Abstract:

The double barrier reef in the Visayan seas is one of the most productive but heavily exploited fishing grounds in the Philippines. Signs of over-exploitation and depletion of marine resources in the area have been reported in the literature. Turrid snails, although not harvested for food, are becoming threatened due to the increasing demands for ornamental shells and pharmaceutical research on the promising bioactive compounds found in their venoms. In this study, the turrid population was assessed using compressor diving. Overall, a total of 61 turrid species were recorded from the four collection trips (from 2008 to 2010), with an average of 19% new species added to the existing species-list in every collection trip. Family Turridae has the highest contribution of 46% among the six turrid families recorded. Average turrid density extrapolated from 2 m by 50 m belt transect method was 217 individuals^.ha^-1. Catch per unit effort was about 12 individuals^.h diving^-1.fisher^-1. Repeated collection in the same sites resulted in declining catch rates. In addition, significant shell length reduction, particularly of Crassispiracerithina(Anton 1838) between collection trips, was observed, which could be attributed to the unsustainable harvesting activities of the organism. The results of our study serve as important baseline information of turrid populations in the double barrier reef and provide valuable fisheries management insights for the sustainability of these valuable resources.

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Date 2014/03/31

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