Balancing Biological Sustainability with the Economic Needs of Alaska's Sockeye Salmon Fisheries (original) (raw)
Related papers
North American Journal of Fisheries Management, 2009
A simultaneous-equation equilibrium model of international salmonid markets is used to examine the combined effect of variability in the landings of Alaska's sockeye salmon Oncorhynchus nerka and increases in the production of Chile's Atlantic salmon Salmo salar, coho salmon O. kisutch, and rainbow trout O. mykiss on Alaska's sockeye salmon exvessel prices and revenues. While Atlantic salmon, coho salmon, and rainbow trout from Chile and sockeye salmon from Alaska are not identical commodities, they compete in many of the same domestic and international markets, and Alaska's earnings in those markets have declined as Chile's production has increased. Although Alaska's average annual harvests have remained nearly constant, Alaska's production is now a small percentage of the total salmonid production in a world that eats significantly more salmonids than it did 25 years ago. Nevertheless, our model indicates that sockeye salmon prices continue to be sensitive to interannual variations in the quantity of sockeye salmon harvested in Alaska and to changes in the quantity of Atlantic salmon, coho salmon, and rainbow trout produced in Chile. However, the model indicates that exvessel revenues are less sensitive than exvessel prices and that Alaska's recent levels of sockeye salmon landings have been near the maximum of the total exvessel revenue curve. In addition, the model suggests that because Alaska's share of the production of high-value salmon (Chinook, coho, and sockeye salmon) has declined, exvessel prices for sockeye salmon are now less sensitive to changes in Chilean production of Atlantic salmon, coho salmon, and marine-reared rainbow trout. The implication of these findings is that, under current market conditions, exvessel revenues from Alaska's sockeye salmon fisheries can be maximized by maintaining catches at or near historic levels and that exvessel prices are unlikely to continue to decline as rapidly as they did in the 1990s.
Bioeconomic modelling and salmon aquaculture: an overview of the literature
International Journal of Environment and Pollution, 2008
Bioeconomic models can be used to assist producers and decision-makers in identifying optimal production system designs, operation management strategies, and alternative development and policy approaches. This paper reviews the literature on bioeconomic modelling in aquaculture since 1993 and builds on an earlier article by Leung (1994) which examines this literature for the 1974-1993 period. In order to identify the papers reviewed in the present study, a thorough online search in various databases and some specific journals was conducted. Observations on the general state-of-the-art of bioeconomic modelling in aquaculture are discerned based on a comparative analysis of work in the field, with specific reference to salmon aquaculture. Implications for salmon aquaculture systems in Chile and elsewhere are discussed.
The managed decline of British Columbia's commercial salmon fishery
Marine Policy, 2019
Commercial salmon harvests have declined dramatically for all Pacific salmon species in British Columbia, mainly over the period 1995-2000. Much of this decline is attributable to declining abundance, but some of it has been due to deliberate reduction in allowable exploitation rates. Various reasons have been given for this reduction, but the main rationale appears to have been concern about declines in a few relatively small and unproductive stocks that are intercepted in mixed-stock fisheries. Reductions in exploitation rate have generally not been followed by the increases in stock size that would be expected if overfishing had been the main cause of the declines. Current procedures for setting exploitation rate goals do not appear to involve explicit analysis of the risk-reward trade off relationship between mixed stock exploitation rates and yields.
2014
Recent legal restrictions on water exports in the Southern Delta to protect listed fish populations have brought public attention to the trade-off relationship between fish conservation and agricultural economy. The restrictions may result in losses of agricultural returns in the Central Valley. This paper aims to examine the economic costs of conserving the endangered Winter-run Chinook salmon for two water year assumptions: one without environmental correlations and the other with the environmental correlations. The combination of a modified statewide agricultural production model and a multistage Winter-run Chinook salmon model allows me to assess the economic costs per age 3 and 4 adult for two cases. The estimated costs range from 1,304to1,304 to 1,304to114,966 for the first case and from 864to864 to 864to721,120 for the second case. They generally increase at an increasing rate as the pumping cuts back from 10% to 100%. The consideration of environmental correlations does not change the order of ...
