Invasion History

First Non-native North American Tidal Record: 1957
First Non-native West Coast Tidal Record: 1977
First Non-native East/Gulf Coast Tidal Record: 1957

General Invasion History:

Codium fragile is believed to have originated in the Northwest Pacific in waters around Japan. In Europe, it was first collected on the west coast of Ireland in 1845, but not recognized as an introduced species until around 1900 (Chapman 1999; Provan et al. 2008). A morphotype, C. f. subsp. atlanticum, of uncertain taxonomic and invasion status, was collected even earlier in 1839, in Ireland, but has had a limited range in Europe (Provan et al. 2008). The more typical C. fragile was first collected in the Mediterranean in 1950 (Verlaque 1994). In North America, Codium fragile was first collected on Long Island, New York in 1957 (Bouck and Morgan 1957). This seaweed spread rapidly to the north and south, reaching Nova Scotia in 1991 (Begin and Scheibling 2003); the Magdalen Islands, in the Gulf of St. Lawrence, Quebec, by 2003 (Drouin et al. 2011); and the south coast of Newfoundland by 2012 (Matheson et al. 2014). To the south, it colonized Beaufort Inlet, North Carolina in 1981 (Searles et al. 1984) and the current southernmost record is Cape Fear Inlet, North Carolina (Geraldi et al. 2014).

On the West Coast, at least one separate species of Codium or a separate subspecies of C. fragile is native from Baja California to Alaska, but an introduced population of C. fragile was discovered in San Francisco Bay in 1977 (Silva 1979; Cohen and Carlton 1995). Other invasions by C. fragile are widely scattered in space and time, including the Falkland Islands in 1849 (Provan et al. 2008); Cape Horn in1842; New Zealand in 1841 (Provan et al. 2008); Cape Town, South Africa in 1884 (Provan et al. 2008); Tasmania in 1890 (Provan et al. 2008); Iceland, before 1985 (South and Tittley 1986); Azores in 1993 (Cardigos et al. 2006); and Chile in 1998 (Castilla et al. 2005). Some of these populations were named as new subspecies, but were found, by genetic methods, to belong to C. fragile subsp. fragile (Provan et al. 2008).

North American Invasion History:

Invasion History on the West Coast:

Early Codium specimens from the West Coast of North America were identified as C. mucronatum forma californicum ( J. Agardh 1887), later known as C. fragile subsp. californicum (J. Agardh) C.A. Maggs & J. Kelly (Guiry and Guiry 2016). This form of Codium is found from Baja California to Alaska, mostly on the open coast (Abbott and Hollenberg 1976; Silva 1979; Miller et al. 2011). In 1977, a population of C. fragile, then identified as subspecies tomentosoides, was found only at Coyote Point in San Francisco Bay (Silva 1979). Codium fragile was found at Coyote Point and Redwood City in 1978-1983 (Josselyn and West 1985). In 1993-94, Cohen and Carlton (1995) found it growing on floating docks from Richmond to San Leandro, and a Pier 39, in San Francisco Harbor (Cohen and Carlton 1995). This seaweed has also been collected in Tomales Bay (Miller 2004; Miller et al. 2011).

Invasion History on the East Coast:

Codium fragile's first appearance in Northwest Atlantic waters was in Gardiners Bay, Long Island in 1957 (Bouck and Morgan 1957). Its introduction has been attributed to ship fouling, ballast water, or to the introduction of European or Japanese oysters. The first mode seems likeliest, because precautions were taken to prevent introduction of fouling organisms with European oysters planted experimentally in 1949 (Loosanoff 1975; cited by Carlton and Scanlon 1985) and because the dates and sites of oyster plantings do not correspond with those of C. fragile. The spotty nature of its spread in East coast waters suggests a diversity of transport mechanisms. Codium fragile spp. fragile was first collected in East Marion New York on the Eastern Fork of Long Island, in Gardiners's and Peconic Bays in 1957 (Bouck and Morgan 1957). It reached the Connecticut side of Long Island Sound by 1961 and Rhode Island by 1962-68. It was then brought to Chatham and Cotuit on Cape Cod in 1961 with transplanted oysters from Long Island. By the early 70's, it was widespread on the south side of Cape Cod (Carlton and Scanlon 1985).

Codium fragile was first collected north of Cape Cod in Boothbay Harbor Maine in 1964, where it was probably introduced with transplanted oysters (Carlton and Scanlon 1985). Its spread in Cape Cod Bay occurred later. It reached the Cape Cod Canal by 1969, and successively was found in Barnstable Harbor, MA in 1972; Wellfleet Harbor, MA in 1974; Duxbury Bay in 1981; and Provincetown in 1981. By 1983, it was collected at Appledore Island, Isles of Shoals, Maine (Carlton and Scanlon 1985). However, it was present to the north, at Bar Harbor, Maine by the late 1970's or early 1980's (Bird et al. 1993). The northward spread was spotty, with first records in Massachusetts Bay (Salem) in 2000 (MIT Sea Grant 2003), and in Great Bay, New Hampshire in 1985 (Mathieson et al. 2003). Codium fragile was first collected in Mahone Bay, on the central Atlantic coast of Nova Scotia in 1991. It has not yet been seen in the Bay of Fundy, although it was found in Sam Orr's Pond, a tributary of Passamaquoddy Bay, New Brunswick in 2009 (Saunders et al. 2013). It may have been brought to Nova Scotia, with transplanted shellfish, as packing material for bait, or by Gulf Stream eddies from New England (Bird et al. 1993).

In 1996, Codium fragile was collected for the first time in the Gulf of St. Lawrence, in Caribou Harbour, on the Northumberland Straits (Garbary et al. 1997). Since then, the spread has continued, both in the Gulf of St. Lawrence, and on the Atlantic Coast of Nova Scotia and Newfoundland. Codium fragile has been spreading through Northumberland Straits, in Nova Scotia, New Brunswick and on the Straits and Gulf Side of Prince Edward Island (Hubbard and Garbary 2002; Garbary et al. 2004). One population in Malpeque Bay included plants with the morphology of C. f. subsp. atlanticum (Hubbard and Garbary 2002). In the Gulf, it has spread as far north as the Magdalen Islands, Quebec in 2002 (Simard et al. 2005; Drouin et al. 2011, 47.3 N). Codium fragile is now patchily distributed on the whole Atlantic Coast of Nova Scotia, from Cape Sable Island, at the southwestern end to Canso, a distance of 450 km (Hubbard and Garbary 2002; Watanabe et al. 2010). In 2012, C. fragile was found at several sites in Placentia Bay, Newfoundland (Matheson et al. 2014, 47.8 N).

