotic species., In: Mann, Roger.(Eds.) Symposium on Exotic Species in Mariculture.. , Cambridge. Pp. 265-293

Lin, Xuezheng; Huang, Xiaohang (2007) Introduced marine species in China from Japan, and their impacts, Nippon Suisan Gakkaishi 73(6): 1138-1146

Lipej, L.; Mavric, B.; Orlando-Bonaca, M.; Malej, A. (2012) State of the art of the marine non-indigenous flora and fauna in Slovenia, Mediterranean Marine Science 13(2): 243-249

Lipton, Douglas W.; Lavan, Eileen F.; Strand, Ivar E. (1992) Economics of molluscan introductions and transfers: the Chesapeake example, Journal of Shellfish Research 11(2): 511-519

Lipton, Douglas; Lavan, Eileen F.; Strand, Ivar E. (1992) Economics of molluscan introductions and transfers: the Chesapeake Bay dilemma, Journal of Shellfish Research 11(2): 511-519

Low-Pfeng, Antonio; Recagno, Edward M. Peters (2012) <missing title>, Geomare, A. C., INESEMARNAT, Mexico. Pp. 236

Mach, Megan E.; Levings, Colin D.; Chan, Kai M. A. (2016) Nonnative species in British Columbia eelgrass beds spread via shellfish aquaculture and stay for the mild climate, Estuaries and Coasts Published online: <missing location>

Mann, Roger (1979) Some biochemical and physiological aspects of growth and gametogenesis in Crassostrea gigas and Ostrea edulis grown at sustained elevated temperatures, Journal of the Marine Biological Association of the United Kingdom 59: 95-110

Mann, Roger; Burreson, Eugene M. (1994) Growth of triploid Crassostrea gigas under natural conditions in the lower Chesapeake Bay, Journal of Shellfish Research 13: 279

Mann, Roger; Burreson, Eugene M.; Baker, Patrick K. (1991) The decline of the Virginia oyster fishery in Chesapeake Bay: Considerations for introduction of a non-endemic species, Crassostrea gigas (Thunberg, 1793), Journal of Shellfish Research 10(2): 379-388

Markert, Alexandra; Esser, Wiebke; Frank, Dietrich; Wehrmann, Achim; Exo, Klaus-Michael (2013) Habitat change by the formation of alien Crassostrea-reefs in the Wadden Sea and its role as feeding sites for waterbirds, Estuarine, Coastal and Shelf Science 13: 41-51

Markert, Alexandra; Wehrmann, Achim; Kroncke, Ingrid (2010) Recently established Crassostrea-reefs versus native Mytilus beds: differences in ecosystem engineering affects the macrofaunal communities (Wadden Sea of Lower Saxony, southern German Bight), Biological Invasions 12: 15-32

2006-2016 MarLin- Marine Life Information Network. http://www.marlin.ac.uk/aboutMarLIN.php

Mathieson, Arthur C.; Dawes, Clinton J. (2017) Seaweeds of the Northwest Atlantic, University of Massachusetts Press, Amherst MA. Pp. <missing location>

Matthiessen, George C. (1979) Oyster industry of Massachusetts and the introduction of exotic species., In: Mann, Roger.(Eds.) Symposium on Exotic Species in Mariculture.. , Cambridge. Pp. <missing location>

McKindsey, Christopher W.; Landry, Thomas; O’Beirn, Francis X.; Davies, Ian M. (2007) Bivalve aquaculture and exotic species: a review of ecological considerations and management issues., Journal of Shellfish Research 26(2): 281-294

Mead, A.; Carlton, J. T.; Griffiths, C. L. Rius, M. (2011b) Introduced and cryptogenic marine and estuarine species of South Africa, Journal of Natural History 39-40: 2463-2524

Meistertzheim, Anne-Leila; Arnaud-Haond, Sophie; Boudry, Pierre; Thebault, Marie-Therese (2013) Genetic structure of wild European populations of the invasive Pacific oyster Crassostrea gigas due to aquaculture practices, Marine Biology 160: 453-463

