मत्स्य पालन एवं पशुधन उत्पादन

अमूर्त

Fishes in the Ocean are affected by Biological Disorders

Vamica Harish

In this article, we examine how the biology of marine fishes interacts with external threats to influence how populations and species react to such challenges. Less than 5% of the world’s approximately 15, 500 marine fish species, the majority of which are significant commercially, have information on their status. Marine fish breeding biomass had decreased by an average of 65% from known historic values by 2001, according to data from 98 populations in the North Atlantic and Northeast Pacific; 28 populations had decreased by more than 80%. According to international threat standards, the majority of these decreases would be sufficient to justify a threatened with extinction designation. It is widely believed that marine fishes have a variety of life cycle traits, such as high fecundity and wide geographic distributions, which may impart better resilience than that displayed by terrestrial vertebrates. Nevertheless, this view is somewhat contentious. We examine 15 comparative studies that investigated these and other life history variables of vulnerability in marine fishes. Regardless of how fishing mortality varies among taxa, the empirical evidence points to large body size and late maturity as the greatest indicators of sensitivity to fishing; there is no indication that high fecundity increases resilience. The information examined here is directly relevant to the various standards used by various authorities to evaluate the threat status of fishes at the national and international levels. Simple life history features can be used as early screening criteria for assessment of the approximately 95% of marine fish species whose status has not yet been assessed by conservationists or fisheries scientists. They can also be used to change the conclusions of quantitative analyses.