Shark movements and the design of protected pelagic environments within and beyond the Galapagos Marine Reserve
James Ketchum, Alex Hearn, George Shillinger, Eduardo Espinoza, César Peñaherrera & Peter Klimley
In: Galapagos Science Symposium, 2009.
The Galapagos Archipelago is one of the last outposts where large numbers of sharks and other marine predators still remain in the eastern tropical Pacific. The Galapagos Marine Reserve (GMR) offers some protection, but its effectiveness is limited because the movements of marine predators were not considered in the general layout of the reserve. We intend to alleviate this management problem by incorporating the spatial distribution of sharks in the design of protected pelagic environments. Satellite and shipboard tracking at the Galapagos Islands have led to the description of the movements of scalloped hammerhead and Galapagos sharks on insular (< 50 km), inter-island (50-400 km) and oceanic (> 500 km) spatial scales. This implies 1) a high degree of use of areas bordering islands, 2) inter-island connectivity within the GMR, and 3) the likelihood of migratory corridors between the Galapagos and open ocean regions beyond the reserve either adjacent to the GMR 40-mile limit or further offshore. Our work demonstrates that hotspots vary in scale, from small-scale hotspots along the coast to large-scale hotspots encompassing Darwin and Wolf islands. These findings have profound implications in the shaping of marine reserves.
marine predators, pelagic reserve, home ranges, satellite tracking, telemetry