To better understand how density-dependent growth of ocean-dwelling Pacific salmon varied with climate and population dynamics, we examined the marine growth of sockeye salmon in relation to an index of sockeye salmon abundances among climate regimes, population abundances, and body sizes under varied life history stages, from 1925 to 1998 using ordinary least squares and multivariate adaptive regression spline threshold models. The annual marine growth and body size during the juvenile, immature, and maturing life stages were estimated from increments on the scales of adult age 2.2 sockeye salmon that returned to spawn at Karluk River and Lake on Kodiak Island, Alaska. Intra-specific density-dependent growth was inferred from inverse relationships between growth and sockeye salmon abundance based on commercial harvest. Density-dependent growth occurred in all marine life stages, during the cool regime, at lower abundance levels, and at smaller body sizes at the start of the juvenile life stage. The finding that density-dependence occurred during the cool regime and at low population abundances suggests that a shift to a cool regime or extreme warm regime at higher population abundances could further reduce the marine growth of salmon and increase competition for resources. Alaska salmon production fluctuates with climate and ocean conditions in the North Pacific Ocean. In this study, we evaluated the hypothesis that faster marine growth was related to higher survival as a consequence of more favorable ocean conditions for growth during the 1927-46 and 1977-2000 warm regimes, and slower growth was related to lower survival as a consequence of less favorable climatic and oceanic conditions for growth during the 1947-76 cool regime. We measured and compared the annual growth on scales collected from age 2.2 sockeye salmon that returned to Karluk Lake on Kodiak Island, Alaska from 1927 to 2000 to regime periods, climatic and oceanic indices, and survival. First and second marine-year scale growth fluctuated with the cool regime and recent warm regime. Survival estimated as the ratio of offspring to parental escapement was lower during the 1925-46 warm regime and 1947-76 cool regime. Survival was positively related to first and second marine year scale growth, eastern North Pacific atmospheric circulation, and reduced winter and spring coastal downwelling in the Gulf of Alaska. Winter and spring climatic and oceanic conditions influences on first and second year marine growth of Karluk Lake sockeye are a possible mechanisms linking Karluk Lake sockeye salmon survival to climate over the past half century.

Radio telemetry was used to determine the distribution, locate spawning sites, and evaluate the tagging response of wild Chinook salmon Oncorhynchus tshawytscha returning to a large, free-flowing river basin. A total of 2,860 fish were radio tagged in the lower Yukon River and tracked upriver. Fish traveled to spawning areas throughout the basin, ranging from several hundred to over 3,000 km from the tagging site. We found similar distribution patterns across years, suggesting that the major components of the return were identified. Most spawning fish were clustered in a number of principal tributaries, although small numbers of fish were located in other spatially-isolated areas. The cumulative contribution of these minor stocks was appreciable, making up 28-31% of the tagged sample. There was suggestive evidence of mainstem spawning in upper reaches of the basin. Large-scale elevation and physiographic data were useful in categorizing spawning areas, with most fish returning to relatively entrenched upland rivers. Fish were largely absent in lowland reaches characterized by meandering, low gradient, alluvial channels often associated with main river floodplains. The fish generally responded well to the capture, handling, and tagging procedures with most (2,790, 97.6%) resuming upriver movements, although the fish initially displayed a negative tagging response, with slower migration rates observed immediately after release. The duration of this response was relatively short (several days) and less severe as the fish moved upriver. The swimming speeds of radio-tagged fish after the initial delay were comparable to estimates for untagged fish, further suggesting that the capture, handling, and tagging methods used were relatively benign. Identifying the primary components of the run (including both major and minor stocks) and determining site-specific utilization patterns can fundamentally enhance salmon management in large river basins, and facilitate research and conservation efforts.

Swimming depth and water temperature were recorded every 3 minutes during the 2002-2004 spawning migration for Yukon River Chinook salmon tagged with radio-archival tags. Telemetry data, obtained using remote tracking stations and aerial surveys, were used to determine the upriver movements of the fish. Ninety-five tags were recovered, including 35 tags returned by fishermen and 60 tags retrieved during spawning ground surveys.

