analysis Agar production by macroalga Gracilariaopsis persica in pond the Qeshm Island

Production of agar from marine macroalga Gracilaria, makes it important for local enterprise of coastal communities. The aim of this study is to gather basic technical data for the development of G. opsis persica mariculture in Persian Gulf of Iran. Monoline and net methods were applied to determine biomass and the agar productivity. Biological parameters of chlorophyll, thallus length, position along the thallus, and color; and environmental parameters of temperature, pH, salinity, TDS and TSS were measured during cultivation. The changes of NO2-, NO3-, PO43- and SiO42- ions were monitored daily. STATISTICA 10 Software was used for statistical analyze of data. The experiments were performed from May through June in Qeshm Island. Biomass values increased during experiment period and reached to maximum 5890-g Fw m-1 (30th day) and 5300-g Fw m-1 (36th day) in monoline and net methods, respectively. Mean growth rate (GR) and relative growth rate (RGR) for the mono and net methods were 4.4-% d-1, (4.0 ± 0.30) and 4.3-% d-1, (3.0 ± 0.25), respectively. Positive correlations were found between biomass (r = 0.59; p < 0.001) and GR (r = 0.61; p < 0.001). 1148 During the study period, temperature was changed in the range of 25.35 - 30.75°C (Mean: 28.03 ± 1.23), pH in the range of 7.9 - 8.4 (Mean: 8.2 ± 1.14), and salinity from 41.2 - 49.75 (Mean: 46.13 ± 2.11) PSU. Extracted agar yield in the cultivation period ranged from 40.4 to 15-%. These results demonstrated the great potential of G. opsis persica for mariculture system and its economic potential use for agar production by Persian Gulf coastal communities.

Keywords:

G. opsis persica , macroalgae mariculture , agar production , monoline technique , net technique