Blog Post By: Chase, Sea Turtle Intern
Our sea turtles’ threats are mostly easy to spot - raccoons, beach erosion, and artificial lights, just to name a few, can all be simply observed by anyone. One of the most dangerous threats affecting the future of our sea turtles, however, is one that we find a little bit harder to spot on a walk down our beach: Earth’s changing climate.
The Earth’s climate is changing - that’s a fact. Regardless of how it is happening, however, we have to adapt to it, and so do our sea turtles. As much fun as some warm weather sounds for our cold-blooded friends, the coming changes are especially challenging for our marine life.
Rising temperatures pose a threat for our sea turtles before they are even born. As you may know, sea turtles’ sex is determined by their temperature as the eggs reach about ¾ of the way through incubation. Warmer temperatures produce females, and cooler temperatures produce males (“hot chicks and cool dudes,” if you will). Even though we only ever see nesting females, male sea turtles are still very integral to keeping up with sea turtle populations. So, as temperatures rise and nests warm up, more females will be produced than males. In nesting areas like Florida and Australia, scientists are finding that hatchlings are overwhelmingly female, up to 99% of hatchlings on some beaches.
Without males, even further population decline is inevitable.
Almost more alarming is that for some beaches, nests are getting so much hotter that hatchlings just don’t hatch. Although an overly-female population is alarming, the annual decline in hatch rates is an immediate threat. Published estimates have found that populations will continue to decline by about seven percent per year due to rising temperatures. Boca Raton’s nests used to have an average hatch rate of 78-81 percent, until 2015, when temperatures increased further and hatch rate dropped to 54 percent. In 2016, that hatch rate dropped further to 42 percent.
Increases in temperature mean a lot more than just warmer air, though. Carbon dioxide, one of the “greenhouse gases” contributing to climate change, is naturally absorbed from the atmosphere into the oceans. Climate change is the main cause of coral reef destruction all over the world, and the coral bleaching associated with rising CO2 levels in the main cause of death. Coral reefs serve not only as habitats for many species of sea turtles, but also as ecosystems for their food to grow. Reefs serve global coastlines as well by slowing waves and protecting them from erosion, ensuring that sea turtles’ nesting habitats stay in place.
Along with our coral reefs, coastlines are disappearing at faster-than-normal rates. As the oceans rise, good nesting ground for our sea turtles is covered in water. As well as covering the coasts, rising oceans also pull more sand and sediment away, eroding the beachfront faster than before. Climate change has also very likely increased the severity of tropical cyclones in recent years, helping to further wash away our beaches, and taking sea turtles’ nesting zones with them.
No matter how you want to see it, things are changing. Our turtles are in trouble, too, and we are trying to adapt to help them. Turtle teams in Florida are testing shading and water-cooling methods for nests to combat the effects of rising temperatures on sea turtle eggs. Scientists are working on breeding corals that can resist bleaching and heating in order to survive and grow. Many hope to counteract the side effects of climate change while its roots are being addressed, to give nature time to adapt.
A global problem requires a global solution, and everyone’s effort adds together. Our sea turtles need our help, and we’re doing everything we can. Just understanding the problem is a great beginning to solving it.
Sea Turtle Biologist