Bigger is Better for Leatherback Sea Turtles: Fatter Turtles Swim Better

When it comes to leatherback sea turtles, bigger is better. Scientists have found that fatter sea turtles have an easier time swimming through the ocean, and are able to conserve more energy to up their chances of survival.

As our climate changes, the habitable ranges of sea animals are also changing. This means that the ability to predict an animal's physical interactions with the environment is important to understanding how they'll react to these changes.

In this case, the scientists examined the fluid dynamics of a swimming creature in addition to the energetics required to perform the work. They tethered turtles to instruments that allowed them to measure the force they produced while swimming. The scientists also measured the oxygen the turtles consumed and the heat they exchanged with the environment.

Then, the scientists recreated a virtual environment with a swimming turtle to see if they could predict how much energy the turtle was using to swim. In the end, they found that fatter turtles actually were better swimmers than leaner ones.

"That was a surprise and I thought it was a mistake when I originally did it," said Peter Dudley, lead author of the new study, in a news release.

The flippers of thinner turtles come closer together at the bottom of their stroke. This, in turn, causes them to lose more power than larger turtles, which means that they expend more energy to move through the water.

"Now that we have (models) for both marine and terrestrial environments, we can answer those types of questions and get back to the big mass extinctions and get some insights into how did animals live before and after those extinctions," said Warren Porter, one of the researchers. "Why were the animals that survived able to survive?"

The findings reveal a bit more about how sea turtles in particular cope with their environment. More specifically, it shows that larger turtles have more of an edge, which may have implications for future studies.

The findings are published in the journal PLOS One.