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2018 Status of Alaska Marine Ecosystems Considerations - Eastern Bering Sea Report in Brief
The eastern Bering Sea was characterized by anomalously warm conditions in 2018. Over the northern…
Yellowfin Sole
Yellowfin Sole
Limanda aspera
Also Known As
Sole, Flounder
Quick Facts
Region
Alaska
Yellowfin sole. Credit: NOAA Fisheries
Yellowfin sole. Credit: NOAA Fisheries
About the Species
U.S. wild-caught yellowfin sole is a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations.
Population
Above target population levels.
Fishing Rate
At recommended levels.
Habitat Impacts
Area closures and gear restrictions protect habitats affected by bottom trawls used to harvest yellowfin sole.
Bycatch
Regulations are in place to minimize bycatch.
Population Status
- There are two stocks of yellowfin sole: one in the Bering Sea/Aleutian Islands and one in the Gulf of Alaska. According to the most recent stock assessments:
- The Bering Sea/Aleutian Islands stock is not overfished (2020 stock assessment) and not subject to overfishing based on 2020 catch data. Summary stock assessment information can be found on Stock SMART.
- The Gulf of Alaska Shallow Water Flatfish Complex, which includes yellowfin sole, is not overfished, based on the stock assessments of Northern rock sole and rock sole. This complex is not subject to overfishing based on 2020 catch data. Summary stock assessment information for Northern rock sole can be found on Stock SMART and for rock sole on Stock SMART.
Appearance
- Yellowfin sole are a flatfish with a small mouth and moderately large eyes that are both on one side of their body.
- Their body shape is generally round with rounded edges on the tail fin.
- Their upper side is olive to dark brown with dark mottling, and their underside is pale.
- Yellowfin sole are named for their yellowish fins. Their fins also have faint dark bars and a narrow dark line at their base.
- Their anal spine is thin, sharp, and exposed.
- They have rough scales on both sides of the body.
Biology
- Yellowfin sole grow up to more than 1½ feet long and can live up to 39 years.
- Most females are able to reproduce when they reach 10½ years old, or when they’re about 1 foot long.
- They spawn in the spring and summer in shallow waters on the inner continental shelf. Females produce between 1 and 3 million eggs.
- Larvae and early juveniles eat plankton and algae. Late juveniles and adults eat bivalves, worms, amphipods, mollusks, krill, shrimp, brittle stars, sculpins, and other crustaceans.
- Pacific cod and halibut prey on juvenile yellowfin sole.
Where They Live
- In the United States, yellowfin sole are found in the North Pacific Ocean from British Columbia up to the Chukchi Sea (north of the Bering Sea).
Fishery Management
- NOAA Fisheries and the North Pacific Fishery Management Council manage the yellowfin sole fishery.
- Managed under the Fishery Management Plan for Groundfish of the Bering Sea/Aleutian Islands:
- Permits are required, and the number of available permits is limited to control the amount of fishing.
- Managers set an annual catch limit for yellowfin sole.
- A percentage of the catch limit is allocated to the community development quota program, which benefits fishery-dependent communities in Western Alaska. The rest is allocated among the various fishing sectors based on gear type, vessel size, and ability to process their catch.
- All yellowfin sole caught must be retained for processing.
- Catch is monitored through record keeping, reporting requirements, and observer coverage.
- Managed under the Fishery Management Plan for Groundfish of the Gulf of Alaska:
- Yellowfin sole is included under this fishery management plan, but only a very small amount is incidentally caught in this area.
Harvest
- In 2020, commercial landings of yellowfin sole totaled 290.5 million pounds, and were valued at $60 million, according to the NOAA Fisheries commercial fishing landings database.
- Gear types, habitat impacts, and bycatch:
- Bottom trawls are used to catch yellowfin sole.
- Trawls that are used to harvest yellowfin sole can contact the ocean floor and impact habitats, depending on the makeup of the ocean bottom and the size of the gear.
- Bottom trawls cause minimal damage to habitat when targeting yellowfin sole over soft, sandy, or muddy ocean bottoms in Alaska.
- NOAA Fisheries and the North Pacific Fishery Management Council have implemented large closed areas to protect sensitive habitats from bottom trawls.
- Vessel monitoring systems allow enforcement staff and fishery managers to monitor GPS locations of fishing activities to ensure vessels are complying with closed areas.
- There are limits on the amount of halibut and crab that groundfish fisheries can incidentally catch. If the limit is reached, managers close the fishery for the remainder of the season to minimize bycatch.
Science Overview
Yellowfin Sole Research in Alaska
Yellowfin sole is one of the most abundant flatfish species in the eastern Bering Sea and a target of the largest flatfish fishery in the United States. It is found in North American waters from British Columbia to the Chukchi Sea and as far south as the Sea of Japan.
Our research has focused on the study of yellowfin sole growth, reproduction, diet, distribution, and juvenile habitat. We have learned that this fish is slow-growing reaching up to 45 cm in length and 39 years of age. Males become reproductive at about age 7 and females at about age 10, with females producing from 300,000 to 3.6 million eggs. Adults undergo annual spawning migrations of more than 500 km (1000 km round trip) from wintering grounds west and southeast of the Pribilof Islands to nearshore summer spawning grounds in Kuskokwim and Bristol bays. Juveniles live in shallow coastal waters and feed on small animals that live on or in the sandy sea bottom, mostly polychaetes (bristle) worms, shrimp-like amphipods, and clams.
Yellowfin sole are most abundant on the eastern Bering Sea shelf, where annual long-term research surveys have shown biomass to exceed 2 million tons over most years dating back to 1982. Research associated with these surveys has shown that yellowfin summer distributions differ among years depending on bottom temperatures which affect the timing of the yellowfin sole spawning migrations.