Unraveling The Secrets Of Mediterranean Sharks: Critical Research Receives National Geographic Funding

University of Haifa researchers have received a substantial $100,000 grant from National Geographic Wayfinder to conduct a groundbreaking study to track the movement of sharks in the eastern Mediterranean Sea (EMS). Home to a rich and diverse marinescape, its biodiversity encompasses a wide range of marine organisms, including fish, invertebrates, corals, marine mammals, and seabirds. Despite the region's climate change challenges, sharks thrive in this basin, and the researchers aim to unravel the reasons behind their resilience. And given the transboundary nature of the Mediterranean Sea, international collaboration is vital for studying and conserving the animals here.

Led by National Geographic Explorer Dr. Aviad Scheinin from the University of Haifa's Morris Kahn Marine Research Station, and supported by Dr. Leigh Livne (a postdoc in his lab), the project collaborates with partners across the EMS to combine research and education for long-term conservation outcomes. The Wayfinder grant is crucial to pinpointing the movement and reproduction of sharks and why they return to specific hotspots year after year. “Through National Geographic’s influential platform, we can scale up our story to reach the hearts and minds of scientists, children, and decision makers alike,” Scheinin said. “This is a story about endangered species at the brink, and our ability to discover the secrets about where they are most likely to survive under changing climatic conditions. It can also highlight humanity’s ability to protect and sustain these populations for future generations.”

To date, Scheinin has tagged over 100 sharks, and is leading the Mediterranean’s first “Shark Tagging School” to deploy various state-of-the-art tags to monitor shark distribution. Most sharks have been tagged with acoustic transmitter tags, and his team has deployed a network of 10-15 passive acoustic receivers in areas of known aggregations along the Israeli coastal shelf. The idea for the school originated as a means to bridge the knowledge gap regarding the distribution of Israeli-tagged sharks, fostering a lasting collaboration between Scheinin and his Turkish counterparts. By training fellow shark researchers in safe and ethical catch-tag-and-release practices, the aim is to spread this expertise over the years and extend tagging efforts further west. After carefully building strong collaborations with shark researchers across the eastern Mediterranean, he hopes to unravel the mysteries of the sharks in the EMS. Using a range of minimally invasive satellite tags (including a “Birth Alert Tag” to find parturition grounds of sharks), a network of fixed acoustic receivers, a suite of biological analyses, and the collection of environmental metadata, researchers hope to find where sharks are migrating and residing year-round here.

“Since sharks know no political borders, the researchers’ network of partners is seeking to provide science-based evidence to policymakers with the goal of enacting similar national-level protections for their shark aggregations that already exist in Israel,” National Geographic state in a press release.

To date, Israel stands as the sole country to offer full protection to all elasmobranch species (sharks and rays) within its maritime boundaries. And it here where the study focuses on two specific shark species – the endangered sandbar sharks and data-deficient dusky sharks – both aggregating around the warm water effluent from coastal power stations. According to the IUCN Red List, Sandbar sharks (Carcharhinus plumbeus) are endangered and the Dusky sharks (Carcharhinus obscurus) are data deficient in the Mediterranean Sea and since 2016, Scheinin has been diligently collecting biological, morphometric, and passive acoustic data to assess the well-being and distribution of both these sharks.

The grant will fund the researchers' efforts to answer key questions such as “For what species-specific reasons do the two shark species use the warm water havens from the effluent waters of Hadera power plant cooling water in winter?” and “Where do they go in the summer months?” The EMS basin’s significance lies in serving as a model for other marine regions, offering valuable insights into species’ requirements amid the escalating impacts of climate change. This unique opportunity will allow the collaborative team to study the various habitats in the EMS, which exist in a “post-warming” state, and better comprehend the evolving dynamics of marine life in response to changing environmental conditions.

Another crucial aspect of the study is conservation physiology, spearheaded by Livne. This part will delve into the fecundity and maternal condition of sharks using hormone and blood biochemical markers and ultrasonographs. A part of the Israeli shark tagging team since 2019, she will assist Scheinin with implementing the catch-and-release training and sampling on-board, as well as analyzing the data for meaningful conclusions which will benefit both species' conservation. And with Shark Awareness Month having just finished, Livne emphasizes the importance of shifting the public’s perception of sharks from mere threats to essential stabilizing forces within marine ecosystems: “I think the danger aspect of sharks is a bit sensational. In the 70s and 80s, when the movie Jaws came out, the idea of sharks as predators dominated the conversation. Now, the public is learning more about what scientists have been saying for decades and that is that sharks are very important to our ecosystem. They're a stabilizing force and are critical to maintaining ecological balance in marine life.”

The ultimate goal is to explore whether the insights from this study can be extrapolated and applied to benefit other species across the globe.