COSEWIC Assessment Summary

Assessment Summary – April 2009 Common name American - Maritime population Scientific name platessoides Status Threatened Reason for designation This right-eye flounder burrows in the sediment to escape predators and ambush prey. It is widely distributed on both sides of the North , from the Barents Sea to the British Isles in the east, and from northern Baffin Island to Rhode Island in the west. This population occurs in the Gulf of St. Lawrence, the Scotian Shelf, the Bay of Fundy and Georges Bank. A relatively sedentary, non-schooling species, it was likely once the most abundant in the northwest Atlantic. Over a 36 year time series (about 2.25 generations) abundance of mature individuals has declined about 86% in the Gulf of St. Lawrence, and 67% on the Scotian Shelf. Overfishing is a major cause of the decline, but an apparent increase in natural mortality in the 1990s, when the largest part of the decline occurred, may also have contributed. The decline appears to have ceased in the Gulf but may be continuing on the Scotian Shelf. There are small ongoing directed fisheries in the Gulf with a quota in the south but no quota management in the north. On the Scotian Shelf and in the Bay of Fundy, this species is managed together with other as a multispecies stock and there are no specific management measures to ensure sustainability. Occurrence Atlantic Ocean Status history Designated Threatened in April 2009. Assessment based on a new status report.

Assessment Summary – April 2009 Common name American Plaice - Newfoundland and Labrador population Scientific name Hippoglossoides platessoides Status Threatened Reason for designation This right-eye flounder burrows in sediment to escape predators and ambush prey. It is widely distributed on both sides of the North Atlantic Ocean, from the Barents Sea to the British Isles in the east, and from northern Baffin Island to Rhode Island in the west. This population occurs from Hudson Strait to the southern limit of the Grand Bank, and westward north of the Laurentian Channel to the southwestern corner of Newfoundland. A relatively sedentary, non-schooling species, it was likely once the most abundant flatfish in the northwest Atlantic, and the fishery for it in Newfoundland waters was once the largest flatfish fishery in the world. Over a 47 year time series (about 3 generations) abundance has declined approximately 96%. Overfishing is a major cause of the decline, but an apparent increase in natural mortality in the 1990s, when the largest part of the decline occurred, may also have contributed. The decline now appears to have ceased, but numbers remain below a precautionary threshold estimated for this stock. The directed fishery is under moratorium but some significant and poorly regulated bycatches are negatively influencing recovery. In addition, fishing gear is size selective, cropping large individuals, and reducing population reproductive potential. There is evidence that natural mortality has increased which reduces the ability of the population to withstand fishing mortality. Occurrence Atlantic Ocean Status history Designated Threatened in April 2009. Assessment based on a new status report.

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Assessment Summary – April 2009 Common name American Plaice - Arctic population Scientific name Hippoglossoides platessoides Status Data Deficient Reason for designation Information to establish any COSEWIC risk category with assurance is not available. Data on distribution, abundance and specific habitat, including any observed changes over time, are especially needed. Occurrence Arctic Ocean Status history Species considered in April 2009 and placed in the Data Deficient category. Assessment based on a new status report.

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