We’ve been hearing a lot about climate change and the negative effects that come along with it. But what is it? And what does this phenomenon mean for sea turtles?
To put in simple terms, climate change is when the average condition of a region e.g. rainfall and temperature, changes over a long period. This is not an unfamiliar occurrence, and sea turtles have been able to survive nature’s alterations throughout the years. However, the on-going rate of climate change, especially global warming, is alarming, and sea turtles cannot keep up and adapt to such striking shifts and imbalance.
As the ocean-to-earth ratio is about 7 to 3, the ocean absorbs most of the heat caused by greenhouse gas emissions, prompting the rise of ocean temperatures. When this happens, sea turtles have more trouble navigating their way in the waters and detecting prey. This is because higher ocean temperature alters currents, thus influencing the availability of prey for sea turtles. Additionally, as coral reefs get “bleached” due to warm temperatures, the algae living in them—which sea turtles feed on—too disappear.
Global warming also leads to the heating up of sand on beaches, typical nesting grounds for female sea turtles. Did you know that the gender of sea turtle hatchlings is determined by its environment? During the incubation period, if the temperature of the sand is anything above 31.5°C, the hatchlings will become females, and a lower temperature will produce males (hot babes, cool guys). However, with the ever-increasing rate of global warming, there is little wonder how there are more female hatchlings instead of males ones. A study once recorded that, in the northern region of Australia’s Great Barrier Reefs, the ratio of female-to-male hatchlings was 116 to 1. Without males, sea turtles cannot reproduce.
Warmer sand also negatively influence hatching rates, sometimes resulting in complete nest failure. The optimal sand incubation temperature is between 25 to 33°C and anything above could lead to shorter incubation period, physical abnormalities for hatchlings, and lower hatching success. It is worth noting that the shorter the incubation period, the smaller the body size or the mass of the hatchlings, which lowers their survival rate.
Next, climate change also brings about the rise of sea levels, which leads to—among others—floods. When a flood occurs at nesting grounds, it could suffocate submerged turtle eggs, with a study showing a drop as much as 30% of survival chances for flooded eggs, hence decreasing successful nesting rates. Furthermore, frequent floods could also cause beach erosion, directly impacting the nesting areas where female sea turtles return to lay their eggs, even after several decades. If there are fewer beaches to lay their eggs, there will be fewer hatchlings, and thus diminishing the number of the already endangered sea turtles.
All in all, there is no surprise that climate change greatly threatens sea turtles, and their adapting abilities are no match for the turmoil coming their way. This is why we, as everyday people, should help lessen the blow. Perhaps start with using public transportation, consume less electricity, reduce, reuse, and recycle, and maybe even plant a tree?
Remember, every action counts!