Devin M. Bartley

Ecosystem approach to inland fisheries: research needs and implementation strategies

Inland fisheries are a vital component in the livelihoods and food security of people throughout the world, as well as contributing huge recreational and economic benefits. These valuable assets are jeopardized by lack of research-based understanding of the impacts of fisheries on inland ecosystems, and similarly the impact of human activities associated with inland waters on fisheries and aquatic biodiversity. To explore this topic, an international workshop was organized in order to examine strategies to incorporate fisheries into ecosystem approaches for management of inland waters. To achieve this goal, a new research agenda is needed that focuses on: quantifying the ecosystem services provided by fresh waters; quantifying the economic, social and nutritional benefits of inland fisheries; improving assessments designed to evaluate fisheries exploitation potential; and examining feedbacks between fisheries, ecosystem productivity and aquatic biodiversity. Accomplishing these objectives will require merging natural and social science approaches to address coupled social–ecological system dynamics.

Genetic Structure and Gene Flow in Chinook Salmon Populations of California

Abstract We analyzed genetic variation in 35 populations of Chinook salmon Oncorhynchus tshawytscha from northern California by use of allozymes detected by horizontal starch gel electrophoresis. Products of 53 loci from 27 enzyme systems were used to characterize the genetic structure, assess hierarchical relationships, and estimate levels ofgene flow among the populations. Average heterozygosity, 0.038, and percent polymorphic loci, 41 %, found in California populations were similar to previously reported values from more northern locations. Ten hatchery populations were included in the analysis and generally possessed levels ofgenetic variability similar to nearby wild populations. Although estimated average gene flow was 1.16, high from an evolutionary standpoint, and genetic identities were greater than 0.990, we observed genetic differentiation among populations. Distribution of specific alleles, cluster analysis based on genetic identity estimates, and gene diversity analyses indicated that inland ...

Restocking, Stock Enhancement, and Sea Ranching: Arenas of Progress

There are concerns about the sustainability of the worlds capture fisheries at the current total level of ∼ 96 million tons per year. The warning signals are an increase in the proportion of depleted or recovering stocks, from about 10% in 1974 to 28% in 2004, and a corresponding decrease of under-to moderately exploited stocks from about 40% to 24%. It is widely acknowledged that reductions in fishing effort and restoration of fish habitats are needed to improve resilience of capture fisheries. Nevertheless, for some coastal fisheries, application of aquaculture technology through restocking, stock enhancement, and sea ranching also promises to help restore lost production and possibly increase harvests beyond historical levels. However, application of this technology still has a long way to go before integrated management systems are in place that successfully address all the biological, ecological, social, cultural, and economic issues. The main challenges include identifying when and where to use the interventions to add value to other forms of management; integrating these initiatives with institutional and fisheries management regimes; monitoring success of the interventions; producing cultured juveniles cost-effectively; and releasing them in the wild so that they survive in high proportions. We summarize progress to date by describing the main lessons learned from 30 years of research into the potential for releasing cultured juveniles into coastal fisheries, and from application of this technology at various scales. We also describe other lessons to be learned from stocking freshwater habitats and other emerging issues for enhanced coastal fisheries, such as market opportunities and the need to develop widely accepted definitions for “restocking,” “stock enhancement,” and “sea ranching.” These definitions are needed so that nations can report and monitor different strategies used to improve productivity of capture fisheries.

