Comparação do uso de três malhas diferentes de crivo no estudo da macrofauna bentónica no saco da Inhaca

Abstract

Simultaneous analysis of the effect of sieve mesh size and the study of benthic macrofauna was investigated in Saco, Inhaca Island, from 6 to 9 January 1996. 22 samples were sieved through 2,000 mm, 1,000 mm and 0.500 mm mesh sieves, superimposed one on top of the other. Data were analyzed as number of species, number of individuals, biomass and time spent throughout the study. A total of 760 individuals representing 69 species were found. Polychaetes dominated the benthic macrofauna in terms of number of individuals and biomass. organic biomass registered was 4.9354 gr AFDW.m2. The average time spent ranged from 4.53 to 195.10 minutes. The number of species, the number of individuals and the time spent increased with the use of a smaller mesh screen (0,500 mm). Species abundances were underestimated using 2000 mm and 1000 mm mesh sieves compared to 0.500 mm mesh sieve. Macrofauna samples screened through 0.500 mm meshes required significantly more time to separate the organisms than 1000 mm and 2000 mm samples. Organic biomass did not produce significant differences between the three different types of sieves, with larger organisms contributing with greater biomass in 2,000mm mesh sieves.