There is global concern about the decline of shark populations. With an estimated 100 million sharks captured annually worldwide, many populations are declining and threatened with extinction. The Galapagos Marine Reserve is one of the last shark refuges in the world and home to abundant populations of species such as the whale shark, scalloped hammerhead, tiger shark and Galapagos shark. However, urban and tourism growth has significantly increased human pressure on marine resources, including fisheries, and it is generally perceived that some shark species populations in Galapagos have declined over the last few decades.
CDF scientists provide the Galapagos National Park Directorate (GNPD) with information on shark distribution, abundance and population structure to monitor population changes over time. Surveys occur across a range of marine ecosystems, from underwater seamounts to mangrove bays, in order to provide the best scientific knowledge on the location of shark sensitive areas such as nursery and feeding grounds. We are also working with local and international collaborators to track sharks with acoustic and satellite tags to understand their habitat use and regional migratory routes. Sharks are highly mobile species and understanding migratory patterns is key to promoting their international protection. Of particular interest is the occurrence of whale sharks around the Islands of Darwin and Wolf. Recent studies by CDF and collaborators revealed that whale sharks visit the islands between July-December. Up to 90% of whale sharks in the region have been recorded as pregnant and appear to stop-over for a couple of days before moving to presumed pupping grounds. This is the first reproductive migration ever recorded for the largest fish on earth.
Project collaborators: Galapagos National Park Directorate, Massey University (NZ), Curtin University (Australia), OCEARCH, Turtle Island Restoration Network, Jonathan Green, Georgia Aquarium.
Project funders: IWC Watches, the Lindblad Expeditions/National Geographic Fund
Follow the movement of tagged sharks at ocearch.org