Today started off with probably the most crushing activity that we had done thus far, marine debris (trash) collection at different sites on the island. I chose to be in what we call the Coral Graveyard, a site that is on the windward side of the island near the open ocean. I expected to find a lot of trash, but what I saw just dumbfounded me. Even on an island 28 miles offshore, there’s still so much plastic, Styrofoam, and other things that accumulate on the shoreline. At the end of our collection time (which was only 30 minutes) we had filled a large trash bag to the brim and still saw so much trash that we didn’t pick up. I even found a hermit crab stuck in a bottle, completely out of its shell. It seemed like it was roasting alive in the bottle. Another group found a hermit crab using a plastic bit as its shell.
To lift spirits, we performed a lionfish (which is an invasive species) dissection after. The dissection was fun and very interesting. My group was able to sex our lionfish (which was an immature male), and cut open its stomach to examine the contents. Fortunately, our lionfish hadn’t had a meal recently. Lionfish are piscivorous and tend to eat small fish, which many herbivorous fish are. Since the lionfish has no predators in these reefs, they can reproduce quickly and thus eat more fish. If the herbivorous fish populations decrease too much, then macroalgae could overtake coral populations and outcompete them. This is why, as a little PSA, it’s important to not release your aquarium fish or other pets into the wild as they can become invasive species and can severely damage an ecosystem.
When life gives you sharks, you swim as fast as you can and take a selfie.
It hit us today that some of the things we did today were among the last things we will do. We gave our last taxonimic briefings and made our last poster. Although it is surely sad, we did contribute to our island in a real way. We picked up trash that has been washed up on Middle Caye, on two sides of the island, one windard and the other leeward. Yesterday, we learned that humans have contributed immensely to the amount and type of debris in the ocean. Depending on the trash (whether it is very or not very transportable, bouyant, and degradible), it can have variable amount of presence on our environment. Plastic like size of a shoebox, for example, can be broken up to millions of smaller pieces, called microplastics. Their degrability is extremely low and can last for thousands of years.
We set out to see what kind of trash we will find on the island and found that the leeward side of the island received more individual pieces of trash and more kinds of trash, including cloth, metal, and paper. However, the windward side received less of the more transportable debris like hard plastic and styrofoam. The transportability differential likely contributes to the leeward side’s receiving more pieces and more kinds of trash because easily transported trash are more likely to end up in areas that do not receive as much wave energy and hence have a higher chance of being stuck there.
After trash collection, we went out to a portion of the reef inside the atoll called “the aquarium” due to its abundance and diversity of marine life. Huge mounds of coral and human size sharks are found here, and when we found nurse sharks, we all kicked our fins as hard as we could toward the shark. Don’t worry, if you are worried, because nurse sharks are not known to be actively aggressive to humans. Their main response to humans is to flee, if they notice close human presence. In other news, we tracked down schools of blue, silver fish as they travel through and sometimes knock themselves into coral. Our excited tracking of the fish caused the fish to swim fastly before us, as if we were herding them. When surprised of our presence, some reacted by fleeing so quickly that they scraped against coral rubble in the process, with their collision audible to us.
Another unexpected encounter was when I observed a large fat parrot fish eat a handful of the wrinkled brown algae. It was so disproportionally big to the fish that I laughed out loud underwater. Fortunately, this reef was covered in this type of brown algae, in addition to a lot of crustose coralline algae and blistered saucer-leaf algae. A lot of y-branched red algae also grew on other types of algae, which often grew on limestone deposited by corals. Life on life on life has been a big theme of this trip and it has really come to a culmination in today’s trip to reefs and channels in the atoll. The geography of the water also lent very well to my practicing diving to the benthos, and I am very happy to say I am not only comfortable in the water, but extremely fond of being in the water, and not to mention swimming with sharks. That is one thing I owe to this place, my new relationship to water, going from barely able to swim to doing all sorts of tricks 15-20 feet underwater all the while avoiding the burning fire coral.
Today was a good day. It was pretty laid back and I really enjoyed the time allotment of activities. After breakfast, we decided to knockout the taxonomic presentations (mollusks and annelids presented by Damien and crustaceans presented by Anna) because we planned for a night snorkel if the wind was not too choppy. Afterwards, we started a new project at 9AM today- we were asked to test host preference of Christmas tree worms in relation to certain species of coral. Figuring out the logistics of the operation took some time, and it also involved going to a back reef through “the mangroves of death” as Scott and Adrienne refer to them- this name was given primarily because the mangroves are known to be a wet habitat with roots waiting to trip someone over and mosquitos by the millions. Today, we were lucky though; there were hardly any mosquitos (first time ever according to Scott and Adrienne) and the roots were visible and dodgeable.
In the water, we collected Christmas tree worm data- in the middle of data collection, the water safety officer Adolpho yelled at me across the ocean telling me he found 2 huge Great Barracuda (Sphyraena barracuda). Unfortunately, I did not make it to Adolpho on time to see the barracuda. No piscivorous fish were seen by me on the back reef. Data collection finished around 11:40AM and after lunch, we performed data analysis of the Christmas tree worm data and then Isaac presented on marine debris. This discussion led us to the next project of the day- quantifying marine debris on Middle Caye.
Christmas tree worm on a Pseudodiploria coral
The main goal was to see which type of debris (plastic, metal, fabric, rubber, etc.) is the most abundant on the island. After 30 minutes of trash collecting, the group ended up with 40 kg of debris! This project really put the amount of debris in the world into perspective. Controlling how much trash someone produces and proper waste disposal and recycling and creating biodegradable materials and so many more aspects of debris are such complicated topics to discuss, but it’s a discussion that needs to be had in order to preserve the world that we live in today.
We did a large variety of things today, although none of them was as physically draining as our boat day or really any of our snorkeling days.
In the morning we did a beach cleanup on the windward side of the island and assessed what kind of trash is most likely to make it onto the beach. Things I learned: Styrofoam is the worst, don’t give children toys, and the ocean is full of trash even in pristine environments like this one.
In the afternoon we went to the back reef that is through the mangroves of death on the other side of the island. The mangroves weren’t as buggy as they usually are so we got lucky. We measured live coral coverage of one coral colony on the back reef and then swum around and looked at things.
Adrienne showed us black band disease and some baby Acropora cervicornis. I also saw a few flamingo tongues and I picked one up and saw its mantle retract to reveal the white shell underneath.
At night we did a night snorkel. I sadly missed seeing the Caribbean reef squid, but I did get to see a bunch of very odd fish. Mostly it was just difficult to stay out of everyone’s way with all the flippers and wave energy.