Perspectives and Policy Recommendations on the Relevance of the Stock Concept to Fishery Management

1981 ◽  
Vol 38 (12) ◽  
pp. 1908-1914 ◽  
Author(s):  
G. R. Spangler ◽  
A. H. Berst ◽  
J. F. Koonce
Keyword(s):  
Fishery Management ◽  
Species Recognition ◽  
Individual Species ◽  
Policy Recommendations ◽  
Fish Stocks ◽  
Rehabilitation Programs ◽  
Management Actions ◽  
History Information ◽  
The Impact ◽  
The Relationship

The Stock Concept International Symposium (STOCS) addressed a broad range of concerns about the relationship between intraspecific stocks and their genetic and environmental origins. STOCS produced an understanding of the stock concept that makes it possible to develop operational stock definitions reflecting the key elements of concern to fishery managers. These definitions can change as circumstances dictate because stocks represent states in a dynamic process. Extensive life history information available for Great Lakes fish provides a basis for estimating the significance of intraspecific stock structure in management of these species. Recognition of the potential for stock formation is important for evaluating the impact of management actions and for planning the restoration of individual species in fishery rehabilitation programs. Finally, we present a brief set of recommendations for research and management based on our perception of the stock concept and its relevance to fish community rehabilitation.Key words: fish stocks, fishery rehabilitation

Tracking Species in Space and Time: Assessing the Relationships Between Paleobiogeography, Paleoecology, and Macroevolution

2008 ◽  
Vol 14 ◽  
pp. 233-248 ◽  
Author(s):  
Alycia L. Stigall
Keyword(s):  
Ecological Factors ◽  
Geographic Range ◽  
Individual Species ◽  
Species Ranges ◽  
Speciation Rate ◽  
Biogeographic Patterns ◽  
Environmental Controls ◽  
Historical Factors ◽  
The Impact ◽  
The Relationship

In all species, geographic range is constrained by a combination of ecological and historical factors. Ecological factors relate to the species' niche, its environmental or biotic limits in multidimensional space, while historical factors pertain to a species' ancestry, specifically the location at which a species evolved. Historical limitations are primary during speciation, while ecological factors control the subsequent expansion and contraction of species range. By assessing biogeographic changes during the lifespan of individual species, we can assess the relationship between paleobiogeography, paleoecology, and macroevolution. Quantitative paleobiogeographic analyses, especially those using GIS-based and phylogenetic methods, provide a framework to rigorously test hypotheses about the relationship between species ranges, biotic turnover, and paleoecology. These new tools provide a way to assess key questions about the co-evolution of life and earth. Changes in biogeographic patterns, reconstructed at the species level, can provide key information for interpreting macroevolutionary dynamics–particularly speciation mode (vicariance vs. dispersal) and speciation rate during key intervals of macroevolutionary change (biodiversity crises, widespread invasion events, and adaptive radiations). Furthermore, species ranges can be reconstructed using ecological niche modeling methods to examine the effects of environmental controls on geographic range shifts. Particularly fruitful areas of investigation in future paleobiogeographic analysis include (1) the relationship between species ranges and speciation events/mode, (2) relationship between shifting ecological regimes and range expansion and contraction, (3) the impact of interbasinal species invasions on both community structure and macroevolutionary dynamics, (4) the mechanics of transitions between endemic to cosmopolitan faunas at local, regional, and global scales, (5) how ecology and geographic range impacts species extinction during both background and crisis intervals.Three case studies are presented to illustrate both the methods and utility of this theoretical approach of using paleobiogeographic patterns to assess macroevolutionary dynamics. The first case study examines paleobiogeographic patterns in shallow marine invertebrates during the Late Devonian Biodiversity Crisis. During this interval, speciation by vicariance declined precipitously and only species exhibiting expanding geographic ranges survived the crisis interval. Patterns of biogeographic change during the Late Ordovician Richmondian invasion (Cincinnati Arch region) reveal similar patterns; speciation rate declines during invasion intervals and widely distributed endemic species are best able to survive in the new invasive regime. Phylogenetic biogeographic patterns during the Miocene radiation of North American horses suggest climatic parameters were important determinants of speciation and dispersal patterns.

scholarly journals A framework for ecosystem impacts assessment using an indicator approach

2005 ◽  
Vol 62 (3) ◽  
pp. 592-597 ◽  
Author(s):  
P.A. Livingston ◽  
K. Aydin ◽  
J. Boldt ◽  
J. Ianelli ◽  
J. Jurado-Molina
Keyword(s):  
Fishery Management ◽  
Ecosystem Impacts ◽  
Implementation Challenges ◽  
Management Actions ◽  
Indicator Approach ◽  
Research Organizations ◽  
Ecosystem Indicators ◽  
Ecosystem Level ◽  
Associated Species ◽  
The Impact

