Stock structure of billfishes observed during the exploratory surveys in the Indian Exclusive Economic Zone- A Decadal study

The billfishes such as Sailfish (Istiophorus platypterus), Swordfish (Xiphias gladius) and Marlins (Makaira nigricans, Makaira Indica and Tetrapturus audax) are observed to be occurring in the Indian Exclusive Economic Zone (EEZ) as revealed through the exploratory surveys. In the Indian EEZ, the area between 4° and 23°N covering the Arabian Sea in the west, and 2°-21°N covering the Bay of Bengal and Andaman & Nicobar Islands in the east have been surveyed and the results derived are presented. The exploratory survey data collected during three decadal periods (1989-2019) have been considered for the study.  Area-wise (latitude) distribution, CPUE and Hooking rates were drawn and are presented. The Catch Per Unit Effort (CPUE) recorded in the Indian EEZ for the billfishes was 34.75 kg/ 1000 hooks and hooking rate was 0.12%, whereas in West coast the CPUE was 41.83 kg/1000 hooks and the hooking rate was 0.16%, in the East coast the CPUE of 11.73 kg/1000 hooks and the hooking rate of 0.05%, while in Andaman and Nicobar waters the CPUE of 40.62 kg/1000 hooks and the hooking rate of 0.13% were recorded. This paper presents species composition; distribution and abundance in time and space are presented.