Keragaman Alga Merah (Rhodophyta) di Pantai Gamo Desa Sisarahili Gamo Kota Gunungsitoli Nias

Abstract

An experiment in Gamo Seashore, Sisarahili Gamo Village Gunungsitoli City Nias has been conducted to know red algae diversity, physical and chemical parameters of water in relation to the diversity of red algae. Red algae diversity assessed through “ line transect method” at three locations where twenty five plots (1 x 1 m) are positioned. All plots sampled during low tide. Six genera of red algae classified into five ordos and six families are recorded from the study area. The highest of species density, relative density and attendant frequency observed on Actinotrichia fragilis at the third location with the number 17,6 ind/m2, 87,30% and 100 %, respectively and the lowest observed on both Eucheuma sp. and Gracilaria salicornia at the first location with the number 0,16 ind/m2, 1,52 % and 20 %, respectively. For the diversity index, the highest is recorded from the first location (0,98), while the lowest is found on the third location (0,52). The highest of equitability index was 0,61 at the first location and the lowest was 0,32 at the third location. Chemical and physical parameters (salinity, light penetration and light intensity) are evidently correlated with the red algae diversity.