Crossing Nets: A Loggerhead Turtle’s Journey Through Bycatch in Catalonia

This story is part of a series designed to introduce the perspectives of alumni from the National Geographic Society and The Nature Conservancy’s global youth externship program. Each guest author is an emerging leader in conservation and storytelling.

I grew up by the Mediterranean, a sea that shapes the culture, diet, and rhythm of life of thousands of people. I swam in its waves, walked along its shores, and watched its sunsets. Yet for many years, I didn’t know much about what lived beneath its surface. To me, as for many others, it was just a backdrop to daily life.

That changed in high school, when I was asked to carry out a research project on any subject I wished. I wasn’t sure what to focus on, until I visited the Fundació per la Conservació i Recuperació d’Animals Marins (CRAM) rehabilitation centre in Catalonia, Spain. There, loggerhead turtles surfaced slowly in saltwater pools, their scarred shells and weary eyes telling stories of collisions with boats, plastic mistaken for food, or entanglement in fishing nets.

I was astonished to learn that these creatures — that I had associated with tropical beaches on the other side of the world — actually nest and swim here in the Mediterranean. Seeing the threats they endure every day made me realize that beneath the calm horizon stretched a fragile world in need of our attention.

If I didn’t know this, even though I live by the sea, how many others were also unaware? And if people do not know these creatures exist here, how can they be expected to care for them?

Ancient Creatures

Turtles have survived for millions of years. Modern sea turtles (Chelonioidea) first appeared around 110 million years ago, adapting to changing environments over time. Today, only seven species of sea turtles remain.

Two of these species breed in the Mediterranean: the loggerhead turtle (Caretta caretta) and green turtle (Chelonia mydas), though the loggerhead turtle is by far the most common to find.

This was the species I encountered at the rehabilitation center, and the one that first captured my curiosity. But the more I learned, the more I wanted to understand not just Mediterranean turtles, but their story worldwide.

During a gap year I took after high school, I traveled to Costa Rica to volunteer in sea turtle conservation. There, on a night patrol under a sky heavy with stars, I saw a turtle nesting for the first time. She moved slowly, heaving herself across the sand with ancient determination. I remember kneeling in silence, feeling the weight of her presence, carrying wisdom older than our species. In that moment, respect turned into responsibility.

Changing Times for Turtles

For centuries, loggerhead turtles mainly nested in the eastern Mediterranean. But today, rising sea temperatures are reshaping their patterns. The sex of sea turtle hatchlings depends on the temperature of the surrounding sand. Warmer beaches produce more female eggs, and so climate change is now skewing the sex ratio of populations. And as beaches in the east heat up, turtles have begun to appear more frequently on the coasts of the western Mediterranean.

Most people don’t know this shift is happening, making turtle encounters more dangerous for the animals and for us.

During my high school research project, I learned that the leading cause of sea turtle admissions to the CRAM rehab center was bycatch, or the unintended capture of marine animals in fishing gear.

Unlike visible injuries from boats or plastic, bycatch often leaves invisible wounds. Turtles hauled quickly to the surface can suffer from decompression sickness, the same condition that can affect human divers. From the outside they may look healthy, and most of the time are released back into the sea. But inside, the damage lingers, often leading to death days later.

Crossing Nets Off Catalonia

After my gap year, my commitment to conservation only grew. I started a bachelor’s in biology in France, but I wanted to keep learning and growing beyond the classroom. That opportunity came when I undertook an externship with the National Geographic Society and The Nature Conservancy.

Through the program, I learned how GIS tools can support conservation efforts. I returned to the issue I had first explored during high school: bycatch affecting sea turtles in Catalonia, applying new skills to map and analyze the problem. Using GIS, I could visualize where fishing activity overlapped with turtle presence.

Yet something was still missing. While I could access data on sightings on land or bycatch reports from ports, I couldn’t pinpoint where incidents occurred at sea. That inspired my current project, a collaborative initiative connecting fishers and scientists to register bycatch incidents via a mobile app.

From past experiences, I learned that conservation is never just about protecting animals. It’s about people, their choices, and the connections we build to safeguard nature.

In recent years, the number of sea turtles nesting along the Catalan coast has increased, and is expected to continue growing. This is due not only to environmental pressures bringing new populations, but also to their philopatry, or the tendency of females to return to the beaches where they were born to nest.

At the same time, the number of reported bycatch incidents in Catalonia has also risen. At first sight, this may seem negative, suggesting more interactions and greater impact on sea turtles. Yet it can also be a positive sign; fishermen are becoming more aware of the issue and increasingly report encounters, allowing experts to provide proper care and improve the turtles’ chances of survival.

The role of fishermen is therefore essential. They are on the front line at sea, and their active involvement is key to ensuring the coexistence and conservation of marine species.

A Sea Worth Knowing, A Future Worth Protecting

Fishing is an essential livelihood, but not all methods have the same impacts. Bottom trawling is among the most destructive: massive nets are dragged across the seabed, scraping up habitats that may take centuries to recover. It is also the fishing method that causes the highest levels of sea turtle bycatch in Catalonia.

For sea turtles, this type of gear is deadly. For marine ecosystems, it’s devastating. And yet, bottom trawling still happens even inside designated Marine Protected Areas (MPAs), places that are meant to safeguard biodiversity, at least on paper.

Since the externship, I have continued to engage with ocean conservation issues, which led to opportunities such as attending the 3rd United Nations Ocean Conference and working with EarthEcho International as an Ocean Protection Ambassador.

Through these experiences, I learned that effective ocean conservation requires political action, not just words. Actions like banning bottom trawling in MPAs are essential to allow ecosystems to recover and to protect the species that depend on them.

My externship helped me gain invaluable skills, including storytelling and understanding the importance of connection between people and within communities. It opened doors to new opportunities and allowed me to keep learning and growing, transforming my knowledge into actions with real impact.

For me, the Mediterranean is no longer just the sea I grew up with. It’s a place of hidden giants, fragile ecosystems, and urgent challenges. It’s also where I learned that protecting nature begins with awareness, because we only protect what we know and love.