Today is our last day on the island, since we leave at 6 am tomorrow in order to catch our plane back to the US. We had to squeeze in our last dive before noon because you should always leave 24 hours in between diving and flying. The excess nitrogen that we inhale from our SCUBA tanks needs time to get out of our systems.
The final dives were on a spot just outside the atoll edge. Even though the wind has been consistently strong, this reef area is close enough to the atoll that the waves aren’t too bad. However, since the small boat can’t anchor, we have to get ready to jump in the water the minute the captain stops. Otherwise the boat starts drifting, and the divers entering the water might get separated. We’ve all become pros at gearing up quickly!
The final dive was split into two. The big boat we usually use had to make a run into the mainland this morning, so we used one of the smaller boats instead. Unfortunately the smaller boats can only fit about 7 divers, instead of all 14 of us. So we split up, with the fish survey team going first, and the two benthic survey teams going second. As usual, the dive was gorgeous! Lots of coral that’s looking very familiar by now and fishes we’re all well acquainted
with. The ‘nauts are getting so familiar with the Belizean reefs that they can now spot unusual fishes and corals.
After the dives, we rinsed our dive gear for the first time all week. Let me tell you, a week of sun, salt water, and high humidity leads to some stinky gear. The rinse didn’t even begin to get rid of the smell. I feel bad for the customs agent who happens to open my gear bag… And with the diving for the trip over, it was time to finish up the science portion.
All week long, the ‘nauts have been collecting data on underwater paper during their dives. They’ve been entering in the data on the computer so we’ll have a record of everything they did. They also learned the importance of quickly reviewing their data – oftentimes the little marks we make during the survey to remind ourselves of something become cryptic notations after a few days. Looking over the datasheets the same day allows them to fill in any blank spots and make those little marks more understandable. The final count for the week was 18 fish surveys, 10 Point Count transects, and 5 Coral transects. That’s an impressive amount of data, and even more impressive is how knowledgeable all the kids are about their specific survey now.
Early in the week, I asked the kids to think up a small science project, collect data throughout the week (either independent from the surveys, or using them to answer a question), and give a short presentation at the end of the week. They were given free range to pick a project, and they came up with a diverse set. The presentations evolved from a quick science meeting to a large gathering of many of the research station residents and visiting scientists, and the kids definitely showed their skills at public speaking. I know I would have been nervous!
Brooke spent the week studying different sediment samples from around the island and at several reef sites. She taught us about how sediment is formed, what causes the grains to be different sizes, what small animals live in the sediment she collected, and how sediments can affect coral reefs. One of the visiting scientists will soon be
studying sediments, and Brooke was able to connect her project with the scientist’s future work.
Morgan, who spent the week focusing on fish counts and identification, chose to focus on juvenile fish distribution. Fish can be very tricky animals to identify, since their juvenile, initial and terminal phases can all look very different.
Morgan was able to identify lots of juvenile fishes, and she compared their depth distribution at our dive sites. She found that more baby fish hang out in the shallow waters, to stay safe from the larger predators. However, some young fish were found at every depth.
Connor W. and Colin also observed fishes, but they decided to focus on a single patch reef. This reef is a favorite of the ‘nauts since it’s within snorkeling distance of the dock. Connor and Colin snorkeled out to the reef at different times of the day (morning, afternoon, evening, and night) and counted fishes. They found that more fish were out during the day, and that there were a lot of several types of fish. However, one of the more prevalent reef fish, the blue chromis, was fairly rare. Given more time, the guys wanted to figure out why that is!
Madison was able to take advantage of some of the science equipment we brought along. She worked with our intrepid Science Officer, Keith Kolasa, to measure temperature, dissolved oxygen concentration and pH
of the waters around the island throughout the day and night. Dissolved oxygen can help us find out how much photosynthesis is happening, since that process produces oxygen. In low oxygen waters, very few animals can survive. Maddie found that there were some clear patterns in the temperature (colder at night), and dissolved oxygen
(lower at night, since photosynthesis needs light to occur). However, one of her sites had dissolved oxygen was consistently the opposite from all the rest of the sites. No one can offer an explanation why!
And finally, our coral experts gave us a talk on coral distribution at different depths. Conner and Danny observed the different species of coral at the three depths we dove, looking at the abundance and shapes of the coral. They found that some species have definite depth preferences. Other corals can live at all the depths we visited, but they have very different shapes: the deeper the coral was, the flatter it looked. This is so the coral can catch as much light filtering down from the surface as possible. In shallow waters, there’s so much light that corals can form more upright structures.
The experiments the ‘nauts thought up and performed were amazing, and the station crew was extremely impressed. I’m so proud of the kids for putting in so much time learning and working this week. They have improved their dives skills, become experts at their various survey methods, and put together science projects from start to finish in a
week’s time. And the whole time, they’ve had a smile on their faces!
Congrats for all you have accomplished, Belize Crew!
