Using an International Econometric Model to Forecast Alaska Salmon Revenues

As Alaska prices tumbled in the 1990s, Alaska's Senate Special Committee on Domestic and International Commercial Fisheries requested a comprehensive review of the Alaska salmon enhancement program. As part of this review, a revenue analysis was performed to examine the effects of various salmon enhancement production levels on future revenue generated to salmon fishers working in Alaska waters. The results were then used in a cost/benefit analysis of the state's enhancement program for sockeye, chinook, coho, chum, and pink salmon. This report focuses on the two most important Alaska salmon species, sockeye and pink. Results of the revenue analysis indicate that for sockeye salmon, future revenues would increase if output from salmon enhancement were expanded. For pink salmon, revenues would decrease if salmon enhancement were expanded and increase if salmon enhancement were scaled back. However, a complete elimination of the pink hatchery program would decrease revenues. For both species, there are important regional differences.Consumer/Household Economics, Demand and Price Analysis, Environmental Economics and Policy,

The Economic Importance of the Bristol Bay Salmon Industry

By any measure, the Bristol Bay sockeye salmon fishery is very large and valuable. It is the world’s most valuable wild salmon fishery, and typically supplies almost half of the world’s wild sockeye salmon. In 2010, harvesting, processing, and retailing Bristol Bay salmon and the multiplier effects of these activities created $1.5 billion in output or sales value across the United States. In 2010, Bristol Bay salmon fishermen harvested 29 million sockeye salmon worth$165 million in direct harvest value alone. That represented 31% of the total Alaska salmon harvest value, and was greater than the total value of fish harvests in 41 states. Salmon processing in Bristol Bay increased the value by $225 million, for a total first wholesale value after processing of$390 million. The total value of Bristol Bay salmon product exports in 2010 was about $250 million, or about 6seafood exports. In 2010, the Bristol Bay sockeye salmon fishery supported 12,000 fishing and processing jobs during the summer salmon fishing season. Measuring these as year-round jobs, and adding jobs created in other industries, the Bristol Bay salmon fishery created the equivalent of almost 10,000 year-round American jobs across the country, and brought Americans$500 million in income. For every dollar of direct output value created in Bristol Bay fishing and processing, more than two additional dollars of output value are created in other industries, as payments from the Bristol Bay fishery ripple through the economy. These payments create almost three jobs for every direct job in Bristol Bay fishing and processing. United States domestic consumption of Bristol Bay frozen sockeye salmon products has been growing over time as a result of sustained and effective marketing by the industry, new product development and other factors. This growth is likely to continue over time, which will result in even greater output value figures for the industry’s economic impacts across the U.S. The economic importance of the Bristol Bay salmon industry extends far beyond Alaska, particularly to the West Coast states of Washington, Oregon and California.Bristol Bay Regional Seafood Development Associatio

Sea Louse Infection of Juvenile Sockeye Salmon in Relation to Marine Salmon Farms on Canada\u27s West Coast

Background Pathogens are growing threats to wildlife. The rapid growth of marine salmon farms over the past two decades has increased host abundance for pathogenic sea lice in coastal waters, and wild juvenile salmon swimming past farms are frequently infected with lice. Here we report the first investigation of the potential role of salmon farms in transmitting sea lice to juvenile sockeye salmon (Oncorhynchus nerka). Methodology/Principal Findings We used genetic analyses to determine the origin of sockeye from Canada\u27s two most important salmon rivers, the Fraser and Skeena; Fraser sockeye migrate through a region with salmon farms, and Skeena sockeye do not. We compared lice levels between Fraser and Skeena juvenile sockeye, and within the salmon farm region we compared lice levels on wild fish either before or after migration past farms. We matched the latter data on wild juveniles with sea lice data concurrently gathered on farms. Fraser River sockeye migrating through a region with salmon farms hosted an order of magnitude more sea lice than Skeena River populations, where there are no farms. Lice abundances on juvenile sockeye in the salmon farm region were substantially higher downstream of farms than upstream of farms for the two common species of lice: Caligus clemensi and Lepeophtheirus salmonis, and changes in their proportions between two years matched changes on the fish farms. Mixed-effects models show that position relative to salmon farms best explained C. clemensi abundance on sockeye, while migration year combined with position relative to salmon farms and temperature was one of two top models to explain L. salmonis abundance. Conclusions/Significance This is the first study to demonstrate a potential role of salmon farms in sea lice transmission to juvenile sockeye salmon during their critical early marine migration. Moreover, it demonstrates a major migration corridor past farms for sockeye that originated in the Fraser River, a complex of populations that are the subject of conservation concern