Abstract Assessment of the historical, present, and future states of marine ecosystems and the effects that humans and climate have on the state of an ecosystem are crucial to the scientific advice required to implement an ecosystem-based fishery management system. Management of federal groundfish fisheries in Alaska considers not just the target fishery, but also the possible impact those fisheries might have on other species and the ecosystem. Management actions have ranged from providing protection of endangered species in the region to preventing new fisheries from starting on key foodweb components such as forage fish. A scientific framework for providing ecosystem-based advice that puts the ecosystem first has been evolving over the past few years. This framework provides a way of assessing ecosystem factors that influence target species, the impact the target fishery may have on associated species, and ecosystem-level impacts of fishing. An indicator approach that describes ecosystem status, and trends and measures of human and climate influence has been developed to provide advice to fishery managers. This approach is now being expanded to utilize a variety of models to predict possible future trends in various ecosystem indicators. Future implementation challenges include the refinement of these predictive models, and the inclusion of climate into the models. Identification of sensitive and meaningful ecosystem indicators is also required before a more formalized decision-making process, one that includes ecosystem considerations, can be developed. Most important, the culture of fishery management and research organizations needs to change to embrace the ecosystem-based protections already mandated by various laws.

Biological Model of Fisheries Production Based on Physiological and Ecological Scalings of Body Size

1989 ◽  
Vol 46 (4) ◽  
pp. 614-623 ◽  
Author(s):  
P. R. Boudreau ◽  
L. M. Dickie
Keyword(s):  
Body Size ◽  
Individual Species ◽  
Data Series ◽  
Biomass Density ◽  
Fish Stocks ◽  
Population Sampling ◽  
Functional Relationships ◽  
Relationship Of ◽  
The Relationship ◽  
Population Equilibrium

Earlier ecological studies showing regularity in the relationship of certain indices of production to body size are used to develop a predictive equation of fish production on a year to year basis, with biomass and body size as independent stock variables. The prediction system makes use of the observed regular adjustments of local biomass density with body size and the parallelism of the functional relationships of production and biomass with body size both between and within stock cohorts. The method obviates the need to invoke assumptions of population equilibrium. The model is applied to three data series for individual species exploited by commercial fisheries on the Scotian Shelf. The results suggest that despite the vagaries of population sampling, ecological information can provide practical estimates of the production potential of fish stocks.

Monitoring and Management of the Northeast Atlantic Herring Stocks

1985 ◽  
Vol 42 (S1) ◽  
pp. s207-s221 ◽  
Author(s):  
Jakob Jakobsson
Keyword(s):  
Fishery Management ◽  
Rapid Decline ◽  
Fish Stocks ◽  
Northeast Atlantic ◽  
Management Actions ◽  
Recruitment Failure ◽  
Management Objectives ◽  
Maximum Benefit ◽  
Spawning Stock ◽  
History Of

The collapse of all the major herring stocks in the Northeast Atlantic in the late 1960s and the early 1970s was undoubtedly the most striking phenomenon in the history of the European fisheries. The events leading to the collapse show similar features for all the herring stocks: a sharp increase in catches over a few years, followed by a rapid decline and a fishing ban. During the period of declining stock abundance, management actions came too late and were not sufficiently restrictive. It appears that managers found it easier to accept a total fishing ban than to agree on severely reduced catches. In many cases it is clear that the fishing ban has been thoroughly enforced, while in other cases illegal fishing has seriously delayed the recovery of the stocks. This has been monitored by various fishery independent methods, such as tagging experiments, trawl surveys, larval surveys, and acoustic surveys. Before advising the reopening of the fishery it has been the general policy of the ICES Advisory Committee for Fishery Management that the spawning stock would be about to reach a minimum target abundance and that there should be firm evidence that recruitment should be on a similar level as it was prior to the collapse. Some stocks are about to or have already fulfilled these criteria, while others are still at a low level and suffering from recruitment failure. When reopening fisheries, setting of total allowable catches (TACs) and national quotas has been universal. Enforcement practices vary greatly within the European countries. In some countries, enforcement of fishing regulations is very strict and carried out on real time bases, while in other countries there appears to be very little enforcement of the existing regulations. Large quantities of herring are sometimes landed and even sold as sprat, whiting, or mackerel. Overshooting TACs is therefore common, and inadequate reporting of catches makes assessment difficult and less reliable than need be. In those cases where fishery regulations are enforced, management is mainly concerned with restricting the activities of the participating vessels so that they do not overfish. In doing so, the best fishing areas have in some cases been closed to fishing, because otherwise the catches would be far too large for the small quantity allocated to each boat. In other cases the catches per boat per night have to be so restricted (because of the large number of participating vessels) that large but unknown quantities of herring are dumped at sea. With the modernized fleets and the large number of boats participating, management has assumed the image of concentrating on "anti-effectiveness." Although the biological management objectives have been well defined and agreed to, the overall management objectives have neither been defined nor agreed to. These must take into account not only the biological objectives but also socioeconomic aspects. A management objective could be to fish the TACs with minimum expense, thus gaining maximum benefit in terms of profits from harvesting the resource. The traditionally free entry and free participation would then be the main obstacle to such an objective. This is especially acute in the case of a schooling species, which can be fished cheaply in large quantities. It is therefore important to develop new methods to restrict effort and investment. This leads to the basic problem of redefining the ownership of the fish stocks. Before an owner is firmly established, management will be under very severe constraints in limiting the entry to the fisheries.