Melo, Claudio M. R.; Silva, Francisco C.; Gomes, Carlos Henrique A. M.; Solea-Cava, Antonio M.;Lazoski, Cristiano (2010) Crassostrea gigas in natural oyster banks in southern Brazil, Biological Invasions 12: 441-449

Mendez, Maria M.; Schwindt, Evangelina; Bortolus, Alejandro; Roche, Andrea; Maggioni, Mat?as; Narvarte, Maite (2015) Ecological impacts of the austral-most population of Crassostrea gigas in South America: a matter of time?, Ecological Research 30: 979-987

Miller, Penny A.; Elliott, Anthony Koutoulis; Kube, Peter D.; Vaillancourt, René E. (2012) Genetic diversity of cultured, naturalized, and native Pacific Oysters, Crassostrea gigas, determined from multiplexed microsatellite markers, Journal of Shellfish Research 31(3): 611-617

Minchin, Dan (1996) Management of the introduction and transfer of marine molluscs, Aquatic Conservation: Marine and Freshwater Ecosystems 6: 229-244

Minchin, Dan (2007) A checklist of alien and cryptogenic aquatic species in Ireland., Aquatic Invasions 2(4): 341-366

Mineur, Frederic; Le Roux, Auguste; Maggs, Christine A.; Verlaque, Marc (2014) Positive feedback loop between introductions of non-native marine species and cultivation of oysters in Europe, Conservation Biology published online: <missing location>

Molnar, Jennifer L.; Gamboa, Rebecca L.; Revenga, Carme; Spalding, Mark D. (2008) Assessing the global threat of invasive species to marine biodiversity., Frontiers in Ecology and the Environment 6(9): 485-492

National Research Council (2003) <missing title>, National Academies Press, Washington DC. Pp. <missing location>

2002 Invasive species will take over America's wildlife refuges.. <missing description>

Needles, Lisa A. (2007) <missing title>, M.S. Thesis, California Polytechnic State University, San Luis Obispo. Pp. <missing location>

Nehring, S. (2005) International shipping - A risk for aquatic biodiversity in Germany., Neobiota 6: 125-143.

Nell, John A. (2001) The history of oyster farming in Australia., Marine Fisheries Review 63(3): 14-25

Nell, John A.; Holliday, John E. (1988) Effects of salinity on the growth and survival of Sydney Rock oyster (Saccostrea commercialis) and Pacific oyster (Crassostrea gigas) larvae and spat, Aquaculture 68: 39-44

Norling, P.; Lindegarth, M.; Lindegarth, S.; Strand, Å. (2015) Effects of live and post-mortem shell structures of invasive Pacific oysters and native blue mussels on macrofauna and fish, Marine Ecology Progress Series 518: 123-138

Norris, James N. (2010) Marine Algae of the northern Gulf of California: Chlorophyta and Phaeophyceae, Smithsonian Contributions to Botany 94: 1276

Ó'Foighil, D.; Gaffeny, P. M.; Wilbur, A. E.; Hilbish, T J. (1998) Mitochondrial cytochrome oxidase I gene sequences support an Asian origin for the Portuguese oyster Crassostrea angulata, Marine Biology 131: 497-503

Odlaug, Theron O. (1946) The effect of the copepod, Mytilicola orientalis upon the Olympia Oyster, Ostrea lurida., Transactions of the American Microscopical Society 65(4): 311-317

Orensanz, Jose Maria and 14 other authors (2002) No longer the pristine confines of the world ocean: a survey of exotic marine species in the southwestern Atlantic, Biological Invasions 4(1-2): 115-143

Otero, M.; Cebrian, E.; Francour, P.; Galil, B.; Savini, D. (2013) <missing title>, International Union for Conservation of Nature, Malaga, Spain. Pp. 136

Padilla, Dianna K. (2010) Context-dependent impacts of a non-native ecosystem engineer, the Pacific Oyster Crassostrea gigas, Integrative and Comparative Biology <missing volume>: published online

Patris, Sharon; Martin, Laura E; Bell, Lori J.; Dawson. Michael N. (2019) Expansion of an introduced sea anemone population, and its associations with native species in a tropical marine lake (Jellyfish Lake, Palau), Frontiers in Biogeography 11(1): Published online

