Effect of Environmental Variations on Fishery Biology and Fisheries: The Indian Oil Sardine - A Case Study In: ICAR Sponsored Winter School on Recent Advances in Fishery Biology Techniques for Biodiversity Evaluation and Conservation, 1-21 December 2018, Kochi.

The marine ecosystem is dynamic and the variations several abiotic and biotic factors directly and indirectly affect the fish stocks and their population structure. Spawning and recruitment success is to a large extent linked to these environmental variations. It is well known that resources occupy a particular habitat because of their preference to the environmental variables prevalent there and also due the availability of food. We have large shoal forming small pelagic fishes like the sardines and anchovies and the deep water large pelagic and demersals occupying the marine ecosystem from the upper pelagic zone to the benthic realms. Fishing is one of the major activities directly impacting the fish stocks and fishery records show several cases of overfishing leading to stock collapses. Definitely, fishery management tools have supported revival of several of these stocks but have failed to do so in few others. Almost equally important in inducing the biological changes that control maturation, spawning and recruitment are the some ocean atmospheric processes which change inter-annually in the tropics