Because petrale sole was overfished off the West Coast, managers placed limits on the amount that could be incidentally caught while targeting other groundfish. These bycatch limits significantly reduced catch of abundant groundfish such as Dover sole and English sole. However, due to above-average petrale sole reproduction and survival rates in the past few years, as well as overall productivity of flatfish stocks, managers slightly increased petrale sole bycatch limits for 2012. As a result, current catch limits have more than doubled for the 2013–2014 management cycle and fishing season. The successful rebuilding of the petrale resource should have a positive effect on catch of other groundfish.
- Ocean perch
- Sea Bass
- Turbot (Greenland)
ALSO KNOWN AS:
Sole, Flounder, California Sole, Brill, Petral, Jordan's Flounder, Round Nosed Sole
U.S. wild-caught from Washington to California
- FISHING RATE
- HABITAT IMPACTS
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Photo credit: Daniel W. GotshallLAUNCH GALLERY
Despite their name, petrale sole are not a true sole and are related more closely to flounder. A sweet, delicately flavored fish, petrale sole has been harvested off the West Coast since World War II. Today, most U.S.-caught petrale sole is harvested by trawlers over sandy, muddy bottoms off Oregon, California, and Washington.
Declared overfished in 2009, the West Coast petrale sole stock is now rebuilding under strict harvest limits. Managers implemented a rebuilding plan for the stock, outlining a management strategy that will help the stock fully recover. Petrale sole is harvested along with several other groundfish species in the West Coast groundfish trawl fishery, which is now managed under a "catch share program." Under this program, managers divide the annual catch limit for the fishery into shares controlled by fishermen. Fishermen can catch their share whenever they want, allowing them the flexibility to better plan their season, fish during safer weather and when market prices for their catch are highest, and reduce bycatch of overfished species.
LOCATION & HABITAT
Petrale sole are found from Alaska to Coronado Island, Baja California. They’re rare north and west of southeast Alaska and in the interior waters of British Columbia. Petrale sole is common on the outer continental shelf in water 330 and 500 feet deep, but can be found in depths ranging from over 50 to 1,370 feet. Eggs and larvae are found in surface waters, and juveniles and adults live on sand and mud bottoms. Adults migrate seasonally between deep water where they spawn in the winter (November–February) to shallower water where they feed in the summer (March–October).
Petrale sole 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 the eggs are fertilized externally. Depending on their size, females can produce 400,000 to 1.5 million eggs with a diameter of approximately 0.05 inches each. Eggs hatch in 6 to 13.5 days, depending on water temperature. Petrale sole larvae spend their first 5 to 6 months up in the water column before they metamorphose to the adult form and settle to the bottom.
Petrale larvae eat plankton (tiny floating plants and animals). 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.
Petrale sole grow fast when they’re young. Females grow faster and larger than males after the first few years of life. Females can reach up to 2 feet in length; males grow up to 1 ½ feet. Petrale sole can live up to 35 years, but recent data suggest that few live longer than 17 years. They’re able to reproduce when they reach 3 to 8 years old, when they’re about 1 foot long. 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 is a right-eyed flounder (both eyes are on its right side), with an oval to round body. Its eyed side is uniform light to dark brown, and its blind side is white, sometimes with pink traces. Petrale sole have a large mouth. They have two rows of small, arrow-shaped teeth on their upper jaw; there is one row of teeth on the lower jaw.
Off the West Coast, scientists with the Northwest Fisheries Science Center conduct annual bottom trawl surveys that collect data on petrale sole abundance and the size and age of the fish in the population. The science center also runs an observer program for the West Coast groundfish fishery. This program places fisheries observers on commercial fishing vessels to monitor and record catch and critical biological data (such as fish age, reproduction, length, sex, and weight). This information improves our understanding of fishing activities and helps provide accurate accounts of total catch, bycatch, and discards associated with various fisheries and fish stocks.
The 2013 stock assessment for petrale sole on the Pacific coast concluded that petrale sole was no longer experiencing overfishing and the stock is rebuilding.
In the Gulf of Alaska, petrale sole is part of the “shallow water flatfish” complex. This complex was last assessed in 2013 and is not overfished or subject to overfishing. Population status determinations are based on abundance estimates of indicator species (Northern and Southern rock sole) from the complex.
In the Bering Sea/Aleutian Islands, petrale sole is part of the “other flatfish” complex. This complex was last assessed in 2013, but data were insufficient to determine whether the complex is overfished. Unlike the flatfish complex in the Gulf of Alaska, this complex does not have any indicator species that are used to assess population levels. However, an overfishing level is set for the complex, and as long as this level is not exceeded the complex is not subject to overfishing.
The coastal states and treaty tribes conduct port-side monitoring programs, which provide valuable biological data to support stock assessment science and aid in proper management decisions.
