Variability in catch composition and CPUE of bottom trawl fishery along Parangipettai, Cuddalore and Pazhayar, Southeast coast of India, Bay of Bengal

The present study intended to find out the variations in fish composition and CPUE (Catch Per Unit Effort) (November 2017 - March 2018) of bottom trawl fishery at three stations viz., Parangipettai, Cuddalore and Pazhayar. Out of 16 sampling from these three stations, the highest CPUE was recorded from Parangipettai (70 kg/hr) and Cuddalore (51.4 kg/hr) between January and February 2018. Altogether, 67 finfish and shellfish species were identified from the trawl catches, of which Trichiurus lepturus, Leiognathus equula, Nemipterus furcosus, Rastrelliger kanagurta, Nibea maculata, Deveximentum insidiator, Nemipterus randalli, Terapon theraps, Eubleekeria splendens, Loligo vulgaris, Nemipterus japonicus, Sepia officinalis, and Leiognathus berbis were found as commercially important fishes. Additionally, Loligo vulgaris (165 kg) and Leiognathus berbis (35 kg) were found dominantly in the total catches from January to March 2018. The present investigation revealed that amid three study areas investigated, Parangipettai and Cuddalore exhibited higher total catch, CPUE, and fish diversity, which is also highlighted in the PCA (Principal Component Analysis). The high catch noticed in these areas might be due to increased productivity in the post-monsoon season supported by corresponding monsoonal nutrient influx, as Parangipettai and Cuddalore coastal waters experience high estuarine influx. Further, it was also evidenced by the observed higher values of essential nutrients such as nitrate (Cuddalore: 7.66 mu M; Parangipettai: 8.17 mu M) and silicate (Cuddalore: 6.68 mu M; Parangipettai: 8.48 mu M), and chlorophyll-a concentration (Cuddalore: 1.43 mu g/l; Parangipettai: 2.09 mu g/l) at both the stations.