Underwater Explorations

The archipelago of Bocas del Toro is a biodiversity hotspot with both lowland tropical rain forest and coral reefs, which are the most biodiverse terrestrial and marine ecosystems on earth, respectively. For this reason, I was thrilled to have the opportunity to study in this location. I had never visited a coral reef, not to mention snorkeled or observed any marine ecosystem firsthand, and coming primarily from an entomological background, I really lacked knowledge in fish biology and other invertebrate life, most of which occurs in the ocean. Because of this, everything I experienced both at the coral reefs and out of the water in lecture was new to me. Before speaking about the coral reefs as I experienced them, it is important for me to emphasize the vulnerability of the both the forest and marine ecosystems. Islands consist of extremely diverse habitats packed with high biodiversity and intricate interspecific interactions that maintain balance, making them both unique and fragile – perturbations in ecosystems (including human-induced ones) such as decline/loss of certain species can have profound cascading effects if there is no other species to fill in their functional role. Island species tend to be distinct from mainland ones since geographical isolation has allowed for divergence as well as the accumulation of adaptations specific to the island dynamics. One example that was evident in Bocas del Toro was the yellow morph of the poison dart frog Oophaga pumilio, most famous for its red and blue (strawberry/blue jeans) morph that can be found in areas such as La Selva. Since each island in Bocas del Toro has been isolated for thousands of years, there is a distinct color morph found on each of them.

            Because I had never snorkeled before, it was exhilarating to be able to see the expansive coral reefs through almost crystal clear water just a few meters below me. Prior to this moment, I had considered myself as a very terrestrial-oriented person, but watching all the fish and invertebrates at work made me realize the complexity and richness of life that was occurring in this foreign world. It was as if I was swimming in an aquarium, except with seafloor activity packed with unexpected creatures: sea urchins pulsated as I approached, starfish were plastered against the sand, and coral reefs, sea grass, and sponges of every color imaginable were present. I saw brain corals half the size of a small car, teeming with tropical fish of assorted and attractive coloring. Many moments left lasting impacts for me, and here I will share just a few of them. As I entered the waters connecting the mangrove forest with the coral reefs, I saw a large cloud of dust as if a large animal was kicking up sand. As I neared, a large stingray exited the cloudy waters and rested on the sea floor under me. I could see the edges of its body fluctuating as it moved and the gills near its eyes open and close every second or so. Its large barbed tail was both impressive and mildly alarming since it measured a little under a meter. When my friend, Sequoia, moved around to the backside of the ray I was able to get a better idea of its size, and I felt honored that this sea animal would allow us humans as poorly-equipped aquatic beings to observe it. One of my goals of the trip was to find a cephalopod, so I was very excited to find several squid in deeper waters. I am not a very good snorkeler, so diving down to get a good look at the squid took a lot of effort on my part, but I ended up diving down dozens of times just to be able to be in closer proximity to these remarkable beings. Cephalopods intrigue me since such a developed nervous system and intelligence has evolved in a taxon that fundamentally differs in structure to that of humans and other vertebrates.

            Another time I was following a large school of fish, each about 1/5 of a meter in length. Since these fish were larger than fish in other schools I had been surrounded by, I briefly thought: how cool would that be if I saw a predator nearby? Almost instantaneously, I decided to look in front of me in the water, since I had been looking down, and a couple of meters ahead floated a large barracuda. I could not believe how big it was at first, but after moving my head and realizing my depth perception was accurate, I understood that I was looking at a 4.5-5 foot animal, almost as long as I am tall. Although the barracuda held a stern and focused expression, it didn’t seem to mind my presence or perceive me as a threat. After a couple of seconds it slowly swam away from me, and as I followed, it casually slipped into the darkness. Like in most of my experience underwater, I felt such a privilege to be able to see life that lives in a medium that is not my element.

Christian Perez

Harvard University

Just Keep Swimming

Growing up on Long Island Sound, I always loved hearing the sounds of the ocean, swimming with the fish, and traveling along the water on a boat. I knew that I would not get to spend a lot of time in the water this semester, but by the time it was finally the day to go to Panama and begin a week of underwater field work I could not wait.