Between 1957 and 1968, C. fragile became widespread and abundant in Long Island Sound (Carlton and Scanlon 1985). It was first found in Barnegat Bay in 1966 and was widely distributed by 1969 (Taylor et al. 1969). The next southern record was in Assateague Channel, part of Chingcoteague Bay, Virginia in 1976 (Hillson 1976). Surprisingly, C. fragile was not collected at other estuaries in the region until much later. It was found washed up on the beach in Poquoson Neck, Virginia, on the western side of the lower Chesapeake Bay in 1995 (Scott Godwin, personal communication). It was found at Cape Henry, Virginia in 1999 (Ruiz et al., unpublished data), and was found in Atlantic coastal bays from Indian River Bay, Delaware to Hog Island Bay, Virginia in 2000-2003 (Thomsen 2004; Miller and Brown 2005; Thomsen and McGlathery 2006). However, we have no records from Delaware Bay. Codium fragile approached its southernmost limit at Topsail Inlet, south of Cape Hatteras, North Carolina in 1979, Masonboro Inlet in 1982, and Beaufort Inlet in 1981 (Searles et al. 1984). It was found growing abundantly on artificial substrates in Cape Fear Sound, near Wilmington, North Carolina in 2009 (Geraldi et al. 2014).

Invasion History Elsewhere in the World:

Codium fragile was an early invader to European waters, but was unrecognized. The possibly synonymous or related C. f. subsp. atlanticum was collected in Ireland in 1839 (Provan et al. 2008). However, taxonomists disagree on whether this form is introduced or native in Europe (Silva 1955; Provan et al. 2008; Guiry and Guiry 2016). It has a mostly European distribution from Norway to Spain, but 'atlanticum-like' plants have been found in Nova Scotia and the Azores (Hubbard and Garbary 2002; Tittley and Neto 2005). The typical C. fragile was collected on the west coast of Ireland in 1845, but was mistaken for the native C. tomentosum (Provan et al. 2008). It and other early C. fragile herbarium specimens were re-identified using chloroplast DNA (Provan et al. 2008). Codium fragile was recognized as a non-native species when it was collected in the Netherlands in 1900 (Silva 1955). However, it had already been collect in Devon, England in 1853 (Provan et al. 2008). It has spread extensively along the coast of Europe, reaching Sweden by 1939, the Danish Kattegatt (Baltic mouth) by 1985 (Chapman 1999), and Galicia, Spain by 1989 (Pérez-Cirera et al. 1989). It was first collected in the Mediterranean in France in 1950 (Verlaque 1994) and has spread east, reaching the Turkish Aegean by 1985 (Ribera and Boudouresque 1995). In the eastern Atlantic, C. fragile was established in Iceland by 1985 (South and Tittley 1987), the Canary Islands by 1990 (Haroun et al. 2002) and the Azores by 1993 (Tittley and Neto 2005).

Codium fragile was introduced to several locations in the Southern Hemisphere in the 18th century, including Cape Horn, Chile in 1842; the Falkland Islands in 1849; Bay of Islands, New Zealand in 1841; and the Cape of Good Hope, South Africa in 1884 (Provan et al. 2008). We have not found information on established populations in Atlantic South America, but C. fragile is established in several locations on the northern and central coasts of Chile (Castilla et al. 2005; Neill et al. 2006). Codium fragile is established on the southern Atlantic coast of South Africa, but its range is unclear, because of confusion with presumed native forms of Codium (Mead et al. 2011b). The South African form was described as C. f. capensis, but the type specimen proved to be genetically identical to C. fragile (Provan et al. 2008). Similarly, in New Zealand, a native subspecies, C. f. nova-zelandiae was described in 1935, but the type specimen was found to actually be C. fragile (Provan et al. 2008). Prior to this discovery, the introduced C. fragile was thought to have been introduced to New Zealand in 1973 and to have a limited range near Auckand (Dromgoole and Foster 1983; Trowbridge 1995). In Australia, Codium fragile subsp. tasmanicum was described from Tasmania in 1889, but was also found to be identical to typical C. fragile (Provan et al. 2008). A herbarium specimen of C. fragile was collected in Port Philip Bay in 1890 (Provan et al. 2008), but the first reported discovery of this plant was made in 1996 (Campbell 1999). It was subsequently found near Sydney in 2001 (NIMPIS 2015); in West Lakes, South Australia in 2002 (Wiltshire et al. 2010); and Albany, Western Australia in 2008 (McDonald et al. 2015).


Description

Codium fragile has thick, spongy, finger-like and forking branches, which extend from an irregular holdfast. The branches are covered with densely packed, short hairs, giving the plant a felt-like appearance and slimy texture. The tips of the branches are tapered. A plant may be about 0.5-1 m tall, with about 12 orders of branching, and weigh up to 3 kg. The branches are buoyant in the water due to the production of oxygen inside the plant. Older branches are dark green, while the tips and newer branches are a bright lighter green. Dead branches are whitish-yellow and resemble thick spaghetti. This species has many descriptive common names, including 'Dead-Man's Fingers', 'Green Fleece', Sponge Weed', 'Sponge Fingers', ‘Sputnik Weed’, 'Staghorn Weed' and 'Oyster Thief'. Oyster Thief describes the tendency of the oxygen-filled weeds to float and carry away oysters, while Sputnik Weed refers to its mysterious appearance around Long Island in 1957, soon after the launching of the Russian satellite.

The body of a green alga is called a thallus, a mass of undifferentiated filaments ('siphons'). In the genus Codium, the thallus is thick and spongy, and formed into the distinctive dichotomous branches. The internal structure of the thallus is comprised of a medulla, densely packed colorless siphons, surrounded by a green palisade-like layer of vesicles called utricles. The siphons are coenocytic and lack walls between the cells. The uitricles are the outer tips of these filaments. The holdfast is composed of a web of rhizoids (root-like filaments). The utricles in C. fragile are club-shaped, with a small pointed tip. Utricles bear one or two hairs below the tip, 25-60 µm long, 50-600 µm long. The dense field of hairs gives the branches a fuzzy appearance. The growth form is highly variable. This description is based on: Silva 1955, Bold and Wynne 1978, Gosner 1978, Schneider and Searles 1991, Trowbridge 1998, Van Patten 2006, Fisheries and Oceans Canada 2011, and Guiry and Guiry 2016.

