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A Costa Rican national park has an annual 'mass arrival' of female sea turtles - and one biologist has spoken out about the incredible day the park encountered the biggest swarm of the creatures to ever be captured on camera.
The stunning footage shows the huge gathering of turtles, known as an 'arribada' in Spanish, and sees hundreds of thousands of the animals heading to the coast to lay their eggs on the beach at the country's Ostional National Wildlife Refuge.
Biologist Vanessa Bézy has studied the incredible phenomenon for years. She filmed the reptiles as part of her research, in which you can see the huge swarm of olive ridley sea turtles making their way to shore.
Recording on a drone, she got lucky one day and caught the massive gathering of turtles, said to be the biggest swarm ever recorded.
Bézy told National Geographic: "I immediately knew there was something special going on.
"To this day I'm still blown away by the video. They look like bumper cars out there."
The video was shared on YouTube, with the caption: "A sea turtle sanctuary in Costa Rica is under threat from over-development and mass-tourism.
"The Wildlife Conservation Association is developing programs to protect sea turtles and other wildlife at this site and is currently leading a campaign to establish a Center that will house all of these activities. Find out more at www.NosaraSustainability.org."
The drone footage reveals that they are gathered at a rate of around one turtle per square metre and over the wet season, around 250 turtles per square kilometre were measured. The video also shows turtles, which can live to around 50 years old, rising in to view, suggesting there are more than initially estimated hiding under the surface.
Filmed in November 2016, the mass arrival is one of the only ones that still takes place - with only a Mexican beach reported to have a greater concentration of the animals.
However, Bézy warns that development and mass tourism in the area present a huge risk to the species, which is one of six classed as under threat. These mass gatherings are an important part of their life cycle.
She has stressed the importance of regulations for real estate developers who are investing in the area, saying the rules must limit building height, light usage and other factors that could impact the environment and the turtles.
Although she believes the regulations are too lenient, she believes that they are much needed and better than nothing.
Featured Image Credit: PA
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