Winter Flounder
Winter flounder are a flatfish of the Canadian Maritimes, concentrated in the Bay of Fundy and the southern Gulf of St. Lawrence.
They move into protected bays, estuaries, and river mouths in cooler months to feed and spawn — putting them within reach of shore anglers and small-boat fishermen.
Excellent table fare, they've supported both commercial and recreational fisheries in Atlantic Canada for decades.
Scientific Name: Pseudopleuronectes americanus
Also known as Blackback, plie rouge
- Oval, thick-bodied flatfish with both eyes on the right side; the left eye migrates to the right during development — a key ID feature separating them from summer flounder (fluke), which are left-eyed.
- Top side ranges from olive green and reddish-brown to dark slate or near-black depending on the bottom they're resting on; underside is white.
- Small mouth with few or no teeth — noticeably smaller than a fluke's mouth, which helps with ID.
- Typical catch runs 1–3 lbs; fish over 6 lbs are possible, and the species can exceed 2 feet in length and live 15+ years.
What to know
Habitat Distribution
- Native to the western Atlantic; in Canada, range extends from Labrador and Newfoundland south through the Maritimes, with the Bay of Fundy and southern Gulf of St. Lawrence (NAFO Division 4T) being the core Canadian fishery areas.
- Live on soft and mixed bottoms — mud, sand, and gravel — typically at depths under 100 metres, but most accessible fishing happens in shallow inshore zones.
- Tolerate a wide salinity range, moving freely between full-strength seawater and brackish estuaries near river mouths.
- Seasonally inshore: in the colder northern waters of Atlantic Canada, fish move into shallow bays and estuaries in spring and summer to spawn, then shift to deeper offshore water in winter.
Key Locations
- Bay of Fundy — historically the core of the Canadian recreational and commercial winter flounder fishery; protected bays and estuaries along both the New Brunswick and Nova Scotia shores.
- Southern Gulf of St. Lawrence (NAFO Division 4T) — including waters around the Magdalen Islands, though this stock is under a commercial closure and recreational rules should be confirmed with DFO.
- Coastal estuaries and tidal rivers of Nova Scotia and New Brunswick — sheltered inlets where flounder move inshore during the spring and early summer feeding period.
Specific Spots
- Flat muddy or sandy bottoms in protected bays and tidal estuaries — flounder hold tight to the bottom and favour areas sheltered from strong current and wave action.
- Edges of eelgrass beds, where juvenile forage concentrates; historically these were prime holding areas before eelgrass declined in many Maritime bays.
- Tidal river mouths and the lower reaches of estuaries, where brackish water meets salt — flounder use these transition zones heavily during their inshore feeding period.
- Slight depressions or channel edges on otherwise flat bottom give flounder a current break and a place to intercept drifting food without fighting the tide.
Winter Flounder FAQ
Answers from onWater's species guide.
What are the best lures and bait for Winter Flounder?
Sea worms (sandworms or bloodworms) are the go-to bait across Atlantic Canada, rig them so the tail flutters freely in the current rather than bunching the worm on the hook.
When is the best time to fish for Winter Flounder?
Spring (May–June), prime season as water temperatures climb into the upper 40s–50s°F and flounder move actively into shallow inshore areas to feed; this is the most productive window in Atlantic Canada.
How do you catch Winter Flounder?
Most flounder fishing in Atlantic Canada is done from small boats or kayaks anchored over soft-bottom flats in protected bays and estuaries, presenting baited bottom rigs and waiting out the bite. Shore fishing from docks, wharves, and tidal river banks is also productive during the inshore season.
What do Winter Flounder eat?
Bottom feeders that root through soft sediment for marine worms (sandworms, bloodworms), small crustaceans, and molluscs, sea worms are the top-producing bait because they match what flounder are already eating on the bottom.
Where do Winter Flounder live?
Native to the western Atlantic; in Canada, range extends from Labrador and Newfoundland south through the Maritimes, with the Bay of Fundy and southern Gulf of St. Lawrence (NAFO Division 4T) being the core Canadian fishery areas.
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