A study on photosynthesis and respiration of corals in Terengganu waters

Abstract

In this study, the photosynthesis and respiration of hermatypic corals that symbiosis with zooxanthellae were examined through the determination of photosynthetic and respiration rates based on dissolved oxygen and total carbon dioxide determination. Comparisons were made between four species of corals namely Acropora famosa, Pocillopora damicronis, Fungai repanda and Hydnopora grandis. The experiment were conducted in-situ under light and dark condition. Dissolved oxygen and total carbon dioxide concentration were measured after 9 hour of exposure to calculate the gross photosynthetic and net respiration rates throughout the day (morning, afternoon and evening). Photosynthetic rates of F repanda based on dissolved oxygen produced during the light reaction was highest in morning (5.1274 ± 0.4030 xl0- 9 1 02 mg L- 1 1 ceU- h- and 13.2649 ± 1.0971 xl0- 3 1 02 mg L- 2 cm- h- 1 ) compared to the other species of corals. Conversely A. famosa (Redand Island) had the highest net respiration rate in the evening based on dissolved oxygen consumed which were 1.7688 ± 0.9845 02 xl0- 9 1 1 mg L- 1 ceU- h- and 2.2877 ± 1.273 xl0- 3 1 2 02 mg L- cm- h- 1 . However, the highest gross photosynthetic and net respiration rates based on total carbon dioxide alteration were A. famosa (Lang Tengah Island) in the afternoon and H grandis in the evening respectively.