Science & Data

The goal of the Ecosystem Considerations report is to provide stronger links between ecosystem research and fishery management.

This database contains the Stock Assessment Result data from the 2014-2016 research season.

The Gulf of Alaska (GOA) arrowtooth flounder (Atheresthes stomias) stock is managed in Tier 3a and is assessed on a biennial basis to coincide with the annual GOA groundfish trawl survey.  These surveys occur in odd years, and for these years a full assessment of arrowtooth flounder in the GOA area is conducted.

The goal of the Ecosystem Considerations report is to provide stronger links between ecosystem research and fishery management and to spur new understanding of the connections between ecosystem components by bringing together the results of many diverse research efforts into one document. However, this year the report has been split into four separate documents, one for the Gulf of Alaska, Aleutian Islands, eastern Bering Sea, and the Arctic1. This new presentation allows for a more cohesive focus on each large marine ecosystem (LME). While this simplifies navigation for the reader, it also better highlights data gaps and research needs within each LME.

Arrowtooth flounder (Atheresthes stomias) are relatively large flatfish that 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.  Spawningoccurs in deep water in the Gulf of Alaska and along the shelf break in the eastern Bering Sea. 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). 

n 2013 a Tier 3 approach was used to describe the stock status of Kamchatka flounder using survey and fishery age and length structured modeling.  The assessment previously used Tier 5 methodology reliant upon trawl survey biomass from the Bering Sea shelf, slope and the Aleutian Islands and an estimate of natural mortality.  ABC and OFL were determined from a 7-year averaging technique of survey biomass.

The age-structured assessment model is similar to the model used for the 2014 and 2015 assessments and was developed using AD Model Builder (a C++ software language extension and automatic differentiation library).

A Snack Before Bedtime?

Arrowtooth Flounder, A Voracious Predator!

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).