The winter flounder, blackback, or lemon sole, Pseudopleuronectes americanus , is distributed in the Northwest Atlantic from Labrador to Georgia. Abundance is highest from the Gulf of St. Lawrence to Chesapeake Bay. The diet consists primarily of benthic invertebrates. Movement patterns are generally localized. Winter flounder undertake small-scale migrations into estuaries, embayments, and saltwater ponds in winter to spawn, subsequently moving to deeper water during summer.
Winter flounder tend to return to the same spawning locations in consecutive years.
Restricted movement patterns, and differences in growth, meristic, and morphometric characteristics suggest that relatively discrete local groups exist. Tagging and meristic studies indicate separate groups of winter flounder north of Cape Cod, east and south of Cape Cod, and on Georges Bank. Winter flounder are typically exploited in coastal locations, although offshore shoal areas, particularly Georges Bank and Nantucket Shoals, support important winter flounder fisheries. The principal commercial fishing gear used is the otter trawl. Recreational catches are significant, especially in the southern parts of the range.