Overloading threatens short macos but science offers a survival strategy

Sharks Mako Shortfin (Isurus oxyrinchus) They are faster sharks at sea, but they are failing to overcome the things that lead them to extinction: overload. The global demand for their meat and the valuable fines has placed this predator in the International Union for maintaining the endangered list of nature and in Annex II of the Convention on the Trade of Endangered Fauna Fauna and Flora. The situation is particularly serious in the Atlantic, where populations are managed as two ‘separate’ actions’. Fisheries -based estimates show that Northern Atlantic mackets are redundant, but independent studies of satellite labels suggest that the current fishing mortality may be ten times higher than previous estimates. With increasing pressure from international fishing, scientists are wondering if short makos still have genetic resistance to adapt … and if the current strategy of managing their treatment as two populations is scientifically healthy.

A new study led by Dr. Andrea Bernard and Professor Mahmood Shivji from Save Our Seas Foundation Shark (SOSF-SRC) and Guy Harvey Institute at Southeast Nova offers essential answers to these questions. Published EvolutionaryWork represents the first sequences of the full genome of mitochondrial DNA and high-resolution nuclear DNA scans by short Makos throughout the Atlantic range. These genetic estimates have discovered a startling finding (and what some say are a hope): despite decades of severe fishing pressure, short makos still exhibit relatively high genetic diversity. This is very important because genetic diversity helps species to adapt to environmental changes and survive from catastrophic events. Shivji explains that while overestimation is the biggest threat to sharks around the world, many species also face additional risks from habitat loss, deep sea mines, pollution and climate change. The fact that short macos have maintained genetic diversity means that they can still have the ability to adapt – but only if the overload has stopped before their populations are pushed to the recovery point.

“Typically, in most used shark species we study we see quite low diversity,” Shivji says. “We were very surprised, but also satisfied, to see that the genetic health of the short Mako does not seem to have been severely compromised – however – by population discounts caused by overload. […]

This means that if we can prevent the further erosion of this genetic diversity in short macch sharks by urgently inhibiting overload, we have more hope that this species will maintain the resistance needed for its population to adapt to Our climate in rapid and surviving. “

The research team also revealed that Makos Shortfin, known for their broad oceanic migrations, mixes freely across the Atlantic. High-resolution scanning of nuclear DNA (inherited from both parents) confirm that male males do, in fact, widely vary and spread their genes throughout the Atlantic. However, the mitochondrial DNA – passed only through mothers – tells a different story. She discovers that Makos short females exhibit a strong matrilineal structure, which means that while they can travel widely, they turn into specific areas within their hemisphere to give birth. This confirms that the populations of the North and South Atlantic are genetically distinct, and strengthen the need to manage them as separate actions.

“With the increase in the loss of genetic diversity of species and assessments and monitoring of genetic diversity now required by the United Nations Convention on Biological Diversity as important activities to inform national policy actions on the conservation and restoration of species, data Genetic diversity we report here for Mako Shark provide an initial basis for future evaluation and monitoring, genetic health of this iconic species during its global distribution, “the team concludes. While Mako Shortfin’s genetic health offers a poss Rarely to protect their future, their resistance is not endless. Save them.