scholarly journals Fishery-dependent information and the ecosystem approach: what role can fishers and their knowledge play in developing countries?

2011 ◽  
Vol 68 (8) ◽  
pp. 1805-1808 ◽  
Author(s):  
Sebastian Mathew
Keyword(s):  
Developing Countries ◽  
Fishery Management ◽  
Habitat Degradation ◽  
Good Practice ◽  
Ecosystem Approach ◽  
Anthropogenic Factors ◽  
Industrialized Countries ◽  
Fish Stocks ◽  
Cultural Aspects ◽  
The Impact

Abstract Mathew, S. 2011. Fishery-dependent information and the ecosystem approach: what role can fishers and their knowledge play in developing countries? – ICES Journal of Marine Science, 68: 1805–1808. An ecosystem approach to fishery management is as much a mechanism to deal with the impact of fishing on targeted, associated, and dependent fish stocks, and on the habitat, as it is to deal with the impact of habitat degradation from natural and anthropogenic factors on fishing. In developing countries, often with little institutional capacity for generating timely and reliable information for managing fisheries, effective integration of the knowledge possessed by fishers and their communities regarding, for example, oceanographic, biological, economic, social, and cultural aspects can contribute to an ecosystem approach to fisheries. The challenge is to identify and validate such knowledge and to create policy and legal space to integrate it into management, also drawing upon good practice in industrialized countries. An attempt is made to identify such knowledge, to discuss its salient aspects, and to look at the conditions under which its practical value can be enhanced and integrated into formal fishery-management systems in developing countries.

scholarly journals Impact of Rehabilitation on Outcomes after TAVI: A Preliminary Study

2018 ◽  
Vol 7 (10) ◽  
pp. 326 ◽  
Author(s):  
Christian Butter ◽  
Jessica Groß ◽  
Anja Haase-Fielitz ◽  
Helen Sims ◽  
Cornelia Deutsch ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Severe Aortic Stenosis ◽  
Rehabilitation Program ◽  
Geriatric Rehabilitation ◽  
Rehabilitation Programs ◽  
Transcatheter Aortic Valve ◽  
Included Patient ◽  
Valve Implantation ◽  
The Impact ◽  
The Relationship

The benefit of rehabilitation in elderly patients undergoing transcatheter aortic valve implantation (TAVI) for treatment of severe aortic stenosis is unknown. The impact of declining rehabilitation programs on mortality has also not been described. In a longitudinal cohort study of 1056 patients undergoing elective TAVI between 2008 and 2016, logistic regression analysis was used to assess the relationship between treatment modality and outcome according to whether or not patients participated in a three-week rehabilitation program after TAVI. Subgroup analyses included patient outcome separated according to cardiac, geriatric, or no rehabilitation. A total of 1017 patients survived until hospital discharge (96.3%) and were offered rehabilitation, 366 patients (36.0%) declined to undergo rehabilitation, with the remaining patients undergoing either cardiac (n = 435; 42.8%) or geriatric rehabilitation (n = 216; 21.2%). Mortality at six months was lower for patients receiving rehabilitation compared with those who had not (adjusted odds ratio (OR): 0.49; 95% confidence interval (confidence interval [CI]: 0.25–0.94; p = 0.032). Sub-analysis showed the benefit of cardiac (adjusted OR: 0.31; 95% CI 0.14–0.71, p = 0.006), but not geriatric rehabilitation (adjusted OR 0.83; 95% CI 0.37–1.85, p = 0.65). A program of rehabilitation after TAVI has the potential to reduce mortality. Future studies should focus on health-orientated behavior and identifying risk factors for declining rehabilitation programs.

The Precautionary Approach and risk management: can they increase the probability of successes in fishery management?

