Geo-spatial distribution and faunal diversity in the trawling grounds off Mumbai coast, Maharashtra, India

Investigations were carried out to assess the spatio-temporal distribution and ichthyofaunal diversity along the Mumbai coast of Maharashtra, India, with the help of GIS technology. The catch data from single-day and multi-day trawlers for the period September 2013 to February 2014 were recorded. A total of 120 fish species belonging to 85 genera, 56 families and 23 orders were caught by 55 hauls of multi-day and single-day trawlers. Bathymetric distribution showed availability of maximum number of species at the depth of 15-19 m (70 species) followed by the depth of 20-24 m (65 species) and that of 10-14 m (64 species). Biodiversity in terms of number of species was found to be maximum during January 2014. The value of Shannon-Wienner index (H') was recorded between 1.42 and 1.63 indicating less diverse nature of fishes along Mumbai coast. Value of Margalef richness index (d) ranged between 7.08 and 8.79. The average value for Simpson index (λ) recorded was 0.047. K-dominance plot clearly demonstrated the diversity pattern during the study period.