The genus Codium is challenging taxonomically. At least 130 species are recognized, mostly in tropical and subtropical zones (Appeltans et al. 2016). For example, the occurrence of C. fragile in Europe was overlooked for at least 50 years after its introduction, because of its similarity to the native European C. tomentosum (Provan et al. 2008). The taxonomy of C. fragile is also complex at the subspecies level. At least 17 subspecies have been recognized, from different parts of the world, but the status of these is uncertain. Codium fragile was originally described by Suringa, from specimens collected in Japan, in a book by Hariot et al. 1889 (cited by Provan et al. 2008). European specimens were identified as Codium fragile subspecies tomentosoides, based on the type from the Netherlands, collected in 1900 (Silva 1955). This name was widely applied to introduced populations in many parts of the world, including the East Coast of North America (Bouck and Morgan 1957), San Francisco Bay (Silva 1979), Australia (Campbell 1999), and New Zealand (Trowbridge 1998). A worldwide genetic survey of the subspecies of C. fragile concluded that the invasive C. f. subsp. tomentosoides was identical to the original type form, and should be known as C. f. subsp. fragile, or simply C. fragile (Provan et al. 2008; Guiry and Guiry 2016).

Specimens of three named geographical subspecies, including subsp. capensis from South Africa, subsp. novae-zelandiae from New Zealand, and subsp. tasmanicum proved to be C. fragile (Provan et al. 2008). One or more apparently native Codium species grow on the West Coast of North America from Alaska to Mexico, with a sporadic distribution on rocks of the outer coast. The apparently native plants have been known as C. f. subsp. californicum, and appear to be distinct from the introduced C. fragile growing in San Francisco Bay (Silva 1979; Trowbridge 1998; Miller et al. 2011). However, Provan et al. (2009) found that one herbarium specimen, marked as C. f. subsp. californicum from Washington State belonged with the other C. fragile populations. Armitage et al. (2017) did find that a small sample of C. f. ssp. californicum was geneticall distinct (Armitage et al. 2017). More extensive study of West Coast populations is needed.

Two nominal subspecies, C. f. subsp. atlanticum, and C. f. subsp. scandinavicum coexist with C. fragile in Europe and are of uncertain taxonomic and introduction status. They are not regarded as invasive. Codium fragile subsp. atlanticum is smaller (usually 15-25 cm high) and has much smaller utricle tips than typical C. fragile (Silva 1955). Some herbarium specimens, labelled as atlanticum were genetically distinct, while others matched typical C. fragile (Provan et al. 2008). One population, morphologically resembling atlanticum, was found in Malpeque Bay, Prince Edward Island, Canada (Hubbard and Garbary 2002). Codium fragile subsp. scandinavicum has a limited reported range in Norway and Sweden. Provan et al. (2008) found that herbarium specimens of scandinavicum were genetically identical to C. fragile. Both of these subspecies may be synonymous and are best regarded as ecotypes. ‘The degree of both genotypic variation reported (small) and phenotypic variation described (large) makes the described subspecies and varieties unsustainable and it would be better to recognize one variable species for all practical purposes.’ - Wendy Guiry (29 Dec. 2007, in Guiry and Guiry 2016). A recent moleclular analysis of the DNA barcoding marker tufA suggests that there at least 2 species within the Codium fragile clade, but the authors suggest hat more genetic research is needed to divide C. fragile into native and introduced clades throughout its worldwide range (Verbruggen et al. 2016).


Taxonomy

Taxonomic Tree

Kingdom:   Plantae
Phylum:   Chlorophycota
Class:   Chlorophyceae
Order:   Caulerpales
Family:   Codiaceae
Genus:   Codium
Species:   fragile

Synonyms

Codium fragile ssp. capensis (Papenfuss, 1937)
Codium fragile ssp. tomentosoides (P. C. Silva, 1955)
Codium mucronotatum var. tomentosoides (Van Goor, 1923)
Acanthcodium fragile (Suringar in Hariot, 1889)
Codium fragile ssp. Atlanticum ( (A.D.Cotton) P.C.Silva, 1912)
Codium fragile ssp. Scandinavicum (P. C. Silva, 1957)

Potentially Misidentified Species

Codium carolinianum
Native to Western Atlantic south of Cape Hatteras to Puerto Rico (Schneider and Seales 1991)

Codium decorticatum
Native to Western Atlantic south of Cape Hatteras to Puerto Rico (Schneider and Seales 1991)

Codium fragile ssp. californicam
Native to Northeast Pacific, Alaska to Baja California (Miller et al. 2011)

Codium ishthmocladium
Native to Western Atlantic south of Cape Hatteras to Brazil (Schneider and Seales 1991)

Codium taylorii
Native to Western Atlantic south of Cape Hatteras to Brazil, also Canary Island and West Africa (Schneider and Seales 1991)

Codium tomentosum
Native in European Atlantic waters (Silva 1955)

Ecology

General:

Sexual reproduction in Codium fragile takes place through the production and release of flagellated swarmers (zoospores). In other species of Codium, reproduction is anisogamic and usually dioecious, with female plants producing spores and males producing smaller spores. The spores are produced by gametangia, reproductive structures protruding from the surface of the utricle. Female gametangia are dark green and lumpy, while male gametangia have an even outline and are brightly-colored (Bold and Wynne 1978). True C. fragile are monecious (Trowbridge 1998; Prince and Trowbridge 2004). Populations of C. fragile in Long Island Sound, Europe, and Japan, reproduce by stem fragmentation and by release of zoospores, of roughly equal size and believed to be female. One population in the Northwest Atlantic (Appledore Island, Maine) produces gametes (Prince 1988). Germination of the spores of all these populations occurred without the fusion of gametes and so was parthogenetic (Ramus 1971; Churchill and Moeller 1972; Bulleri et al. 2007). In Long Island Sound, the release occurs from May to September (Churchill and Moeller 1972). The spores settle and germinate about 24 hours after release and grow into masses of filaments. Mechanical shaking was necessary for growth of primordia in culture, suggesting that tides and currents are needed to stimulate growth (Ramus 1972). In Rhode Island populations, fragmentation was most common in winter, but these winter fragments are probably not viable (Hanisak 1979). In Nova Scotia populations, fragmentation occurred in summer, as a result of wave stress, and these fragments functioned as propagules (Bégin et al. 2003). Strong light exposure results in accumulation of oxygen in the thalli, and favors long-distance dispersal and colonization by the fragments (Gagnon et al. 2014).

