About The Species

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

Population Level

Above target population levels in Alaska. The population status is unknown off the West Coast.

Fishing Status

At recommended levels.

Habitat Impact

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

Bycatch

Regulations are in place to minimize bycatch.

Status

  • According to the 2015 stock assessment, flathead sole in the Bering Sea/Aleutian Islands are not overfished and are not subject to overfishing.
  • According to the 2015 stock assessment, flathead sole in the Gulf of Alaska are not overfished and are not subject to overfishing.
  • Flathead sole are quite abundant in Alaska, and populations are well above target levels.
  • On the West Coast, flathead sole make up only a small percentage of groundfish harvests. Scientists do not formally assess this species so the population status is unknown.
  • Flathead sole are part of the “other flatfish” complex on the West Coast, and are not subject to overfishing based on 2014 catch data
Appearance
  • Flathead sole have an oval-shaped, compressed body.
  • They are a right-eyed flatfish. The left eye migrates over to the right side during development.
  • Their upper side is dark olive brown to reddish gray-brown, sometimes with dusky blotches, and their underside is white. 
  • Their dorsal and anal fins have dusky blotches. 
Behavior and Diet
  • Flathead sole grow up to 1.8 feet and can live at least 34 years.
  • They are able to reproduce at 2 to 3 years old in the southern part of their range, but not until 6 years old in the northern part.
  • Flathead sole spawn from February through April in deeper waters on the continental shelf.
  • Depending on their size, females release 72,000 to 600,000 eggs. Eggs are large and are fertilized externally.
  • Eggs hatch in 9 to 20 days, depending on water temperature.
  • Flathead sole generally feed on bottom-dwelling invertebrates such as crustaceans, mollusks, and brittle stars, as well as fish and squid.
  • Pacific cod, halibut, Alaska pollock, and arrowtooth flounder prey on flathead sole. 
Location Description

Flathead sole are found from Alaska south along the west coast of North America to northern California.  


Management
  • NOAA Fisheries and the North Pacific Fishery Management Council manage this fishery in Alaska.
  • Managed under the Fishery Management Plans for Groundfish of the Bering Sea and Aleutian Islands and Gulf of Alaska:
    • Fishermen must have a permit to participate in the fishery, and the number of available permits is limited to control the amount of fishing.
    • Managers determine how much flathead sole can be caught each year, and they allocate this catch quota among groups of fishermen.
    • In the Bering Sea/Aleutian Islands a percentage of the allowable catch is allocated to the community development quota program, which benefits fishery-dependent communities in Western Alaska. The rest is allocated among various fishing sectors based on gear type, vessel size, and ability to process their catch.
    • In the western and central Gulf of Alaska, allowable catch is allocated by gear type and processing sector, and in the eastern Gulf of Alaska by processing sector.
    • Catch is monitored through record keeping, reporting requirements, and observer monitoring.
  • NOAA Fisheries and the Pacific Fishery Management Council manage this fishery on the West Coast.
  • Managed under the Pacific Coast Groundfish Fishery Management Plan:
    • Only a small amount of flathead sole is harvested incidentally in fisheries off the West Coast.
    • Flathead sole is included in the groundfish fishery management plan, but it is not assessed or directly managed.