Today we went out on the boat and dove into the atoll, snorkeling in the real Caribbean ocean. After about three hours of practicing with our methodology, counting squares on the quadrat to determine proportions, we all piled into the boat and sailed away from our little island. About ten minutes away is another island, surrounded by patch reefs. We all dove in, holding our equipment, and were sent to explore the reef and collect data.
Diving from the boat into the water was one of the prettiest parts for me. As soon as you hit the water, you sink a few feet and all around is pure blue ocean. Sometimes you can see the bottom, twenty or thirty feet below you, and you feel suspended in mid-air, surrounded by nothing by cerulean water. This is the thermocline, where the passive margin that provides a shallow seafloor for the reef ecosystem drops off and is replaced by open ocean.
We collected data at two areas for comparison. The first one was distinctively shallower than the second. I was almost touching the corals right beneath me, and could stand up in the sand with half my body out. The second one was a lot deeper, the corals about seven feet down. This was a lot easier of an area to snorkel, though the data collection was more difficult because we had to dive down to pick up our quadrats and transect tape. I attempted to dive down and was not particularly successful.
I didn’t take note of any green algae today. I saw a lot of what I thought might have been green algae, seaweed-like organisms anchored to the bottom of the sea, and I saw some non-calcified algae that clung to corals or rocks. But I didn’t identify any of them or take a very good, mainly because I was trying to get used to snorkeling. Tomorrow I’ll do a more thorough search for my taxon.