Fishery and GIS Based Spatio-Temporal Distribution Analysis of Smooth Blaasop, Lagocephalus inermis , in South-Eastern Arabian Sea

Investigations on distribution of species on a spatio-temporal scale has ecological and management significance. Study was carried out in one of the productive zones of south eastern Arabian sea on Lagocephalus inermis one of the emerging fishery resource from 2015 to 2017 in comparison with 2008. GIS tools was used to support fishery analysis, abundance and distribution of species. Average catch for 2015-17 period was 3456 t which showed twelve fold increase compared to 2008. Spatial and temporal analysis of the abundance of species showed a range from 7-277 kg/hr (Catch Per Hour) at a depth range of 20-100 m. Juveniles were observed more towards near shore area with aggregation in clayey region. Spatial indicators (spatial dispersion, directional dispersion and directional trend) were calculated by year. Spatial distribution value was highest in 2016 indicating a wider distribution of L. inermis, whereas this distribution was more compact in 2008. It was also observed that in 2008 the central tendency is located in the Southern-most part of the study area whereas during recent period shifted to the Northern side. Species associated with L. inermis were all mid- level carnivores similar to the species indicating a trophic cascading happening in the Arabian Sea.