Pauley, Gilbert B.; Van der Raay, Birgitta; Troutt, David (1988) <missing title>, US Fish and Wildlife Service, Army Corps of Engineers, Washington DC. Pp. <missing location>

Pederson, Judith and 6 authors (2011) Climate change and non-native species in the North Atlantic, ICES Cooperative Reseach Report 310: 174-190

Pejovic, Ivan; Ardura, Alba; Miralles, Laura; Arias, Andres; Borrell, Yaisel J.; Garcia-Vazquez, Eva (2016) DNA barcoding for assessment of exotic molluscs associated with maritime ports in northern Iberia, Marine Biology Research 12(2): 168-176

Perdue, James A., Erickson, Gerald (1984) A comparison of the gametogenic cycle between the Pacific oyster Crassostrea gigas and the Suminoe oyster Crassostrea rivularis in Washington State, Aquaculture 37: 231-237

Proctor, William (conductor) (1932) V.Marine Fauna, In: Proctor, William (editor)(Eds.) Biological Survey of the Mt. Desert Island Region. , <missing place>. Pp. 38

Quayle, D. B. (1969) Pacific oyster culture in British Columbia, Canadian Fisheries Research Board Bulletin 169: 1-192

Rajogopal, Sanjeevi and 7 authors (2005) Thermal tolerance of the invasive oyster Crassostrea gigas: Feasibility of heat treatment as an antifouling option., Water Research 39: 4334-4342

Reece, Kimberly S.; Cordes, Jan F.; Stubbs, Julie B.; Hudson, Karen L.; Francis, Elizabeth A. (2008) Molecular phylogenies help resolve taxonomic confusion with Asian Crassostrea oyster species, Marine Biology 153: 709-721

Reise, K. (1998) Pacific oysters invade mussel beds in the European Wadden Sea, Senckenbergiana Maritima 28(4/6): 169-175

Reise, K.; Gollasch, S.; Wolff, W.J. (1999) Introduced marine species of the North Sea coasts., Helgoländer Meeresuntersuchungen 52: 219-234

Renault, Tristan; Stokes, Nancy A.; Chollet, Bruno; Cochennec, Nathalie; Berthe, Franck; Gerard, Andre; Burreson, Eugene M. (2000) Haplosporidiosis in the Pacific oyster Crassostrea gigas from the French Atlantic coast., Diseases of Aquatic Organisms 42: 207-214

Riggs, Sharon R. (2011) <missing title>, Padilla Bay NERR, Padilla Bay WA. Pp. 5

Ritchie, Erika I. (2021) Invasive algae found in Newport Harbor needs to be quickly contained,, Orange County Register <missing volume>: <missing location>

Robinson, T. B.; Griffiths, C. L.; Tonin, A.; Bloomer and Hare, M. P. (2005) Naturalized populations of oysters, Crassostrea gigas along the South African Coast: distribution, abundance and population structure., Journal of Shellfish Research 24(2): 443-450

Rodriguez, Laura F.; Ibarra-Obando, Silvia E. (2008) Cover and colonization of commercial oyster (Crassostrea gigas) shells by fouling organisms in San Quintin Bay, Mexico, Journal of Shellfish Research 27(2): 337-343

Rohfritsch, Audrey and 5 authors (2013) Population genomics shed light on the demographic and adaptive histories of European invasion in the Pacific oyster, Crassostrea gigas, Evolutionary Applications 6(7): 1064-1078

Rosenfield, Aaron, Kern, Frederick G. (1979) <missing title>, Massachusetts Institute of Technology Press, Cambridge. Pp. 165-189

Ruesink, J. L.; Feist, B. E.; Harvey, C. J., Hong, J. S.; Trimble, A. C.; Wisehart , L. M. (2006) Changes in productivity associated with four introduced species: ecosystem transformation of a ‘pristine’ estuary., Marine Ecology Progress Series 311: 203-215.