Codium fragile is tolerant of a wide range of temperatures (-2-30°C) and salinities (12-42 PSU) (Malinowski and Ramus 1973; Hanisak 1979), but has not colonized tropical regions. It has colonized a wide range of habitats, including rocky and cobble shores, driftwood, jetties, breakwaters, seawalls, docks, piers, and floats. On soft bottoms, it grows on scattered stones and shells (Ramus 1971; Gosner 1978; Bulleri and Airoldi 2005; Geraldi et al. 2014). This seaweed has considerable tolerance to desiccation and extends into the lower intertidal zone. In experiments, it was able to survive periods of emersion of up to 90 days in high relative air humidity, leading to the likelihood on transport in fishnets, boat decks, or fouled shellfish (Schaffelke and Deane 2005). This seaweed quickly recovers normal photosynthesis after short (5-6 h) exposure to desiccation or freshwater (Kim and Garbary 2007). Codium fragile has colonized kelp beds, particularly after disturbance by storms, herbivores such as sea urchins, or the killing of kelps by the invading bryozoan Membranipora membranacea (Harris and Mathieson 2000; Chapman et al. 2002; Scheibling and Gagnon 2006). Eelgrass (Zostera marina) beds are also invaded by C. fragile, often growing on stones or shells (Ramus 1971), but also attaching to roots and rhizomes of the plant. Garbary et al. (2004) has described a growth form which attaches to eelgrass and sends out horizontal axes and vertical branches.

Growth rates of Codium fragile, at an optimum temperature, were greatest at low to moderate light intensities, 30-90 µE m-3s-1, and long photoperiods, 16h L: 8h D, or 24 h L, but fell off a bit at high intensities (150, µE m-3s-1), suggesting best growth under summer conditions. Total daily irradiance, rather than photoperiod appears to be the major feature of light that affects growth. On a daily basis, at 24 C growth rates stopped increasing above 4 µE m-3s-1 (Hanisak 1979). Sporelings were more sensitive to light, with growth saturating at 1.2 µE m-3s-1 -day and declining above 4 µE m-3s-1 -day (Hanisak 1979). Nitrate, nitrite, ammonium, and urea were equally good as nitrogen sources (Hanisak 1979).

Codium fragile is a potentially important food item for marine herbivores, a substrate for epiphytes and epifauna, and a refuge for mobile animals. For some generalist herbivores, it is a low-quality food, however. Herbivores feeding or growing poorly on this alga include the amphipod Ampithoe longimana (Cruz-Rivera and Hay 2001) and the Green Sea Urchin Strongylocentrotus droebachiensis (Prince and LeBlanc 1992; Scheibling and Anthony 2001). However, the introduced Asian Shore Crab Hemigrapsus sanguineus preferred C. fragile and Ulva spp. to Chondrus crispus, Fucus spp., and Ascophyllum nodosum (Bourdeau and O'Connor 2003). Grazing by the introduced Common Periwinkle (Littorina littorea) may control C. fragile in the intertidal zone (Scheibling et al. 2008). Saccoglossan seaslugs include specialized herbivores on green algae. Placida dendritca (probably a complex of several cryptic species) is a major herbivore on Codium fragile in the Gulf of Maine (Bleakney 1989; Trowbridge et al. 1998; Harris and Jones 2005).

Consumers:

Placida dendritica (sea slug)

Trophic Status:

Primary Producer

PrimProd

Habitats

General HabitatGrass BedNone
General HabitatUnstructured BottomNone
General HabitatOyster ReefNone
General HabitatMarinas & DocksNone
General HabitatRockyNone
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Tidal RangeLow IntertidalNone
Vertical HabitatEpibenthicNone


Tolerances and Life History Parameters

Minimum Temperature (ºC)-2Field data, New England (Malinowski and Ramus 1972)
Maximum Temperature (ºC)30Experimental data growth of thalli (Hanisak 1979)
Minimum Salinity (‰)12Experimental data, growth of thalli at 24 C (Hanisak 1979)
Maximum Salinity (‰)42Experimental data, growth of thalli at 24 C ( (Hanisak 1979)
Minimum Reproductive Temperature12Experimental data, growth of sporelings (Hanisak 1979)
Maximum Reproductive Temperature24Experimental data, growth of sporelings (Hanisak 1979)
Minimum Reproductive Salinity18Experimental data, growth of sporelings (Hanisak 1979)
Maximum Reproductive Salinity48Experimental data, growth of sporelings (Hanisak 1979)
Maximum Length (mm)1,000More typically to 500 mm or less (Silva 1955; Gosner 1978; Schneider and Searles 1991; Van Patten 2006)
Broad Temperature RangeNoneCold temperate-Warm temperate
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

Codium fragile is widely regarded as a troublesome invader. The DAISIE website lists it as one of the '100 worst' invaders in Europe (DAISIE 2009), as does a species list for the Mediterranean (Streftaris and Zeneros 2006). Common economic impacts include interference with fishing gear and aquaculture, and aesthetic impacts on recreation, due to masses of the slimy weed washed up on beaches (Ramus 1971; Boudouresque 1994). Codium fragile's invasion of productive marine habitats such as kelp and seagrass beds may have impacts on fisheries, but these are difficult to measure (Ramus 1971; Schmidt and Sheibling 2006; Kelly et al. 2011).

Economic Impacts

Fisheries - Codium fragile can attach to shellfish, interfering with movement in scallops and causing shellfish, mussels, and oysters to be washed ashore with the buoyant seaweed (Ramus 1971). The weed also frequently fouls fishing lines and nets in shallow waters (Galtsoff 1964; Boudouresque 1994; Campbell 1999; Garbary et al. 2004). In Chile, it overgrew red algae (Gracilaria chilensis), being cultured for agar, reducing the harvest of the crop (Neill et al. 2006).

Aesthetic - Accumulations of Codium fragile on beaches are unattractive and unpleasant to walk on, perhaps more so than most seaweeds. On public beaches, the seaweeds are regularly removed by cleaning crews (Fofonoff personal observation). On French Mediterranean beaches, in the 1960s, blooms of C. fragile washed ashore, and had to be removed with heavy equipment (Boudouresque 1994).

Ecological Impacts

Competition - In invaded areas, C. fragile has often been reported to invade native plant communities and to partially replace native species. The extent of this competition seems to vary greatly in different regions and different plant communities. It appears to do best as a colonizer of bare surfaces, such as artificial structures, and areas cleared by storms, grazers (such as sea urchins), or the overgrowing bryozoan Membranipora membranacea, and rarely invades areas of undisturbed, established vegetation, such as kelp or seagrass beds (Malinowski and Ramus 1973; Harris and Tyrell 2001; Chapman et al. 2002; Scheibling et al. 2006). Its advantages over native seaweeds include rapid growth and longevity, since most native marine plants are annuals. It rapidly responds to added nutrients, giving it an advantage in eutrophic areas (Ramus 1971). In European waters, it was reported to be replacing the native C. tomentosum and C. vermilaria (Farnham 1980), but in a later survey, native Codium were found to dominate on natural surfaces, while C. fragile dominated on docks and breakwaters (Trowbridge and Farnham 2009). A similar pattern was seen in North Carolina, with C. fragile replacing the native C. decorticatum on artificial substrates (concrete, bulkheads, and granite seawalls), while the native species remains abundant on natural substrates such as oysters (Geraldi et al. 2014).

