Upriver movements were determined for Chinook salmon Oncorhynchus tshawytscha returning to the Yukon River, a large, relatively pristine river basin. A total of 2,860 fish were radio tagged during 2002-2004, and 2,790 fish (98%) tracked upriver. Most fish exhibited continual upriver movements and strong fidelity to the terminal tributaries entered, with only a small percentage (2.5%) deviating from this pattern. Average movement rates were substantially slower for fish spawning in lower river tributaries (28-40 km d-1) compared to upper basin stocks (52-62 km d-1). Three distinct migratory patterns were observed, including a gradual decline, pronounced decline, and substantial increase in movement rate as the fish moved upriver. Stocks destined for the same region exhibited similar migratory patterns. Migratory patterns among individual fish within a stock showed substantial variation, but tended to reflect the regional pattern. Differences between consistently faster and slower fish explained 74% of the within-stock variation, whereas relative shifts in sequential movement rates between hares (faster fish becoming slower) and tortoises (slow but steady fish) explained 22% of the variation. Pulses of fish moving upriver were not cohesive. Fish tagged over a 4-day period took 14 and 16 d to pass tracking station sites 580 and 872 km upriver, respectively. Movement data provided valuable insights into the run dynamics of the return, but individual variation among fish complicates efforts to manage in-river fisheries. The diverse migratory patterns exhibited by the fish also suggest that movement studies based on small numbers of individuals may not adequately reflect the patterns exhibited by the larger population. Movement rates were substantially faster and the percentage of atypical movements considerably less than reported in more southern drainages, but may also reflect the pristine conditions within the Yukon River, wild origins of the fish, and relatively discrete run timing of the returns.

Electrophoretic analysis of Asian even brood-year pink salmon stocks has shown regional heterogeneity (Noll et al. in review). Hypothetical mixed fisheries were created using data from 24 variable loci from Noll et al. in review. The mixture was analyzed to test the accuracy and precision of this baseline data for potential use in mixed fishery analyses. Thirteen stocks were separated into four management regions: Japan, Sakhalin, eastern Kamchatka, and western Kamchatka. Simulations were varied in sample size, number of loci, and percent regional contribution. The simulated mixtures were analyzed using the Conditional Maximum Likelihood Estimate (MLE). The mean estimate, standard deviation, and coefficient of variation were calculated for standardized comparison by both stock and region. Computed MLEs showed that estimates for the Noll et al. baseline improved in accuracy and precision with increased sample size and retention of important loci. When 24 loci and a minimum of 200 samples in a mixture were used, the baseline was approximately 80% accurate in its ability to distinguish regions from a mixture.

A database describing a 67-year time series for Sashin Creek pink salmon (Oncorhynchus gorbuscha) data is presented. The database details the survival and other biological parameters of the pink salmon population living in Sashin Creek, a pristine environment in Little Port Walter, Baranof Island, Alaska. We assembled all the published and unpublished biological and environmental data pertaining to this population, which has been evaluated almost continually by researchers since 1934. We developed a database using Microsoft Access that includes annual estimates of the freshwater and saltwater survival for these fish. The database contains the daily counts of the number of emigrating fry and escaping adults during their annual migrations since 1934, and their lengths, weights, or fecundity. Environmental parameters in the database include stream temperature, stream discharge, daily minimum and maximum air temperatures, and precipitation where Sashin Creek enters seawater at Little Port Walter. All records have been evaluated and transformed to ensure comparability. References for all data are provided, including unpublished sources. The Sashin Creek Weir Database (SCWDATA) can be accessed through the Internet.

