نتایج جستجو برای: fishing mortality proxy
تعداد نتایج: 325174 فیلتر نتایج به سال:
Age and size at maturation have declined dramatically in many commercial fish stocks over the past few decades - changes that have been widely attributed to fishing pressure. We performed an analysis of such trends across multiple studies, to test for the consistency of life history changes under fishing, and for their association with the intensity of exploitation (fishing mortality rate). We ...
Fisheries management systems around the world are highly diverse in their design, operation, and effectiveness at meeting objectives. A variety of management institutions, strategies, and tactics are used across disparate regions, fishing fleets, and taxonomic groups. At a global level, it is unclear which particular management attributes have greatest influence on the status of fished populati...
Abstract Target and limit reference points are fundamental management components used to define sustainable harvest strategies. Maximum Sustainable Yield (MSY) the precautionary principle underpin many points. Non-proxy based on MSY in age-based single-species assessments depend stock–recruitment (SR) relationship, which can display complex variability. Current ignore persistent dynamic change ...
Fish stocks experiencing high fishing mortality show a tendency to mature earlier and at a smaller size, which may have a genetic component and therefore long-lasting economic and biological effects. To date, the economic effects of such ecoevolutionary dynamics have not been empirically investigated. Using 70 y of data, we develop a bioeconomic model for Northeast Arctic cod to compare the eco...
Population and community indicators for the impact of fishing are often estimated using abundance estimates instead of raw sampling observations. Methods are presented for testing null hypotheses of non-significant impacts and where possible, for calculating the statistical power. The indicators considered concern populations (intrinsic growth rate, total mortality, exploitation rate and a new ...
OBJECTIVE To analyze the relationship between macroeconomic conditions and health in Brazil. METHODS The analysis of the impact of employment and income on mortality in Brazil was based on panel data from Brazilian states between 1981 and 2002. Mortality rates obtained from the national mortality database was used as a proxy for health status, whereas the variables employment, income, and ill...
The striped bass (Morone saxatilis) is an economically and ecologically important finfish species along the Atlantic seaboard of the United States. Recent stock assessments in Chesapeake Bay (U.S.A.) indicate that non-fishing mortality in striped bass has increased since 1999, concomitant with very high (>50%) prevalence of visceral and dermal disease caused by Mycobacterium spp. Current fisher...
Survival analysis was applied to fisheries catch at age data to develop maximum likelihood estimators for stock assessment. This new method estimated natural mortality, fishing mortality and catchability from typical catch at age matrices. Monte Carlo simulations suggested estimates were unbiased and provided a better fit than the traditional multinomial approach. Application to a dataset from ...
An investigation of the population parameters of Indian mackerel, Rastrelliger kanagurta (Cuvier, 1816) in the Marudu Bay, Sabah, Malaysia was carried out from January to September 2013. The relationship between total length and body weight was estimated as W=0.006TL3.215 or Log W=3.215LogTL – 2.22 (R2=0.946). Monthly length frequency data of R. kanagurta were analyzed by FiSAT software to eva...
An investigation of the population parameters of Indian mackerel, Rastrelliger kanagurta (Cuvier, 1816) in the Marudu Bay, Sabah, Malaysia was carried out from January to September 2013. The relationship between total length and body weight was estimated as W=0.006TL3.215 or Log W=3.215LogTL – 2.22 (R2=0.946). Monthly length frequency data of R. kanagurta were analyzed by FiSAT software to eva...
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