Habitat Change - Codium fragile is an 'ecosystem engineer', and can alter coastal habitats in multiple ways, especially in regions like the Northeast coast of North America, where no native Codium is present, and where no other alga has a similar growth form. Codium fragile, and its buoyant branches, can interfere with the movement of scallops, help waves wash mussels and stones on to beaches, and float oysters away from their beds (Ben-Avraham 1971; Ramus 1971). On the other hand, they also provide a substrate for epiphytes and epifauna, and a refuge for mobile prey, although often differing in structure, food quality, and physical characteristics from native seaweeds and sea grasses.

Codium fragile is widely thought to provide inferior habitat to native seaweeds and seagrasses, but the evidence for this is mixed. Codium fragile in the Gulf of Maine replaced kelp canopy with less favorable habitat and supported fewer juvenile fishes (Cunner, Tautogolabrus adspersus). This was attributed to the inferior food quality of C. fragile, and a scarcity of epiphytes (Levin et al. 2002). However, experiments elsewhere suggest more complex effects, with different species responding differently to changes in plant communities. In Narragansett Bay, C. fragile supported a more diverse and dense community of native and introduced epiphytic algae, than the native algae Fucus vesiculosus (Jones and Thornber 2005). In Cranberry Cove, Nova Scotia, C. fragile had a greater density (but not diversity) of epiphytes than kelps (Laminaria spp.). The differing structure of a C. fragile canopy permits greater survival of juvenile fishes and crabs than in barren regions or kelp beds (Schmidt and Scheibling 2006). However, these changes were transient in regions off Nova Scotia, where the large growths of C. fragile were removed by winter storms and recolonized by native kelps (Kelly et al. 2011). Small bivalves and amphipods were most abundant in the C. fragile-dominated state, compared to amphipods and small gastropods in the kelp-dominated state (Kelly et al. 2011). In Magdalen Islands, Quebec, eelgrass beds (Zostera marina) had greater diversity and abundance of invertebrates and fishes when invaded by C. fragile (Drouin et al. 2011). In the Adriatic Sea, C. fragile increased the recruitment and survival of Mediterranean Mussels (Mytlilus galloprovincialis) on breakwaters, offering an irregular surface, colonized by filamentous epiphytic algae, favorable for settlement, and buffering mussels from thermal stress and desiccation (Bulleri et al. 2006).

Food/Prey - For many generalized herbivores C. fragile is an inferior food. However, it can support edible epiphytic algae and it also hosts some saccoglossan slugs, which are green-alga-specialists (Trowbridge 1988). Among East Coast species showing poor feeding, growth, or reproduction on C. fragile were the snail Lacuna vincta (Northern Lacuna), the amphipod Ampithoe longimana (Cruz-Rivera and Hay 2001), and the Green Sea Urchin Strongylocentrotus droebachiensis (Prince and LeBlanc 1992; Scheibling and Anthony 2001). However, the introduced Asian Shore Crab Hemigrapsus sanguineus preferred C. fragile to several native seaweeds (Bourdeau and O'Connor 2003). The herbivorous saccoglossan sea-slug Pacifia dendritica feeds on C. fragile, and can control the seaweed's populations, but is vulnerable to predators, including the introduced Green Crab (Carcinus maenas) (Harris and Jones 2005). This cosmopolitan sea slug (probably a species complex) may have been present, but rare on the East Coast, before the Codium invasion, but is now abundant (Bleakney 1989; Harris and Jones 2005).

Regional Impacts

NA-ET1Gulf of St. Lawrence to Bay of FundyEcological ImpactCompetition
Codium fragile invades after disturbance to kelp beds, and displaces native kelps (Laminaria digitata and L. longicruris). Major causes of displacement of kelps include outbreaks of the sea urchin Strongylocentrotus droebachiensis, and the killing of kelps by the introduced bryozoan Membranipora membranacea. A survey in the year 2000 found extensive meadows of C. fragile in Mahone and St. Margarets Bays (Chapman et al. 2002). In experiments, removal of Laminaria and a smaller native brown alga, Demarestia sp. resulted in an increase in C. fragile biomass. Conversely, removal of C. fragile resulted in increased growth of Laminaria and Demarestia species. Codium fragile meadows inhibit the recruitment of native kelps and other algae (Scheibling et al. 2006). However, in areas off the coast of Nova Scotia, large growths of C. fragile were vulnerable to winter storms, and declined from 2000 to 2008, and were replaced by the native kelp L. digitata (Kelly et al. 2011).
NA-ET1Gulf of St. Lawrence to Bay of FundyEcological ImpactHabitat Change
Codium fragile can replace a kelp canopy with less favorable habitat (Chapman et al. 2002). The differing structure of canopy of Codium fragile permits better survival of juvenile fishes and crabs (Schmidt and Sheibling 2007). These changes were transient, in regions off Nova Scotia, where the large growths of C. fragile were removed by winter storms, and recolonized by native kelps (Kelly et al. 2011). Small bivalves and amphipods were most abundant in the C. fragile-dominated state, compared to amphipods and small gastropods in the kelp-dominated state (Kelly et al. 2011).
NA-ET2Bay of Fundy to Cape CodEcological ImpactCompetition
Codium fragile invades kelp beds after disturbances, and displaces kelps, and inhibits kelp recruitment. It exploits the fouling and killing of kelps by the introduced bryozoan Membranipora membranacea (Levin et al. 2002). In shallow waters along the Isle of Shoals, there was a gradual shift from kelps to Codium and to an opportunistic red alga community (Harris and Tyrell 2001).
NA-ET2Bay of Fundy to Cape CodEcological ImpactHabitat Change
Codium fragile replaces kelp canopy with less favorable habitat, and supports fewer juvenile fishes (Cunner, Tautogolabrus adspersus) (Levin et al. 2002). Around the Isles of Shoals, NH-ME, from the 1979 to 2015, there has been a trend of replacement of kelps and other larger brown seaweeds, by smaller, bushier red seaweeds (Bonnemaisonia hamifera, Dasysiphonia japonica, and Neosiphonia spp.) and Codium fragile, increasing the structural complexity of the environment, and the abundance and diversity of meso-sized invertebrates (Dijkstra et al. 2017).
NA-ET1Gulf of St. Lawrence to Bay of FundyEcological ImpactFood/Prey
Codium fragile was poor food for the sea urchin Strongylocentrotus droebachiensis. The urchins consumed 3.5X more algae than those fed Laminaria sp., but had less growth, and no gonadal production (Scheibling and Anthony 2001).
M020Narragansett BayEcological ImpactHabitat Change
Codium fragile supports a diverse community of native and introduced epiphytic algae, year-round. The latter include Antithamnion hubbsii, Bonnemaisonia hamifera, and Neosiphonia harveyi. Epiphyte communities on C. fragile were denser and more abundant than those on the native Fucus vesiculosus (Jones and Thorber 2010). The epiphytes N. harveyi (introduced) and C. virgatum (native) also provided an important food source for the native snail Lacuna vincta (Northern Lacuna) (Jones and Thornber 2005).
NA-S3NoneEcological ImpactHabitat Change
In the Magdalen Islands, Quebec, Zostera marina seagrass beds had greater diversity and abundance of invertebrates, and greater abundance of fishes, when invaded by Codium fragile (Drouin et al. 2011).
B-IINoneEcological ImpactCompetition
In the Kattegat, C. fragile was classified as having a low level of community impacts (Zaiko et al. 2011).
M050Great South BayEcological ImpactHabitat Change
Survival of young Bay Scallops (Argopecten irradians) did not differ greatly between Eelgrass (Zostera marina beds and patches of Codium fragile in Sag Harbor, Long Island. A longer term study in Sag Harbor and Shinnecock Inlet found some evidence for impacts for differences in growth rates and condition between scallop populations in eelgrass and Codium beds, but this appeared to vary among bays and years (Carroll and Peterson 2013).
NA-ET3Cape Cod to Cape HatterasEcological ImpactHabitat Change
Research in the 1970s suggested that Codium fragile may have the potential to change a sandy beach to a gravel beach (Nobska Beach, Woods Hole) by attaching and transporting stones onto shore (with it's buoyant fronds) (Ben-Avraham 1971). However this beach was still mostly sand in 2015 (Paul Fofonoff, personal observation).