This study is a cooperative effort between Douglas Island Pink & Chum (DIPAC), the University of Alaska Fairbanks, School of Fisheries and Ocean Sciences (UAF, SFOS), the National Oceanic & Atmospheric Administration, Auke Bay Lab (ABL), and the Alaska Department of Fish & Game (ADF&G) to determine the potential for interactions between DIPAC hatchery chum salmon (Oncorhynchus keta) fry and wild chum salmon fry in Taku Inlet, Southeast Alaska. We analyzed patterns in spatial and temporal distribution, size, and condition of juvenile chum salmon collected in the littoral and neritic waters of Taku Inlet in 2004 and 2005. Energy density and diet of wild and hatchery chum salmon fry in Taku Inlet were analyzed and compared to data obtained later in the season for chum salmon stocks caught in Icy Strait. The greatest potential for wild/hatchery interactions was in the outer inlet, directly following early hatchery releases (May 9-11). Peak outmigration for wild chum salmon fry coincided with early hatchery releases; in contrast, most wild chum salmon fry had already emigrated from the estuary by the time of late hatchery fry release (May 22 June 1). In both years, hatchery fry were rare in the inner inlet, but comprised over 95% of the catch in the outer estuary during the peak of outmigration. Hatchery chum salmon were significantly larger than wild fry in both beach and neritic samples. Wild and early hatchery chum salmon were smaller in the littoral than the neritic habitat, indicating that both groups moved from shallow to deeper water with ontogeny. In spite of large differences in abundance, no negative correlation between abundance of hatchery fish and condition of wild fish was identified. Both wild and early hatchery chum salmon fry showed apparent growth through the season, while late hatchery fry appeared to leave the estuary soon after release. Regardless of origin, most chum salmon juveniles emigrated from the study area in late May and early June, indicating a high probability for mixed-stock schools. Hatchery chum salmon juveniles were initially larger and had greater energy content than wild fish; however, energetic values converged by mid-June in Taku Inlet. In Icy Strait, energetic condition of wild and hatchery chum salmon juveniles was also similar. Multivariate analysis of 54 prey measures indicated that diets of the two groups were distinctly different throughout the season in all Taku Inlet locations and converged in Icy Strait.

The project objectives were to assess potential salmon predation impact on juvenile salmon and herring by: (1) comparing diets of adult pink salmon during their homing migrations using samples taken from surface trawls in SEAK straits and purse seines in SEAK and PWS; (2) contrasting predation incidence of these abundant pink salmon with the less abundant, more piscivorous adult coho and immature (age-1+) Chinook salmon in SEAK straits; and (3) examining potential climate mechanisms that could influence predator-prey match-mismatch by altering life history patterns of growth, migration timing, or stock-specific characteristics.

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.

Diel epipelagic sampling for juvenile Pacific salmon (Oncorhynchus spp.), rockfish (Sebastes spp.), sablefish (Anoplopoma fimbria), and associated species was conducted in order to identify factors that may affect year-class success of these commercially important species. Sampling occurred in offshore marine habitats of the coastal northeast Pacific Ocean from 10-20 August 2005 and was conducted with a surface trawl fishing the upper 20 m of the water column along transects up to78 km offshore near 58 N. Three habitats were sampled along each transect over a 24-hr period: the continental shelf (<200 m depth), the continental slope (400-750 m depth), and the abyss (>2,000 m depth). A total of 38,747 fish and squid representing 24 species were sampled in 56 trawl hauls. Of the targeted juvenile fish species, a total of 587 salmon, 11 rockfish, and 70 sablefish were captured. Sampling during day (1500-1900) and night (2200-0200) periods indicated that biomass of fish and squid was 2-4 times higher at night at (each?)all habitat types pooled across transects. No distinct patterns between day or night occurrence were noted for juvenile pink salmon (O. gorbuscha), chum salmon (O. keta), sockeye salmon (O. nerka), or coho salmon (O. kisutch), however, juvenile Chinook salmon (O. tshawytscha) were encountered only at night. Catches of juvenile rockfish and juvenile sablefish were quite low in this study, and larger sample sizes of these fish are needed to adequately determine their diel distribution. Diel differences were apparent with forage species such as Pacific herring (Clupea pallasi), capelin (Mallotus villosus), and eulachon (Thaleichthys pacificus) that were almost exclusively sampled at night. The offshore distribution patterns of target species were distinctly different, with the most common occurrences of juvenile salmon over continental shelf habitats, juvenile sablefish over continental shelf and slope habitats, and juvenile rockfish over slope and abyss habitats. Pacific herring, capelin, eulachon, and Pacific sardines (Sardinops sagax) were found over continental shelf habitats, whereas small squid and myctophids occurred primarily at slope and abyssal habitats. The greatest overall catch biomass was of gelatinous species (jellyfish), which was consistently higher than that of all fish and squid combined, usually by an order of magnitude. Individual fish or squid species with highest average weight per haul were pomfret (Brama japonica), adult coho salmon, Humboldt squid (Dosidicus gigas), and blue sharks (Prionace glauca). The occurrence of the latter two warm-water species and Pacific sardines were of interest because this study occurred during an anomalously warm year and the capture of Pacific sardines and Humboldt squid represent northern range extensions for these species. Stomach content analysis of potential predator species of the target species showed that only adult coho salmon were predating on juvenile salmon and sablefish, and only pomfret were predating on juvenile rockfish. Further sampling of the target species is needed in these habitats during more normal environmental conditions to validate these observations.

