Invasion
Invasion Description
1st Record: WA/Puget Sound; (1902, sporadic but successful reproduction and settlement, since 1934, Carlton 1979)
Geographic Extent
WA/Puget Sound; (1902, sporadic but successful reproduction and settlement, since 1934, Carlton 1979; widely established, 2000-2020, Korbluth et al. 2022)\); Kamilche Point/WA/Totten Inlet (12:30-1:40 pm, 19 May 2000 47° 09' 07.253' N; 123° 01' 06.195' W, Salinity 30 psu, Water temperature 15°C, on cobble beach; Cohen et al. 2001); WA/Hood Canal (Ruesink et al. 2005); WA/Quilcene and Dabob Bay, Hood Canal (natural settlement, Chew 1979); Belfair/WA/Hood Canal (1942, Valdez andRuesink 2017)
Vectors
| Level | Vector |
|---|---|
| Probable | Oyster Intentional |
Regional Impacts
| Economic Impact | Fisheries | |
| 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). | ||
| Ecological Impact | Parasite/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). | ||
| Ecological Impact | Food/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). | ||