As many as 23 species were found in only one of the three focus regions, while 16 species were found in only one location. The 2017 count has reported just 49 species, and only 10 of these were widely distributed - meaning that they were found in all 15 locations examined. The counts also point to a general decline in species. Many of the commonly harvested marine fish, such as mullets and sea bass, were rarely found during the counts. In fact, of the missing species, 86 per cent were marine migrants, while among the newly identified species, 75 per cent were non-migrants. While the older studies indicated that the lake had predominantly more marine species, the fish counts found fewer such species. Intriguingly, 24 new species were identified. While the last major study of fish populations in Vembanad during 1985-89 identified around 60 species, 28 of them were missing during the subsequent fish counts. The most striking finding is that of ‘missing’ species. This rather straightforward method of survey has gathered alarming evidence on odd patterns in fish population. The volunteers also draw water samples from these locations - by dipping bottles to an arm’s length below the water surface - to measure temperature, acidity, salinity and oxygen levels. Five samples of each species are preserved in jars for future analysis.
The caught fish are identified with the help of a field handbook, and then counted. For reasons described later, the count is carried out only in the southern sector of the lake.Īt each location, fish is caught in three kinds of nets: gill nets - large rectangular nets that are suspended vertically in the water to trap passing fish cast nets - circular nets that are thrown into the water and immediately pulled out and scoop nets - quite simply, badminton racquets with a fishing net to scoop out fish. Over the course of the day, each boat visits five survey locations marked out by ATREE in consultation with fishermen. On the day of the count, three boats - each with around 40 volunteers and two fishermen of the Samithi - set off in three different regions of the lake: west bank, east bank and the riverine parts. Since it is impossible to count every fish in the lake, unlike in a census of human population, an ‘experimental fishing’ method is used instead. The volunteers gather a day ahead for an orientation session, which familiarises them with the method used for the counting. In its 10th year now, the count is organised by the Ashoka Trust for Research in Ecology and the Environment (ATREE), in collaboration with the Samyuktha Vembanad Kayal Samrakshana Samithi (Federation of Vembanad Lake Protection Forums), a collective of traditional fishermen, and several government departments including the Kerala State Biodiversity Board.
The fish count takes the next step by asking, “What happens to the fish?” A “Wetland of International Importance” under the global Ramsar Convention, and the largest such site in India, Vembanad also ranks among the world’s most polluted lakes, as sewage, plastic, chemicals and mismanagement have sullied its waters, especially in its southern sector. The Vembanad Fish Count gets underway in the saline waters of Vembanad lake, which forms the heart of India’s favourite backwaters. On one day every May, the tourist drill in the Kerala backwaters - book resort, hire houseboat, open beer, laze - is broken by a unique volunteer-driven activity that looks, quite literally, at several underlying factors. Suddenly the silence was broken as a few dozen people assembled carrying an assortment of objects - buckets, fishing nets, laboratory beakers, bottles - and boarded a boat, before disappearing into the waters. Swanky houseboats were still tied to the shores and bobbing in the water the palatial resorts were yet to open their gates. At 6 am on May 27, the backwaters of Alappuzha, Kerala, were soundless.