Summary of Abstract Submission

Abstract Submission No. IO50-10-0009PresentationPoster

A SURVEY OF JELLYFISH SWARMING IN THE MARINE ECOSYSTEM ALONG RATNAGIRI COAST, MAHARASHTRA

Purushottama, G. B*1, Swapnil S. Tandel1, Katkar, B. N.1, Chavan, B. B.1, Ramkumar, S.1, Saravanan, R.1, Muktha, M. 1, Singh, V. V. 1

1 ICAR - Central Marine Fisheries Research Institute, India

ABSTRACT :

In India incidences of jellyfish swarming are on the rise. This work was undertaken to study the distribution of jellyfish swarms using commercial multiday and single day shrimp trawlers operating in different regions along Ratnagiri coast, Maharashtra from November 2013 to December 2014. The experimental trawling was also conducted during study period to confirm the jelly fish swarming. The information on latitude and longitude of fishing operation, sea water temperature, salinity, depth, duration of fishing operation and catch details were collected from two boats separately on voyage basis. Jellyfish swarms were observed during September-December. The contribution of jellyfish to total catch in single day trawlers ranged from 9.7% to 94% with highest contribution in October. In multiday trawler, the contribution of jellyfish to total catch ranged from 70% to 90% with highest values in both October and November. The analysis of catch composition of jelly fish showed that Cephea cephea followed by Lychnorhiza malayensis were the dominant species. Jellyfish catch showed positive correlation with cuttlefish catch. The distribution and relative abundance of jellyfish was studied in different months in relation to sea surface temperature (SST). Highest landings of jellyfish in multiday trawlers occurred in October and November which were also the months with highest average SST of 30.4C and 28.4C respectively. The salinity range recorded by both trawlers was 32x10-3- 35x10-3. The swarming of jellyfish reduced the catch of high-commercial value groups of finfish and shellfish.