Biomass estimation of seaweeds in the intertidal waters of the Oman Sea along the coasts of Sistan-o-Baluchistan Province

Abstract

Sampling and determination of seaweed biomass was carried out in the Oman Sea coasts along the intertidal waters of Sistan &Baluchistan province stretching 300Km from Guater area to Jood from October 2001 to September 2002. The regions covered included Guater, Passabandar, Beris, Kachoo, Ramin, Chabahar, Pozm, Gurdim, Tang, and Jood as sampling stations from east to west. The intertidal zone was determined by measuring and recording of geographical positions by GPS. Fifteen transects were aligned randomly each month with equal distance to the coast. All sampling attempts were made by applying quadrats 50t50cm in dimension. The samples were transferred to the lab and the weight of each species was measured after being cleaned, and identified. The biomass of each species per unit area and in the total area was obtained after determining the average weight of species. During the research, 69 species were collected, of which, 16 species were green algae, 18 species were brown algae and 35 species were red algae. There were some important families including green algae (Ulvaceae and Caulerpaceae), brown algae (Sargassaceae and Dictyotaceae) and red algae (Gracilariaceae, Gelidiaceae and Hypneaceae). Wet biomass of seaweeds in the total area of Sistan &Baluchestan coasts was 10286340.3 kg of which 2645192.1kg (25.7%) were green algae, 2955963.9kg (28.7%) were brown algae and 4685184.2 kg (45.5%) were red algae. The estimated monthly average was 264522.3, 295327.9 and 467089.7Kg for green, brown and red algae respectively. The maximum biomass was 15.4kg/m super(2) seen in Chabahar and the minimum biomass was 4.9kg/m super(2) obtained in Pozm.