GIS for Assessing Spatio-temporal Variations in Trawl Bycatch off Mangalore Coast

Abstract

In India, trawl is the major gear contributing more
than 50% of the marine fish landing and during
2008-2011, the average landing along the Indian
coast was estimated at 1.7 million t. In India, fish
brought from trawl fishery for human consumption
in fresh or processed form is termed as commercial
landing and the rest is called low valued bycatch
(LVB). The increased demand for LVB from fish
meal plants is an emerging threat for marine fish
production in the future, since LVB was constituted
mainly by juveniles of commercial fishes. The study
showed that the percentage of LVB from the trawlers
in India increased from 21% in 2008 to 23% in 2011.
The results of the study identify some of the fishing
grounds and seasons, in which the percentage of
juvenile bycatch of the commercial species is very
high. Implementing operational restrictions in the
fishery in such areas will help in reviving the stock.
The paper illustrates the utility of the spatiotemporal
data in suggesting seasonal and spatial
restrictions in fishing operations in tropical
multispecies scenario.