Groundfish Assessment Program

Map showing groundfish survey coverage, from Gulf of Alaska to the North Bering Sea. Click image to enlarge

The AFSC Groundfish Assessment Program (GAP) regularly conducts bottom trawl surveys to assess the condition of groundfish and shellfish stocks in Alaskan marine waters.

GAP plans, executes, analyzes, and reports results from the surveys to establish time series estimates of the distribution and abundance of Alaska groundfish resources in the Gulf of Alaska, Bering Sea Shelf, Bering Sea Slope, and Aleutian Islands.

GAP also investigates biological processes and interactions with the environment to estimate growth, mortality, and recruitment to improve the precision and accuracy of forecasting stock dynamics. Impacts of bottom trawls on the seafloor and the description of bottom type are also being studied in the Bering Sea and Aleutian Islands.

Data derived from Groundfish surveys are documented in scientific reports and are incorporated into stock assessment advice to the Pacific Fishery Management Council, the North Pacific Fishery Management Council, international fishery management organizations, the fishing industry, and the general public.

*Featured Items*

Reconciling ambiguity resulting from inconsistent taxonomic classification of marine fauna assessed in the field: Querying a database to reclassify by lowest accountable inclusive taxon (LAIT). Go there >>

Validating and improving species distribution models for structure forming invertebrates using an independent survey in the eastern Bering Sea. Go there >>

Is the survey selectivity curve for Pacific cod (Gadus macrocephalus) dome-shaped? Direct evidence from trawl studies. Go there >>

Recent Poster Presentations, Publications, Reports & Activities

KASTELLE, C. R., T. E. HELSER, J. L. MCKAY, C. G. JOHNSTON, D. M. ANDERL, M. E. MATTA, and D. G. NICHOL. 2017. Age validation of Pacific cod (Gadus macrocephalus) using high-resolution stable oxygen isotope (δ18O) chronologies in otoliths. Fish. Res. 185:43-53. http://dx.doi.org/10.1016/j.fishres.2016.09.024 Online.
SOMERTON, D. A., R. A. McCONNAUGHEY, and S. S. INTELMANN. 2017. Evaluating the use of acoustic bottom typing to inform models of bottom trawl sampling efficiency. Fish. Res. 185:14-16. http://dx.doi.org/10.1016/j.fishres.2016.09.029 Online.
STEVENSON, D. E., and R. R. LAUTH. 2012. Latitudinal trends and temporal shifts in the catch composition of bottom trawls conducted on the eastern Bering Sea shelf. Deep-Sea Res. II 65–70:251-259. http://dx.doi.org/10.1016/j.dsr2.2012.02.021 Online.
GARDNER, J. R., J. W. ORR, D. E. STEVENSON, I. SPIES, and D. A. SOMERTON. 2016. Reproductive parasitism between distant phyla: Molecular identification of snailfish (Liparidae) egg masses in the gill cavities of king crabs (Lithodidae). Copeia 104:645-657. http://dx.doi.org/10.1643/CI-15-374 Online.
Using Triggered Cameras to Determine Fish Behavior in Rocky, Untrawlable Areas
By: KRESIMIR WILLIAMS, CHRIS ROOPER, MIKE LEVINE, ALEX De ROBERTIS
Conference: Western Groundfish Conference (19th), Newport, OR, Feb 2016
(2016 poster, .pdf, 468 KB) Online.
Introducing the Working Group on Maturity Assessment and Reproductive Variability of Life Stages
By: SUSANNE McDERMOTT, SANDI NEIDETCHER, CHRISTINA CONRATH, PAUL SPENCER
Conference: Western Groundfish Conference (19th), Newport, OR, Feb 2016
(2016 poster, .pdf, 1.85 MB) Online.

See the poster and publications databases for additional listings.

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