How changing temperatures, increased marine debris, and threats to global habitats are requiring a holistic change in how we approach sea turtle conservation

Written by Jack E. Lighton
President & CEO, the Sea Turtle Hospital at Loggerhead Marinelife Center

2017 LMC post-hatchling patient with microplastics that were found in the turtle’s gut.

A recent research study published in Current Biology and shared on National Geographic’s Facebook page, regarding how heat impacts sea turtle gender, sent shockwaves across our planet. The headlines transitioned from National Geographic to mastheads like the Washington Post and others, this exposure was a wakeup call and sent chills down the spines of many marine scientists and conservationists.

Here at Loggerhead Marinelife Center we welcome nearly 350,000 guests and over 50,000 students every year. It is our responsibility to educate our guests and keep ourselves on the leading edge of sea turtle and ocean conservation. In our exhibit hall a major and very memorable educational element is the statement, “Hot chicks, cool dudes.” Often met with a chuckle, this is one of our most impactful educational ‘ah-ha’ moments.

Here is how temperature works to develop male or female sea turtles:

Within limits, warmer temperatures during a sea turtle nest’s incubation are more likely to produce females. This is why we say, “hot chicks.”

Cooler temperatures, which can result from rainfall or shade from a building or a tree, increase the likelihood that eggs will develop into males – hence the term, “cool dudes.”

Obviously, both male and female sea turtles are necessary to create the next generation of their species. After reading the National Geographic article I had quite a few questions so, our team, comprised of some of the most thoughtful sea turtle and ocean conservation experts gathered to compare and contrast data, and observations.

As I sat in our conference room with Dr. Justin Perrault, Dr. Charles Manire, and our chief conservation officer, Tommy Cutt, we realized that it was absolutely imperative to share (with anyone that would listen) that conservation of sea turtles is evolving at a shockingly fast pace.

At our center, we have a statement that helps us connect our work directly to the critical importance of our ocean, and ultimately our planet – “Sea turtles tell us the health of our ocean; the ocean tells us the health of our planet.”

In 2017 we kicked off our official study of sex ratios (gender) of sea turtles; our center will set the baseline and then monitor how this baseline changes over time – critical science to better save sea turtles for future generations.

Over the past five decades, we have made huge strides to help protect sea turtle populations and their coastal habitats. For example, the Endangered Species Act of 1973 significantly increased sea turtle conservation. Because of it, certain populations of sea turtles that were on the brink of extinction are now rebounding significantly.

This is great news, but don’t get too excited. Threats to sea turtles, marine life and our oceans over the past 50 years are vastly different than they were in the 1970s; the worst offenders?

Hatchlings must safely make their way from the nest, across the beach and into the water. Then, they must swim for miles until they reach sargassum weed lines near the Gulf Stream – where marine debris tends to collect. (Photographed without flash; under FWC permits)

Marine debris, light pollution, habitat loss and changing temperatures.

Here at the Sea Turtle Hospital at Loggerhead Marinelife Center, our scientists monitor the health of our local sea turtle population. Interestingly enough, we are able to collect more data in one year than many research laboratories can collect in multiple decades. Why? Our 9.5-mile stretch of beach is one of the most densely populated sea turtle nesting beaches in the Americas. Our hope is that our data, analyses and insights will tell a compelling story, quickly as some of us are unsure how much time we have to impact our changing planet.

We are committed to trend spotting and collaborating with top notch scientists. We must do this, because our sea turtles and their ocean home appear to be under greater threat than ever before. The study from Australia gives us great concern, in particular when we layer in the insights from our laboratory and sea turtle hospital.

Let’s for a moment focus on one of the newer threats to sea turtles, and our ocean, marine debris, especially plastics that are discarded into the ocean in unprecedented amounts. One of the common age classes our hospital treats are post-hatchlings – the first few months of a sea turtle’s life. During this time, post-hatchlings live in convergence zones where sargassum (a type of brown algae) collects in the open ocean – the same zones where marine debris collects.

“Plastic pollution is a global epidemic,” says Tommy Cutt, LMC’s Chief Conservation Officer. “Once in the ocean, plastic does not biodegrade; it breaks down into smaller fragments, which are then ingested by fish, sea turtles, sea birds and other marine life.”

Over the past three years, we have found more plastic inside the stomachs of post-hatchlings, often leading to their death. We now find plastic in nearly 100 percent of these turtles, making it no longer a question of “if” we will find debris, but “how much” will we find.

Because this life stage lives in the open ocean, it is likely that we are seeing only a small portion of turtles that are affected. Therefore, it is probable that many more are dying from plastics. Of even bigger concern is that it is not a local problem. Our oceans are interconnected by currents, one ocean, one planet; this is a global challenge.

So now what? We may not know the true impact of our changing threats for 20-30 years; why? It takes a sea turtle 20-30 years to reach reproductive adulthood. We need two or three decades of more data, but do we have enough time to collect this data as our planet and oceans continue to change? This question, among others, keeps us up at night.

“The increasing mortality from marine debris at this early life stage has the potential to decimate sea turtle populations before we can do much about it,” states Dr. Charles Manire, the Center’s director of research and rehabilitation.

Another factor that influences sea turtle populations is light pollution. Last year our research team documented 195 hatchling and adult disorientations as a result of beach front lighting. Disorientation occurs when a sea turtle crawls toward a source of artificial light rather than the water. This results in expenditure of precious energy reserves or even mortality. Some hatchlings on Florida beaches have been known to crawl over a mile in response to non-natural light.

The disorientation events documented by LMC research staff are very low in comparison to other populations in Florida. We are lucky here at LMC that our local residents remain vigilant about “lights out for sea turtles.” Other Florida sea turtle populations disorient at a much higher rate than we see here; a number of beaches in Florida see 50–90 percent of their hatchlings disorient as a result of improper lighting or sky glow.

The ‘natural odds of survival’ for hatchlings are already low, but now with changing climates, marine debris, light pollution and changing temperatures, we believe the odds continue to change – and perhaps not for the better.

Although we see nesting success on shore, we have little – if any – control to help sea turtles once they reach the ocean.

From the data, we know the ocean needs our help more than ever before. So what now? We need more advocates. Please join us in our efforts by getting involved in the conservation conversation, our sea turtles, our ocean, and the next generation need us to act, right now.