Ruesink, Jennifer (2011) Encyclopedia of Biological Invasions, University of California Press, Berkeley and Los Angeles. Pp. 494-499

Ruesink, Jennifer L. (2007) Biotic resistance and facilitation of a non-native oyster on rocky shores., Marine Ecology Progress Series 331: 1-9

Ruesink, Jennifer L. and 6 authors (2005) Introduction of non-native oysters: Ecosystem effects and restoration implications., Annual Review of Ecology and Systematics 36: 643-689

Ruiz, C., Abad, M., Sedano, F., Garcia-Martin, L. O., Sanchez Lopez, J. L. (1992) Influence of seasonal environmental changes on the gamete production and biochemical composition of Crassostrea gigas (Thunberg) in suspended culture in El Grove, Galicia, Spain, Journal of Experimental Marine Biology and Ecology 155: 249-262

Scheiffarth, Grego; Ens, Bruno; Schmidt, Andreas (2007) What will happen to birds when Pacific Oysters take over the mussel beds in the Wadden Sea?, Wadden Sea Newsletter 2007(1): 10-14

Schofield, P. J.; Morris, J. A., Jr.; Akins, L. (2009) <missing title>, US Geological Survey, Gainesville FL. Pp. <missing location>

Shapiro, S. (1971) Our Changing Fisheries, In: (Eds.) . , Washington, DC. Pp. <missing location>

Shatkin, Greg, Sumway, Sandra E., Hawes, Robert (1997) Considerations regarding the possible introduction of the Pacific Oyster (Crassostrea gigas) to the Gulf of Maine: A review of global experience, Journal of Shellfish Research 16(2): 463-477

Shick, J. Malcolm; Hoffman, Richard J.; Lamb, Allen N. (1979) Asexual reproduction, population structure, and genotype-environment interactions in sea anemones., American Zoologist 19: 699-713

Shpigel, Muki; Barber, Bruce J.; Mann, Roger (1992) Effects of elevated temperature on growth, gametogenesis, physiology, and biochemical composition in diploid and triploid Pacific oysters, Crassostrea gigas Thunberg., Journal of Experimental Marine Biology and Ecology 161: 15-25

Sigwart, Julia D.;; Wong, Nur Leena W. S.; Esa, Yuzine (20201) Global controversy in oyster systematics and a newly described species from SE Asia (Bivalvia: Ostreidae: Crassostreinae), Marine Biodiverisity 51(83): Published online

Simoes Ramos, Maria Indaya; Nascimento, Iracema Andrade; de Loyola e Silva, Jayme (1986) The comparative growth (and) survival of Pacific Oyster (Crassostrea gigas) Thunberg, G. gigas Kumamoto) and Mangrove Oyster (C. rhizophorae) in Todos o Santos, Brazil, Ciencia e Cultura 38(9): 1604-1615

Skolka, Marius; Preda, Cristina (2010) Alien invasive species at the Romanian Black Sea coast: present and perspectives, Travaux du Muséum National d’Histoire Naturelle «Grigore Antipa» 53: 443-467

Smaal, A. C.; Schellekens, T.; van Stralen, M. R.; Kromkamp, J. C. (2013) Decrease of the carrying capacity of the Oosterschelde estuary (SW Delta, NL) for bivalve filter feeders due to overgrazing?, Aquaculture 404-405: 28-34

Small, Sadie S.;; Edwards, Matthew S. (2021) Thermal tolerance may slow, but not prevent, the spread of Sargassum horneri (Phaeophyceae) along the California, USA and Baja California, Mex coastline, Journal of Phycology Published online: <missing location>

Smith, I. Philip; Guy, Claire; Donnan, David (2015) Pacific oysters, Crassostrea gigas, established in Scotland, Aquatic Conservation: Marine and Freshwater Ecosystems 25: 733-742

Span, John A. (1978) Successful reproduction of giant Pacific oysters in Humboldt Bay and Tomales Bay, California., California Fish and Game 64: 123-124

Steele, S.; Mulcahy, M. F. (2001) Impact of the copepod Mytilicola orientalis on the Pacific oyster Crassostrea gigas in Ireland., Diseases of Aquatic Organisms 47: 145-149

