Selective Breeding and Hybridization in Fisheries Management

1976 ◽  
Vol 33 (2) ◽  
pp. 316-321 ◽  
Author(s):  
Peter Ihssen
Keyword(s):  
Fisheries Management ◽  
Selective Breeding ◽  
Reproductive Potential ◽  
Inbred Lines ◽  
Hybrid Vigor ◽  
Genetic Changes ◽  
Fish Stocks ◽  
Quantitative Genetic ◽  
Genetic Techniques

Selective breeding of fish using quantitative genetic techniques is discussed. Fish offer advantages over other livestock for selective breeding procedures because of their relatively high reproductive potential and low reproductive barriers.Maintaining fish stocks in artificial environments can cause undesirable genetic changes such as loss in heterozygosity due to inbreeding and loss in fitness. Methods to minimize inbreeding are given. The study of cross breeds of inbred lines, and hybrids among strains or even species, to produce high levels of heterozygosity and heterosis or hybrid vigor is suggested.

Genetic Techniques in Flatfish Culture

1976 ◽  
Vol 33 (4) ◽  
pp. 1088-1093 ◽  
Author(s):  
C. E. Purdom
Keyword(s):  
Fish Farming ◽  
Inbred Lines ◽  
Hybrid Vigor ◽  
Fish Culture ◽  
Common Phenomenon ◽  
F1 Hybrid ◽  
Hybrid Production ◽  
Environmental Component ◽  
Genetic Techniques ◽  
Selection For

Selection for improved growth rate does not appear to be feasible in flatfish because the environmental component of variation is very large. Selection for other characters has not been studied. The development of inbred lines, and their use in F1 hybrid production, seems warranted in fish farming if only as a means of avoiding inbreeding depression of fitness. Gynogenesis may be a practical means for accelerating the rate of inbreeding in fish. Induced triploidy is a potentially useful technique in fish culture in that it prevents sexual maturation and limits the depression of growth associated with this. Hybridization is a common phenomenon among fish and can lead to a form of hybrid vigor. Its application in fish culture may be limited by marketing problems where fish are sold under a specific name.

Guidelines for the Culture of Fish Stocks for Resource Management

1981 ◽  
Vol 38 (12) ◽  
pp. 1867-1876 ◽  
Author(s):  
J. D. Hynes ◽  
E. H. Brown Jr. ◽  
J. H. Helle ◽  
N. Ryman ◽  
D. A. Webster
Keyword(s):  
Resource Management ◽  
Selective Breeding ◽  
Temperature Tolerance ◽  
Artificial Rearing ◽  
Genetic Changes ◽  
Fish Stocks ◽  
Rearing Techniques ◽  
Induced Changes ◽  
Reduced Temperature ◽  
Practical Recommendations

Examples of desired genetic changes produced in fish by selective breeding are contrasted with those of unintentional and often harmful genetic changes resulting from artificial propagation over prolonged periods, e.g. reduced longevity and reduced temperature tolerance. Evidence for undesired effects caused by the hatchery environment on captive fish stocks is also presented, e.g. precocity, inappropriate feeding behavior, and the risks posed by artificial rearing techniques are discussed. Methods for identifying both genetic and environmentally induced changes are outlined along with experimental designs for distinguishing between them. Some practical recommendations are offered for establishing, developing, and maintaining brood stocks in hatcheries and for managing wild fish populations in ways that maximize genetic variability while avoiding the occurrence of undesirable changes. Adherence to the recommended procedures will improve progress in fisheries rehabilitation efforts.Key words: fish culture, genetics, environmental effects, brood stocks, resource management

Taking Stock of Genetic Concepts in Fisheries Management

1991 ◽  
Vol 48 (4) ◽  
pp. 722-731 ◽  
Author(s):  
R. W. Gauldie
Keyword(s):  
Fisheries Management ◽  
Growth Rates ◽  
Allele Frequencies ◽  
Frequency Variation ◽  
Sustainable Yield ◽  
Fish Stocks ◽  
Meristic Count ◽  
Intuitive Idea ◽  
Selection Mechanisms ◽  
Insight Into

The historical development of the idea of isolated stocks of fish that can be managed as separate management units has been as strongly tied to the intuitive idea of separate races as it has been to the practical necessities of jurisprudence and the estimation of both biomass and sustainable yield by fisheries managers. Demonstrating the existence of isolated fish stocks and delineating their boundaries has generally proved unsuccessful. Various techniques ranging from meristic count differences to polymorphic allelism have usually failed. However, in the pursuit of isolated stocks, biochemists have uncovered a great deal of information about the variation of polymorphic allele frequencies over time and space. Following the shift in opinion away from stochastic to natural selection mechanisms in allele frequency variation, it is evident that the observed variation in allele frequencies allows more insight into the biology of fishes than into the breeding structure of populations. These insights argue against the idea of isolated stocks of fish with homogeneous growth rates that are the basis of the sustainable yield models in favour of migration-linked stocks with heterogeneous growth rates.

