In April 2021 members from the Nature Foundation St. Maarten, the Dutch Caribbean Nature Alliance (DCNA), the Saba Conservation Foundation (SCF), and Beneath the Waves conducted multiple ‘scientific firsts’ as part of the “Shark Shakedown” project. The research expedition was a part of a wider research project into tiger sharks in the region funded by World Wide Fund for Nature (WWF-NL) through the Biodiversity Funds and the Dutch National Postcode Lottery. The researchers tagged eleven sharks, including for the first time a female pregnant tiger and endangered Caribbean reef shark in the Dutch Caribbean. The data will provide vital information for conservation strategies not only in St. Maarten, but for the wider Caribbean.

The expedition lasted five days in which three species of sharks were tagged, including tiger sharks (Galeocerdo cuvier), Caribbean reef sharks (Carcharhinus perezi), and nurse sharks (Ginglymostoma cirratum) all ranging from sub-adults to adults.

Participants received hands-on training with experts from Beneath the Waves in preparation for the upcoming expedition to the Saba Bank in August 2021. The goal of this upcoming expedition is to determine whether the Saba Bank is a breeding area for tiger sharks in the Eastern Caribbean. The high-definition ultrasound technology the team used was created by E. I. Medical Imaging and pioneered by collaborator Dr. James Sulikowski, of Arizona State University. This technology has successfully been used to identify maturity state and the stage of pregnancy in various shark species, a first for shark science in the region.

The scientists successfully confirmed early pregnancy stage in a large female tiger shark, as well as placed a satellite tag on the shark during the workup process. Using satellite tracking over the next few months, the scientists hope to confirm evidence of Sint Maarten being a breeding location for these globally threatened animals. In another shark tagging ‘first’, Beneath the Waves’ Chief Scientist, Dr. Austin Gallagher, placed the first camera tag on a tiger shark in the Dutch Caribbean. The team successfully recovered the camera package during the expedition, and the animal has already shown promising results regarding shark behavior in the region.

Both the satellite tag and camera tag have shown that these tiger sharks prefer to travel in the area between St. Maarten and St. Barths; however, these are only the first detections. No assumptions can be made yet regarding the movement of these animals.

The information gained from 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. Tiger sharks are currently categorized as Near-Threatened by the International Union for Conservation of Nature while Caribbean reef sharks have very recently been upgraded to Endangered. Sharks play key roles in maintaining the balance within local and regional marine ecosystems and maintaining biodiversity and therefore their protection is crucial.

Follow the Dutch Caribbean Nature Alliance’s Facebook, Instagram (dcnanature) or DCNA’s website (https://dcnanature.org/news/) to learn more about the shark expedition and other nature news from the Dutch Caribbean.

Photo credit:  ©  Sami Kattan/Beneath the Waves (all rights reserved)