Influences of abiotic factors on the return, ocean abundance, and maturity of sockeye salmon (Oncorhynchus nerka) in the northern North Pacific Ocean

Thesis (Ph.D.) University of Alaska Fairbanks, 1987The fluctuations in return, ocean abundance, and maturity of sockeye salmon (O. nerka) were examined and related to wind stress curl, sea suface temperature (SST), sea level pressure, and cloudiness, in the area between 40\sp\circN-60\sp\circN and 160\sp\circE-140\sp\circW. Historical records, during two periods, 1971-76 and 1955-86, were the primary source of data. Spectral analysis of a 360-month period of mean wind stress curl during 1955-85 showed 3.1- and 5.3-year cycles. The 5.3-year cycle was correlated (r =.32 to.44, P $<$.10) with the return of Bristol Bay sockeye salmon mostly at 0- (the year of spawning migration) and 1-year lag (the first year of lake residence). The relative ocean abundance of sockeye salmon in the northwestern Northern Pacific during 1971-76 was lowest during the three periods: 1961-70, 1971-76, and 1977-85. Mature Kamchatka sockeye salmon were 24% more abundant than mature Bristol Bay sockeye salmon during 1971-76. A significant relationship was found between the May-June mean SST and abundance of sockeye salmon (r =.56 to.66, P $<$.01) during 1961-85. In the northern North Pacific, the SST was positively (r =.73 to.86, P $<$.001) related with the gonad weight of sockeye salmon. The results indicated a close relation between the return, ocean abundance, and maturity of sockeye salmon and most of the abiotic factors

Sea Louse Infection of Juvenile Sockeye Salmon in Relation to Marine Salmon Farms on Canada's West Coast

BACKGROUND: Pathogens are growing threats to wildlife. The rapid growth of marine salmon farms over the past two decades has increased host abundance for pathogenic sea lice in coastal waters, and wild juvenile salmon swimming past farms are frequently infected with lice. Here we report the first investigation of the potential role of salmon farms in transmitting sea lice to juvenile sockeye salmon (Oncorhynchus nerka). METHODOLOGY/PRINCIPAL FINDINGS: We used genetic analyses to determine the origin of sockeye from Canada's two most important salmon rivers, the Fraser and Skeena; Fraser sockeye migrate through a region with salmon farms, and Skeena sockeye do not. We compared lice levels between Fraser and Skeena juvenile sockeye, and within the salmon farm region we compared lice levels on wild fish either before or after migration past farms. We matched the latter data on wild juveniles with sea lice data concurrently gathered on farms. Fraser River sockeye migrating through a region with salmon farms hosted an order of magnitude more sea lice than Skeena River populations, where there are no farms. Lice abundances on juvenile sockeye in the salmon farm region were substantially higher downstream of farms than upstream of farms for the two common species of lice: Caligus clemensi and Lepeophtheirus salmonis, and changes in their proportions between two years matched changes on the fish farms. Mixed-effects models show that position relative to salmon farms best explained C. clemensi abundance on sockeye, while migration year combined with position relative to salmon farms and temperature was one of two top models to explain L. salmonis abundance. CONCLUSIONS/SIGNIFICANCE: This is the first study to demonstrate a potential role of salmon farms in sea lice transmission to juvenile sockeye salmon during their critical early marine migration. Moreover, it demonstrates a major migration corridor past farms for sockeye that originated in the Fraser River, a complex of populations that are the subject of conservation concern