Codium fragile is believed to have affected the growth and mortality of Bay Scallops (Argopecten irradians), Blue Mussels (Mytilus edulis), and Eastern Oysters (Crassostrea virginica). Attached C. fragile can inhibit the movement of scallops, by attaching to their shells, causing them to float in the water column and possibly be washed ashore by waves (Ramus 1971). Survival of young Bay Scallops (Argopecten irradians) did not differ greatly between Eelgrass (Zostera marina) beds and patches of Codium fragile in Sag Harbor, Long Island. A longer term study in Sag Harbor and Shinnecock Inlet found some evidence for impacts for differences in growth rates and condition between scallop populations in eelgrass and Codium beds, but this appeared to vary among bays and years (Carroll and Peterson 2013).

Codium fragile supports a diverse community of native and introduced epiphytic algae, year-round. The latter include Antithamnion hubbsii, Bonnemaisonia hamifera, and Neosiphonia harveyi. Epiphyte communities on C. fragile were denser and more abundant than those on the native Fucus vesiculosus (Jones and Thorber 2010). The epiphytes N. harveyi(introduced) and C. virgatum (native) also provided an important food source for the native snail Lacuna vincta (Northern Lacuna) (Jones and Thornber 2005).

S030Bogue SoundEcological ImpactHabitat Change
Codium spp. are associated with both nitrogen-fixing and denitrifying bacteria. Codium fragile, which prefers artificial substrates, supports a greater rate of denitrification than the native C. decorticatum, increasing N2 release, and decreasing nitrate concentrations, potentially decreasing eutrophication (Geraldi et al. 2014).
S050Cape Fear RiverEcological ImpactHabitat Change
Codium spp. are associated with both nitrogen-fixing and denitrifying bacteria. Codium fragile, which prefers artificial substrates, supports a greater rate of denitrification than the native C. decorticatum, increasing N2 release, and decreasing nitrate concentrations, potentially decreasing eutrophication (Geraldi et al. 2014). In experiments, C. fragile in single-species treatments supported a lower diversity of consumers, possibly because of lower habitat complexity, or because of lower food quality (Ramus and Long 2016).
CAR-VIICape Hatteras to Mid-East FloridaEcological ImpactHabitat Change
Codium spp. are associated with both nitrogen-fixing and denitrifying bacteria. Codium fragile, which prefers artificial substrates, supports a greater rate of denitrification than the native C. decorticatum, increasing N2 release, and decreasing nitrate concentrations, potentially decreasing eutrophication (Geraldi et al. 2014). In experiments, C. fragile in single-speacies treatments supported a lower diversity of consumers, possibly because of lower habitat complexity, or because of lower food quality (Ramus and Long 2016).
AR-VNoneEcological ImpactCompetition
Codium fragile competes for space with the native brown seaweed Fucus serratus, but only in the lower subtidal part of F. serratus' range. Codium fragile tends to replace F. serratus in sheltered subtidal environments, and stony substrate. Fucus serratus is more successful on bedrock, in exposed sites (Armitage and Sjotun 2014).
AUS-VIIINoneEconomic ImpactFisheries
Codium fragile was discovered in Corner Inlet, Victoria, when it was fouling fishing nets (Campbell 1999).
S030Bogue SoundEcological ImpactFood/Prey
Codium fragile was found to be a poor food source for the amphipod Ampithoe longimana, resulting in lower growth and survivorship (Cruz-Ribera and Hay 2001).
CAR-VIICape Hatteras to Mid-East FloridaEcological ImpactFood/Prey
Codium fragile was found to be a poor food source for the amphipod Ampithoe longimana, resulting in lower growth and survivorship (Cruz-Ribera and Hay 2001).
S050Cape Fear RiverEcological ImpactCompetition
Codium fragile appears to have replaced the native C. decorticatum on artificial substrates (concrete, bulkheads, granite seawalls) in Cape Fear and Masonboro Sounds, in comparisons with 1940s surveys. However, C. decorticatum remains abundant on natural substrates such as oysters (Geraldi et al. 2014).
S045_CDA_S045 (New)Ecological ImpactCompetition
Codium fragile appears to have replaced the native C. decorticatum on artificial substrates (concrete, bulkheads, granite seawalls) in Cape Fear and Masonboro Sounds, in comparisons with 1940s surveys. However, C. decorticatum remains abundant on natural substrates such as oysters (Geraldi et al. 2014).
S045_CDA_S045 (New)Ecological ImpactHabitat Change
Codium spp. are associated with both nitrogen-fixing and denitrifying bacteria. Codium fragile, which prefers artificial substrates, supports a greater rate of denitrification than the native C. decorticatum, increasing N2 release, and decreasing nitrate concentrations, potentially decreasing eutrophication (Geraldi et al. 2014).
CAR-VIICape Hatteras to Mid-East FloridaEcological ImpactCompetition
Codium fragile appears to have replaced the native C. decorticatum on artificial substrates (concrete, bulkheads, granite seawalls) in Cape Fear and Masonboro Sounds, in comparisons with 1940s surveys. However, C. decorticatum remains abundant on natural substrates such as oysters (Geraldi et al. 2014).
NEA-IINoneEcological ImpactCompetition
Codium was reported to replace the native C. tomentosum on the south and west coasts of the British Isles (Farnham 1980; Eno et al. 1997). However, in the English Channel region, dense populations of C. fragile are seen on artificial structures, such as docks and breakwaters, but populations of the native C. tomentosum and C. vermilara persist in natural habitats (Trowbridge and Farnham 2009).
