Contributing Writer
Capt. Cathy Eagle
Bottlenose Dolphins (Tursiops truncatus) are warm-blooded mammals that manage cold weather by migrating to warmer waters, increasing their insulating blubber layer, and reducing heat loss through specialized blood flow called thermoregulation. It is a countercurrent heat exchange system in their flippers and fins, where arterial heat warms venous blood returning to the body core.
While they prefer water temperatures between 50 and 90 degrees, they can withstand colder waters, though extreme cold spikes can cause high mortality.
As of February 3, 2026, the water temperature in Pine Island Sound near Pineland is approximately 55 degrees. The measurement was taken by a NOAA buoy reflecting cold conditions following recent air temperatures in the upper 30s and 50s Fahrenheit.
When water temperatures drop below 50 degrees, dolphins develop a thicker layer of blubber, which can make up a significant portion of their body weight, providing essential insulation against freezing temperatures. They also move into shallower waters where it is warmer.
Animals whose body temperature is maintained by internal metabolic processes have a body temperature usually warmer than the external environment. Birds and mammals are the only organisms that are endothermic. Although these animals regulate body temperature internally, heat can be lost to the environment quite easily.
It is especially important for marine mammals to have adaptations allowing them to keep body heat from escaping because water draws heat away from the body much more quickly than air.
Seals, sea lions, polar bears, and sea otters all have hair covering their bodies, and this acts as an insulator to help them keep warm. Dolphins and whales must remain streamlined, and hair would slow them down.
Although I’ve been on the water through some of our cooler temperatures lately, the dolphins have been very present and active. I find myself wanting to be more active to stay warm. Perhaps that is what the dolphins are doing!
Winter brings clearer water visibility and more dolphins are near shore for the warmer waters.
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Captain Cathy Eagle has spent over 45 years boating on our local waters. As a professional Charter Captain, she specializes in Dolphin and Nature Tours. You can reach her at CaptainCathy.com or call /text 239 994-2572. Welcome aboard!
Capt. Cathy Eagle
Capt. Cathy's Boat Tours
Matlacha, Florida
(239) 994-2572
www.CaptainCathy.com
