18-APR-2021 - During the week of April 11, members from the NFSXM, the DCNA, the SCF, and Beneath the Waves conduct shark research in the territorial waters of Sint Maarten. The goal of the week-long project is to gather data on sharks in Sint Maarten and for participants to be trained in ultrasonography technology, to later determine whether the Saba Bank is a breeding area for tiger sharks.

Members from the Nature Foundation St. Maarten (NFSXM), the Dutch Caribbean Nature Alliance (DCNA), the Saba Conservation Foundation (SCF) and Beneath the Waves are conducting this shark research. This activity is a part of a wider research project into tiger sharks in the region, funded by the Dutch department of the World Wild Fund for Nature (WWF-NL), through the Biodiversity Funds and the Dutch National Postcode Lotterij. The week-long project is called the ‘Shark Shakedown’.

Tiger sharks (Galeocerdo cuvier) are large, apex predators found throughout the world on coral reefs, pelagic environments and oceanic atolls, including the Saba Bank. A previous study by Wageningen University showed that the Saba Bank might be an important nursery area for tiger sharks. Tiger sharks are currently categorized as Near Threatened by the International Union for Conservation of Nature. Currently, however, there is little data regarding the reproductive biology of tiger sharks. 

The team uses a high-definition ultrasound technology that has been created by E. I. Medical Imaging and pioneered by collaborator Dr James Sulikowski, of Arizona State University. This technology has been used successfully to identify the maturity stage and the stage of pregnancy in various shark species. This methodology will be used to produce an image of the inside of a shark, which will help determine the presence and reproductive stage of female tiger sharks present on the Saba Bank, including their movement patterns outside the boundaries of the Dutch Caribbean. Tiger sharks are a transboundary species, meaning they travel and live in more than one area or country.

The information gained by this research will provide a better understanding of the importance of both the status of sharks in Sint Maarten’s territorial waters and in the Yarari Sanctuary and the role these ecosystems play in the life cycle of tiger sharks in the wider Caribbean Region.

Additionally, the data will provide vital information for conservation strategies, not only in the Dutch Caribbean, but the wider Caribbean as a whole. A week-long expedition to the Saba Bank is currently scheduled for August 2021.

Although tiger sharks occur in the region, they spend most of their time offshore in deeper water and are rarely recorded close to shore. Unfortunately, there have been two incidents in previous months involving negative shark-human interactions: one in Sint Maarten and one in Saint Kitts. The week-long project will also investigate if there is any change in the behaviour and distribution of sharks in the area. Tiger sharks play key roles in maintaining the balance within local and regional marine ecosystems and are critical to the health of the marine biodiversity of the wider Caribbean region.

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Text: Nature Foundation St. Maarten, Dutch Caribbean Nature Alliance (DCNA), Saba Conservation Foundation (SCF) en Beneath the Waves
Photo: Peter de Maagt