UCB Moorea Class: Biology and Geomorphology of Tropical Islands

Aquaculture has many effects on the surrounding landscape. In Mo’orea, the only aquaculture operation is a shrimp farm in Opunohu Bay. To test the effect of shrimp farm runoff into the bay, a macroalgae field survey was conducted at different distances from the Opunohu River, where the effluent outlets. Algae cover was used to indicate nutrient concentration. I found that there is no significant relationship between distance from the shrimp farm outlet and algae cover. The red algae Acanthophora spicifera is a cultivated human food source and also a highly invasive species in Hawaii. It is found in Opunohu Bay. To test the effect of shrimp farm runoff on the growth rate of A. spicifera, I grew the algae in a laboratory setting in shrimp farm water and in ocean water. I found there to be no significant difference between the growth rates in the two water mediums. Additionally, I found that algae cover increases as distance from shore increases, and that algae prefers rock substrate over sand substrate.