As a Development Officer at Earthwatch headquarters in Boston, I’m the go-to person when people call us for information about expeditions. I’m expected to be an expert on more than 50 expeditions all over the world! So to get some first-hand, on-the-water experience in how an Earthwatch-supported research project operates, I spent 8 days participating with volunteers on our Shark Conservation in Belize expedition – and I just got back last month!
Our Mission: Saving Sharks
Shark populations around the world are collapsing from overfishing. Because of their role as top predators, this could have important consequences for marine ecosystems. Since 2000, Dr. Demian Chapman has conducted research on sharks at the Glover’s Reef Marine Reserve in the Central American country of Belize. This research aims to demonstrate how marine reserves help conserve sharks, study the role of sharks in the tropical marine ecosystem, and help the Belizean Fisheries Department enact good policies to protect sharks. The results will be used to help save the sharks in the Caribbean and in other parts of the world. And the experience helped me better understand what Earthwatchers really do on the expedition.
Observing Life at Glover’s Reed Atoll
We were based at Glover’s Reef Atoll, a beautiful, remote tropical island 30 miles (45 kilometers) from the coast of Belize, in the heart of the Mesoamerican Barrier Reef System. Stretching for 620 miles (1,000 kilometers) from Yucatan to Honduras, this is the largest reef in the Western Hemisphere and is second in the world only to Australia’s Great Barrier Reef. The waters around the atoll are within a well-protected reserve and abound in dolphins, sea turtles, coral, sponges, sea fans, and many species of fish, including large sharks. We had a chance to observe the spectacular life of the reef while snorkeling along patch reefs and while exploring the walking trails on the island. Alex, a volunteer from New Jersey, even stared down a barracuda!
Gone Fishing – for Sharks
Our main activity as volunteers was fishing sharks. On the first day, we were given a quick course in shark biology and a thorough briefing on techniques of safely catching and releasing them. Jasmine, the field team leader, used a life-sized inflatable shark to demonstrate how to secure them to the boat.
That evening we went fishing. We were six volunteers and four project staff and crew members in a 25-foot (8-meter) wooden boat. By spotlight, we followed a line of hooks that had been previously baited with small fish. The waters are crystal clear, so even at night you could see if a shark was on the line before pulling it in. If a shark had been caught, we pulled it in and brought it next to the boat. A two-meter, fiercely struggling Nurse Shark could take us 10 minutes to secure to the side of the boat, while we brought smaller sharks on board. That first night, we caught 15 sharks!
As volunteers, we would take turns securing the shark’s tail to the back of the boat with a sturdy rope, while one of the scientists held it by the hook end. We then measured the length of each shark, took fin and muscle samples for later analysis, copied down its gender, and tagged the shark for identification. Some of the sharks had been previously tagged, so we recorded their numbers to compare measurements to previous data.
Before the shark was released, one of the project staff would cut the barb off the hook so it wouldn’t damage the shark’s mouth when it was removed. All of these tasks had to be done very quickly, so the many pairs of volunteers’ hands had plenty to do.
For the rest of the expedition, we tagged sharks, sometimes by day and sometimes at night. We caught more sharks at night: 15 the first night, 7 the last, and usually 2 or 3 during the day. We mostly caught Nurse Sharks, as well as Caribbean Reef and Sharpnose Sharks. When we weren’t tagging sharks, we helped to catch bait fish, prepare the hooks and lines, and set out the lines with the baited hooks.
Results of Our Work
Data obtained in the field by capturing and recapturing tagged sharks are enabling researchers to build up a picture of the relative abundance of different shark species, how relative abundance changes over time, and the growth rates and movements of individual sharks.
Analysis of their tissue samples provides further information on their diets. The samples are sent to Stony Brook University in the United States, and then on to Windsor, Ontario, where the ratios of different nitrogen isotopes are measured. These ratios can identify what fish species the sharks are eating. All of this together can help determine if marine reserves really do protect sharks and other ocean life!
The research has already shown that sharks have a complex role in the ecosystem, feeding on many more species in the food web than was believed. All of these results are being disseminated to scientists and conservation officials in Belize and other countries and will be used to inform decisions about the management of tropical reef systems.
Experiencing a Different Kind of Science
My background is in politics and environmental advocacy, not science. Before Earthwatch, I worked for a nonprofit advocacy organization as a community organizer. I spent my time encouraging elected officials to enact strong environmental and consumer policies, and while I knew the science to back up those decisions, I was never immersed in the research itself.
This expedition gave me a chance to participate in what Earthwatch offers to volunteers: hands-on experience in a real research project. It was an experience I’ll never forget. Oh, and the weather wasn’t too shabby either!