A Model for Optimal Salmon Management
1972
Considerable attention has been given in the literature recently to continuous time dy namic maximizing models for fisheries in general, but the time discreteness and inter dependency problems encountered in the case of most salmon fisheries have been largely ignored. Hence, a discrete time profit maximizing model for a salmon fishery is devel oped in this paper, and it is shown that a correct salmon management policy takes the form of an investment decision with respect to the level of escapempnt and that a man agement policy of maximum sustained yield may be incorrect from an economic stand point. It is hoped that continued research including construction of a working model will provide some indication of the difference between the magnitude of spawner stocks se lected on the basis of maximum sustained yield and stocks selected on the basis of economic optimality. Continuous time dynamic maximIzmg models have been developed in the literature recently to handle the problem of...
The salmon MALBEC Project: a North Pacific-scale study to support salmon conservation planning
2009
The Model for Assessing Links Between Ecosystems (MALBEC) is a policy gaming tool with potential to explore the impacts of climate change, harvest policies, hatchery policies, and freshwater habitat capacity changes on salmon at the North Pacific scale. This article provides background information on the MALBEC project, methods, input data, and preliminary results pertaining to (1) hatchery versus wild salmon production in the North Pacific Ocean, (2) rearing, movement, and interactions among Pacific salmon populations in marine environments, (3) marine carrying capacities, density-dependent growth, and survival in Pacific salmon stocks, and (4) climate impacts on productivity in salmon habitat domains across the North Pacific. The basic modeling strategy underlying MALBEC follows the full life cycle of salmon and allows for density-dependence at multiple life stages, and it includes spatially explicit ecosystem considerations for both freshwater and marine habitat. The model is supported by a data base including annual run sizes, catches, spawning escapements, and hatchery releases for 146 regional stock groups of hatchery and wild pink, chum, and sockeye salmon around the North Pacific for the period 1952-2006. For this historical period, various hypotheses about density-dependent interactions in the marine environment are evaluated based on the goodness-of-fit between simulated and observed annual run sizes. Based on the information we used to inform our ocean migration table, interactions among stocks that originate from geographically distant regions are greatest in the Bering Sea in summer-fall and in the eastern sub-Arctic in winter-spring. While the model does not reproduce the observed data for some specific stock groups, it does predict the same overall production pattern that was observed by reconstructing run sizes with catch and escapement data alone. Our preliminary results indicate that simulations that include density-dependent interactions in the ocean yield better fits to the observed run-size data than those simulations without density-dependent interactions in the ocean. This suggests that for any level of ocean productivity, the ocean will only support a certain biomass of fish but that this biomass could consist of different combinations of stocks, stock numbers and individual fish sizes. MALBEC simulations illustrate this point by showing that under scenarios of Pacific-wide reduced hatchery production, the total number of wild Alaskan chum salmon increases, and that such increases are large where density-dependent effects on survival are large and small where they are not. Under scenarios with reduced freshwater carrying capacities for wild stocks, the impacts of density-dependent interactions also lead to relative increases in ocean survival and growth rates for stocks using ocean habitats where density-dependence is large.
Trans Amer Fish Soc, 1993
This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.
Transactions of the American Fisheries Society, 1993
This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.
Performance of salmon fishery portfolios across western North America
The Journal of applied ecology, 2014
Quantifying the variability in the delivery of ecosystem services across the landscape can be used to set appropriate management targets, evaluate resilience and target conservation efforts. Ecosystem functions and services may exhibit portfolio-type dynamics, whereby diversity within lower levels promotes stability at more aggregated levels. Portfolio theory provides a framework to characterize the relative performance among ecosystems and the processes that drive differences in performance. We assessed Pacific salmon Oncorhynchus spp. portfolio performance across their native latitudinal range focusing on the reliability of salmon returns as a metric with which to assess the function of salmon ecosystems and their services to humans. We used the Sharpe ratio (e.g. the size of the total salmon return to the portfolio relative to its variability (risk)) to evaluate the performance of Chinook and sockeye salmon portfolios across the west coast of North America. We evaluated the effec...