Developing a Euphausiid biomass time series for the central Gulf of Alaska continental shelf, June 2003, 2005, 2011 and 2013

In this study, we identified euphausiid (krill) backscatter using relative frequency response and targeted trawling, and created an annual index of abundance for euphausiids. Four years of AT and bottom-trawl survey data (June-August 2003, 2005, 2011, and 2013) were available from consistently sampled areas around Kodiak Island, including Shelikof Strait, Barnabas Trough, and Chiniak Trough. These data were collected during summer acoustic-trawl (AT) surveys conducted by NOAA’s Alaska Fisheries Science Center aboard the NOAA ships Oscar Dyson or Miller Freeman using standard acoustic survey techniques (Simmonds and MacLennan 2005). In the eastern Bering Sea, a time series of euphausiid biomass was developed using data from acoustic-trawl surveys of walleye pollock that are regularly conducted by NOAA Fisheries, Alaska Fisheries Science Center. Data are presented as two CSV files: NPRB_1208_data_bylatlon.csv NPRB_1208_data_byyear.csv