OU T D O O R S
Plummeting temperatures hit pretty hard for those of us on dry land, but for sea life in our local waters, it can be much worse.
Stunning Weather, Isn’t It? By Fran Marler
THE WIND PULLS AND PUSHES, CALLS AND LEADS. Like an arctic maestro unleashing a wintry tune, the elements seem to be at the mercy of its every whim. Rising and falling, a swirling cold front eventually collides with an area of relative warmth over the Gulf Stream, and more often than not, there’s only one outcome. The cold air wins. An abrupt temperature drop on the Outer Banks isn’t uncommon during the winter season – and we’re all familiar with how bone chilling an icy tempest can feel when you factor in the wind chill. But as bothersome as those cold snaps may be on land, their offshore effects are many and far reaching. Especially when it comes to marine life. “During these strong cold fronts, there can be a quick drop in water temperature,” says Dr. Jim Morley, a biologist with the Coastal Studies Institute (CSI) and East Carolina University whose research focuses on marine ecosystems. “Because fish and other marine life are ectotherms – cold-blooded creatures whose body temperature matches the surrounding water – these cold snaps can take them by surprise, causing them
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to become stressed and immobilized during these periods.” The resulting condition is most commonly known as cold stunning, and it’s a hypothermic reaction that can affect an array of sea creatures. While symptoms such as lower heart rates, decreased circulation and lethargy might not seem that dire to the general public, prolonged exposure to dangerously frigid water can lead to secondary health issues that can ultimately be deadly. Those who are familiar with cold stunning here on the Outer Banks have likely been introduced to the phenomenon through the Sea Turtle Assistance and Rehabilitation (STAR) Center at the North Carolina Aquarium on Roanoke Island – a state-of-the-art facility that provides medical care to sick or injured turtles. In conjunction with volunteers from the Network for Endangered Sea Turtles and National Park Service personnel, local beaches are combed for turtles showing symptoms of a cold stun when temperatures drop dramatically. Once they’re found, the turtles are then carefully transported to the STAR Center where their recovery process can begin. But while sea turtles seem to suffer the brunt of these brutal cold snaps – and therefore tend to dominate the news surrounding cold stunning – fish can also be deeply affected by abrupt changes in temperature. “Fish blood contains a specific amount of salt – sodium and chloride – and part of gill function helps regulate this balance,” Jim says. “When metabolism slows due to cold stunning, gill movement and cellular function also begin to slow, and the concentration of salt can increase in their blood – which can be fatal. Their physiology simply isn’t