Quantity and quality of freshwater rearing habitat in relation to juvenile Pacific salmon abundance in the Kulukak River, Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2012Monitoring of freshwater habitat and its influence on stream-rearing fish is essential for recognizing and mitigating the impacts of human- and climate-induced changes. For the purposes of developing a monitoring program in the U.S. Fish and Wildlife Service Togiak National Wildlife Refuge, densities and habitat relationships of juvenile coho salmon Oncorhynchus kisutch and sockeye salmon O. nerka were estimated in two tributaries of the Kulukak River, Alaska, in July 2010. Multiple-pass depletion electrofishing was used to estimate density in a random sample of habitat units belonging to one of four categorical habitat classes. Regression methods were also used to quantify the physical habitat associations of juvenile coho and sockeye salmon density in the study areas. Densities of juvenile coho and sockeye salmon ranged from 0.22 fish-m⁻² in West Fork riffles and 0.05 fish·m⁻² East Fork riffles to 2.22 fish M⁻² and 1.32 fish-m⁻² in East Fork eddy drop zones (EDZ), respectively. The largest proportions of freshwater habitat were comprised of run (71 %) and EDZ habitats (44%) in the East Fork and West Fork, respectively. Regression coefficients for coho and sockeye salmon densities were positive with respect to proportional areas of in-stream overhanging vegetation (0.78 and 0.74, respectively), large wood (0.99 and 0.97, respectively), and undercut banks (0.99 and 0.02, respectively). Conversely, coho and sockeye salmon density was negatively related to depth ( -1.45 and -0.52, respectively) and velocity ( -2.45 and -1.67, respectively). Although substrate size was negatively related to sockeye salmon density ( -0.40), this variable had a weak positive relationship with coho salmon density (0.08). These findings suggest that EDZ habitats are important for juvenile coho and sockeye salmon during summer rearing and in-stream cover is an essential component of these rearing habitats.1. Estimation of coho and sockeye salmon density and abundance by habitat class -- 2. Relationships between juvenile coho and sockeye salmon density and physical characteristics of freshwater rearing habitat -- Conclusions -- References

Effects of density-dependence, environment and species interaction during spawning and incubation on population dynamics of pink and sockeye salmon in the Auke Lake system, southeast Alaska

Thesis (Ph.D.) University of Alaska Fairbanks, 1996Mechanisms that regulate or influence fry and smolt production of pink and sockeye salmon in the Auke Lake system, southeast Alaska, were studied with special emphases on effects of: (1) density-dependence; (2) environmental effects; and (3) species interaction. There has been an increasing trend in the residuals of spawner-recruit models for pink and sockeye salmon since the late 1970's. A strong positive influence of precipitation was found in sockeye smolt production. Estimated spawner capacity of pink salmon was 15 times greater than sockeye salmon in the system. Pink salmon spawners varied in stream life (5-11 days), spawning efficiency (30-70% of daily cohorts of females retained less than 500 eggs at death), and habitat selection (30-70% spawned in Auke Creek rather than Lake Creek, the inlet stream). Variation of these attributes in female pink salmon was explained by various environmental variables using generalized linear models. Repeated use of limited spawning grounds by Pacific salmon, i.e., redd superimposition, can cause density-dependent mortality. Pink salmon egg loss from part of Auke Creek, estimated by a series of mark and recapture experiments, was roughly proportional to spawner abundance and not related to discharge. The maximum daily egg loss was estimated to be 3-400,000 eggs. Eggs in samples were more advanced in development later in the season. Eggs were washed out from the streambed due to redd superimposition; eggs spawned by early pink salmon spawners suffered higher mortality than eggs spawned by later spawners. The peak sockeye spawning preceded the peak pink spawning by approximately one week in Lake Creek, and the major spawning areas of sockeye salmon occurred approximately 250-350 m upstream from those of pink salmon. Microhabitat selection measured by four variables differed significantly between the species, but discrimination between the species was impossible because of large overlaps. Habitat variation was greater among different runs of sockeye salmon than between the two species. Sockeye salmon shifted spawning sites from riffles to pools as the season progressed