Scientists have identified a number of areas where additional research would substantially improve their ability to reliably and precisely model trends in the abundance of petrale sole, including comprehensive catch histories from Washington, further study on age and reproduction, and increased collaboration with Canada (petrale sole are likely a single stock that moves across the Canadian border).
Harvesting Petrale Sole
Most U.S.-caught petrale sole is harvested in the West Coast groundfish trawl fishery. During the summer, petrale are harvested with other flatfish species. During the winter, petrale are targeted in spawning aggregations (groups that gather to mate) at specific, well-known locations in deep water. Although some managers have expressed concern about the sustainability of harvesting on spawning aggregations, there is no evidence that it is more harmful to the stock than harvest of non-spawning aggregations. Furthermore, these spawning aggregations are confined to deep water areas where bycatch of other overfished rockfish species is of less concern.
Bottom trawls cause minimal damage to habitat when targeting petrale sole over soft bottoms off the West Coast. West Coast bottom trawl fisheries are highly regulated under a new trawl “catch share” program, which encourages responsible fishing practices. Management measures also prohibit bottom trawling in certain areas to protect groundfish habitat and overfished species. Vessels use a vessel monitoring system, which allows enforcement staff and fishery managers to monitor GPS locations of fishing activities and ensure that vessels are complying with closure areas.
Who’s in charge? NOAA Fisheries and the Pacific (West Coast) and North Pacific (Alaska) Fishery Management Councils
West Coast: Groundfish Fishery Management Plan (Petrale sole are often caught in “multispecies complexes” - several different groundfish species caught together at the same time – and managed along with 90 other species that also live on or near the bottom.)
- All vessels fishing in the groundfish fishery off Washington, Oregon, and California must have a federal limited entry permit. With only a limited number of permits available (about 400), this program controls the capacity of the groundfish fishing fleet by limiting the overall number of fishing vessels, the number of vessels using each of the three specified gear types (trawl, trap/pot, and longline), and increases in harvest size by limiting vessel length.
- As of January 2011, the West Coast groundfish trawl fishery is now managed under a trawl rationalization catch share program. Under this new program, managers establish annual catch limits based on the health of each fish stock. They then allocate a share of this catch limit to individual fishermen or groups of fishermen, who can decide how and when to catch their share – preferably when weather, markets, and business conditions are most favorable. This program gives the fishery the flexibility to be more environmentally responsible, safer, more efficient, and more valuable. Observers monitor 100 percent of the fishing trips, which helps reduce bycatch through improved accountability and provides better data for future stock assessments.
- A variety of gear restrictions and closed areas affect both West Coast groundfish fisheries and fisheries that may take groundfish incidentally. These regulations are in place to reduce bycatch of overfished groundfish, to allow juvenile fish to escape through net meshes, and to protect sensitive groundfish habitat.
For Alaska, petrale sole are included in the North Pacific Fishery Management Council’s Gulf of Alaska Groundfish Fishery Management Plan as part of the “shallow water flatfish” complex, and in the Bering Sea and Aleutian Islands Groundfish Fishery Management Plan as part of the “other flatfish” complex. There is no directed fishery for this species off Alaska, and only minor amounts are landed incidentally in other fisheries.
Petrale sole have been caught in the flatfish fishery off the U.S. Pacific coast since the late 19th century. Petrale sole were lightly fished during the late 1800s and early 1900s, but by the 1950s the fishery was well developed and showing clear signs of depletion and declines in catches and biomass. Landings peaked at a high of 4,515 metric tons in 1950 followed by a decline to a low of 1,417 metric tons in 1994. Landings remained at historical lows until the mid-2000s. In 2009, petrale sole was declared overfished and 2010 management restrictions limited the catch to 701 metric tons. In 2012 more than 1,000 metric tons were harvested in California, Oregon, and Washington. As the stock continues to rebuild, harvest limits will increase.
Petrale sole is an important commercial seafood species, prized for its taste. They often bring the highest price per pound among the trawl-caught flatfish on the West Coast. Petrale sole make up a substantial portion of annual revenues from the West Coast trawl fishery. In 2009, petrale sole landings were valued at $3.5 million, landings in 2010 were valued at $2 million, 2011 landings were valued at almost $3 million, and 2012 landings were valued at more than $3 million.
Petrale sole have a fine texture and a sweet, delicately nutty flavor. Like all flatfish, the fillets are thin and can be cooked using a variety of methods.
Petrale sole is an excellent source of low-fat protein, calcium, and other important nutrients.
|Serving Weight||100 g|
|Fat, total||1.19 g|
|Saturated fatty acids, total||0.283 g|
|Sugars, total||0 g|
|Fiber, total dietary||0 g|
Petrale sole table of nutrition