            I had previously done work in lakes and streams throughout Vermont with some of my classes and had learned about marine systems, but actually being able to learn about the ocean by snorkeling in the clear, warm water of the Caribbean with colorful fish, crabs, and squids all around me was almost too good to be true.

            For our faculty led project with Mark Ladd, we looked at whether chemical or physical aspects of algae deterred herbivores. To do this we built feeding assays that we placed along the reef and waited for the fish to eat them so we could measure which groups of algae had the most herbivory. While we were observing and setting up the experiment we had to be sure not to harm the coral or sponges by stepping on them, while also avoiding stepping on the urchins as they would harm us. Being able to do research on the coral reef was an amazing experience as it is a very vulnerable ecosystem that few people get to experience.

            While we left the fish alone to nibble at the algae, we were able to snorkel in the surrounding area and see the marine life. While we have been able to see and experience many different ecosystems in Costa Rica, this one really felt like another world. The mask and snorkel over my face and the fins on my feet were a constant reminder that I was not well adapted to live in the water like the organisms I saw below me. The equipment necessary just to survive underwater, let alone to conduct research, adds an extra level of excitement to studying coral reefs and other aquatic systems.

            When it was time to measure how much algae the fish had eaten in each treatment, we swam over to collect our assays, and to our surprise, no algae had been eaten. After a second day of no herbivory, we had a discussion to hypothesize why this might be happening. While it may seem like having no data is boring or disappointing, it is actually the opposite because it means there are more questions you need to ask and test and therefore you get to spend more time observing the reef. We came up with some ideas about how the interactions within the reef may not have been exactly like what we thought, such as the importance of the urchins as herbivores in the system or the number of fish in the area feeding at that time of day. After some more discussion however, Mark pointed out that a likely reason the experiment didn’t work was that we had sunscreen on our hands when we handled the algae, therefore it was our method that deterred herbivores. A future study will have to be done that involves a method of building the assays with less possibility of sunscreen affecting the algae.

            After a week of observing life in the ocean and learning about the challenges of conducting research underwater, I could definitely see myself doing more marine ecology in the future.

Kali McGown

Middlebury College

Not Just Another Stamp in My Passport

This trip has been full of firsts for me: my first time leaving the country, my first time on an airplane, my first time speaking Spanish, and my first stamp on my first passport. Going to Panama I received another stamp on my passport, but I also gained more knowledge. Our time in Panama is spent mostly in the water, and it happens to be my first time snorkeling and my first time seeing a reef. For this site we had to complete a field notebook, an activity that involves recording what we see for thirty minutes. Naturally, I had to complete my notebook in the water.

            The Caribbean Sea is full of more creatures than anyone could imagine. We saw at least two different types of sea urchins, various types of coral, algae, sponges, starfish, and fish. My first time snorkeling I was so excited seeing my first ever starfish. But, I really learned to appreciate the sea water and all it holds while completing my field notebook. The area I examined contained three sea urchins and some yellow sponges – sounds a little boring, but this little ecosystem contains many interactions. For example, two small fish, less than 1 centimeter, were swimming into and out of the sponge. Maybe the fish were trying to confuse a predator? Or were there prey inside the sponge? Is the sponge a possible habitat for the fish? The reason for their behavior, I do not know, but it surely is interesting.

            At one point, one of the sea urchins, which are large, black, and spiny, started to move. Now mind you, these spines are at least 25 centimeters in length, but the sea urchin literally just starts to roll away. It did not move far, but clearly something startled the urchin. Again, the actual reason for why the urchin started to move, I do not know, but as a biologist I cannot help but be interested. My time in Panama has been interesting, as it is not often that one gets to snorkel for five days in a row observing the coral reef ecosystem. While my time in Panama has been way too short, I’m glad to say that every minute was filled with wonder and knowledge, making Panama so much more than just another stamp on my passport. 

Bridget Gross

College of Wooster