Great white sharks face a thermal trap of their own biology. A new report in Science identifies mesothermic species, including great whites and several large tuna, as acutely vulnerable to ocean warming because they actively maintain body temperatures above ambient seawater. That metabolic advantage costs energy, and rising ocean temperatures are now pushing it toward a lethal threshold.
The threat is a double jeopardy: warming water forces these animals to burn more fuel to regulate temperature while overfishing simultaneously collapses the prey populations they depend on to meet that demand. The result is a species already stressed by food scarcity being cornered by heat. Forced migration to cooler waters is the projected response, but cooler water means compressed habitat and new competition.
The full Science paper is worth reading for the mechanistic detail on how mesothermy becomes a liability at specific temperature thresholds, and for what it implies about other large apex predators sharing the same physiological profile. The evolutionary trait that made great whites dominant for millions of years is now a vector for collapse.
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