If larval exchange is key to conchs’ sustainability, then knowing the dispersal pathways, or connections, among populations is key to their conservation.
To trace this connectivity, Andy and his team, which includes other researchers as well as citizen scientists, must first collect data on where remaining adult conch populations are. Using Shedd’s research vessel as a basecamp in the Bahamas, they survey remote seagrass, hard-bottom and sand flat habitats to count conchs and measure density. To cover a lot of ground quickly, the researchers use a method that’s a cross between snorkeling and sledding. Gripping the handles of a camera-equipped tow board pulled by a small motorboat, they dive beneath the surface to count conchs and take photos to describe the ecosystem beneath them.
The next step is to determine dispersal pathways that link habitats where the researchers found conchs. While divers can’t follow microscopic larvae through the ocean, biophysical computer models can combine data about currents, seafloor topography and conch biology to simulate the movements of virtual larvae and predict potential planktonic pathways.
These data are passed along to conservation partners lobbying for management strategies supported by sound science. Our research is in partnership with the Conchservation Campaign, a group of not-for-profit organizations, spearheaded by the Bahamas National Trust, that are working together for a sustainable future for queen conchs.
Goal: Saving conch and eating it too
Queen conchs have been collected at a sustainable level by local subsistence fishers for centuries. Beginning in the 1970s, however, a commercial fishery developed for international markets, dominated by the United States, and for a growing tourist trade. The fishery expanded and thrived for a couple of decades, but conch populations have since declined, and the fishery is overexploited in much of its range. Yet the demand for conch meat, and therefore fishing pressure, remains high.
So what is the solution? Our research will provide policymakers with data on population assessments, protected area efficacy and larval connectivity for queen conch in the Bahamas. Together, these data can be used to inform the future placement of a network of protected areas that exchange larvae and replenish stocks of conch and other species. Ultimately, we want a sustainable fishery that features a healthy population of conch both in the ocean and in the bellies of Bahamians.