Shortraker rockfish
| Sebastes borealis | |
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| Species: | S. borealis
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| Sebastes borealis Barsukov, 1970
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Shortraker rockfish (Sebastes borealis) is an offshore, demersal species distributed from the southeastern Kamchatka Peninsula, Russia, to Fort Bragg, California.[1] It attains lengths greater than one metre (>39 inches) and weighs up to 20 kg (44 pounds). In the Gulf of Alaska, shortraker rockfish are sampled annually during longline surveys and are most abundant between depths of 300–400 metres (980–1,310 ft).
Commercial harvesting in the Gulf of Alaska began in the early 1960s when foreign trawl fleets were targeting more abundant.[2][full citation needed] In recent years, high catch rates indicate that the domestic trawl fleet targets this species; shortraker rockfish comprised 14.9% of the species composition of slope rockfish harvested in 1990, although trawl survey data indicates they comprised only 2.5% of the biomass.[3]
In 1991, catch limits were established for shortraker rockfish to prevent overharvesting of this species in the Gulf of Alaska. Catch limits are based on biomass estimates derived from bottom trawl catch rates. These biomass estimates are questionable, however, because the catch efficiency of bottom trawls on shortrakers is unknown. Fishermen report that shortrakers school off-bottom and above rugged habitat in steep-slope areas where bottom trawls cannot sample effectively.[4]
Old specimens
In 2007, fishermen caught a specimen that was estimated to be between 90 and 115 years old. The fish weighed in at 62 pounds (28 kg) and was measured at 112 centimetres (44 in). It was caught south of the Pribilof Islands at an estimated depth of 2,100 feet (640 m).[5][6][7][8]
In 2013, a sport fisherman from Seattle caught a specimen from 900 feet (270 m) below the surface and 10 miles offshore near Sitka, Alaska.[9][10] At 39.08 pounds (17.73 kg), experts believed the 42-inch shortraker is the oldest ever caught, with an estimated age of 200 years.[9][10] It was later found that the fish was only 64 years old.[11]
References
- ^ Kramer, D.E.; O'Connell, V.M. (1986). "Guide to northeast Pacific rockfishes". Marien Advisory Bulletin (25). Alaska Sea Grant College Program, University of Alaska Fairbanks.
- ^ Sebastes spp
- ^ Heifetz and Clausen, 1991
- ^ Encyclopedia.com Archived 2007-04-09 at the Wayback Machine
- ^ Century-old fish found off Alaska BBC News, 2007-04-06. Retrieved 2007-04-07.
- ^ The Sideshow (July 2, 2013). "Man catches 200-year-old, 40-pound fish". News.Yahoo.com. Retrieved 2013-07-09.
- ^ Photo in the News: Century-Old Fish Caught in Alaska National Geographic, 2007-04-06. Retrieved 2007-04-07
- ^ Joling, Dan (2007-04-06). "Fishermen catch big, old Alaska rockfish". Yahoo! News. Yahoo! Inc. Archived from the original on 2007-04-08. Retrieved 2007-04-09.
- ^ a b Barber, Elizabeth (3 July 2013). "200-year-old rockfish caught off Alaska coast". The Christian Science Monitor. Retrieved 4 July 2013.
- ^ a b Hesse, Tom (25 June 2013). "Record-Sized Rockfish May Also be the Oldest". Daily Sitka Sentinel. Retrieved 4 July 2013.
- ^ Pooch, Andrew (5 July 2013). "Record "Old" Rockfish Aged at 64 Years". Angling Unlimited.
External links
- Shortraker rockfish from the Alaska Fisheries Science Centre Guide to Rockfishes (National Marine Fisheries Service)