Rising Jellyfish Populations: Can Leatherback Sea Turtles Come to the Rescue?

By Keeley Zimmerman

Moon Jellyfish. Teresa Shumaker photo.

Moon Jellyfish. Teresa Shumaker photo.

Have you noticed more jellyfish washing up on the beaches of South Padre Island in the last few years? Maybe you aren’t concerned yet, but worldwide jellyfish blooms are being observed more frequently.
Dr. Lisa-ann Gershwin, director of the Australian Marine Stinger Advisory Services, links the rising number of jellyfish blooms to human activity such as habitat destruction from increases in land development, trash, toxic chemicals, global warming, and overfishing.
The increasing number of jellyfish blooms may be an indication that the ocean environments are changing, and not for the better. Increases in jellyfish populations don’t just mean a rise in the number of people stung by jellyfish each year — increases in jellyfish numbers also lead to decreases in phytoplankton and zooplankton populations. Jellyfish eat the larvae of many different species of fish, which affects larger marine animals as well as tourism, aquaculture and fisheries. The rising jellyfish populations could negatively influence the environment, other animals and humans alike. So what can be done to slow down and ultimately stop this increase?
One of the most important things we can do to reduce the increases in jellyfish blooms is to protect the natural predators of jellyfish, such as tuna, swordfish, salmon, triggerfish and sea turtles — especially the leatherback sea turtle.
According to the World Wildlife Foundation (WWF), leatherback sea turtles provide natural ecological control over jellyfish populations. Leatherback sea turtles eat only jellyfish, and they have to eat their body weight in jellyfish everyday. They are also the largest species of sea turtle meaning that they eat on average 800 to 900 lbs of jellyfish each day. Unfortunately, leatherback sea turtles are already critically endangered. On top of that, plastic bags, balloons and other trash look extremely similar to jellyfish! Plastic can block the digestive tract of sea turtles, which may lead to a slow and painful death. The WWF continues to see declines in the leatherback sea turtle populations worldwide, but especially in the Pacific Ocean. We need to protect leatherback sea turtles before it is too late! These turtles desperately need our help, and in return they can protect us from jellyfish for generations to come.
Plastic bags need to be kept out of oceans worldwide. We can eliminate the use of plastic bags overall if we chose paper or canvas grocery bags instead. Also, pop our balloons and place them in a trash can instead of letting them float into the sky. In order to eliminate trash in ocean environments, we need to reduce, reuse and recycle. Spread the word to friends, family and everyone! Let’s help leatherback’s help us and the ocean!

Keeley Zimmerman wrote this article last summer, while interning for Sea Turtle, Inc. She has a Master’s degree in Marine Biology from University of North Carolina Wilmington and a B. S in Biology/Ecology and Environmental Biology from Appalachian State University. Her master’s work was on moon jellyfish musculature. She is from Summerfield, a small town in North Carolina.