scholarly journals Depleted marine fish stocks and ecosystem-based management: on the road to recovery, we need to be precautionary

2010 ◽  
Vol 68 (1) ◽  
pp. 212-220 ◽  
Author(s):  
Anna Gårdmark ◽  
Anders Nielsen ◽  
Jens Floeter ◽  
Christian Möllmann
Keyword(s):  
Fisheries Management ◽  
Marine Fish ◽  
Assessment Model ◽  
Fishing Mortality ◽  
Fish Stocks ◽  
The Road ◽  
Stock Status ◽  
Ecosystem Based Management ◽  
Management Plans ◽  
On The Road

Abstract Gårdmark, A., Nielsen, A., Floeter, J., and Möllmann, C. 2011. Depleted marine fish stocks and ecosystem-based management: on the road to recovery, we need to be precautionary. – ICES Journal of Marine Science, 68: 212–220. Precautionary management for fish stocks in need of recovery requires that likely stock increases can be distinguished from model artefacts and that the uncertainty of stock status can be handled. Yet, ICES stock assessments are predominantly deterministic and many EC management plans are designed for deterministic advice. Using the eastern Baltic cod (Gadus morhua) stock as an example, we show how deterministic scientific advice can lead to illusive certainty of a rapid stock recovery and management decisions taken in unawareness of large uncertainties in stock status. By (i) performing sensitivity analyses of key assessment model assumptions, (ii) quantifying the uncertainty of the estimates due to data uncertainty, and (iii) developing alternative stock and ecosystem indicators, we demonstrate that estimates of recent fishing mortality and recruitment of this stock were highly uncertain and show that these uncertainties are crucial when combined with management plans based on fixed reference points of fishing mortality. We therefore call for fisheries management that does not neglect uncertainty. To this end, we outline a four-step approach to handle uncertainty of stock status in advice and management. We argue that it is time to use these four steps towards an ecosystem-based approach to fisheries management.

scholarly journals Opportunity for marine fisheries reform in China

2017 ◽  
Vol 114 (3) ◽  
pp. 435-442 ◽  
Author(s):  
Ling Cao ◽  
Yong Chen ◽  
Shuanglin Dong ◽  
Arthur Hanson ◽  
Bo Huang ◽  
...  
Keyword(s):  
Resource Management ◽  
Fisheries Management ◽  
Cultural Context ◽  
Scientific Data ◽  
Coastal Development ◽  
Chinese Government ◽  
Marine Fisheries ◽  
Marine Resource ◽  
Fish Stocks ◽  
Marine Resource Management

China’s 13th Five-Year Plan, launched in March 2016, provides a sound policy platform for the protection of marine ecosystems and the restoration of capture fisheries within China’s exclusive economic zone. What distinguishes China among many other countries striving for marine fisheries reform is its size—accounting for almost one-fifth of global catch volume—and the unique cultural context of its economic and resource management. In this paper, we trace the history of Chinese government priorities, policies, and outcomes related to marine fisheries since the 1978 Economic Reform, and examine how the current leadership’s agenda for “ecological civilization” could successfully transform marine resource management in the coming years. We show how China, like many other countries, has experienced a decline in the average trophic level of its capture fisheries during the past few decades, and how its policy design, implementation, and enforcement have influenced the status of its wild fish stocks. To reverse the trend in declining fish stocks, the government is introducing a series of new programs for sustainable fisheries and aquaculture, with greater traceability and accountability in marine resource management and area controls on coastal development. As impressive as these new plans are on paper, we conclude that serious institutional reforms will be needed to achieve a true paradigm shift in marine fisheries management in China. In particular, we recommend new institutions for science-based fisheries management, secure fishing access, policy consistency across provinces, educational programs for fisheries managers, and increasing public access to scientific data.

scholarly journals Costs and Returns of Fishermen in the Massachusetts Inshore Lobster Fishery

1975 ◽  
Vol 4 (2) ◽  
pp. 195-210 ◽  
Author(s):  
J. M. Gates ◽  
J. M. D'Eugenio
Keyword(s):  
Fisheries Management ◽  
Fishing Effort ◽  
The State ◽  
Economic Factors ◽  
Sufficient Criterion ◽  
Fish Stocks ◽  
The Past ◽  
Resource Managers ◽  
Lobster Fishery

The inshore lobster fishery is one of the more important ones in the Commonwealth of Massachusetts, accounting for approximately 14 percent of the total landed value of all species in Massachusetts in 1971. Until recent years this fishery accounted for virtually all the pot landings in the state. Despite numerous attempts at conservation such as gear regulation, size restrictions, and prohibitions on harvesting egg-bearing females, the fishery has been subject to rapidly increasing effort and virtually constant landings. In the past decade it has become obvious to many fishery biologists and economists that conservation of fish stocks is a necessary but not sufficient criterion for fisheries management. Resource managers have become increasingly aware of the interdependence between economic factors and the intensity, location and composition of fishing effort.