This dataset contains 2-boat tow, push net and scoop net catches from the Yukon River Delta for 2014

Data is available from annual bottom longline surveys conducted cooperatively by Japan (1979-1994) and the U.S. National Marine Fisheries Service, Alaska Fisheries Science Center (1988-present). Starting in 1988, the U.S. started conducting the survey, creating overlap between the two countries between1988-1994. Since 1994, the U.S. has conducted the survey independently. Stations are spaced systematically (~20-30 km apart) along the slope from the eastern Gulf of Alaska west to the Aleutian Islands and north into the eastern Bering Sea. At each station, depths from ~150-1000 meters are sampled. Each year the captain attempts to set the gear along the same path. The same stations are sampled each year except in the Aleutian Islands and the Bering Sea, which are sampled every other year at the beginning of the survey (last week of May-early June). Since 1995, in odd years the Bering Sea stations are sampled and in even years the Aleutian Islands are sampled. The status of each hook is recorded. Lengths are taken from major species including, sablefish, giant grenadier, Pacific grenadier, Greenland turbot, arrowtooth flounder, Pacific cod, shortspine thornyhead, and all rockfish caught.

The dataset is comprised of individual fish records from collections made during port sampling at Kodiak Alaska for the purpose of updating maturity estimates for selected GOA flatfish. The collections were made by an Alaska Fisheries Databank funded sampler. Sample preparation, ageing and histological determination of maturity state were completed by AFSC staff.

The scientific objective of the Gulf of Alaska Survey (GOA Survey) is to assess Young of the Year (YOY) groundfish, salmon, plankton, and oceanographic conditions across the coastal, shelf, slope, and offshore waters of the GOA and to provide information on species distribution, ecosystem structure, and marine productivity in response to changes in season, region, and climate. Specific objectives are to 1) observe epi-pelagic fish communities by sampling with a rope trawl towed at the surface; 2) collect electronic oceanographic data including CTD (Conductivity-temperature-depth) vertical profiles of temperature, salinity, light transmission, chlorophyll a fluorescence, and photosynthetic available radiation (PAR); and 3) collect biological oceanographic samples (zooplankton and water) by oblique bongo tows and water sampling.

Variable mesh gillnets were used to evaluate the abundance of young of the year sablefish during 1995-2002. Data include. Vessel, cruise, station. Species caught, and lengths of fish caught. The data were collected to be able to forecast year-class strength of sablefish.

This study is part of the Auke Bay Laboratoryb??s Ocean Carrying Capacity (OCC) which has extensively sampled salmon in the North Pacific since 1996 to obtain information on marine life history and migration patterns. Genetic stock identification techniques (protein electrophoresis) indicated that Bristol Bay stocks of immature sockeye salmon (Oncorhynchus nerka) made up the largest percentage in two samples taken near Unalaska Island in 1998. The substantial numbers of immature sockeye salmon captured at Cape Cheerful during May 1998 were unexpected, based on current migration models of western Alaska sockeye salmon. Immature sockeye constituted the largest percentage of our immature salmon catch captured at Cape Prominence during August 1998. This was also unexpected since immature chum salmon (O. keta) were the predominant catch during August 1996 and 1997 at the same location. These unexpected events may be due to changes in distribution resulting from the strong El NiC1o event during 1997-1998.

Ecosystem-based fisheries management requires the development of physical and biological time series that index ocean productivity for stock assessment and recruitment forecasts for commercially important species. Since recruitment in marine fish is related to ocean condition, we developed proxies for ocean conditions based on sea surface temperature and biometric measurements of chum salmon (Oncorhynchus keta) captured in the walleye pollock (Gadus chalcogrammus) fishery in the eastern Bering Sea in three periods (July 16-30, September 1-15, and September 16-30). The main purpose of this paper was to evaluate Pacific salmon (Oncorhynchus spp.) growth as a possible indicator of ocean conditions that, in turn, may affect age-1 pollock recruitment. Marine growth rates of Pacific salmon are the result of a complex interplay of physical, biological, and population-based factors that fish experience as they range through oceanic habitats. These growth rates can therefore be viewed as indicators of recent ocean productivity. Thus, our hypothesis is that estimated intra-annual growth in body weight of immature and maturing age-4 male and female chum salmon may be used as a biological indicator of variations in rearing conditions also experienced by age 0 walleye pollock; consequently, they may be used to predict the recruitment to age-1 in walleye pollock. Summer SSTs and chum salmon growth at the end of July and September explained the largest amount of variability in walleye pollock recruitment indicating that physical and biological indices of ocean productivity can index fish recruitment.