Stiger-Pouvreau, Valérie; Thouzeau, Gérard (2015) Marine species introduced on the French Channel-Atlantic coasts: a review of main biological invasions and impacts, Open Journal of Ecology, 5: 227-257

Strand, A.; Waenerlund, A.; Lindegarth, S. . STRAND,* A. WAENERLUND AND S. LINDEGARTH (2011) High tolerance of the Pacific oyster (Crassostrea gigas, Thunberg) to low temperatures, Journal of Shellfish Research 30(3): 733-735

Streftaris, N.; Zenetos, A. (2006) Alien marine species in the Mediterranean - The 100 ‘worst invasives’ and their impact., Mediterranean Marine Science 7(1): 87-118

Sylvester, Francisco and 8 authors (2011) Hull fouling as an invasion vector: can simple models explain a complex problem?, Journal of Applied Ecology 48: 415-423

Taylor, Michael; Cameron, Hay; Forest, Barrie (2000) Patterns of marine bioinvasions in New Zealand and mechanisms for internal quarantine., In: Pedreson, Judith(Eds.) Marine Bioinvasions: Proceedings of a conference, January 24-27, 1999.. , Cambridge, MA.. Pp. 289-295

Terlizzi, Daniel E. (1996) Toward regional management of aquatic nuisance species in the Chesapeake Bay basin, Aquatic Nuisance Species Digest 1(4): 38, 46-47

Thieltges, D. W.; Bordalo, M. D.; Caballero Hernandez, A.; Prinz, K.; Jensen, K. T. (2008) Ambient fauna impairs parasite transmission in a marine parasite-host system, Parasitology 135: 1111-1116

Thieltges, David W.; Reise, Karsten; Prinz, Katrin; Jensen, Thomas (2009) Invaders interfere with native parasite-host interactions, Biological Invasions 11: 1421-1429

Tokarev, Yuriy; Shulman, Georgiy (2009) Biodiversity in the Black Sea: effects of climate and anthropogenic factors, Hydrobiologia 580: 23–33

Tovar-Hernández, M. A.; Villalobos-Guerrero, T. F.; Yáñez-Rivera, B., Aguilar-Camacho, J. M.; Ramírez-Santana, I. D. (2012) [Guide to exotic aquatic invertebrates in Sinaloa] , Geomare, A. C., USFWS, INE-SEMARNAT, Mazatlán, México. Pp. 41

Troost, Karin (2010) Causes and effects of a highly successful marine invasion: Case-study of the introduced Pacific oyster Crassostrea gigas in continental NW European estuaries, Journal of Sea Research 64: 145-165

2003-2015 Nonindigenous Aquatic Species Database. Gainesville, FL. http://nas.er.usgs.gov

Utting, S. D.; Spencer, B. E. (1992) Introductions of marine Bivalvia Mollusca into the United Kingdom, International Council for Exploration of the Marine Science Symposium 194: 84-91

Vaughan, David B.; Grutter, Alexandra S.; Hutso, Kate S. (2018) Cleaner shrimp are a sustainable option to treat parasitic disease in farmed fish, Scientific Reports 8(13959): Published online

Verlaque, Marc (2001) Checklist of the macroalgae of Thau Lagoon (Herault, France), a hot spot of marine species introduction in Europe, Oceanologia Acta 24(1): 29-49

Vinagre, Catarina; Silva, Rodrigo; Mendonça, Vanessa; . Flore, Augusto A.V.; Baeta, Alexandra; Marques, João Carlos (2018) Food web organization following the invasion of habitat-modifying Tubastraea spp. corals appears to favour the invasive borer bivalve Leiosolenus aristatus, Ecological Indicators 85: 1204-

Wagner, Eric and 5 authors (2012) Density-dependent effects of an introduced oyster, Crassostrea gigas, on a native intertidal seagrass, Zostera marina, Marine Ecology Progress Series 468: 149-160

Walles, Brenda and 5 authors (2015) Demography of the ecosystem engineer Crassostrea gigas, related to vertical reef accretion and reef persistence, Estuarine, Coastal and Shelf Science 154: 224-233

