To investigate the distribution, life history, and interactions of biological communities in the U.S. Continental Region of the NE Chukchi Sea, a survey was conducted from August - September 2017. Acoustic data was collected as part of an acoustic-trawl effort to classify the midwater fish community of the region. The survey was conducted along 0.5 degree spaced transect lines from 67N to 72N between 168.5W and 153.25W. The primary water column acoustic instrument for the survey was a Simrad EK60 scientific echosounder equipped with a Simrad ES38-B 38 kHz transducer and ES120-7C 120 kHz transducer. The ship departed Dutch Harbor, AK on 01 August 2017 and began the survey in the Chukchi Sea on 09 August 2017. The survey ended in Nome, AK on 28 September 2017. The echosounder was calibrated with a 38.1 mm tungsten-carbide sphere via the standard sphere method during installation on 24 July 2017 and again at the start of the survey on 01 August 2017.

Island Wake Hotspots. Subsurface features were sampled with multi-frequency acoustics, CTD profiles, pairovet and bongo nets sampling different components of the ichthyoplankton and zooplankton assemblages. Juvenile fishes and squid were sampled with an Isaacs-Kidd mid-water trawl (IKMT). Repeat passes of a glider upstream of the area at Point Conception provided detailed sections of temperature, salinity, fluorescence, velocity and acoustic backscatter. Surface plankton will be sampled with manta nets, the Continuous Underway Fish Egg Sampler, thermo-salinograph, and remote sensing. The wakes are expected to be relatively small, with complex sub-mesoscale structure, and strong temporal variability. The primary species focus of this study was small pelagic fish, rockfishes, and squids. However, the full ichthyoplankton community was counted according to usual protocols, and all species from the IKMT were identified, counted and preserved. Calibrated acoustic backscatter data were interpreted using catches from bongo nets and IKMT and predicted frequency-dependent scattering. CUFES data were enumerated and samples preserved according to normal protocols.

Summer surveys of the Chukchi Sea indicate that high densities of age-0 gadid fishes, historically Arctic cod (Boreogadus saida) but recently also walleye pollock (Gadus chalcogrammus), dominate the pelagic fish community. Adults are comparatively scarce, suggesting that either overwinter survivorship of age-0 gadids is low, or that they emigrate to other areas of the Pacific Arctic. To examine population movement, we conducted repeat acoustic surveys with saildrone autonomous surface vehicles equipped with echosounders throughout summer 2018. Results of these surveys were published in Levine et al. (2021). The survey was completed by two 7-meter saildrone USVs. The primary water column acoustic instrument for the survey was a Simrad EK80 mini scientific echosounder system equipped with a dual frequency ES38-18/200-18CR transducer (38 kHz split-beam, 200 kHz single beam). The vessels departed Dutch Harbor, AK on 30 June 2018, conducted acoustic surveys of the eastern Chukchi Sea from 20 July to 11 September, and returned to Dutch Harbor on 06 October. The echosounder system was calibrated via the standard sphere method before and after the cruise. Levine, R.M., De Robertis, A., Grünbaum, D., Woodgate, R., Mordy, C.W., Mueter, F., Cokelet, E., Lawrence-Slavas, N. and Tabisola, H. (2021), Autonomous vehicle surveys indicate that flow reversals retain juvenile fishes in a highly advective high-latitude ecosystem. Limnol Oceanogr, 66: 1139-1154. https://doi.org/10.1002/lno.11671

