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HAIFA, Israel — In a groundbreaking achievement for marine research in Israel, scientists at the Morris Kahn Marine Research Station of the University of Haifa have successfully conducted the first-ever ultrasound examination on a sandbar shark (Carcharhinus plumbeus) in the Mediterranean.
The procedure, performed this week off the coast of Hadera, revealed that the shark, named Romi, is in an advanced stage of pregnancy. This breakthrough is part of a long-term study led by the Apex Predator Lab, focusing on the reproductive habits of local shark populations.
Dr. Aviad Scheinin, head of the research division, emphasized the significance of this development. “Our research provides crucial insights into the reproductive behavior of sharks in the region,” he stated. “We aim to determine whether this site serves as a permanent birthing ground or a temporary transit area for pregnant sharks.”
A Dual Discovery
In a simultaneous encounter, researchers discovered another pregnant shark named Emily, a dusky shark (Carcharhinus obscurus), found with a fishing hook lodged near her gills.
The team managed to safely remove the hook and confirmed her pregnancy through subsequent examinations. Emily’s case highlighted the ongoing threat that human activities, particularly fishing, pose to these marine predators.
“This case further illustrates the link between fishing activities and shark conservation,” Dr. Scheinin noted. “The more we understand their movements and reproductive cycles, the better we can implement protective measures for these species.”
Unveiling Reproductive Secrets
The ultrasound scan of Romi provided unprecedented data on the reproductive cycles of sandbar sharks in the Mediterranean.
According to Dr. Lee Livne, a postdoctoral researcher specializing in shark reproduction, the embryos observed during the scan measured between 50 and 77 centimeters, consistent with the species’ known 12-month gestation period.
“Our encounter with Romi was particularly significant, as only five sandbar sharks have been documented in our region,” Dr. Livne explained. “This was the first time we’ve conducted an in-depth reproductive examination on this species.”
Since its launch in 2016, the study has tagged 123 sharks, including Romi and Emily, who are the seventh and eighth sharks tagged this season.
The ongoing research, now in its tenth year, aims to understand the migratory and reproductive behaviors of sharks that seasonally aggregate off Hadera’s coast, a phenomenon whose causes remain under investigation.
Human Impact and Conservation Efforts
The injury sustained by Emily from a fishing hook underscored the impact of human activities on shark populations. Despite their remarkable healing capabilities, researchers stress the need for continued monitoring to assess the long-term effects of such interactions.
“The ability to access sharks for these studies allows us to provide immediate care when necessary, as in Emily’s case,” Dr. Scheinin remarked. The data gathered through tagging, hormone testing, and ultrasound scans is expected to support efforts to protect these vital marine predators.
As researchers continue to track the tagged sharks, they hope the findings will contribute to more effective conservation strategies, ensuring the survival of these crucial marine species in the Mediterranean Sea.