Coral reefs are one of the most fragile, biologically complex, and diverse marine ecosystems on Earth. This ecosystem is one of the fascinating paradoxes of the biosphere: how do clear, and thus nutrient-poor, waters support such prolific and productive communities?

Part of the answer lies within the tissues of the corals themselves. Symbiotic cells of algae known as zooxanthellae carry out photosynthesis using the metabolic wastes of the coral thereby producing food for themselves, for their corals, hosts, and even for other members of the reef community. This symbiotic process allows organisms in the reef community to use sparse nutrient resources efficiently.

Unfortunately for coral reefs, however, a variety of human activities are causing worldwide degradation of shallow marine habitats by adding nutrients to the water. Agriculture, slash-and-burn land clearing, sewage disposal and manufacturing that creates waste by-products all increase nutrient loads in these waters. Typical symptoms of reef decline are destabilized herbivore populations and an increasing abundance of algae and filter-feeding animals. Declines in reef communities are consistent with observations that nutrient input is increasing in direct proportion to growing human populations, thereby threatening reef communities sensitive to subtle changes in nutrient input to their waters.

I should say one more thing about theory. It’s a … It’s great to discover theory, but there .. the .. you have to lose a lot, and you may have noticed, or maybe you didn’t, how much you lose.

Partly you don’t notice it much because here at the university everybody’s dedicated to theory, and what is … what’s left out is ,uh, perception cause you-you use your mind not your eyes. Skill-you’re not supposed to have to have any particular, uh, sort of bodily kind of skills; there’s a kind of mental thing, but I’m not … let’s not call that skill. I’m just calling skill the way you cope with everyday stuff that you use and so forth. Intuition, it’s not fair to have intuition, I mean you can have intuition, but it’s not … it’s not theory, it’s not something that everybody has to believe until you can put it into language and argue for it. Gets rid of emotions, the body, tradition.