Winter flounder
Right-eyed flatfish of the western North Atlantic coast.
The winter flounder is a right-eyed flatfish native to shallow coastal waters from Labrador to Georgia. It supports commercial and recreational fisheries, though stocks have declined since the 1980s due to fishing pressure and habitat changes.
- Right-eyed flatfish native to western North Atlantic.
- Spawns in shallow estuaries during late winter.
- Can live for more than 15 years.
- Commercial landings dropped from 40 million pounds peak.
- Distinct from summer flounder by eye position and teeth.
What it is
The winter flounder is a right-eyed flatfish belonging to the family Pleuronectidae. Its eyes sit on the right side of its body, distinguishing it from left-eyed relatives. Adults typically reach lengths of 61 cm in most areas, though those on Georges Bank grow larger, up to 70 cm. The fish has a flattened shape suited for life on the seafloor. It is the only member of its genus found in the Atlantic Ocean, with four other species residing elsewhere.
Where it lives
This species inhabits coastal waters along the western North Atlantic. Its range extends from Labrador in Canada down to Georgia in the United States. It is most abundant in near-shore shallow waters from Newfoundland to Massachusetts Bay. South of Delaware Bay, it becomes less common. Adults frequent saltwater coves, coastal ponds, estuaries, and protected bays. They may remain inshore year-round if temperatures stay below 15 °C and food is plentiful.
How it lives
Larvae feed on tiny planktonic organisms such as nauplii and phytoplankton. As they mature, their diet shifts to include copepods, amphipods, and polychaetes. Adult winter flounder are opportunistic sight-feeders. They hunt annelids, crustaceans, bivalves, and small fish depending on what is available. Northern populations tend to grow slower than those in southern parts of their range. They can live for more than 15 years.
Breeding and life cycle
Sexual maturity occurs at two to three years of age, when fish reach 25–30 cm in length. Mature adults migrate into shallow estuaries in late fall and early spring. Spawning takes place in late winter or early spring. Females lay up to 3.3 million demersal, adhesive eggs that stick to the spawning ground. Larvae hatch in two to three weeks, depending on water temperature. The left eye migrates to the right side after five to six weeks, and juveniles settle on the seafloor.
Fish and people
Winter flounder are prized for their white meat and are sometimes marketed as lemon sole in the United States. They historically supported major commercial and recreational fisheries. Peak harvests reached 40.3 million pounds commercially and 16.4 million pounds recreationally. Landings have dropped significantly since the 1980s. In 2013, commercial landings were 6 million pounds and recreational landings were 77,000 pounds. Management divides the population into three stock units along the U.S. coast.
Status and threats
Populations have declined since the 1980s due to heavy fishing pressure and habitat degradation. Low genetic variability and climate change may also hinder recovery. The Southern New England/Mid-Atlantic stock is considered overfished, although overfishing is not currently occurring. The Georges Bank stock is not overfished. The status of the Gulf of Maine stock is unknown regarding overfishing, but overfishing is not occurring there. Little mixing occurs between these distinct populations.
Questions people ask about Winter flounder
How can you tell a winter flounder from a summer flounder?
Winter flounder have their eyes on the right side of their body and possess small teeth. Summer flounder have eyes on the left side and feature large, conspicuous teeth.
Where do winter flounder spawn?
Mature adults migrate into shallow estuaries, saltwater coves, and protected bays. They spawn in late winter or early spring, laying adhesive eggs that remain on the seafloor.
Why have winter flounder catches decreased?
Landings have fallen since the 1980s due to heavy fishing pressure, habitat degradation, low genetic variability, and potential climate change impacts on their environment.
Good reading and sources
- Winter flounder on WikipediaEncyclopedia
- More photos on Wikimedia CommonsPhotos
- Wikidata recordOpen data
The facts on this page come from the Wikipedia article "Winter flounder", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). EveryFish rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes, and figures change over time. Nothing here is investment or buying advice. If something is wrong, tell us. Last refreshed 2026-11-15.
Like Winter flounder
All flatfish
🇺🇸 United States and 1 moreSummer flounder
A predatory flatfish of the US Atlantic coast.Flatfish · Coasts and shelves
EuropeEuropean flounder
A right-eyed flatfish found in European coastal waters and rivers.Flatfish · Rivers and lakes
EuropeCommon dab
Small flatfish of the North Sea sandy bottomsFlatfish · Coasts and shelves · 1758