Soft-Bottom Macrofauna of Four River Mouths in Roxas, Palawan

Abstract

Surveys were carried out in four river mouths along the coastal area of Green Island Bay in October 2004, March, June and September 2005. Two replicate samples were obtained by using 0.028 m2 modified Petersen grab and were washed through a sieve of 0.5 mm mesh. Benthic animals collected were classified into major taxa. The density ranged from 50 to 3178 individuals/m2 for the whole sampling stations. The densest station was recorded in Caramay River mouth and the least in Magara/Rizal River mouth. Benthic macrofauna were most abundant in October 2004 and least in June 2005. Polychaetes were the densest, widely distributed and the most consistent organisms during the entire period of investigation. Crustaceans show seasonal abundance in Caramay in October 2004 and absent in Magara/Rizal for the entire period. Gastropods comprised the most abundant taxa in Tinitian, Roxas.