August 31, 2011

Why does Reef Check California use a uniform point contact method to characterize the reef habitat?

Many of the invertebrates that cover the primary substrate of the reef, such as the strawberry anemones, barnacles and algae in this picture are difficult to count, therefore RCCA uses the UPC method to survey them

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Reef Check California – Why do we use a uniform point contact method to characterize the reef habitat?

When Reef Check California performs its surveys, we characterize the physical substrate and structure of the reef as well as the community of reef attached organisms. We do this in addition to counting and sizing the mobile organisms on the reef. Since many of the organisms attached to the reef are encrusting and colonial, it would be impossible to distinguish individuals and count the number of organisms along the transect line. Therefore, we use a different survey method called Uniform Point Contact (UPC) transects. Instead of counting, we record the substrate and attached organisms under a point every meter along the transect and estimate the reef relief within a half square meter rectangular box at each point. This generates thirty data points for substrate, relief, and attached organism type respectively, along each transect. This approach lets us quantify the substrate and relief of the reef and generate a ‘photo style’ representation of the attached organisms along the transects. Since these UPC transects are performed in the same locations as the fish and invertebrate transects, this information can be used to interpret the distribution and abundance of the mobile organisms counted on the fish and invertebrate transects.