World Wildlife Fund

Join WWF’s Priscilla Martinez as she travels to Galapagos’ Darwin and Wolf Islands to help study the movement patterns of key shark species through various tagging and tracking techniques. Read more on her unprecedented research trip to help conserve shark species in the Galapagos Marine Reserve.

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Introduction | Days 1-3 | Days 4-5 | Days 6-8 | Days 9-10
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Introduction
Sharks are important components of the marine ecosystem as they fulfill the role of top predators in their respective habitats. As such, sharks are a driving force of natural selection and a measure of health of marine ecosystems in general.

© Sterling Zumbrunn

In recent years, sharks have become the focus of international concern as current studies have shown large-scale declines in populations throughout the world’s oceans from overfishing due to their low fecundity, late onset of sexual maturity, and slow growth. Although sharks – especially hammerhead and Galapagos sharks – are still seen in large numbers in the legally protected Galapagos Marine Reserve (GMR), even here, their numbers have decreased in recent years.

The sharks in the GMR are still subjected to fishing pressures that include industrial long-line vessels which enter the GMR illegally, and by local fishers who target them for their fins. At the same time, over the last decade, their importance as a living resource for dive tourism has increased dramatically.

The Study of Sharks

In 2006, a regional initiative including researchers from Galapagos and the neighboring marine protected areas of Cocos, Coiba and Malpelo, began a study of the movement patterns of key shark species: the scalloped hammerhead (Sphyrna lewini), the Galápagos shark (Carcharhinus galapagensis) and the whale shark (Rhincodon typus).

In Galapagos, this study was led by Alex Hearn (Ph.D), scientist at the Charles Darwin Foundation, with the technical support of Prof. Pete Klimley, a pioneer of shark research, and his team from University of California Davis (UC Davis). The study was backed by WWF-Galapagos, with the financial support of the Legacy Fund, Conservation International and the Galapagos National Park Service. The overall mission of the Shark Research Program was to provide stakeholders and authorities with the necessary technical information for the conservation of shark species in the GMR.

© Sterling Zumbrunn

To understand the spatial dynamics of the sharks, various tagging and tracking techniques were used, including

• Ultrasonic coded beacons attached to sharks which are detected by receivers placed at key sites
• Ultrasonic continuous transmitters which are detected by onboard hydrophones and are used to track sharks over short periods (48 hours)
• Satellite tags attached to sharks, some of which store information, others which emit whenever the animal is on the surface – these are used to follow migratory pathways.

The preliminary outcomes of this research showed that the sharks marked during the pilot phase of the project a year ago maintained a high connectivity between the islands of Darwin and Wolf, particularly between the southern point of Wolf and Darwin’s Arch. This led us to believe that sharks have preferences for specific spots where they spend most of their time, and then move to open waters for relatively short periods of time.

Based on these interesting results, WWF considered it vital to continue supporting this important research which is contributing to fill gaps in our knowledge of shark behavior and distribution patterns, not only around the Galapagos Islands, but in the “Marine Corridor” region.

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