Dynamics of Indian chank fisheries

Abstract

The demand for chanks from the bangle industry in West Bengal had persisted at about 25 million chanks per year from the early part of this century to the present. The present supplies, which meet only about 40% of the demand, come mainly from the Gulf of Mannar. The average annual stock in the Gulf of Mannar is 2.0 million adult chanks of which 44-83% are exploited. The initial stock size, however, varies from year to year, and hence, there exists different levels of optimum yields for different Initial stock sizes. Chank fisheries in Palk Bay and the Coramandal coast yield annually an average of 49,000 chanks and 24.600 chanks respectively while in Kerala the average annual yield is 20,100 chanks. The average annual stock of chanks in the intertidal Gulf of Kutch is 25,000 of which only 30.6% is exploited, but additional catch is possible only for the 60 80 mm diameter size chanks as the y 81 mm diameter size groups ate already well exploited. There is prospect for increasing the present supplies by introducing SCUBA diving in 20-30 m deep grounds in the Gulf of Mannar and by exploiting the Gulf of Kutch beyond the Intertidal zone.