Petrale Sole

Also Known As

Sole, Flounder, California sole, Brill, Petral, Jordan’s flounder, Round-nosed sole

Region

Alaska, West Coast

About the Species

U.S. wild-caught petrale sole is a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations.

Above target population levels on the Pacific Coast and in the Gulf of Alaska.

At recommended levels.

Area closures and gear restrictions protect habitats that are affected by bottom trawls used to harvest petrale sole.

Regulations are in place to minimize bycatch.

There are three stocks of petrale sole: Pacific coast, one stock contained in a stock complex in the Gulf of Alaska, and one stock contained in a stock complex in the Bering Sea/Aleutian Islands. According to the most recent stock assessments:
- The Pacific coast stock is not overfished (2015 stock assessment) and not subject to overfishing based on 2018 catch data. Summary stock assessment information can be found on Stock SMART.
- The Gulf of Alaska stock is managed as part of the Shallow Water Flatfish Complex, which is not overfished (2020 stock assessment) and not subject to overfishing based on 2020 catch data. Northern rock sole is assessed and petrale sole is a secondary species in the complex. Summary stock assessment information for Northern rock sole can be found on Stock SMART.
- The Bering Sea/Aleutian Islands stock is managed as part of the Other Flatfish Complex and has not been assessed so the population status is unknown. This complex is not subject to overfishing based on 2020 catch data.

Petrale sole is a right-eyed flounder (both eyes are on its right side), with an oval to round body.
Its upper side is uniform light to dark brown, and its underside is white, sometimes with pink traces.
Petrale sole have large mouths, with two rows of small, arrow-shaped teeth on their upper jaw and one row of teeth on the lower jaw.

Petrale sole grow fast when they’re young, and females tend to grow faster than males.
Females can reach up to 24 inches long, while males may reach up to 18 inches long.
They can live up to 35 years, but recent data suggests few live longer than 17 years.
Petrale sole can reproduce when they are 3 to 8 years old, or when they’re about 1 foot long. Females can produce 400,000 to 1.5 million eggs.
They spawn from November to April in British Columbia, Washington, and Oregon. Spawning begins slightly earlier in California.
Petrale sole is a broadcast spawner. Males and females release their sperm and eggs into the water column and eggs are fertilized externally.
Eggs hatch in 6 to 13.5 days, depending on water temperatures.
Petrale sole larvae spend their first 5 to 6 months up in the water column before they transform to their adult form and settle to the bottom.
Petrale sole larvae eat plankton. Small juveniles eat mysids, sculpins, and other juvenile flatfish. Large juveniles and adults eat shrimp and other crustaceans, as well as krill, pelagic fishes, brittle stars, and juvenile petrale sole.
Plankton-eating invertebrates and pelagic fishes eat petrale sole eggs. Adult petrale sole and other large flatfishes prey on juvenile petrale sole.
Sharks, bottom-feeding marine mammals, larger flatfishes, and pelagic fishes feed on adults.

Petrale sole are found from Alaska to Coronado Island, Baja California.
They are rare north and west of southeast Alaska and in the interior waters of British Columbia.

NOAA Fisheries and the Pacific Fishery Management Council manage the petrale sole fishery on the West Coast.
Managed under the Pacific Coast Groundfish Fishery Management Plan:
- Limits on the number of permits and fishermen allowed.
- Limits on the minimum size of fish that may be harvested.
- Limit on how much may be harvested in one fishing trip.
- Certain seasons and areas are closed to fishing.
- Gear restrictions help reduce bycatch and impacts on habitat.
- A trawl rationalization catch share program includes:
  - Catch limits based on population information for each fish stock and divided into shares that are allocated to individual fishermen or groups.
  - These fishermen can decide how and when to catch their share – preferably when weather, markets, and business conditions are most favorable, allowing the fishery the flexibility to be more environmentally responsible, safer, more efficient, and more valuable.
NOAA Fisheries and the North Pacific Fishery Management Council manage the petrale sole fishery in Alaska.
Managed under the Fishery Management Plan for Groundfish in the Gulf of Alaska, and the Bering Sea and Aleutian Islands:
- There is no directed fishery for this species off Alaska, and only minor amounts are landed incidentally in other fisheries.

In 2019, commercial landings of petrale sole totaled more than 5.7 million pounds and were valued at $6.9 million, according to the NOAA Fisheries commercial fishing landings database.
Gear types, habitat impacts, and bycatch:
- Bottom trawls are used to catch petrale sole.
- Trawls that are used to harvest petrale sole can contact the ocean floor and impact habitats, depending on the characteristics of the ocean bottom and the size of the gear.
- Bottom trawls cause minimal damage to habitat when targeting petrale sole over soft, sandy, or muddy ocean bottoms on the West Coast and Alaska.
- On the West Coast, NOAA Fisheries and the North Pacific Fishery Management Council have implemented large closed areas to minimize bycatch and protect habitat.
- Vessel monitoring systems allow enforcement staff and fishery managers to monitor GPS locations of fishing activities to ensure vessels are complying with closed areas.