How Microplastic Pollution May Be Creating More Female Turtles

Loggerhead (Caretta caretta) sea turtle hatchling. Photo by Airman st Class Alex Echols.

We’ve all encountered plastic trash in places they don’t belong: A broken spoon laying on the beach, a soda bottle the wind blew into your yard or even a chunk of broken car bumper laying in the street.

This plastic may seem like harmless trash in the moment, but have you ever considered the effects of plastic as it breaks down into smaller pieces — called microplastics — on large marine species like sea turtles?

Microplastics are small pieces of plastic less than five millimeters long and come from a variety of sources, including larger plastic debris that degrades into smaller pieces, synthetic fibers, and microbeads. Microbeads are manufactured polyethylene plastic that are added in beauty products as exfoliants, such as face wash and toothpaste, and are small enough to pass basic water filtration systems and enter the ocean.

But how are they affecting sea turtles?

A study led by Dr. Mariana Fuentes and a team of researchers from Florida State University set out to find the answer. Fuentes and her team traveled to the northern Gulf of Mexico to quantify the amount and type of microplastic in loggerhead sea turtle nesting beaches.  What they found was disturbing.

Fuentes writes that plastic, microplastic, microbeads, and synthetic fibers change the composition and temperature of sandy beaches where marine turtles lay their nest and incubate their eggs. The change in beach sand composition and temperature influences hatching success, gender, and size of the baby turtles, called hatchlings.

Fuentes notes, “Since plastics warm up when exposed to heat, when combined with sand, microplastics may increase the sand temperature, especially if the pigment of the plastic is dark. This could potentially affect the nesting environment of marine turtles, biasing the sex ratio of turtles toward producing only females and affecting the future reproductive success of the species.”

In simple terms, the sex of the baby hatchling is determined by the temperature of the sand during incubation. Eggs deep in the cool nest produce males. Eggs closer to the warm surface produce females. As an influx of plastic is finding its way onto nesting beaches, researchers are worried that increasing sand temperatures could produce more females than males, severely affecting future populations of this marine mega-fauna by potentially reducing the number of fertile males.

The other implications of plastic pollution on nesting beaches and their long-term effects on sea turtles is still being studied.

Unfortunately, microplastics have been found on almost all sea turtle nesting sites across the globe. To move forward as an eco-conscious society, we must consider how our material consumption and waste methods are influencing the natural world and the species that live in it. Remember that we’re all in this together and that we create the future we want by the actions we take today!

Here’s a of things you can do TODAY to help protect the ocean, sea turtles, and other marine species:

  • Stop buying products that contain polyethylene microbeads. Check out this incredibly resourceful website for a list of products to avoid.
  • The adage of Reduce, Reuse, Recycle is as imperative today as the day it was coined in 1976. Follow it!
  • Switch to carrying a reusable canvas grocery bag. Jellyfish and plastic grocery bags look the same to a sea turtle.
  • Reduce the use of glitter, wet wipes, to-go cups, laundry and dishwater pods as they all contain polyethylene.
  • Properly dispose of other marine debris like cigarette butts. Their filters are made from a non-biodegradable plastic.
  • Learn your states recycling law. A quick google search will help you find these. Try searching “[State] plastic recycling law.”
  • Avoid single use plastic like straws, cutlery, cups, and shopping bags.
  • If you’re by a beach, volunteer for a local beach and ocean cleanup.
  • Educate your friends and family of the dangers of microplastics on marine life.


What ideas do you have on how we can reduce plastic use, waste, and help marine species like sea turtles? Comment below and follow @beprofoundorg to stay connected.

Written by Evi Karpos

Environmentalist with a Bachelor of Science in Environmental Studies. Obsessed with turtles, sustainability, conservation, waste management, and climate change. Future PhD student.

Would love to connect on Twitter and LinkedIn.  

What is the Land & Water Conservation Fund?

And does it help animals and the environment?

The Land & Water Conservation Fund (LWCF) was signed into law on September 3rd of 1964 and went into effect on January 1st of 1965. Its 2 main purposes were to allow the federal government to acquire and develop land for conservation purposes and to fund state and local grants for outdoor recreation resources. It was originally funded for a period of 25 years but had been extended twice before expiring on September 30th of 2018. On February 12th of 2019, the Senate passed the Natural Resources Management Act (NRMA) by a vote of 92 – 8. This permanently funds about half of the LWCF’s $900 million annual budget. It is expected to pass both the House of Representatives and the President.

The LWCF is probably the most important law on the books when it comes to your experience with public lands. It has benefited every single county in the country. It funds national parks, wildlife refuges, forests, rivers and lakes. It also funds community parks, trails and ball fields in all 50 states. It is funded by royalties from energy companies, paid to the government from off-shore oil and gas drilling on federal lands. The LWCF has grown and evolved over the years and now supports other conservation purposes. Unfortunately, Congress has only appropriated the full $900 million once or twice in the years that the act has been in place. Because of this, there is a backlog of federal conservation needs estimated at more than $30 billion.

Even though the NRMA is considered to be some of the most important public lands legislation since the 1970’s, it’s also a compromise. While there is legislation that is seen as not being completely environmentally friendly, most of it is well regarded and the partial funding of the LWCF is widely considered to be a very large win for our environment.

We would love to know your thoughts regarding either the LWCF or the NRMA. Please write to us by email or on our social media @BeProFoundorg.

AUTHOR: John K. Hagler