One of the less considered aspects of coral reef ecosystem services are the services that are provided by the reef structural framework itself. These include providing a habitat and shelter for juvenile fishes, providing coastal protection from storms including calm, navigable waters inside the reefs that allow fishing almost year round, and through erosion, providing much of the sand that makes up the beaches used for tourism, recreation and other cultural events. As part of the SPACES project, Fraser Januchowski-Hartley is using an underwater census based approach, building on the ReefBudget work conducted by Chris Perry in the Caribbean. The reef framework is a product of the growth of corals, and the erosion of the reef substrate by parrotfish, urchins and other organisms. The Reefbudget approach is a way to work out if the reef is net accretional (growing) or erosional. To do this, we accurately measure how much of each genera and morphology of coral (for example, how much branching Acropora) there is within multiple 10m transects, and combine data these with published growth rates in order to estimate how much carbonate skeleton is being laid down by corals and coralline algae each year. We also count the number, type and size of the parrotfishes and urchins on each reef, and use these data in combination with bite size and feeding rates to work out how much of the reef framework is eroded each year. This also gives us an estimate of how much sand is being on reefs. Full details of the ReefBudget methodology and associated datasheets and spreadsheets can be downloaded here.
Like the coral reef ecological surveys, the carbonate budget surveys allow us to fill in many of the stock components of the ecosystem service chains, but they also allow us to calculate some of the flows and estimate the goods, particularly in the chains that describe the benefits from beaches and coastal protection (such as tourism and sense of place services) and can control the human inputs to some chains. The carbonate budget data is also going to contribute towards a system-dynamics model, which will be able to take inputs from the Ecopath and Ecosim models, and will produce outputs that can be fitted to the toy models that will be used in the stakeholder workshops.