Sustainable flounder, plaice & sole buying guide

Flounder, plaice, and sole are stealthy flatfish that change their colors and patterns to blend into the seafloor, making themselves nearly invisible to prey and predators. If you plan to eat one of these fish, looking for flounder and sole from the U.S. and Canadian Pacific is a good rule of thumb. There are also environmentally friendly options from the U.S. Atlantic, but it’s important to know what to buy and what to avoid.

Quick buying guide

Buy flounder and sole caught in Alaska, California, Oregon, Washington, or British Columbia, Canada.
Buy southern flounder caught in Texas.
Buy American plaice caught in the U.S. Atlantic.
Buy Marine Stewardship Council (MSC) certified flounder, plaice, and sole.
Buy summer flounder and blackback (also called winter flounder) caught in the U.S. Atlantic if you confirm it’s yellow-rated (scroll down for more information).
Avoid witch and yellowtail flounders caught in the U.S. Atlantic.
Avoid California flounder caught in Mexico.

Alaska flounder and sole are on our Super Green list—good for you and the planet!

What to buy or avoid?

Flounder

We recommend four flounder species caught in the U.S. and Canadian Pacific and southern flounder caught in Texas. If you're considering summer flounder or blackback (also called winter flounder) caught in the U.S. Atlantic, make sure it’s yellow-rated. Also, witch and yellowtail flounders are rated red.

Flounder caught in Alaska, California, Oregon, Washington, or British Columbia, Canada.
Southern flounder caught in Texas.
Flounder farmed in indoor recirculating tanks (also called RAS, land-based, and tank-farmed).
Flounder listed below, if you confirm it’s yellow-rated.
- Blackback (also called winter flounder) is yellow-rated when caught in the U.S. Georges Bank and U.S. Gulf of Maine with bottom trawls, but the rest is red-rated.
- Summer flounder caught in the U.S. is yellow-rated when caught with bottom trawls, trap nets, or pole-&-lines, but it’s red-rated when caught with set gillnets.
Avoid witch and yellowtail flounders and red-rated sources of blackback and summer flounders. They may come from a depleted population, be caught with other overexploited species, or both scenarios. Also, the accidental entanglement of other marine life is a risk in some fisheries.
Avoid California flounder caught in Mexico because it’s likely caught with at-risk turtles, marine mammals, seabirds, rays, and finfish.

View flounder recommendations on SeafoodWatch.org

Plaice

Seafood Watch has one recommendation for American plaice, and we also recommend MSC certified Alaska plaice and European plaice.

Buy American plaice caught in the U.S.

View plaice recommendations on SeafoodWatch.org

Sole

We’ve assessed six sole species caught in the U.S. and Canadian Pacific, including Alaska. The good news is we recommend them all.

Buy Dover, English, flathead, petrale, and rex soles caught in the U.S. or British Columbia, Canada.
Buy southern rock sole caught in British Columbia, Canada.

View sole recommendations on SeafoodWatch.org

Blue circular badge with a scalloped edge containing a white checkmark in the center.

Certified flounder, plaice, and sole

Buy Marine Stewardship Council (MSC) certified flounder, plaice, and sole.

View certified flounder, plaice, and sole recommendations on SeafoodWatch.org

Sushi

When sold as sushi, flounder is called karei, and any flatfish species may be sold as hirame.

Follow the above tips and check the Seafood Watch Sushi Guide for quick reference.

More about our flounder, plaice, and sole recommendations

When are flounder, plaice, and sole environmentally sustainable?

Flounder, plaice, and sole rated green by Seafood Watch are the most environmentally sustainable. They come from healthy populations, there are no serious bycatch impacts, and well-managed fisheries have minimal to no impacts on other marine life and habitats.

When flounder, plaice, and sole are rated yellow, it means fishery management is considered moderately effective or better, but there are some concerns about the flounder, plaice, or sole population, or it’s caught with other species that are highly vulnerable, overfished, or experiencing overfishing.

Flounder, plaice, and sole rated red are not environmentally sustainable. They may come from an overexploited population, bycatch or entanglement of other marine life is a significant concern, the lack of science-based management, or a combination of these issues.

Learn how we can make seafood sustainable

What are the main flounder, plaice, and sole fishing methods?

Most flounder, plaice, and sole are caught with bottom trawls, but some flounders are caught with set gillnets. Typically, there’s a greater risk of bycatch impacts when they’re caught with bottom trawls. However, in well-managed fisheries, a variety of measures can significantly reduce the amount of bycatch, even when these methods are used.

The U.S. set gillnet fisheries that catch blackback, summer flounder, and yellowtail flounder operate within the endangered North Atlantic right whale’s range, and there are significant concerns about entanglement risks to whales.

Some flounders are also caught with gigs, trap nets, trolling lines, or handlines and hand-operated pole-&-lines. These more selective methods tend to have fewer bycatch impacts.

Here’s a quick look at these fishing methods:

Bottom trawls herd fish into a cone-shaped net as they’re dragged along the seafloor.
Set gillnets entangle fish when they swim into stationary netting positioned on or near the seafloor.
Gigs are spear-like gears used to catch southern flounder in Texas.
Trap nets are stationary nets that entrap fish when they swim into an enclosed chamber they can easily enter but are difficult to exit. These gears are oriented to take advantage of fish movement or migration patterns.
Trolling lines catch fish with moving fishing lines with baited hooks. Several trolling lines are usually towed at the same time.
Handlines and hand-operated pole-&-lines catch fish with one or more fishing lines with baited hooks. This fishing method is also described as pole-&-lines.

Learn more about fishing and farming methods

How to use this guide

Our green, yellow, and red ratings indicate environmental risk. We use our ratings and third-party certifications to make our recommendations.

Choose

Green-rated seafood because environmental risks are low.
Yellow-rated seafood because environmental risks are moderate.

Avoid

Red-rated seafood because environmental risks are high, often due to overfishing, poor management, or harm to marine life and habitats.

Where to find sustainable seafood

When shopping or dining out, start by asking, “Do you sell sustainable seafood?” You may need to ask what species it is and where and how it was caught or farmed. If the business can’t answer or the label doesn’t provide this information, our Popular Seafood Guide can help you choose another ocean-friendly option.

More retailers and restaurants are sharing where their seafood comes from and how it was caught. But not all businesses have this information. When you ask questions, you help create demand for sustainable seafood and encourage businesses to offer it.

Grocery stores

We work with grocery stores to implement time-bound commitments to follow Seafood Watch recommendations. MOM’s Organic Market and PCC Community Markets follow our recommendations. Whole Foods Market follows our recommendations for wild seafood and has a proprietary standard for farmed seafood.

Restaurants

We work with major restaurant chains—including California Fish Grill and The Cheesecake Factory—that are implementing their sustainable seafood commitments.

Meal delivery services

Blue Apron and Hello Fresh only send their customers green-rated, yellow-rated, or certified seafood. Other meal delivery services may offer sustainable seafood, and we encourage you to ask them if they don’t.

Learn more about our collaborations on SeafoodWatch.org

The Super Green List