The fisheries management implications of maternal-age-dependent larval survival

2006 ◽  
Vol 63 (10) ◽  
pp. 2249-2258 ◽  
Author(s):  
Michael R O'Farrell ◽  
Louis W Botsford
Keyword(s):  
Mortality Rate ◽  
Fisheries Management ◽  
Maternal Age ◽  
Egg Production ◽  
Larval Mortality ◽  
Reproductive Potential ◽  
Larval Survival ◽  
Age Effects ◽  
Fishing Mortality ◽  
Black Rockfish

A common goal of conventional fisheries management is to maintain fishing mortality at a rate that ensures an adequate level of lifetime egg production (LEP) for population sustainability. However, larvae from young spawners can experience higher mortality rates than larvae of older spawners, reducing the effect of egg production by young females (hereafter, maternal age effects). This reduction leads to an error in LEP that can be accounted for by reducing the fishing mortality rate, but raises the question of the magnitude of these errors if they are present but not accounted for. Calculations using parameters from a typical long-lived fish demonstrated that maternal age effects resulted in large errors in estimates of lifetime reproduction when there was a large contrast in the larval mortality rate extending over the reproductive life span. Errors were small when maternal age effects reduced the reproductive potential of only the very youngest spawners, at ages when a small fraction of females are mature. A specific example using the empirically derived maternal age effect for black rockfish (Sebastes melanops) indicated that errors in traditional management would be small for this species.

scholarly journals Effective fisheries management instrumental in improving fish stock status

2020 ◽  
Vol 117 (4) ◽  
pp. 2218-2224 ◽  
Author(s):  
Ray Hilborn ◽  
Ricardo Oscar Amoroso ◽  
Christopher M. Anderson ◽  
Julia K. Baum ◽  
Trevor A. Branch ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Marine Fish ◽  
Food System ◽  
Fish Stock ◽  
Management Tools ◽  
Fish Stocks ◽  
Fisheries Science ◽  
The World ◽  
Fish Catch ◽  
Intensively Managed

Marine fish stocks are an important part of the world food system and are particularly important for many of the poorest people of the world. Most existing analyses suggest overfishing is increasing, and there is widespread concern that fish stocks are decreasing throughout most of the world. We assembled trends in abundance and harvest rate of stocks that are scientifically assessed, constituting half of the reported global marine fish catch. For these stocks, on average, abundance is increasing and is at proposed target levels. Compared with regions that are intensively managed, regions with less-developed fisheries management have, on average, 3-fold greater harvest rates and half the abundance as assessed stocks. Available evidence suggests that the regions without assessments of abundance have little fisheries management, and stocks are in poor shape. Increased application of area-appropriate fisheries science recommendations and management tools are still needed for sustaining fisheries in places where they are lacking.

A Bayesian spatiotemporal approach to inform management unit appropriateness

2019 ◽  
Vol 76 (2) ◽  
pp. 217-237 ◽  
Author(s):  
Rujia Bi ◽  
Yan Jiao ◽  
Can Zhou ◽  
Eric Hallerman
Keyword(s):  
Great Lakes ◽  
Fisheries Management ◽  
Yellow Perch ◽  
Management Strategies ◽  
Computational Cost ◽  
Bayesian Hierarchical ◽  
Fish Stocks ◽  
Spatiotemporal Correlation ◽  
Management Actions ◽  
Gill Net

One prerequisite for sustainable fisheries management is to match management actions with biological processes. Stocks are fundamental units for fisheries management. Understanding the spatial structure of fish stocks is critical for conducting defensible stock assessments, applying efficient management strategies, and ensuring the sustainability of fish stocks. Yellow perch (Perca flavescens) is an important fishery in the Great Lakes. The appropriateness of its management units (MUs) has been identified as of high concern by the Great Lakes Fisheries Commission. Here we established integrated nested Laplace approximations and stochastic partial differential equations as two powerful tools for modeling spatiotemporal patterns of fish relative biomass. These fast computational approaches were applied to fit a Bayesian hierarchical hurdle model to occurrence and positive mass of yellow perch caught in gill-net surveys. Yellow perch relative biomass index has clear temporal variation and spatial heterogeneity, with the two middle MUs for yellow perch within Lake Erie merging together. The method explicitly models the spatiotemporal correlation structure inherent in biomass survey data at a reasonable computational cost, and the estimated spatiotemporal correlation informs stock structure.

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