By Carissa Shipman, Young Explorer
My love affair with nudibranchs, a unique group of marine slugs, began six years ago after seeing one of these fascinating critters in a documentary. I watched the television with eyes wide open, in utter awe of its magnificence! Its ostentatious assortment of colors and intricately decorated appendages intensified my curiosity. In that moment, I knew I wanted to study these amazing underwater jewels in graduate school. Today, I am finishing up my graduate project, studying nudibranchs with Dr. Terry Gosliner, at the California Academy of Sciences in San Francisco.
The Philippines is one of the most diverse areas in the world for sea slugs. This fueled my desire to dive there, to get up close and personal with these stunning invertebrates. This dream was fulfilled when I was accepted to work with Project Seahorse for two months to assist with their long-term monitoring of the Marine Protected Areas (MPAs) in Danajon Bank, Northwest of Bohol. Danajon Bank is one of six double barrier reefs in the world, and it is being adversely affected by overfishing, the use of destructive fishing methods, pollution, and climate change.
The longterm monitoring includes bi-annual surveys, in the wet and dry season, for ten MPAs and four control sites. Longterm monitoring of these areas is important for three reasons: to inform fishing communities of the health of their reefs, mobilize communities to create and manage more MPAs, and to provide long term data to assess the effectiveness of the establishment of these areas on the recovery of reefs. Project Seahorse has worked with the surveys since 1998.
The first two weeks were spent on Jao Island in the barangay (village) Suba, which is about a 30-minute boat ride from the closest municipality, Talibon, Bohol. Here, myself and two other volunteers underwent training to learn the methodologies used to survey these sites. These included a fish visual census, measuring coral cover, and searching for seahorses. The fish visual census entailed identifying and counting tropical fish in 22 different families, and estimating their sizes underwater. To practice our size estimation, we first did a land simulation, where we estimated the fish sizes using several cutout fish forms.
During the surveys, the census was completed along a deep and shallow 50-meter transect for 15 minutes at each site. Two divers would swim on either side of these transects and perform the census within a 2.5 meter area. Notating every fish was a challenge since many of them quickly disappeared into the coral crevices as we swam by.
To measure coral cover, the photoquadrat method was used. An underwater camera, attached to a metal stand was utilized to take images. Photos or images of corals were taken at each site following ten, 25-meter transects, for a total of 250 meters. Vertical coral growth in the area was also measured using the ten transects. For each transect, one diver completed growth, while the other took photos with the monopod.
The seahorse surveys involved snorkeling at night in search of seahorse species in the area. One of these is the vulnerable-tiger-tail seahorse, Hippocampus comes. A specially made lantern attached to a small Filipino boat was used to search for seahorses. Watching the boatman assemble it was both baffling and extremely fascinating. The seahorse fisher (one of the boatmen) dragged the banca with the lantern along the surface, while I snorkeled alongside with a flashlight, searching a 2.5- meter area along six, 50 meter transects.
Sadly, most of the sites had little to no H. comes. Spotting this seahorse at night is difficult since it is often small and well camouflaged in the Sargassum. If a seahorse was found, it was measured from crown to the end of its tail, and its reproductive state was recorded.
During the two months, we stayed in several remote villages and interacted with the local people. Most of our time was spent on the islands of Jao and Jandayan sleeping in open, neatly constructed bamboo houses adjacent to the ocean. For the remaining time, we stayed in the homes of community members or community centers near the sites to be surveyed. Before each survey, we visited the mayor or captain, to inform them of the work we would be conducting in areas under their jurisdiction.
The local Filipinos, especially the children, were excited by our presence and asked a lot of questions. One day, I was wading in the seagrass bed, admiring a horned sea star, while freely expressing my enthusiasm for the Philippine ocean. This attracted the attention of a Filipino woman and her two children who approached me in their boat. They wanted to know what I was looking at. This was a perfect opportunity to talk to them about the beauty of their ocean and the importance of protecting it for future generations. They listened intently, and thanked me for the work I was doing in their country. This was a precious moment, since there are still many Filipinos who do not understand or appreciate the value and importance of their oceans.
You may be wondering, “What about the sea slugs?” Well, while performing the surveys, I saw very few slugs, since I was focused on collecting other data. When not working, I snorkeled near our field sites, and went scuba diving in Anilao, Cabilao, and Balicasag where I saw loads of slugs! Each was spectacular to behold.
On a beach dive in Anilao, my buddies and I came across a triggerfish tangled in an discarded net. We cut it free with a dive knife. The number of fishing nets left behind on the reefs is disconcerting. Dr. Nick Hill, a scientist working with Project Seahorse, has found a way to counteract this problem. He collects these nets and sends them off to be made into carpet tiles. At our main field station in Suba, these nets were piled high, waiting to be packaged and shipped away.
While we were conducting surveys, Expedition: Danajon Bank was also underway. This expedition was a collaboration between the International League of Conservation Photographers (iLCP) and Project Seahorse to increase awareness and to protect this rare and vulnerable reef through underwater photography. A few of the photographers were from National Geographic and accompanied us during one of our surveys to shoot some photos of us working. To learn more about this expedition, you may visit: http://www.indiegogo.com/projects/expedition-danajon-bank.
Overall, this was a life-changing experience for me as a marine biologist and conservationist, since it directly connected me to the fragility of the oceans and the people who depend on it for their sustenance. My passion for the Philippine people and their ocean has grown exponentially since spending two months there. My dream now is to pursue a PhD in Marine Biotechnology searching for anti-cancer compounds within sea slugs.
Each dive in the Philippines was a glorious underwater art gallery! This precious gift, deserves are love and stewardship!
Feature Photo: A horned sea star and sand perch, photo taken by Edwin “Jong” Dumalagan Jr., Project Seahorse Biologist