NA-S3NoneEconomic ImpactFisheries
Codium fragile fouled about 80% of the space on mussel aquaculture lines (Garbary et al. 2004).
N135_CDA_N135 (Piscataqua-Salmon Falls)Ecological ImpactCompetition
Codium fragile invades kelp beds after disturbances, and displaces kelps and inhibits kelp recruitment. It exploits the fouling and killing of kelps by the introduced bryozoan Membranipora membranacea (Levin et al. 2002). In shallow waters along the Isle of Shoals, there was a gradual shift from kelps to Codium and to an opportunistic red alga community (Harris and Tyrell 2001).
N135_CDA_N135 (Piscataqua-Salmon Falls)Ecological ImpactHabitat Change
Codium fragile replaces kelp canopy with less favorable habitat, and supports fewer juvenile fishes (Cunner, Tautogolabrus adspersus) (Levin et al. 2002). Around the Isles of Shoals, NH-ME, from the 1979 to 2015, there has been a trend of replacement of kelps and other larger brown seaweeds, by smaller, bushier red seaweeds (Bonnemaisonia hamifera, Dasysiphonia japonica, and Neosiphonia spp.) and Codium fragile, increasing the structural complexity of the environment, and the abundance and diversity of meso-sized invertebrates (Dijkstra et al. 2017).
N135_CDA_N135 (Piscataqua-Salmon Falls)Ecological ImpactFood/Prey
The native snail Lacuna vincta occurred in lower density on Codium fragile than on the native kelp Laminaria saccharina. In experiments, feeding and growth was reduced in L. vincta on Codium, compared to Laminaria (Chavanich and Harris 2004). Codium fragile was a less-preferred food of the Green Sea Urchin Strongylocentrotus droebachiensis (Prince and Leblanc 1993) The herbivorous saccoglossan sea-slug feeds on C. fragile, and can control the seaweed's populations (Harris and Adams 2005).
NA-ET2Bay of Fundy to Cape CodEcological ImpactFood/Prey
The native snail Lacuna vincta occurred in lower density on Codium fragile than on the native kelp Laminaria saccharina. In experiments, feeding and growth was reduced in L. vincta on Codium, compared to Laminaria (Chavanich and Harris 2004). The herbivorous saccoglossan sea-slug Pacifia dendritica feeds on C. fragile, and can control the seaweed's populations (Harris and Adams 2005). This sea slug may have been present, but rare on the East Coast, before the Codium invasion (Bleakney 1989).
N195_CDA_N195 (Cape Cod)Ecological ImpactHabitat Change
Codium fragile attaches to stones, and was observed to increase the transport of stones onto a sand beach, with the potential to change it to a gravel beach (Nobska Beach, Woods Hole) (Ben-Avraham 1971). However this beach was still mostly sand in 2015 (Paul Fofonoff, personal observation).
M023_CDA_M023 (Narragansett)Ecological ImpactHabitat Change
Codium fragile attached to Blue Mussels (Mytilus edulis caused large quantities of mussels to be washed onto the Beach at Charlestown, Rhode Island (Ramus 1971).
M040Long Island SoundEcological ImpactHabitat Change
Codium fragile attached to the shells of Bay Scallops (Argopecten irradians) in the Niantic River, Connecticut, interfered with the movement of the scallops, and increased their mortality (Ramus 1971).
N185_CDA_N185 (Cape Cod)Ecological ImpactHabitat Change
Codium fragile attached to Eastern Oysters (Crassostrea virignica) caused oysters to be floated away from their beds, when the algae became saturated with oxygen, and lifted the oysters off the bottom (Ramus 1971).
N185_CDA_N185 (Cape Cod)Economic ImpactFisheries
Mortality caused by Codium fragile is believed to have raised the priced of local oysters on Cape Cod. Codium fragile also interfered with oyster-harvesting equipment (Galtsoff 1965; Ramus 1971).
M040Long Island SoundEconomic ImpactFisheries
Codium fragile is believed to have contributed to the mortality of Bay Scallops in Long Island Sound. However, the role of C. fragile is difficult to determine, since the seaweed also attaches to dead shells (Ramus 1971).
NA-ET3Cape Cod to Cape HatterasEconomic ImpactFisheries
Codium fragile is believed to have contributed to the mortality of Bay Scallops in Long Island Sound. However, the role of C. fragile is difficult to determine, since the seaweed also attaches to dead shells (Ramus 1971). Mortality caused by Codium fragile is believed to have raised the priced of local oysters on Cape Cod. Codium fragile also interfered with oyster-harvesting equipment (Galtsoff 1965; Ramus 1971).
MED-IINoneEconomic ImpactFisheries
Codium fragile has fouled ropes used in oyster culture in the Thau Lagoon (Boudouresque 1994).
MED-VIINoneEcological ImpactHabitat Change
The juvenile thalli (primordia) and the adult canopies of Codium fragile both had positive effects on the recruitment and survival of Mediterranean Mussels (Mytlilus galloprovincialis) on breakwaters in the Adriatic Sea. The primordia offered an irregular surface, and may have altered flow, and encouraged filamentous algae, favoring settlement of larvae. The mature canopy may also buffer mussels from thermal stress and desiccation (Bulleri et al. 2006).
N195_CDA_N195 (Cape Cod)Economic ImpactAesthetic
Accumulations of Codium fragile on Cape Cod beaches are unattractive and unpleasant to walk on, perhaps more so than most seaweeds (Fofonoff personal observation).
NA-ET3Cape Cod to Cape HatterasEconomic ImpactAesthetic
Accumulations of Codium fragile on Cape Cod beaches are unattractive and unpleasant to walk on, perhaps more so than most seaweeds (Fofonoff personal observation).
