Temporal Patterns in Fish Community Structure: Environmental Perturbations from a Well-Mixed Tropical Estuary

Seasonal fish species composition, catch rate and catch value in the small scale fishery of a tropical monsoon estuary along southwest coast of India

“…In the tropical coastal ecosystems, estuaries play a major role inhabiting variety of aquatic organisms such as fish and crustaceans (Ansari 1995;George 2013;Sreekanth 2015a). These assemblages of species that inhabit estuaries represent resident estuarine and marine migrant species (Baker and Sheppard, 2005;Franco 2012;Rajesh 2015).…”

“…Thus, estuaries function as a significant nursery ground for several marine and coastal fish species (Dolbeth 2011;Pasquaud 2015), and these species congregate in this zone for reproduction, feeding and shelter. Most of these species have tolerance to the highly varying environmental conditions in the estuaries (Ansari 1995;Barbone and Basset, 2010;Sreekanth 2015a). The seasonal reversal of winds in the Arabian Sea termed as 'southwest monsoon', results in heavy precipitation along the west coast of India during June to September (Shamsan, 2008).…”

“…The seasonal reversal of winds in the Arabian Sea termed as 'southwest monsoon', results in heavy precipitation along the west coast of India during June to September (Shamsan, 2008). This monsoon phenomenon causes et al., et al, et al, et al, et al, et al, et al, et al, et al, seasonality in the coastal environment which is generally classified into three seasons, namely pre-monsoon (February-May), m o n s o o n ( J u n e -S e p t e m b e r ) a n d p o s t -m o n s o o n (October-January) seasons (Shamsan, 2008;Sreekanth 2015a). Therefore, monsoon mediated environmental fluctuations in the coastal ecosystem are expected to affect the spawning and movement activities of aquatic species and thus, influences the diversity of fish species (Ansari 1995;Sreekanth 2015a;Sreekanth 2016).…”

“…This monsoon phenomenon causes et al., et al, et al, et al, et al, et al, et al, et al, et al, seasonality in the coastal environment which is generally classified into three seasons, namely pre-monsoon (February-May), m o n s o o n ( J u n e -S e p t e m b e r ) a n d p o s t -m o n s o o n (October-January) seasons (Shamsan, 2008;Sreekanth 2015a). Therefore, monsoon mediated environmental fluctuations in the coastal ecosystem are expected to affect the spawning and movement activities of aquatic species and thus, influences the diversity of fish species (Ansari 1995;Sreekanth 2015a;Sreekanth 2016). These environmental fluctuations cause seasonal migrations of fish species like movement of young fish from deeper waters to estuarine regions and movement of mature adult fish to spawning grounds and thus bring out seasonal variations in the fish assemblages (Harrison and Whitfield, 2006;Costa 2007;Barbone and Basset, 2010).…”

“…The margins of Zuari estuary have dense mangrove vegetation filled with silt, clay and detritus that has been transported by riverine influx from upper reaches. The entire mudflats along with mangrove vegetation makes the region highly productive supporting large number of economically important species (Sreekanth 2015a). This region receives maximum precipitation during the southwest monsoon accompanied by stormy weather, while quieter conditions prevail during rest of the year.…”