Conservation, Nature, Science

Logging Threatens Leatherback Turtles

Leatherback turtles are under threat from fishing nets, marine debris like plastic, and now it seems that even distant logging activities are threatening the species.
Baby leatherback turtles like this one can become the victims of predators if their way from nest to ocean is impeded by logging debris. Photo: Shutterstock

Leatherback turtles face a number of difficulties, all of which threaten the species as a whole. They are often caught in fishing nets or eat marine debris like plastic. Many of their nesting sites are under pressure from tourism and other human activities. And now it turns out that even logging is a danger to them, despite the fact that it rarely happens near beaches.

The problem is that logging creates quite a lot of debris, which ends up washing ashore on the beaches where leatherback turtles make nests and lay eggs. These turtles have to lay their eggs far enough up the shore that they won’t be flooded by high tide. But that debris can get in the way of mothers building nests, who have to spend more time on that process and have to build their nests closer to the tideline.

Once they hatch, baby leatherback turtles make their way across the sand and down to the water, but that is becoming increasingly difficult in areas subjected to logging debris. The turtles have to navigate around the debris, which requires them to use up more energy and puts them at increased risk of predation. While not every turtle makes it to the water—where they can start eating to replenish the energy spent getting there—with increased obstacles, even fewer are doing so. Over time, this could result in an overall decrease in the leatherback turtle population, which is already struggling.

“Leatherback turtles are already under immense pressure, from fisheries bycatch, and are also one of the species prone to ingesting marine plastic litter,” said Prof. Brendan Godley of the University of Exeter. “Our research clearly indicates that logging presents another threat. It is now paramount that beach cleanup operations are built into logging activities to prevent further damage to the species.”

Luckily, leatherback turtles are a favorite of environmentalists, tourists, and other people with the social clout or budget to try and affect change on their behalf, so the odds are good that they will at least be supported with beach cleanup activities.

“Simple measures could make a real difference, such as repositioning organic waste areas, or salvaging the wood debris as an energy source,” said Dr. Adolfo Marco Llorente of the Doñana Biological Station. “It is also essential that logging practices [which] reduce the impact on the marine environment are implemented.”

Environmental Hazards, Nature, Science

Over Half of Sea Turtles Have Eaten Plastic

Sea turtles are threatened when they ingest plastic trash found in the ocean. This decaying plastic bag looks like a jellyfish and a seat turtle would consider it food.
Sea turtles are threatened when they ingest plastic trash found in the ocean. This decaying plastic bag looks like a jellyfish and a sea turtle would consider it food. Photo: seegraswiese | WikimediaCC.

According to a recent study, roughly 52% of turtles worldwide have ingested some human rubbish, generally plastic. This revelation comes quickly after a study that found 60% of seabird had also ingested plastic in some form or another.

When turtles eat garbage, it has the potential to get lodged in their gut, where it can cause physical harm, take up space within their digestive tract, or even release toxic chemicals into their tissues. The rubbish comes from the roughly 12 million tonnes of plastic that finds its way into the ocean annual.

That’s a lot of plastic and, unfortunately, a lot of it can be mistaken for food by unaware turtles. In the case of olive ridley turtles, this can be especially dangerous as these turtles have a wide distribution, and tend to feed in the open ocean where debris accumulates. They often eat jellyfish and other floating creatures and could easily mistake bits of trash for their regular prey.

The waste problem is especially severe in Australia and North America, both of which host a wide variety of sea turtles, and have large urban populations, the kind which tends to produce trash that ends up in the ocean. As such, people living on these continents have to find ways to reduce the amount of waste that makes it into the sea, beyond what efforts are already being made.

As with seabirds, the number of turtles that have ingested plastic or another type of trash is expected to continue rising as long as pollution levels stay as they are. Reduced trash means fewer animals will be in harm’s way. But researchers were sure to warn that if turtles and birds were ingesting plastic with this kind of frequency, other animals surely are as well. Although studies haven’t been performed on fish or aquatic mammals, it’s only a matter of time until we start finding plastic in their digestive tracts too.

Climate Change, Conservation, Environmentalist, Nature, Wildlife & Animal Rights

Climate Changes Affects Sex of Sea Turtles

Warmer sand temperatures increase the likelihood that sea turtles will be born female.
Image: Shutterstock

A recent study published in the scientific journal Nature Climate Change, shows that continual warming climate could cause greater numbers of sea turtles to be born female. The publication warns that when the sands become too warm, the sea turtle eggs grow too warm. Without enough male sea turtle, the entire population could be at risk for extinction.

“Sea turtles are unusual in that the gender of the offspring is not driven by sex chromosomes, as in humans,” said Professor Graeme Hays, one of the lead authors of the study. Rather, the sex of sea turtle’s is determined by the sand’s temperature where the female turtle decides to bury her eggs.

Scientists have long known that the reproductive process in reptiles is extremely sensitive to shifts in temperature. For species of sea turtles, once the temperature goes above about 84 degrees Fahrenheit (29 degrees Celsius), more female turtles are born. At about 87 degrees Fahrenheit (30.5 degrees Celsius), populations become completely female.

“It will be the end of the story without human intervention,” said co-author Graeme Hays from Deakin University in a report by the Sydney Morning Herald. At temperatures higher than about 91 degrees Fahrenheit (33 degrees Celsius), embryos fail to survive. Sand temperature depends strongly on its color, Hays said.

“The darker the sand, the more heat it absorbs from sunlight. So blacker sand would be much warmer than lighter colored sand.”