Aquatic Adventures at Bocas del Toro

             

Photos: Hayley Stutzman

When I was younger, I liked to pretend I was a mermaid when I went to the local swimming pool. Splashing around happily, I sought to emulate the Little Mermaid. I imagined that I was the benevolent protector of an underwater kingdom comprised of dolphins and whales--my favorite aquatic animals. As I've grown older, my love for all things nautical has stayed with me, but I've learned that dolphins and whales aren't the only aquatic creatures that require protection.

This week, at Bocas del Toro, we discussed some of the most important, but often overlooked, creatures under the sea: coral, algae, and sea grasses. Coral is perhaps the most dynamic and well-appreciated of these three organisms since it comes in a variety of bright colors and is home to eye catching fish (in addition to being the setting of scenes in movies such as Finding Nemo). However, algae and sea grass, despite being less well-known, are both primary producers that form the base of many marine food webs.

            I had never snorkeled before coming to Bocas, so the underwater research portion of our stay here was novel, to say the least. For our research, we looked at the effect of herbivores on structural complexity within coral reef and sea grass beds. Herbivores such as fish and sea urchins help stimulate primary productivity; they act as "lawn mowers" that trim some of the primary producers' tissue without killing the entire organism, which promotes new primary producer growth. In our case, the primary producers were macroalgae or sea grass and the herbivores in question were sea urchins. We wanted to see if there was more structural complexity in areas with more sea urchins. After two days of conducting our under water research--which is trickier than it sounds--we found that sea urchin cover does indeed correlate with structural complexity, although we can't assume there is a cause-and-effect relationship due to the limited scope of our data.

            Outside of research time, we were allowed to explore the reef and I got to see marine life that I'd previously only read about or seen in documentaries. We saw groups of squid, neon-colored parrotfish, clumps of Cyanobacteria, stingrays, and sponges among other organisms. Like so many other reefs, the reef we explored that hosted such a variety of life is in danger due to climate change. Rising temperatures and ocean acidification due to the proliferation of dissolved carbon dioxide leads to coral bleaching, essentially catalyzing mass die-offs of the organisms that provide food and shelter for the organisms described above, and many more. Our time in Bocas del Toro has reminded me of the urgency with which we need to protect our existing reefs and explore options for  conservation.

Emma Roszkowski

Grinnell College

Coral Reef Project in Bocas del Toro

The trip from La Selva to Bocas del Toro is was long and culminated in a bumpy yet fun boat ride to Colón Island where the ITEC field station we stayed at is located. Upon arrival, it looked like we were about to run into the island, which is surrounded for the most part by mangrove forests, when all of a sudden the boat slowed down and entered a small hole in the mangroves that led us to the stations’ dock. After getting off the boat we lugged our packs through pastureland up to the station. The rustic wood station had a deck outside the rooms with a hammock and a view that included birds and a sliver of the ocean. Not a bad place to learn about biology for a week. 

Our focus for this trip was coral reef ecology which is something that I was personally excited about. We spent the first day taking our swim test and getting used to our snorkeling gear. I had previously taken a course on invertebrate animal diversity and it was exciting to recognize some of the organisms I had learned about in that class while we snorkeled. From tube worms that shrunk into their tube when you went near them to brittle stars and a variety of sponges and corals the reef was a new and complex ecosystem to observe. The following two days we completed a faculty lead project that looked at the abundance of macroalgae in comparison to where the abundance and size of sea urchins were. In addition we looked at rugosity which is a measurement of how complex the reef is. Rugosity is measured by placing a metal chain of known length along the ocean floor, next to a measuring tape, and recording how far it goes. If the area the chain is placed on has lots of corals and other structures or organisms that bend the chain then the length measured will be shorter than the actual chain length. If the ground is completely flat it would measure to be about the same length as the chain. In our project we laid out a transect using a 30 meter measuring tape and measured the rugosity, the number of small sea urchins, and the number of large sea urchins for a meter by meter square every other meter along the transect. Alain Duran, our guest faculty, then took pictures at each plot along our transects that we later looked at on the computer to estimate total cover of coral, sea grass, macroalgae, and sponges. It was a very different experience from doing terrestrial fieldwork but it was a fun challenge to work underwater. One of the most difficult parts was avoiding the sea urchins and fire corals that could sting you if you touched them. The idea behind this project is that macroalgae which can be thought of as marine plants are the main competitors for space and sunlight with corals. Corals don’t photosynthesize themselves but have a symbiotic relationship with zooxanthellae (single celled dinoflagellates) which photosynthesis and provide about 95% of the energy corals need to survive. Changes in environmental conditions mostly caused by climate change have caused the zooxanthellae to leave, ultimately killing the coral. Looking at the competitors of corals (macroalgae) is helpful for understanding the best methods for coral reef conservation. We looked at sea urchin abundance because they feed on macroalgae and so we hypothesized that areas with more sea urchins would have less macroalgae. Fish also feed on macroalgae although we did not test for fish abundance.  This ended up playing an important role in what we found from our data. We found that areas with a higher abundance of small sea urchins had less macroalgae whereas areas with a higher abundance of large sea urchins had lower amounts of macroalgae. In addition, plots with higher rugosity, or a more complex reef, had lower abundances of macroalgae. We believe that this is probably due to more herbivorous fish being present in higher rugosity areas because they have more crevices and corals that provide protection from predators. With the differences in sea urchin size we discussed how small sea urchins are more abundant compared to the large sea urchins and can therefore consume more macroalgae. From my personal observation it seemed like areas with higher rugosity and more corals also had more small sea urchins whereas flatter regions had more large sea urchins. Through this project I learned how difficult ecological research is underwater but I was also excited by the complexity and fascinating organisms we found around the reefs. On our last day we snorkeled for fun and found groups of squid that had beautiful fluorescent dots of color along with a couple of large stingrays. Needless to say I think snorkeling and marine biology may be in my future after this week.

Hayley Stutzman

Macalester College

Education as Protection

At Bocas del Toro in Panama, I had the excellent opportunity to explore coral reefs for an entire week. From assisting with a research project to free snorkeling, my time in Bocas was incredible. Following my visit, I have a newfound appreciation for marine conservation and biodiversity. And considering oceans cover more than half our globe, understanding of these aquatic habitats is essential. This is because we depend on our oceans more than we may admit. From deflecting a significant amount of the sun’s light energy to structuring some beautiful ecosystems, oceans impact our life more than we know.

            This message was personally driven home while observing a four-foot long stingray that had been butchered for meat. Washed up on the shoreline, I appreciated just how majestic this sea-faring creature was, despite the jagged cuts that adorned either side of its back. This awe was also met with a particular kind of disappointment that I’ve rarely felt in life. This example of reef disruption still stands out among my other amazing experiences at Bocas, but in a way, I am appreciative of it; the image of the butchered stingray is a testament to the importance of ecological education.

            Those who are passionate about biodiversity can have no better impact than educating their communities. For example, educational programs and responsible reef expeditions could foster sincere appreciation for this gorgeously complex ecosystem. Those who fish in Bocas, or anywhere for that matter, may think twice about butchering large rare reef species if they appreciate their role in reef dynamics. And if we, as ecologists and conservationists, can educate others about the interconnectedness of ecosystems, we’ll have established a protection that could improve how our species interacts with our natural surroundings.

Bryce Pepin

Tufts University