With the migration of a variety of fish from the sea to Chilika lake adversely affected by the rampant use of small and zero mesh size nets, and overfishing further damaging fish breeding, at least five commercially important fish species in the lake face the threat of depletion. Disappearance of commercially-valued fish species has hampered the livelihood of traditional fishing communities that live in and around Chilika, which is one of the fish-rich lagoons of the country. Adverse ecosystem The Central Inland Fisheries Research Institute (CIFRI), Barrackpore, has identified five fish species – Khainga (Mugil cephalus), Dangala (Liza macrolepis), Boraga (Dayscaena albida), Sahala (eleutheromema tetradactylum) and Kundala (Etroplus suratenis), which find adverse ecosystems to grow. The CIFRI had carried out biological and ecological survey for measuring the length, frequency, spawning season, spawning ground and fishery resources in the Chilika lagoon. There has been a marked fall in the length, size and spawning stock biomass (SSB) — the total group of the fish in a stock that are old enough to spawn. The fall in SSB is a matter of concern. The SSB decline in the case of Khainga is 82.64%, Sahala (89.73%), Dangala (87.1%), Boraga (80.9%) and Kundala (80%), said a senior official of the Chilika Development Authority (CDA). The sharp decline means the SSB is assessed below 20% in all five fish varieties. There is rampant use of small and zero mesh size nets in the lake to catch all size groups of fish and shell fish species. This causes serious biodiversity loss besides destruction of larval and juvenile stages of a number of commercial fish species. Fishery of the lake depends to a large extent on species migrating into the lagoon through the sea mouth. Dense deployment of destructive nets blocks free movement of larvae, juveniles and adults. Biggest obstruction The drop in commercial fish catch will affect local fishermen. Destructive fishing practice especially fish enclosure (ghery) for aquaculture is the biggest obstruction for migration of fish between the sea and the lake. We are carrying out a massive ghery eviction drive ever undertaken in Chilika, said Sushant Nanda, Chief Executive of CDA. Mr. Nanda said satellite imageries found 14,590 hectares of Chilika under man-made gheries for illegal prawn cultivation. As of now, more than 2,000 ha of gheries have been removed, he said. During 2016, the total annual fish landing, including fish, prawn and crab from Chilika, was estimated at 14,067.50 tonnes valued at Rs. 190.10 crore which worked out to 10.26% increase as compared to the annual catch in 2014. The average per capita income of the active fishers during 2016 was estimated at Rs. 56,035.