ALAPPUZHA: A clam rehabilitation programme will soon be launched in Vembanad lake where the clam deposits have come down due to climate change. Over 5,000 local people are engaged in the traditional business of clam collection in the Vembanad wetland area, spread over 36,500 hectares, which is fed by six large rivers and seawater.
The programme to be undertaken jointly by the Central Marine Fisheries Research Institute (CMFRI), fisheries department, Vembanad lake protection forums and World Wildlife Fund will be completed in three years.
Though the department had planned clam relaying last year, it failed to take off due to technical problems. The Thanneermukom barrage would be closed for a couple of months and the project will be launched in September. Studies have proved the efficacy of clam-relaying to ensure a five-fold increase in clam breeding.
Mr C.P. Anirudhan, deputy director of fisheries, Alappuzha, said that the project would be implemented in Muhamma, Vechur, Kavalam and Aryad areas. Women have been given special training to create value-added products out of clam shells. “We plan to relay the clams in the southern part from the northern area of Thanneermukkom bund,” he said.
Mr K.M. Poovu, secretary, Lake Protection Forum, said they had relaid clams on an experimental basis earlier in January. But the clams died due to lack of salinity. When the barrage was opened by the end in February, brackish water gushed into the lake helping the breeding of clams. The relaying project will enable clams to multiply without interruption, he said.
Salinity is a major decider of clam breeding. A female clam can lay one to two lakh eggs during breeding. But, breeding takes place only when favourable conditions exists in the eco system. “Now the salinity exists in the bottom area of the lake as the peripheral area is washed with non-saline water as the shutters of the barrage remain shut. So the breeding in these months is extremely difficult,” said traditional clam collectors.
Over the years the clam wealth in the Vembanad lake has gone down due to various reasons. Apart from El Niño factor, salinity of the lake was hit as it was divided by the Thanneermukkom barrage built in 1975 to shut out saltwater ingress into the fields in a bid to promote double cropping of paddy in areas surrounding the lake.
“The optimum point of salinity for clam breeding is from 10 ppt,” said Mr T.D. Jojo, coordinator, ATREE. But the present salinity level of Vembanad is below 10 ppt. The lack of a mix of saline and freshwater, vital to fish breeding, has affected fish and clam species.
“The illegal clam collection with banned motors affects the livelihood of traditional stakeholders. We have started awareness campaigns for clam collectors to protect the wealth,” said Mr V.P. Manoharan, president of the forum.
