نتایج جستجو برای: fishing mortality proxy
تعداد نتایج: 325174 فیلتر نتایج به سال:
Life history theory predicts selection for higher reproductive investment in response to increased mortality among mature individuals. We tested this prediction over the period from 1978 to 2013 for three populations of Atlantic cod (Gadus morhua) off Newfoundland. These populations were heavily fished for a long period. We considered changes in standardized gonad weight as a proxy for changes ...
Effects of age at first capture (tc) and fishing (F) as well as natural mortalities (M) on yield and biomass-per-recruit of tiger tooth croacker, Otolithes ruber were evaluated in the northwest of the Persian Gulf using the Beverton-Holt model. The yield-per-recruit (Y/R) was 175 (g/r), which was less than maximum yield-per-recruit value (217 (g/r)) at fishing mortality of 1 year-1. Current ...
the growth parameters, mortality rates and exploitation population dynamic parameters and exploitation rate of psettodes erumei were assessed between july 2010 to june 2011 using length frequency analysis. the data were collected from landing sites of jask, bandar abass, kong and qeshm hormozgan province waters. using total weight (w) and total length (tl) data, the length- weight relationship ...
This paper aimed to investigate the fishery and biological characteristics of anchovy Kilka in Iranian waters of the Caspian Sea from 2005-2007, including length and age structure ,Von Bertalanffy growth parameters, length and age at first capture, condition factor, sex ratio, natural and fishing mortality. The examination of catch data approved that Kilka population in the Caspian S...
This paper aimed to investigate the fishery and biological characteristics of anchovy Kilka in Iranian waters of the Caspian Sea from 2005-2007, including length and age structure ,Von Bertalanffy growth parameters, length and age at first capture, condition factor, sex ratio, natural and fishing mortality. The examination of catch data approved that Kilka population in the Caspian Sea have b...
The North Atlantic right whale is one of the most critically endangered marine species. Drastic overexploitation has driven this large, slow-swimming baleen whale to virtual extinction in Europe, while a small remnant population of ~350 individuals remains on the US and Canadian east coast. Although this species has been protected for 70 years, recovery has been slight and extinction is still l...
The ocean surgeonfish Acanthurus bahianus, an abundant small herbivore on reefs throughout the tropical west and central Atlantic, is a significant component of Caribbean trapfishery catches. To assess effects of fishing on this species we compared its longevity, survivorship, size and abundance at localities throughout its range that have differing intensities and targets of fishing. Temperatu...
Over the last decades, views on fisheries management have oscillated between alarm and trust in management progress. The predominant policy for remedying the world fishing crisis aims at maximum sustainable yield (MSY) by adjusting gear selectivity and fishing effort. Here we report a case study on how striving for higher yields from the Eastern Baltic cod stock by increasing selectivity has be...
Both theoretical and experimental studies have shown that fishing mortality can induce adaptive responses in body growth rates of fishes in the opposite direction of natural selection. We compared body growth rates in European eel (Anguilla anguilla) from three Mediterranean stocks subject to different fishing pressure. Results are consistent with the hypotheses that i) fast-growing individuals...
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