AquaNISInformation system on aquatic non-indigenous and cryptogenic species |
Species | Magallana gigas | |
Date of the first record (?) | 1877 References (not structured): Wilkins NP (1989) Ponds, passes and parcs: aquaculture in Victorian Ireland. Glendale Press, Sandycove, Co Dublin, 352pp. Utting SD Spencer BE (1992)Introductions of marine bivalve molluscs into the United Kingdom -case histories. ICES Mar. Sci. Symp., 194: 84-91. Comments: Initially introduced for trial cultivation from France as half-grown oysters as Portugese oysters (Crassostrea angulata) but were apparently imported to Britain much later, in 1926. In 1969 imports of Canadian stock of Crassostrea gigas were introduced having been quarantined in Conwy, North Wales in 1965, 1972 and again then from Washington State in 1980. In 1993 Pacific oysters were imported from France. |
Recipient region (?) | Country: Ireland LME: 24. Celtic-Biscay Shelf LME sub-region: Celtic seas References (not structured): Utting SD Spencer BE (1992) Introductions of marine bivalve molluscs into the United Kingdom -case histories. ICES Mar. Sci. Symp., 194: 84-91. Comments: The quarantined oysters were introduced to Cork harbour in 1969. Several sites were developed for cultivation within the decade on all coasts. |
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Source region (?) | Country: France Country: United Kingdom (Britain) --> LME: 24. Celtic-Biscay Shelf; LME sub-region: Celtic seas References (not structured): Wilkins NP (1989) Ponds, passes and parcs: aquaculture in Victorian Ireland. Glendale Press, Sandycove, Co Dublin, 352pp. Comments: Sourced from France in the late 1800s and much later from Britain in 1969 and obtained from the Ministry Laboratory in Conwy, North Wales following quarantine. The original source of this broodstock was from British Columbia. In 1993 oysters were imported from France. |
Pathway / Vector (?) | Level of certainty: Direct evidence Pathway: Culture activities Vector: Regional stock movement References (not structured): Wilkins NP (1989) Ponds, passes and parcs: aquaculture in Victorian Ireland. Glendale Press, Sandycove, Co Dublin, 352pp. Comments: Originally introduced to selected sites about the Irish coast including ponds in Ballinakill Bay, which since still remain unused. |
Habitat type (?) | Aquaculture sites Estuary Lagoon Marina Port vicinity Sheltered coastal area References (not structured): Parsons J (1974) Advantages in tray cultivation of pacific oysters (Crassostrea gigas) in Strangford Lough, N. Ireland. Aquaculture 3(3): 221-229. Comments: It is cultivated in meshed bags held on trestles is the principle form of cultivation. Some may be grown on the lower shore. Where recruitment takes place oysters cement themselves to shell, stones and boulders. |
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Wave exposure (?) | Sheltered Comments: Cultivated in sheltered sites on shore with low gradients. |
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Salinity range (?) | Venice system: 6. Polymixohaline [18-30psu] 7. Euhaline [30-40psu] References (not structured): Miossec L, Le Deuff R‐M, Goulletquer P (2009) Alien species alert: Crassostrea gigas (Pacific oyster). ICES Cooperative Research Report No. 299. 42 pp. Comments: It can endure short periods of low salinity. |
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Temperature range (?) | Not entered |
Zonation / Substratum (?) | Benthic: Littoral (Benthic) Sublittoral beyond photic zone Sublittoral within photic zone Substratum: Artificial (manmade) Biogenic (living or nonliving) Hard (cobbles to bedrock) References (not structured): Miossec L, Le Deuff R‐M, Goulletquer P (2009) Alien species alert: Crassostrea gigas (Pacific oyster). ICES Cooperative Research Report No. 299. 42 pp. Comments: Can attach to the hulls of vessels, floating pontoons and a wide range of submerged structures as well as to shells, stones and bedrock. |
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Reproductive duration (?) | Not entered | |
Reproductive seasonality (?) | Jul. Aug. References (not structured): Steele S, Mulcahy MF (1999) Gameteogenesis of the oyster Crassostrea gigas in southern Ireland. Journal of the Marine Biological Association of the United Kingdom 79(4): 673-686. Minchin D (1993) Possible influence of increases in mean sea temperature on Irish marine fauna and fisheries. Biogeography of Ireland; past, present, and future. M.J. Costello (ed). Occasional Publications of the Irish Biogeographical Society, No. 2, 113-125. Comments: Spawning occurs during warm summers and not at all sites where oysters are in cultivation. Spawning was first noticed in the late 1980s. |
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Migration pattern (?) | Unknown Comments: Oysters cement themselves to the substrate. |
Population status (?) | Common (Moderate level of certainty) References (not structured): Minchin D, Nunn J (2013) Rapid assessment of marinas for invasive alien species in Northern Ireland. A report undertaken for the Northern Ireland Environment Agency, Belfast. 96pp. Lynch S, Carlsson J, Reilly AO, Cotter E, Culloty SC (2012) A previously undescribed ostreid herpes virus 1 (OsHV-q) genotype detected in the pacific oyster, Crassostrea gigas, in Ireland. Parasitology. doi:10.1017/S0031182012000881 Cotter E, Malham SK, O'Keeffe S, Lynch SA, Latchford JW, King JW, Beaumont AR, Culloty SC (2010)Summer mortality of the Pacific oyster, Crassostrea gigas, in the Irish Sea: The influence of growth, biochemistry and gametogenesis. AQuaculture 303: 8-21. Holmes JMC, Minchin D (1995) Two exotic copepods imported into Ireland with the Pacific oyster Crassostrea gigas (Thunberg). The Irish Naturalists’ Journal, 25: 17-20. Minchin D (1993) Possible influence of increases in mean sea temperature on Irish marine fauna and fisheries. Biogeography of Ireland; past, present, and future. M.J. Costello (ed). Occasional Publications of the Irish Biogeographical Society, No. 2, 113-125. Comments: There were three phases of introduction one with the 'Portuguese' oyster from 1877 which did not reproduce in Irish waters but when imported as half-grown oysters could be laid on the shore until of market size. The second phase involved the sowing of seed oysters that had undergone a rigorous quarantine procedure in North Wales on which the main oyster production for Ireland evolved. Then in January 1993 the free-movement enabled unquarantined oysters to be freely distributed in Europe. Subsequently Pacific oysters in Ireland had for the first time demonstrated the summer mortality syndrome now identified as an ostreid herpes virus (OsHV-1). In addition two copeods were introduced with the imports from France. This oyster is locally recruiting in variable numbers each year in bays on all coasts. |
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Species status (?) | Non-indigenous species References (not structured): Menzel RW (1974). Portuguese and Japanese oysters are the same species. Journal of the Fisheries Research Board of Canada 31: 453-456. O'Foighil D, Gaffney PM, Wilbur AE, Hilbisch TJ (1998) Mitochondrial cytochrome oxidase I gene sequences support an Asian origin for the Portuguese oyster Crassostrea angulata. Mar. Biol. 131:497-503. Comments: All indications suggest that G. angulata and G. gigas are different forms of the same species with G. angulata possibly originating from Taiwan. |
Created by | Dan Minchin, 2011-11-09 |
Last update by | Dan Minchin, 2013-12-06 |