In a groundbreaking discovery, scientists tracked a juvenile shortfin mako shark in the Mediterranean Sea, revealing both its impressive mobility and the dangers it faces. The shortfin mako shark, known for its remarkable speed, is now classified as Endangered worldwide and Critically Endangered in the Mediterranean as a result of decades of overfishing, especially factory fishing, combined with poor management.
The shortfin mako shark. (Photo: 出羽雀台 / CC BY-SA 4.0)
First-ever tracking study in the Mediterranean
The new study reports that the mako shark travelled an estimated 408km over a period of 54 days, showcasing the vast distances these creatures can cover even at a young age. This discovery underscores the need to rethink traditional ideas about mako nurseries, areas where young sharks are born and grow up, as the tracked shark moved far from its presumed nursery near Tunisia.
A grim reality
Despite protections under international agreements like the Bern and Barcelona Conventions, mako sharks in the Mediterranean are frequently caught unintentionally by commercial fishers. Most sharks caught this way are not released, even though laws exist to protect them. Alarmingly, young and juvenile mako sharks make up the majority of captures, meaning that many never reach maturity, let alone reproduce. This poses a severe threat to the survival of the species.
Bycatch in fishing operations remains the biggest danger for mako sharks, but unregulated recreational fishing also plays a role. The exact impact of this sector is unknown, but experts believe it is significant. Cooperation among countries bordering the Mediterranean is critical to address these challenges, as sharks frequently move across national boundaries.
New insights
The tracked mako shark’s journey highlighted notable changes in its diving behaviour. Early in the study, it stayed near shallow waters, but as it moved into deeper areas, it began diving to depths of up to 400m. Scientists suggest this shift was driven by temperature changes, foraging needs, or a combination of both. Rising sea temperatures in the region may also influence shark movements, emphasising the importance of understanding their thermal preferences.
Unfortunately, the tracked shark’s life ended abruptly in July 2023. The cause remains unclear, but evidence points to the shark being fished. This tragic outcome mirrors the high mortality rates mako sharks face in the Mediterranean, where fishing pressures are intense.
Collaboration is key
The study’s success was made possible through partnerships with local fishers, a vital strategy for future research and conservation. Scientists stress the importance of engaging stakeholders to develop effective management plans to protect dwindling shark populations.
This single tracking effort offers a glimpse into the dynamic life of a mako shark and highlights the urgent need for more research. Expanded tagging studies across different life stages, better monitoring of fishing practices, and stronger international cooperation are crucial to saving this remarkable species from extinction.
Call to action
With Mediterranean waters warming and fishing pressures unrelenting, immediate action is necessary to safeguard mako sharks. Time is running out for these apex predators, and their fate depends on a collective commitment to responsible management and conservation.