Walne, P. R.; Helm, M. M. (1979) Symposium on Exotic Species in Mariculture, Massachusetts Institute of Technology, Cambridge. Pp. <missing location>

Wang, Haiyan; Guo, Ximing (2008) Identification of Crassostrea ariakensis and related oysters by multiplex species-specific PCR, Journal of Shellfish Research 27(3): 481-487,

Wang, Zhongwei; Lu, Xin; Liang, Yubo; Wang, Chunde (2010) Haplosporidium nelsoni and H. costale in the Pacific oyster Crassostrea gigas from China’s coasts, Diseases of Aquatic Organisms 89: 223-228

Waser, Andreas M.; Splinter,Wouter; Van der Meer, Jaap (2015) Indirect effects of invasive species affecting the population structure of an ecosystem engineer, Ecosphere 6(7): 109

Wasson, Kerstin; Zabin, C. J.; Bedinger, L.; Diaz, M. C.; Pearse J. S. (2001) Biological invasions of estuaries without international shipping: the importance of intraregional transport, Biological Conservation 102: 143-153

Wendling, Carolin C.; Wegner, K. Mathias (2015) Adaptation to enemy shifts: rapid resistance to local Vibrio in invasive Pacific Oysters, Proceedings of the Royal Society of London B 282: Published online

White, C. ;Snodgrass, J. (1988) <missing title>, Office of Natural Resources Management, Brevard County, Titusville FL. Pp. 12 pp.

Wilkie, Emma M.; Bishop, Melanie J.; O'Connor, Wayne A. (2012) Are native Saccostrea glomerata and invasive Crassostrea gigas oysters' habitat equivalents for epibenthic communities in south-eastern Australia?, Journal of Experimental Marine Biology and Ecology 420-421: 16-25

Willan, Richard C. (1985) Successful establishment of the Asian mussel Musculista senhousia (Benson in Cantor, 1842) in New Zealand, Records of the Auckland Institute and Museum 22: 85-96

Wiltshire, K.; Rowling, K.; Deveney, M. (2010) <missing title>, South Australian Research and Development Institute, Adelaide. Pp. 1-232

Wolff, W. J. (2005) Non-indigenous marine and estuarine species in the Netherlands., Zoologische Verhandelingen 79(1): 1-116

Wolff, Wim; Reise, Karsten (2002) Invasive aquatic species of Europe: Distribution, impacts and management., Kluwer Academic Publishers, Dordrecht, Boston, London.. Pp. 193-205

Wonham, Marjorie J.; Carlton, James T. (2005) Trends in marine biological invasions at local and regional scales: the Northeast Pacific Ocean as a model system, Biological Invasions 7: 369-392

Wrange, Anna-Lisa and 8 authors (2010) Massive settlements of the Pacific oyster, Crassostrea gigas, in Scandinavia, Biological Invasions 12: 1145-1152

Yang, Ho Jin; Seo, Ji Eun; Min, Bum Sik; Grischenko, Andrei V.; Gordon, Dennis P. (2018) Cribrilinidae (Bryozoa: Cheilostomata) of Korea, Zootaxa 4377: 216-234

Zaiko, Anastasija; Lehtiniemi, Maiju; Narscius, Aleksas; Olenin, Sergej (2011) Assessment of bioinvasion impacts on a regional scale: a comparative approach, Biological Invasions 13: 1739-1765

Zenetos, A. and 8 authors (2005) Annotated list of marine alien species in the Mediterranean with records of the worst invasive species., Mediterranean Marine Science 6(1): 63-118

Zenetos, A.; Koutsoubas, D.; Vardala-Theodorou, E. (2005) Origin and vectors of introduction of exotic mollusks in Greek waters., Belgian Journal of Zoology 135(2): 279-286

Zibrowius, Helmut (1994) Introduced Species in European Coastal Waters, European Commission, Brussels. Pp. 44-65

Zolotarev, Valentin (1996) The Black Sea ecosystem changes related to the introduction of new mollusc species, Marine Ecology 17(1-3): 227-236