Munrothuruthu (‘Munroe Island’) is a place renowned for continuous settlement, in the Kollam district of Kerala. The Indian Ocean earthquake and Tsunami of 2004 triggered this major problem. The island is located at confluence of the Ashtamudi Lake and the Kallada River. Low lying regions of the island are facing progressive settlement which has become pronounced since the occurrence of Tsunami. The area has been affected by upward seepage of saline water during High Tide events, denoting the axial lowering of land mass.

The Ashtamudi Lake in the Kollam District of Kerala lies in between 76.53°and 76.63° longitude and 8.93° and 8.83° latitude. It is a palm-shaped extensive waterbody with eight prominent arms, adjoining the Kollam town. This extensive estuarine system has a length of 16 km with a maximum width of 14 km and maximum depth up to 6.4m covering an area of 64.2 km2. The Ashtamudi Lake has been designated as a Ramsar Site (No.1204) in November 2002 and is also a major tourist place.

The survey was undertaken during the period from October -2012 to September -2013 in the Vattakkayal, Sakthikulangara panchayath, Kollam district. The major objective of this study was to find out the biodiversity status of fishes in Vattakkayal of Kollam district, South India.