Reef Cruise

10 May
Cairns
Rainy, Windy, and Humid
(Partly sunny on the reef)

The 8th was a free day during the day, with a visit to Reef Teach in the evening. Reef Teach is an organization devoted to educating people about the Great Barrier Reef and the wildlife that lives on it. Our visit consists of a two-hour slideshow that goes over the animals we will see on our visit, the types of coral, and the threats to the Reef. Though a two-hour slide lecture sounds dull, the students always have enjoyed it, and put what they learn to good use the next day on the reef cruise.

There are thousands of types of fish on the Reef, and there's no way we could learn them all -- in all likelihood, the experts do not know them all. Reef Teach sets a more modest goal of getting to recognize the general categories of fish we'd be likely to see: the wrasses, the damselfish, the angelfish, the surgeons, the butterfly fish, the triggerfish, and the sharks. They also showed us other animals we might see: turtles, octopuses, urchins, nudibranches and squid.

And, of course, there's the coral itself. It is animal, though it does behave like a plant in some ways. The coral begin as a small larva that attaches itself to a bit of rock and creates a small protective shell. It periodically leaves its old shell and creates a new one atop the old; hence, the coral colony grows in size at a rate of about 1 cm per year. So, when one sees a boulder coral that is 3 m across, that boulder coral is about 300 years old. And there are boulders much large than that. There are also coral colonies that take the shape of elkhorns, fingers, plates, and other shapes and configurations.

Coral have two sources of nourishment. They have small tentacles that wave in the current, catching what they can. That is usually not enough, so coral will ingest a small amount of algae, which embeds in the tissues of the coral and begin photosynthesis. This is the reason that coral have such beautiful colors.

When the waters get too warm, the algae produce toxins along with the nutrients, and so the coral expel the algae, causing the coral to appear white and colorless. This coral bleaching is very dangerous for the coral, since they lose an important source of nutrition and are thus weakened. As ocean temperatures continue to rise, the Great Barrier Reef, like many other coral reef systems in the world, will be severely stressed.

Coral mate once a year, in a process that that biologists figured out only a few decades ago. A few days after the October full moon, the tides and the temperatures will be exactly right for all the corals -- all of them -- to release sperm and egg into the water, forming a huge slick on the waters above the reef. Much of this slick is gobbled up by fish and some waterbirds, but the eggs that get fertilized will produce larvae that begin the cycle again.

Our reef trip was the next day, Saturday the 9th. The poor weather was in full force as we left the slip, with sprinkles and wind, but a brief break in the clouds produced another rainbow similar to the one we saw at Fraser Island. Nevertheless, the water was choppy, and many people on board got sick. I don't think any students did, though some felt queasy; I did, too. But since our first stop at Michaelmas Cay was on its north side, we were in gentler water, and we did get a bit of sun while we were snorkeling.

I don't think I'm very good in the water. The instructors on the boat give us all these signals and tell us to pay attention in case they call for us to move this way or that. Once I get in the water, I am pretty much disoriented, and can focus on nothing other than the stuff right around me. People bump into me, the current pushes me about. I do enjoy watching the fish, and think I got a couple of passable shots. But when I hear about the things that others saw, I think that I must be doing something wrong.

But I did get a nice photo of a giant clam, so I'm happy about that. I bought this plastic bag that seals completely against the water, so that I can put my digital camera in it and essentially have an underwater digital camera. Needless to say, I did not put the Canon Rebel XS in; I have an old Kodak 7300 that did quite well. The bag is supposed to be good to about 4 meters, but since I stay on the surface, the bag never gets more than an arm's length under.

The students saw so much! Sea turtles, reef sharks, lion fish, sea cucumbers, and many other things. Of the 14, 9 went on dives, and getting lower in the water means seeing more. I do not know how many had underwater cameras, but if we get a few photos, that will be great.
Being on the boat is also a great time to meet other people. I struck up a conversation with a Sydney couple who had taken advantage of some weekend fare discounts from Qantas. The wife had been in Cairns many years ago as a child, but the tropics were all new to her husband. The students found many new friends among the other passengers and the crew -- I'm told that the male divers were very cute. One of the crew told a ribald joke to a group of the students, and so they demanded a similar joke from me. If you don't mind, I will not share it with you -- and even if you do mind ...

The ride back was better than the one out, though it was still a bit rocky. I find that a little TravelCalm plus staying outside on the deck keeps the seasickness at bay, though I must admit that I get a little queasy when it's choppy. But the weather could not dampen the students' spirits; they clearly had a great time and learned a lot about the Reef.

It is now the evening of Mother's day here, though it's early Sunday morning in the USA too early for a phone call. I'll call my mother early tomorrow morning. Then it's off to Kuranda for a look at the Butterfly Garden and Rainforest Station.