We have been talking a lot about the importance of fish pee for tropical coastal ecosystems over the past few years. Most of this research has focused on the importance of fish pee for seagrasses and algae. We are now extending these efforts to understand its importance for coral growth and development.
A recent study of ours provides compelling evidence that fish communities pee nutrients at optimal amounts of nitrogen (N) relative to phosphorus (P) for coral development. In the same way that growing the best tomatoes in your garden requires a fertilizer that has just the right amount of N relative to P, we believe that fish pee does exactly this for coral. In our experiment we have suspended coral above our artificial reefs (from a “coral tree” – see video) to test how coral grow under various nutrient conditions. We change the relative amounts of nutrients being supplied to the coral by manipulating the reefs such that they have high and low densities of fish (high densities being optimal nutrient conditions), but also by adding fertilizer at a very different ratio of N and P, that simulates human sewage (which we believe to be bad for coral). This project is in collaboration with Dustin Kemp (University of Georgia) and made possible by the dedication of a local Frenchmen, Richard Appaldo. We will be pulling the coral to run tests on their growth and fitness in the spring.