Summer surveys (Julyb??August) of juvenile salmon ecology along the continental shelf of the Gulf of Alaska are conducted annually by scientists from the Ocean Carrying Capacity program of the National Marine Fisheries Serviceb??s Auke Bay Laboratory. These surveys are an effort to link changes in salmon production to biological and physical factors in the ocean environment. An improved understanding of salmon distribution is one objective of this research. We identified the origin of juvenile chum salmon collected in transects from around the Gulf of Alaska in 2000 and 2001, using the presence of thermal marks in hatchery fish and the divergence of genetic characteristics among regional groups of populations.

A 2007 pilot study was initiated by the University of Alaska – Southeast in which baseline levels of contaminants, including persistent organic pollutants (POPs) and total mercury, were determined in whole bodies of juvenile coho salmon collected in streams in and near national park units in the Southeast Alaska Inventory and Monitoring Network. Although the concentrations of POPs determined in the juvenile coho were relatively low (< 10 ng/g, wet weight), the preliminary findings of this study indicate that, in the Glacier National Park region, salmon from streams with higher density of spawners had increased levels of certain banned chlorinated pesticides (i.e., alpha-chlordane, o,p’-DDT, p,p’-DDD) compared to salmon collected in other streams with lower salmon spawning density. A follow up study will be initiated in spring/summer 2015 to determine concentrations of POPs in resident salmonids, as well as benthic macroinvertebrates collected from five streams that have fish barriers near or adjacent to Glacier National Park. Comparisons in contaminant concentrations and patterns will be made for fish collected below and above the barrier in each stream to help determine if certain classes of POPs are being transported by the spawners. As part of this study, the NWFSC will analyze whole bodies/muscle of salmonids and benthic macroinvertebrate samples POPs using gas chromatography / mass spectrometry (GC/MS). Percent lipid content of samples (with adequate sample mass) will also be determined. These data will be included in a report to the NIH-sponsored IDeA Network of Biomedical Research Excellence. Determining levels of persistent organic pollutants in salmonids and macroinvertebrates.

The Strait of Juan de Fuca Intensively Monitored Watershed (IMW) began in 2004 to test the watershed-scale response of steelhead and coho salmon to watershed restoration. The Strait IMW includes two treatment watersheds (East Twin River and Deep Creek) and one control watershed (West Twin River). Restoration treatments included LWD placement, road and culvert removal, off-channel habitat creation, and riparian planting. Monitoring of physical habitat as well as coho and steelhead parr densities began in 2004 using the EPA’s EMAP site selection and sampling protocols. Smolt and adult monitoring predates the IMW program and began as early as 1998 in some watersheds. Preliminary results suggest an increase in pool habitat and small increases in steelhead adults and smolts in East Twin River, as well as adult coho in Deep Creek. PIT tagging has revealed a large outmigration of age-0 coho in the fall that contributes to the adult return, stream swapping by juveniles, and varying return times for coho adults. Current research has answered a portion of our original questions and has raised new ones. Restoration treatments were completed fairly recently or are still in progress. As habitat typically does not respond immediately to treatment, additional years of monitoring are needed to determine watershed-scale fish response. Moving forward, analysis of otoliths to validate PIT tag data and new restoration methods such as carcass or nutrient enhancement may be merited. PIT tagging and habitat data. Includes fish weight, length, location, and PIT tag number. Habitat data includes wood measurements and stream surveys.