Feeding ecology of juvenile sockeye salmon in Afognak Lake, Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2016Much attention has been given to juvenile Sockeye Salmon (Oncorhynchus nerka) ecology with particular focus on pelagic food webs in deep nursery lakes. In contrast, this study took place at Afognak Lake, Alaska, to better understand juvenile Sockeye Salmon foraging ecology, potential consumer interactions, and metabolic opportunities and constraints in a shallow nursery lake. I collected fish every two weeks from Afognak Lake from May through August, 2013. I described ontogenetic and temporal variation in the diets of juvenile Sockeye Salmon and a potential competitor, adult Threespine Stickleback (Gasterosteus aculeatus). Notably, this study revealed that adult aquatic insects are an important prey item for lake rearing juveniles. Threespine Stickleback diets showed some overlap with diets of juvenile Sockeye Salmon; however, significant differences in diet composition suggest that Sockeye Salmon and Threespine Stickleback partition prey and habitat resources. I then used my field-derived temperature, demographic, and diet data as inputs to a bioenergetics model to estimate summer consumption rate and growth efficiency of juvenile Sockeye Salmon from Afognak Lake across a range of foraging scenarios. Consumption rate was greater and mean growth efficiency was lower for all littoral-use scenarios relative to pelagic-use scenarios. Further, daily consumption was lowest and mean growth efficiency was highest for model scenarios in which insects were a dominant component of the diet relative to scenarios in which zooplankton were the dominant prey. My findings highlight the importance of benthic-pelagic coupling in Sockeye Salmon nursery lakes and the potential for juveniles to navigate trade-offs between energy acquisition and thermal conditions across lake habitats.General Introduction -- Chapter 1: Feeding ecology of juvenile Sockeye Salmon and a potential competitor, Threespine Stickleback, in a shallow Alaskan lake -- Chapter 2: Bioenergetic tradeoffs among foraging environments for lake rearing juvenile sockeye salmon -- General Conclusions -- Benthic and pelagic production pathways in Afognak Lake -- Potential for competition between Threespine Stickleback and Sockeye Salmon -- Heterogeneity in lake foraging habitat for Sockeye Salmon

The migration and spawning distribution of sockeye salmon within Lake Clark, Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2004Recent declines in the number of sockeye salmon Onchorynchus nerka returning to Lake Clark, Alaska have caused economic hardship in the region and raised resource concerns among local subsistence users and Federal managers. A lack of information regarding the distribution of spawning habitats in the glacially turbid Lake Clark watershed instigated this research. Radio telemetry was used to 1) determine the in-lake movement patterns of adult sockeye salmon and 2) identify sockeye salmon spawning locations. Sockeye salmon were radio tagged at they entered Lake Clark and tracked to spawning locations. After entering Lake Clark, sockeye salmon usually migrated to a region of the lake that was within 15 km of their spawning location. Tagged fish migrated faster and more directly to spawning locations in tributary rivers and lakes than to Lake Clark beaches. Thirty three spawning locations were identified in the Lake Clark watershed including 18 new spawning locations compared to previous scientific research and ten compared to traditional local knowledge. Most radio tagged sockeye salmon (65%) returned to spawning locations in glacially turbid waters and most spawning locations (75%) were adjacent to privately owned lands. Proactive measures should be taken to conserve both migration corridors and spawning habitats.The spawning migration of sockeye salmon within Lake Clark, Alaska -- The spawning distribution of sockeye salmon in a glacially influenced lake: the importance of turbid habitats

Production of single-domain magnetite throughout life by sockeye salmon, Oncorhynchus nerka

Although single-domain particles of biogenic magnetite have been found in different species of pelagic fishes, nothing is known about when it is synthesized, or about whether the time during life when it is produced is correlated with the development of responses to magnetic field stimuli. We have investigated production of biogenic magnetite suitable for use in magnetoreception in different life stages of the sockeye salmon, Oncorhynchus nerka (Walbaum). Sockeye salmon were chosen because responses in orientation arenas to magnetic field stimuli have been demonstrated in both fry and smolt stages of this species. We found significant quantities of single-domain magnetite in connective tissue from the ethmoid region of the skull of adult (4-year-old) sockeye salmon. The ontogenetic study revealed an orderly increase in the amount of magnetic material in the same region of the skull but not in other tissues of sockeye salmon fry, yearlings and smolts. The physical properties of this material closely matched those of magnetite particles extracted from the ethmoid tissue of the adult fish. We suggest that single-domain magnetite particles suitable for use in magnetoreception are produced throughout life in the ethmoid region of the skull in sockeye salmon. Based on theoretical calculations, we conclude that there are enough particles present in the skulls of the fry to mediate their responses to magnetic field direction. By the smolt stage, the amount of magnetite present in the front of the skull is sufficient to provide the fish with a magnetoreceptor capable of detecting small changes in the intensity of the geomagnetic field. Other tissues of the salmon, such as the eye and skin, often contained ferromagnetic material, although the magnetizations of these tissues were usually more variable than in the ethmoid tissue. These deposits of unidentified magnetic material, some of which may be magnetite, appear almost exclusively in adults and so would not be useful in magnetoreception by young fish. We suggest that tissue from within the ethmoid region of the skull in pelagic fishes is the only site yet identified where magnetite suitable for use in magnetoreception is concentrated