Aquarius really is an amazing tool for underwater science. Today I managed to spend close to 10 hours in the water. We started with a 5-1/2 dive in the morning, then had a 4 hour break for lunch and a nap, and made it back out for 3 hours in the evening, and when we got back from that I was able to spend time on the hookah line at storage depth running experiments out on the grating.

We are seeing some very interesting things here, and getting to know an area of the reef quite well. Having this much time on the reef, you start to see not just a lot of fish, but in fact some of the same fish over again. It is quite noticeable just how territorial many of the fish are. Another fish observation that is, in fact, somewhat troubling, is that there really seems to be an unusual number of fish with visible injuries, and external signs of disease. We even found a dead parrot fish on the reef, and a dead hogfish under the Habitat. What is strange about this is that it really is rare to see dead or injured fish around, generally they just don’t last long before getting eaten. Certainly one can’t draw conclusions about the function of an ecosystem from a few observations, but it has occurred to me several times that we really don’t see very many large predators here. Sure we see predatory fish, but large sharks, full grown mature groupers, snappers, the long-lived fish that can grow to large sizes but are also fished extremely heavily in this area are extremely rare on the reefs at this point. I am starting to wonder whether we are seeing an effect of the lack of large predators when we see injured and diseased small and medium size fish on the reef.