The first edition of the fish count was held on 30th May 2008. 51 species of finfish representing 26 families and 35 genera, as well as 10 species of shell fish belonging to 6 families and 7 genera were recorded during this fish count. Out of this, two species of fishes are listed as ‘Critically Endangered’, four ‘Endangered’ and five species are ‘Vulnerable’ according to IUCN Red data book. The sector around Pathiramanal Island was observed to be the richest sector (in terms of fishes) of the total area surveyed.
The second edition of the fish count was held on 26th and 27th May 2009, and involved a wider group of organisers and participants. 65 species of finfish and 14 species of shell fish were recorded. Again, the sector around Pathiramanal Island was observed to be the richest sector surveyed with about 50 fish species recorded.
In total, the survey recorded 13 more native fish species and 3 shell fish species to the fish fauna of the lake over the previous year's fish count. It also recorded two exotic species (Sucker catfish and Sutchi catfish) in the lake, for the first time. Amongst the newly recorded species, 8 were estuarine species which proliferated the lake due to the timely opening of the Thannermukkom salt water barrier and the remaining 5 were typical riverine species. Three species - Indian shortfin eel, Indian mottled eel and Walking catfish were found to have disappeared from the lake. This development has been caused by stake net operations and dams in the northern part of the lake, which obstruct the migratory pathway of eels. The 2009 fish count report also points to a new threat to the native fish species of Vembanad Lake - Invasive Alien Species such as the exotic Sucker catfish.
The attached reports contain a summary of the findings of the two fish count exercises and has details of the various species recorded and water quality results and lists various recommendations towards better conservation and management of the lake. It paves way for future course of action as ATREE plans to make this an annual event, involving more and more interested agencies and people. The fish count exercise is expected to become more accurate and relevant in the years to come with more and more active participation of people, who in turn will take the lead in conserving this great natural heritage of Vembanad lake.
More details about ATREE's work on Vembanad lake are here.
Read the reports: