An investigation of effects of varying densities of red algae (Gracilaria corticata) on Algal growth parameters in fiber glass culture tanks

Possible effects of varying densities of cultured red algae Gracilaria corticata on algal growth parameters were studied using three density treatments 500, 1000 and 20002 g/m2 in nine culture tanks. We conducted the experiment in April to June 2002 and carried out daily tests of salinity, pH and temperature which were in the range 37-40ppm. 0.5-8.04 and 23-32 degrees centigrade. Epiphytes such as Nitzschia, Navicula and Hypnea and grazers such as Amphipoda, Isopoda and Nereis were detected in the tanks during the experiment.
We observed the highest daily growth and net production in treatment one (500g/m2) to be 3.74±0.31 and 38.3±5.4 respectively and the lowest measurements were seen in treatment three (2000 g/m2) recorded as 3.74±0.31 and 38.3±5.4 respectively. Daily growth measurements were significantly different among treatments (P<0.05). Net production as significantly different between treatment one as a group and other treatments (P 0.05). This was not the case between treatments and three.