2015 Assessment of the Arrowtooth Flounder Stock in the Gulf of Alaska
February 21, 2015
Arrowtooth flounder (Atheresthes stomias) range from central California to the eastern Bering Sea and are currently the most abundant groundfish species in the Gulf of Alaska. Arrowtooth flounder occur from central California to the Bering Sea, in waters from about 20m to 800m, although catch per unit effort (CPUE) from survey data is highest between 100m and 300m. Migration patterns are not well known for arrowtooth flounder; however, there is some indication that arrowtooth flounder move into deeper water as they grow, similar to other flatfish (Zimmerman and Goddard 1996). Fisheries data off Washington suggest that larger fish may migrate to deeper water in winter and shallower water in summer (Rickey 1995). Arrowtooth flounder spawn in deep waters (>400m) along the continental shelf break in winter (Blood et al. 2007). They are batch spawners, spawning from fall to winter off Washington State at depths greater than 366m (Rickey 1995).
In the Gulf of Alaska, arrowtooth flounder are managed as a single stock but the ABC is specified separately for the Western (NMFS area 610), Central (620, 630), West Yakutat (640), and Southeast outside (650).
Historically, arrowtooth flounder has not been targeted as a commercial fishery because the muscle degrades rapidly when heated. However, several recent developments have allowed arrowtooth flounder to become more desirable to commercial markets. Several methods exist to neutralize the enzymes that cause the flesh to degrade, including chilling to near zero or immediate processing and freezing. The arrowtooth flounder currently caught, processed, and sold each year from the Gulf of Alaska are typically sold in Asian markets.
Trophic studies (Yang 1993, Hollowed, et al. 1995, Hollowed et al. 2000) suggest they are an important component in the dynamics of the Gulf of Alaska benthic ecosystem. The majority of the prey by weight of arrowtooth larger than 40 cm was pollock, the remainder consisting of herring, capelin, euphausids, shrimp and cephalopods (Yang 1993). The percent of pollock in the diet of arrowtooth flounder increases for sizes greater than 40 cm. Arrowtooth flounder 15 cm to 30 cm consume mostly shrimp, capelin, euphausiids and herring, with small amounts of pollock and other miscellaneous fish. Groundfish predators include Pacific cod and halibut (see Ecosystem Considerations section).