Summer surveys of the Chukchi Sea indicate that high densities of age-0 gadid fishes, historically Arctic cod (Boreogadus saida) but recently also walleye pollock (Gadus chalcogrammus), dominate the pelagic fish community. Adults are comparatively scarce, suggesting that either overwinter survivorship of age-0 gadids is low, or that they emigrate to other areas of the Pacific Arctic. To examine population movement, we conducted repeat acoustic surveys with saildrone autonomous surface vehicles equipped with echosounders throughout summer 2018. Results of these surveys were published in Levine et al. (2021). The survey was completed by two 7-meter saildrone USVs. The primary water column acoustic instrument for the survey was a Simrad EK80 mini scientific echosounder system equipped with a dual frequency ES38-18/200-18CR transducer (38 kHz split-beam, 200 kHz single beam). The vessels departed Dutch Harbor, AK on 30 June 2018, conducted acoustic surveys of the eastern Chukchi Sea from 20 July to 11 September, and returned to Dutch Harbor on 06 October. The echosounder system was calibrated via the standard sphere method before and after the cruise. Levine, R.M., De Robertis, A., Grünbaum, D., Woodgate, R., Mordy, C.W., Mueter, F., Cokelet, E., Lawrence-Slavas, N. and Tabisola, H. (2021), Autonomous vehicle surveys indicate that flow reversals retain juvenile fishes in a highly advective high-latitude ecosystem. Limnol Oceanogr, 66: 1139-1154. https://doi.org/10.1002/lno.11671

Summer 2012 CalCOFI. The California Cooperative Oceanic Fisheries Investigations (CalCOFI) are a unique partnership of the California Department of Fish and Wildlife, NOAA Fisheries Service and Scripps Institution of Oceanography. The organization was formed in 1949 to study the ecological aspects of the sardine population collapse off California. Today our focus has shifted to the study of the marine environment off the coast of California, the management of its living resources, and monitoring the indicators of El Nino and climate change. CalCOFI conducts quarterly cruises off southern and central California, collecting a suite of hydrographic and biological data on station and underway. Data collected at depths down to 500 meters include: temperature, salinity, oxygen, phosphate, silicate, nitrate and nitrite, chlorophyll, transmissometer, PAR, C14 primary productivity, phytoplankton biodiversity, zooplankton biomass, and zooplankton biodiversity.

2014 Spring CalCOFI. The California Cooperative Oceanic Fisheries Investigations (CalCOFI) are a unique partnership of the California Department of Fish and Wildlife, NOAA Fisheries Service and Scripps Institution of Oceanography. The organization was formed in 1949 to study the ecological aspects of the sardine population collapse off California. Today our focus has shifted to the study of the marine environment off the coast of California, the management of its living resources, and monitoring the indicators of El Nino and climate change. CalCOFI conducts quarterly cruises off southern and central California, collecting a suite of hydrographic and biological data on station and underway. Data collected at depths down to 500 meters include: temperature, salinity, oxygen, phosphate, silicate, nitrate and nitrite, chlorophyll, transmissometer, PAR, C14 primary productivity, phytoplankton biodiversity, zooplankton biomass, and zooplankton biodiversity.

This survey is part of a long-term Bonneville Power Administration-funded effort by academic and federal scientists to understand coastal ecosystems and biological and physical processes that may influence recruitment variability of salmon in Pacific Northwest waters. Prior to a potential switch to the R/V Shimada as a long-term platform, we intend to compare catches between vessels (The R/V Shimada and the F/V Frosti) on the continental shelf of Washington. Sampling will occur during the day for 3 days (23-25 May) with surface trawls along pre-specified transects. One trawl will be performed as we leave the Strait of Juan de Fuca on the afternoon of the 22nd. In addition, a bongo net will be towed several times each night between 2300 and 0500 (nights of 19-22 June).

This project continues long-term studies of the Northern California Current (NCC) pelagic ecosystem and includes study of broad-scale patterns of hydrography, phytoplankton and zooplankton and ocean acidification/hypoxia in the NCC Large Marine Ecosystem off Oregon and Washington. Ecosystem studies were initiated in 1996, and studies of ocean acidification/hypoxia were initiated in 2010.

Falkor Cruise FK190612 (EK60)

2019 Joint US-Canada Integrated Ecosystem and Pacific Hake Acoustic-Trawl Survey