This morning was a relaxed one; after a simple breakfast we had a morning debriefing for the day, and then I was free for the rest of the morning while another group went out to do the field exercise. I laid in the hammock garden and did some of the readings for our classes; it’s mostly scientific papers on fishery management, which I actually enjoy. Tropical storm Jerry is coming towards us and rain is forecasted for the next week and a half, so I enjoyed the bit of sunshine while it lasted. Lunch was delicious and healthy, as always. I was on kitchen crew today, so we cleaned up the food after lunch and washed all the dishes together. After lunch, my group and I grabbed our snorkel stuff and piled into the two trucks with our professor and teaching assistants. I sat in the bed of the truck because I love the breeze and the views, despite the mosquitoes and dust. On the way to East Bay Beach we passed the salt flats and saw numerous flamingos, which never seems to get old! As soon as the truck stopped by the beach, the mosquitoes began to swarm. It’s been raining more here, which means there is standing water on the island and hordes of mosquitoes. At least we can have freshwater showers now though (we collect and filter our freshwater from the rainwater). There’s always a silver lining 🙂
At the beach we split into groups of three with our underwater slates, a 100m transect line, and a ½ meter square made out of PVC pipe. One student in each group swam directly out from the coast laying down the transect line and sat out in the water alone until joined by the other members of his or her group. Meanwhile, the other two snorkeled along the transect line and dropped the PVC quadrat at 5 random distances, and on their underwater slates recorded the percentage of different seagrass coverage within the quadrant. Once they reached the third group member, they swam back all together and recorded all of the invertebrates they saw.
Seagrass meadows are homes for the juveniles of lots of different aquatic species; there are plenty of places for them to hide from predators until they grow up a bit. They also help keep the sediment in place and take excess nutrients out of the water, making the water more clear.
It was so much fun to do class exercises while snorkeling, and also very exciting to have a research purpose while snorkeling. It also provided a new perspective on the ecosystem; I was rather surprised at the count of live conch we found! We also found a lobster hiding in an old conch shell, several Giant Caribbean Sea Anemone, and a beautiful sand dollar.
When it was my turn to take the transect out and wait alone in the water, it was beautifully unsettling. The seagrass waved gently in unison in the surge and an occasional fish rushed by. Coming towards me from the distance I recognized a distinct, elongated shadow. Barracuda don’t actually attack humans, but they show a disturbing lack of fear around us and they simply look very mean, a perception that doesn’t improve when they allow their sharp teeth to show. They also have a very radical display when they’re hunting or aggressive: they flash black. This particular barracuda was pitch black, easily half a foot in diameter, and longer than my leg. It came up so close to me that I nervously kept my fins between us, unsure of how it might act. When my group members arrived and we swam back together, this barracuda followed us so close I was afraid I might touch it. Our data may have been a little bit skewed on the return because we were so distracted and somewhat terrified.
When we finished our underwater surveys, my braid was entirely intertwined with a bushel of sargassum, which is a type of seaweed that has a particular affinity to my hair. It took me approximately 30 minutes under the saltwater shower to get it entirely out. The purpose of our field exercise was to collect and later analyze data on the effects of high quantities of sargassum on seagrass coverage. Sargassum is currently the highest algal bloom in all of the world of all time, and it’s causing a lot of problems all over the Caribbean, mainly with the tourism industry. Tourists don’t want to go to beaches that are clogged with rotting sargassum; it really ruins the aesthetic appeal. Researchers are still attempting to determine what is causing this massive algal bloom, but the most probable cause is from excess nutrients in the ocean due to deforestation of the Brazilian rain forest. One of our projects this semester is to help our professor determine the extent of damage that this excess alga causes on the ecosystem. It’s truly amazing to be a part of the worldwide effort to understand reverse climate change before it’s too late.