Snorkeling in Bocas del Toro

By Claire Jackan

We spent five days snorkeling and learning about coral reefs in Bocas Del Toro, Panama.  We had to limit our use of sunscreen in the water because sunscreen can kill the coral, and instead wore long sleeves and pants to protect ourselves from the sun. Our first day in the water we learned how to use the snorkel to breathe while staying near the surface and also how to exhale the water out of the snorkel upon diving deeper underwater. Both of these techniques were important for our underwater research project involving damselfish. Before starting the project, we had the opportunity to explore with a partner and familiarize ourselves with the part of the reef that we would be using in our study. We learned how to identify the damselfish along with parrotfish and surgeonfish, which are all herbivores. 

            The goal of our project was to study damselfish territoriality using pieces of seagrass marking various distances (0, 1, and 2 meters) from the edge of the damselfish’s territory.  We hypothesized that the damselfish would be less likely to attack other fish if they were further from the edge of the damselfish’s territory. We also thought that the damselfish would be more likely to attack other herbivores because herbivores would pose a greater risk of eating the seagrass and the damselfish would try harder to defend it. We observed each of the three stations, in other words three different damselfish, for 10 minutes over the course of three days.  We kept track of the number of times the damselfish made an aggressive move toward another fish and distinguished whether the other fish was an herbivore or a non-herbivore. We were able to record data underwater by using a mechanical pencil to write on a PVC pipe.  We also picked up the seagrass at the end of each data collection in order to estimate the percent eaten by the fish. We noticed that the seagrass furthest from the edge of the damselfish territory showed the greatest amount of herbivory.

            For our last day in the water, we visited a different reef and instead of collecting data, we were free to explore whatever we wanted to with our partners. Towards the end of the morning, it started raining as we were swimming and it became really cold.  Before we left however, I got the chance to see many new kinds of fish that were not present in the other section of reef.  Though I wasn’t able to identify the actual species, my favorite fish that I saw was silver and light blue with a little bit of yellow on the fins. It tended to swim in groups with others; I hardly ever saw it by itself. Another interesting find was a very big, dark brown crab (about 25 centimeters long) that was crawling along the sea floor.  We saw many other smaller crabs but I was surprised to see one that big.  As we swam closer though, it started to hide between some rocks and so I couldn’t get a very good look at it. Overall, I saw many interesting sea creatures at both of the reefs and I really enjoyed our time at Bocas Del Toro before we had to leave for La Selva, our last station here in Costa Rica.