The coral reef ecological surveys are being led by Tim McClanahan and Nyawira Muthiga. These surveys are designed to inform us about the abundance of the coral, algae, and fish communities on the reefs at each of our coral sites (Kongowea, Mkwiro, Vamizi and Pemba). The fish community is surveyed, using two methods along the same 100m long transects. The first data gathered is an estimate of the biomass of fish that are present on the reef. This is done along two 100m transects at each site, and all fish within 5 meters of the transect line are identified to family, and their size estimated to the nearest 10cm. We can then use published data on the relationship between fish weight and fish length to calculate how much fish biomass is present on the reef. The second type of data gathered, is the diversity of fish on the reef, collected by counting the number of fish present within 11 of the most important fish families on coral reefs present along each transect for each species. Coral abundance is collected using line intercept transects, where a 10m long tape is laid over the reef, and the amount of each type of coral, algae, or other substrate cover is measured. This is repeated 6-9 times to give an average amount of coral and algae cover on each reef.
This data underpins much of the way that the ecological aspect of the linked coral reef socioecological system interacts with the social side of the SPACES project. It provides us with a measure of the stocks of many of the ecosystem service chains, and helps us interpret how human activity has impacted on ecosystem processes. From a fisheries perspective, it is a second way, along with the fish catch surveys, to assess the status and sustainability of local fisheries. In addition, these surveys also provide many of the basic parameters that will be used to set up the Ecopath and Ecosim models.