Exploring the diversity of trawl catch composition in Mumbai coastal waters through experimental trawling

The primary focus of our experimental trawling, was to analyse fish composition within specific coordinates (19°06’66” to 19°12’15.09” north latitude, 72°41’23.20” to 72°48’50” east longitude) at depths ranging from 6 to 21 m. We catalogued 127 species comprising 34 shellfish (25 genera, 9 orders and 27 families) and 92 finfish (68 genera, 40 families, 14 orders). Dominant fish orders were Perciformes (74%), Clupeiformes (19%) and Tetraodontiformes (7%), while Decapoda led shellfish (81%) followed by Neogastropoda (19%). Discards contributed 59%, non-target 34% and target catch 7%. Species peaked 18 m (66), followed by 12-15 m (60) and dropped at 6-9 m (36). Monthly averages for discard (4.5 to 24.75 kg h-1) and commercial catch (4.1 to 12.2 kg h-1) fluctuated. Cluster analysis showed high similarity in species and abundance between adjacent months. Bycatch varied seasonally, lowest in winter and highest in post-monsoon. Biodiversity indices indicated rich, evenly distributed diversity. These findings yield vital insights into fish catch composition, distribution, and bycatch diversity. They are crucial for sustainably managing overexploited fisheries, forming a foundational resource for effective and sustainable exploitation. Keywords: Bycatch diversity, Commercial catch, Discard catch, Experimental fishing, Ichthyofauna