Spatial and temporal differences in the coastal fisheries along the east coast of India

Annual average fish landings along the east coast of India increased from 0.15 million tonnes during 1950-59 to 0.85 m t during 2000-06. The contribution of the northeast coast (NE) to the total landings along the east coast of India increased from 5.5% to 30.7% in the last five decades. There were remarkable differences in the catch composition between the NE and southeast (SE) coasts. Among the small pelagics, for instance, the hilsa shad Tenualosa ilisha and bombayduck Harpadon nehereus were dominant along the NE coast, but the oil sardine Sardinella longiceps, lesser sardines and Indian mackerel Rastrelliger kanagurta along the SE coast. Contribution of the fast growing, small-sized and low trophic level hilsa had increased from 0.5% during 1950-59 to 12.5% during 2000-06 along the NE coast, and the oil sardine (from 0.1% to 9.0%) and Indian mackerel (from 1.5% to 5.8%) along the SE coast. This has resulted in a decline in the mean trophic level of the catch by 0.077 and 0.041 per decade during 1950-2006 along the NE and SE coasts, respectively. This process of decline in the mean trophic level of the catch is caused due to substantial increase in the landings of species/groups that are low in trophic level, such as the small pelagics (oil sardine and hilsa), and penaeid and non-penaeid shrimps over the years.