Warmer oceans are bad news for sea turtles and humanity too


As climate change alters temperatures and habitat conditions around the world, species are struggling to adapt. With rising sea temperatures, many marine organisms are threatened with extinction. These temperature increases have the potential to harm already threatened sea turtle populations.

According to the International Union for Conservation of Nature (IUCN), six species of sea turtles are labeled endangered or critically endangered. Sea turtles are threatened for many reasons, including loss of nesting habitats, disturbance of nests by humans and predators, and predation. However, rising sea and sand temperatures are adding to the burden sea turtles already face, but in a slightly different way.

In sea turtles, whether an individual becomes a male or a female is determined by the temperature at which the eggs are incubated. Higher incubation temperatures (above 29°C) produce more female turtles and cooler incubation temperatures (below 29°C) produce more male turtles. Fluctuating hot and cold incubation temperatures result in an almost equal mix of male and female offspring. Climate change is causing sea and sand temperatures to rise, making sea turtle nests warmer. This means that more female turtles are born than males. Less than 0.1% of sea turtles survive to adulthood, and while most of them are female, there may not be enough males to mate with. females, putting these already endangered species at even greater risk of extinction. Rising sea and sand temperatures are also causing more eggs to die before hatching, further threatening these endangered species.

But why is declining sea turtle populations something we should care about? Sea turtles play an important role in maintaining the balance of the marine ecosystems in which they live. For example, loggerhead sea turtles in Mexico play a key role in nutrient cycling. Loggerheads pull nutrients from the water as they eat and lay their nutrient-rich eggs on sandy beaches. This moves energy from nutrient-rich seawater to nutrient-poor beaches, fueling the growth of vegetation that stabilizes shorelines. This helps prevent erosion and simultaneously keeps nutrient levels in seawater at healthy levels. This protects our water bodies from eutrophication, which occurs when nutrient concentrations rise too high, leading to harmful algae blooms. These algal blooms consume oxygen from the water and prevent sunlight from entering the water column, killing wildlife and making the water even more toxic – a vicious cycle. Since so few turtle hatchlings return to the sea after hatching, much of the deposited nutrients remain in the sand, protecting the water from the effects of excess nutrients. This is just one example of the crucial importance of sea turtles for the health and balance of ecosystems.

Sea turtle conservation efforts have been underway for many years. These efforts include designating protected areas for sea turtle nesting, protecting hatchlings as they head out to sea for the first time, and rearing broods in artificial nests to control incubation temperatures. and gender balance. While these efforts have been successful in slowing the extinction of some sea turtle species, they can be costly, time-consuming, and labor-intensive. Anthropogenic climate change continues to worsen, posing a significant threat to our planet’s endangered species – including many species that are already threatened with extinction – such as sea turtles. As climate change worsens, more viable solutions are needed for the long-term management of species at risk. The actions we take to protect sea turtles will also ensure a healthier future for us, as they play a vital role in keeping our planet healthy and balanced.

Sarah Babaei is a fourth-year molecular biology and genetics student at McMaster University.


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