On the sustainability of inland fisheries: Finding a future for the forgotten

At present, inland fisheries are not often a national or regional governance priority and as a result, inland capture fisheries are undervalued and largely overlooked. As such they are threatened in both developing and developed countries. Indeed, due to lack of reliable data, inland fisheries have never been part of any high profile global fisheries assessment and are notably absent from the Sustainable Development Goals. The general public and policy makers are largely ignorant of the plight of freshwater ecosystems and the fish they support, as well as the ecosystem services generated by inland fisheries. This ignorance is particularly salient given that the current emphasis on the food-water-energy nexus often fails to include the important role that inland fish and fisheries play in food security and supporting livelihoods in low-income food deficit countries. Developing countries in Africa and Asia produce about 11 million tonnes of inland fish annually, 90 % of the global total. The role of inland fisheries goes beyond just kilocalories; fish provide important micronutrients and essentially fatty acids. In some regions, inland recreational fisheries are important, generating much wealth and supporting livelihoods. The following three key recommendations are necessary for action if inland fisheries are to become a part of the food-water-energy discussion: invest in improved valuation and assessment methods, build better methods to effectively govern inland fisheries (requires capacity building and incentives), and develop approaches to managing waters across sectors and scales. Moreover, if inland fisheries are recognized as important to food security, livelihoods, and human well-being, they can be more easily incorporated in regional, national, and global policies and agreements on water issues. Through these approaches, inland fisheries can be better evaluated and be more fully recognized in broader water resource and aquatic ecosystem planning and decision-making frameworks, enhancing their value and sustainability for the future.

Genetic differences among year classes in a hatchery population of coho salmon (Oncorhynchus kisutch (Walbaum, 1792)) in Chile

Abstract Coho salmon (Oncorhynchus kisutch (Walbaum, 1792)) was first introduced into Chile from the USA in 1930 and has become an important species for aquaculture. The current Chilean coho salmon aquaculture industry is largely based on eggs imported from the Pacific Northwest. In order to reduce dependence on North America for seed and to improve genetically coho salmon stock in Chile, the Instituto de Fomento Pesquero and the University of Chile started a breeding program at the Coyhaique Hatchery, Region XI of Chile. The genetic variability in two groups of broodstock was determined by horizontal starch gel electrophoresis of allozymes. Twenty-six enzyme systems, representing 51 loci, were resolved. Seven loci were variable (P=13.7%) and a mean heterozygosity (Hi) of 0.007 was estimated. Results indicated a reduction in polymorphism, but not in heterozygosity, with respect to information in the literature on other stocks of coho salmon. The most likely explanation for the results is the occurrence of founder effects while establishing the base population in the hatchery.

A global perspective on the utilization of genetically modified organisms in aquaculture and fisheries

Abstract To evaluate globally the use, desires and constraints associated with the development of genetically modified organisms (GMO) in fisheries and aquaculture, a questionnaire was distributed internationally. The questionnaire focused on five main areas: (1) the current status of aquatic biotechnology, i.e. activities; (2) existing or proposed policies regulating the research, release, commercialization and patenting of GMO; (3) the level of interest in utilizing transgenic and ploidy-manipulated aquatic species; (4) the constraints associated with development of aquatic biotechnology; (5) public perception of biotechnology. Results indicated that policies and regulations on utilization of GMO are lacking in many developed countries, although this is more pronounced in developing areas. The level of interest to utilize GMO was highest in Latin America of the developing countries and they were desired as a means for augmenting production in aquaculture and fisheries. Manipulation of chromosome sets was the most common activity reported, other than education and training activities. Other common activities reported were research on transgenics, hybridization, and sex manipulation. The most important constraint to development of aquatic biotechnology was lack of financial support both in developed and developing countries. Overall, the reported public perception of biotechnology and of genetic modification of animals was favourable concerning moral issues, potential for economic benefit, ability to improve diet, and environmental safety. Results are discussed in terms of their implication to the Convention on Biological Diversity.

Biochemical Genetic Detection of Natural and Artificial Hybridization of Chinook and Coho Salmon in Northern California

Abstract Allelic products of seven isozyme loci were used to identify presumptive hybridization between chinook salmon Oncorhynchus tshawytscha and coho salmon O. kisutch in northern California. First-generation hybrid salmon (N = 3) were observed in samples from a tributary creek to the Trinity River; from rearing ponds at Camp Creek, a tributary to the Klamath River (N = 14); and from the ocean salmon fishery near Eureka (N = 2). The sample from the Camp Creek rearing ponds consisted of progeny from an inadvertent cross of coho and chinook salmon by hatchery personnel at the Irongate Hatchery. In addition to the artificial production of hybrid salmon at Irongate Hatchery, the alteration of traditional salmon spawning routes by Lewiston Dam on the Trinity River may have lead to natural hybridization between chinook and coho salmon in Deadwood Creek. Accurate quantification of the occurrence of hybridization was impossible due to nonrandom sampling of populations, but we presume to have underestimated the...