2014 Assessment of the Arrowtooth Flounder Stock in the Eastern Bering Sea and Aleutian Islands
March 04, 2014
Arrowtooth flounder (Atheresthes stomias) is a relatively large flatfish that is found throughout the BSAI management area. Their abundance is approximately six times higher in the eastern Bering Sea than in the Aleutian Islands region. Spawning occurs in deep water in the Gulf of Alaska and along the shelf break in the eastern Bering Sea. Spawning females have been found at 400m and males at ≥450m in the Gulf of Alaska, and larvae have been found at depths greater than 200 m (Blood et al. 2007; De Forest et al. 2014). The distribution of ages appears to vary by region and sex; male arrowtooth as old as 36 years have been observed in the Aleutian Islands are not commonly observed older than age 10 on the Bering Sea shelf, while the female length and weight relationships do not vary significantly between the two regions (Figure 6.1)
Arrowtooth flounder begin to recruit to the continental slope at about age 4. Based on age data from the 1982 U.S.-Japan cooperative survey, recruitment to the slope gradually increases at older ages and reaches a maximum at age 9. However, greater than 50% of age groups 9 and older continue to occupy continental shelf waters. The low proportion of the overall biomass on the slope during the 1988 and 1991 surveys, relative to that of earlier surveys, indicates that the proportion of the population occupying slope waters may vary considerably from year to year depending on the age structure of the population.
The arrowtooth flounder resource in the EBS and the Aleutians is managed as a single stock although little is known about stock structure. There has been no research on this topic in this species.