NA-S3NoneEcological ImpactCompetition
In Caribou Harbour, Nova Scotia, a distinct horizontal growth form of Codium fragile was attaching to rhizomes of Eelgrass, potentially competing with the grass (Garbary et al. 2004). However, in the Magdalen Islands, experiments indicated that negative effects on eelgrass occurred only at high Codium densities (Drouin et al. 2013). Disturbance and exposure, of Eelgrass rhizomes by storms, ice scour, and boat traffic, appears to be a major factor controlling invasion of the grass beds by C. fragile (Gagnon et al. 2014).
SEP-CNoneEconomic ImpactFisheries
Codium fragile interferes with the aquaculture of the native red alga Gracilaria chilensis, significantly reducing the harvest of the crop (Neill et al. 2006).
NA-ET3Cape Cod to Cape HatterasEcological ImpactFood/Prey
The Asian Shore Crab Hemigrapsus sanguineus preferred C. fragile and Ulva spp. to Chondrus crispus, Fucus spp., and Ascophyllum nodossum (Bourdeau and O'Connor 2003).
M010Buzzards BayEcological ImpactFood/Prey
The Asian Shore Crab Hemigrapsus sanguineus preferred C. fragile and Ulva spp. to Chondrus crispus, Fucus spp., and Ascophyllum nodossum (Bourdeau and O'Connor 2003).
MED-IINoneEconomic ImpactAesthetic
In the 1960s, heavy depositions of Codium fragile on the shore near Marseille required removal with heavy equipment (Boudouresque 1994).
M128_CDA_M128 (Eastern Lower Delmarva)Ecological ImpactCompetition
In Hog Island Bay, Virginia, Codium fragile was competitive on hard substrates where sediment and drift algae did not accumulate, with moderate growth rates, but a long growing season. It was the fourth most abundant alga in Hog Island Bay (Thomsen 2003).
NA-ET3Cape Cod to Cape HatterasEcological ImpactCompetition
In Long Island Sound, Codium fragile cannot invade established Eelgrass (Zostera marina) or native algal communities, but if an area is disturbed and cleared  C. fragile can establish (Malinowski and Ramus 1971). In Hog Island Bay, Virginia, C. fragile was competitive on hard substrates where sediment and drift algae did not accumulate, and had moderate growth rates but a long growing season. It was the fourth most abundant algae in Hog Island Bay (Thomsen 2003).
AR-VNoneEcological ImpactHabitat Change
Epiphytic and epifaunal communities of the introduced C. fragile, off Norway, shared many species with the native Fucus serratus but showed statistical differences in composition. Fucus serratus support more sessile fauna, especially bryozoans (Armitage and Sjotun 2016).
AUS-XNoneEcological ImpactHabitat Change
The non-native subspecies of Codium fragile supports a lower diversity but a higher abundance of amphipods (mostly Hyale spp. and the native gastropod Alaba opiniosa. Abundance and diversity of amphipods were affected by the number of branches of the seaweeds, as much as by species identity (Lutz et al. 2019).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
NWP-4a None 0 Native Estab
NWP-3b None 0 Native Estab
NWP-4b None 0 Native Estab
NA-ET3 Cape Cod to Cape Hatteras 1957 Def Estab
NA-ET2 Bay of Fundy to Cape Cod 1964 Def Estab
NA-ET1 Gulf of St. Lawrence to Bay of Fundy 1991 Def Estab
NA-S3 None 1996 Def Estab
NEP-V Northern California to Mid Channel Islands 1977 Def Estab
NEA-II None 1863 Def Estab
NEA-III None 1845 Def Estab
B-I None 1938 Def Estab
B-II None 1985 Def Estab
AR-IV None 1985 Def Estab
NEA-IV None 1946 Def Estab
NEA-V None 1986 Def Estab
MED-II None 1950 Def Estab
MED-III None 1972 Def Estab
MED-IV None 1974 Def Estab
MED-VII None 1983 Def Estab
MED-VI None 1985 Def Estab
AUS-VIII None 1890 Def Estab
AUS-X None 2001 Def Estab
NZ-IV None 1841 Def Estab
NEA-VI None 1993 Def Estab
SEP-C None 1998 Def Estab
N130 Great Bay 1985 Def Estab
M060 Hudson River/Raritan Bay 1972 Def Estab
M010 Buzzards Bay 1967 Def Estab
M040 Long Island Sound 1961 Def Estab
M020 Narragansett Bay 1968 Def Estab
M130 Chesapeake Bay 1995 Def Estab
P090 San Francisco Bay 1977 Def Estab
CAR-VII Cape Hatteras to Mid-East Florida 1979 Def Estab
S045 _CDA_S045 (New) 1979 Def Estab
S030 Bogue Sound 1981 Def Estab
M128 _CDA_M128 (Eastern Lower Delmarva) 2000 Def Estab
M120 Chincoteague Bay 1976 Def Estab
M110 Maryland Inland Bays 2003 Def Estab
M100 Delaware Inland Bays 2003 Def Estab
M050 Great South Bay 1961 Def Estab
M030 Gardiners Bay 1957 Def Estab
N185 _CDA_N185 (Cape Cod) 1961 Def Estab
N180 Cape Cod Bay 1968 Def Estab
N170 Massachusetts Bay 2000 Def Estab
N135 _CDA_N135 (Piscataqua-Salmon Falls) 1983 Def Estab
N125 _CDA_N125 (Piscataqua-Salmon Falls) 1989 Def Estab
N100 Casco Bay 1994 Def Estab
N080 Sheepscot Bay 1964 Def Estab
AUS-IX None 1889 Def Estab
N195 _CDA_N195 (Cape Cod) 1967 Def Estab
WA-IV None 1885 Def Estab
NZ-VI None 1935 Def Estab
NWP-3a None 0 Native Estab
M023 _CDA_M023 (Narragansett) 1971 Def Estab
M070 Barnegat Bay 1966 Def Estab
N060 Muscongus Bay 1995 Def Estab
N036 _CDA_N036 (Maine Coastal) 1980 Def Estab
N010 Passamaquoddy Bay 1995 Def Estab
EAS-I None 0 Native Estab
EAS-III None 0 Native Estab
AUS-VII None 2002 Def Estab
MED-VIII None 1945 Def Estab
P110 Tomales Bay 2004 Def Estab
WA-I None 1990 Def Estab
S050 Cape Fear River 2009 Def Estab
SA-I None 1849 Def Estab
AUS-V None 2008 Def Estab
AR-V None 1946 Def Estab
SEP-B None 2005 Def Estab
SEP-A None 2005 Def Estab
NA-S2 None 2013 Def Estab
AUS-IV None 2018 Def Estab
MED-I None 2000 Def Estab
AUS-XI None 1957 Def Estab
MED-IX None 1998 Def Estab
MED-V None 1998 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude

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