2001 ◽  
Vol 58 (1) ◽  
pp. 99-107 ◽  
Author(s):  
Ray Hilborn ◽  
Jean-Jacques Maguire ◽  
Ana M Parma ◽  
Andrew A Rosenberg
Keyword(s):  
Risk Management ◽  
Portfolio Management ◽  
Fishery Management ◽  
Fishing Communities ◽  
Individual Species ◽  
Precautionary Approach ◽  
Fish Stocks ◽  
Management Policies ◽  
Management Approaches ◽  
Made In

Considerable progress has been made in the implementation of the Precautionary Approach to the protection of fish stocks, but applying the Precautionary Approach to the protection of fishing communities lags considerably. The principle of intergenerational equity, one of the main tenets of the Precautionary Approach, and the principle of sustainable utilization both imply that the Precautionary Approach should explicitly incorporate the protection of fishing communities, not only the resources they depend on. Risk assessment aims primarily at evaluating the consequences of various harvest strategies in terms of probabilistic statements about future trends in yields, biomass, and dangers to the stock, while risk management involves finding and implementing management policies, strategies, and tactics that reduce the risk to the communities exploiting them. Not all fishery management approaches deal equally well with risk, with some compounding rather than reducing risk. Portfolio management, whereby fishing enterprises have the ability to choose among a diverse portfolio of harvestable resources, would mitigate against the risk of fluctuations in the abundance, availability, or price of individual species. Although much remains to be achieved in better assessing risk, fishery management agencies should immediately implement risk management.

scholarly journals Population Aging Can Aggravate Air Pollution: Evidence from China

2018 ◽  
Vol 11 (2) ◽  
pp. 41
Author(s):  
Hui Shi
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Technological Innovation ◽  
Positive Impact ◽  
Population Aging ◽  
Household Consumption ◽  
Policy Recommendations ◽  
Fossil Energy ◽  
The Impact ◽  
The Relationship

Population, resources and environment have always attracted much attention from the society. Nowadays, pollution and population aging are urgent problems to be solved in China, and many scholars have found a strong correlation between pollution and aging. This paper constructs a KAYA model with aging variables, making an empirical analysis of the relationship between population aging and air pollution based on the panel data of 82 cities in China from 2011 to 2016. We found that population aging has a significant and positive impact on air pollution. 1% change of the population aging will lead to a 0.203% change in AQI. The deepening of China’s aging level will lead to ineffective improvement of air quality and even lead to more serious air pollution. Then we make the further analysis of the impact mechanism of population aging on air quality, the results show that population aging could have a positive impact on air pollution by improving labor productivity, promoting technological innovation, increasing fossil energy consumption and the household consumption, and changing the structure of household consumption. At last, in order to improve the air pollution under the background of population aging, we put forward the policy recommendations according to the conclusion of this paper.

scholarly journals The Effect of Unemployment Rate on the Gross Domestic Product in Nigeria (A Bayesian Approach)

2021 ◽  
Author(s):  
Victor Agboli
Keyword(s):  
Economic Growth ◽  
Regression Analysis ◽  
Gross Domestic Product ◽  
Positive Impact ◽  
Linear Regression Analysis ◽  
Domestic Product ◽  
Policy Recommendations ◽  
Bayesian Linear Regression ◽  
The Impact ◽  
The Relationship

This study investigates the impact of unemployment on the Gross Domestic Product (GDP) of Nigeria for a period of 28 years (1990-2018). The study focuses on the relationship between unemployment and economic growth in Nigeria (GDP). The method used in this study is the Bayesian Linear Regression Analysis, the major findings were that unemployment has a positive impact on the economic growth of Nigeria. Some suggestions and policy recommendations were made based on the findings.

scholarly journals Knowledge and Innovation in Mexican Agricultural Organizations

Economies ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 103
Author(s):  
Sergio Ochoa Jiménez ◽  
Gimena Vianey Cervantes Hurtado ◽  
Carlos Armando Jacobo Hernández ◽  
José Guadalupe Flores López
Keyword(s):  
Knowledge Management ◽  
Agricultural Sector ◽  
Northern Mexico ◽  
New Ways Of Working ◽  
Management Actions ◽  
Agricultural Organizations ◽  
Quantitative Correlational Study ◽  
The Impact ◽  
The Relationship ◽  
Determining Factor

Knowledge is a determining factor in the creation of competitive advantage by generating new ways of working, which has been widely studied. However, in the agricultural sector, the contributions are minimal. Given the importance of the topic and the sector, the objective of this study is to determine the relationship between knowledge management and innovation in rural agricultural organizations in the state of Sonora in northern Mexico. A quantitative, correlational study was carried out, in which a questionnaire of 36 items with answers on a Likert scale was applied to 91 companies. The information was processed and analyzed in the SPSS program using correlation and linear regression. The results showed a positive and significant relationship between the variables under study, which supports that knowledge management in these companies, has as a consequence, innovations in them; however, it was not possible to determine the impact in economic terms. This can be taken up again in subsequent studies and in a practical sense in the companies by promoting knowledge management actions that encourage new processes, services and/or products that allow a monetary impact on them.

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