Invasive Florida Turtles in Pamplona Lake: 100 Now, 300 a Decade Ago 2026

The invasive Florida turtle population in Pamplona's Mendillorri lake has become a growing concern, with recent estimates suggesting around 100 individuals currently inhabit the water. This non-native species, known as the Florida turtle (Trachemys scripta), has been thriving in the artificial lake, prompting local authorities to implement control measures.

Two environmental guards recently captured two specimens during a hunting expedition, highlighting the ongoing issue. According to Dani González, one of the guards involved, the lake currently holds about 100 turtles. While this number may seem high, it pales in comparison to a decade ago when the lake was drained and nearly 300 turtles were found, along with several carp and a voracious catfish.

What Happened When the Lake Was Drained?

In October 2016, the Mendillorri lake was completely drained for the first time in two decades. Technicians used electric fishing to stun the lake's inhabitants and capture them with minimal harm. The operation revealed a surprising abundance of invasive species, including the Florida turtle, which had proliferated unchecked.

The presence of these turtles is not just an ecological curiosity; it's a serious problem. The Florida turtle is listed in the Spanish Catalog of Invasive Alien Species (Royal Decree 630/2013), and since 2021, Navarra has conducted an annual control campaign starting in June. The campaign takes advantage of the turtles' love for sunbathing to set traps every week.

How Are Authorities Controlling the Invasive Turtles?

The control method is ingenious yet simple. As González explains, "It's a square trap with two ramps that they climb to sunbathe. Once they've warmed up and go back down, they fall into the trap, which contains a net where they remain floating and swimming." Afterward, guards use a canoe to collect the captured turtles.

This weekly trapping effort is part of a broader strategy to manage invasive species in Navarra's waterways. The goal is to reduce the population to protect native species and maintain ecological balance. The Florida turtle competes with native turtles for food and habitat, and can also transmit diseases.

Why Is This a Problem?

The Florida turtle is native to the southeastern United States but has become a common invasive species worldwide due to the pet trade. When released into the wild, these turtles can disrupt local ecosystems. In Pamplona's Mendillorri lake, they threaten native fauna and flora. The longer history behind the story is traced in Box Tree Moth Outbreak in Pamplona: The Real Threat Is Its Caterpillars.

The lake's artificial nature makes it particularly vulnerable to invasions. It was created as part of an urbanization project and lacks natural predators to control introduced species. The presence of other invasive fish, such as carp and catfish, further complicates the ecological balance. The background to this story is set out in Sea Turtle Nests Record in Florida, but ESA Cuts Threaten Recovery. A related thread runs through Alligator Snapping Turtle Seized in Spain: What You Need to Know. Earlier coverage in Japan's Stray Cat Invasive Species Plan Sparks Backlash shows how the argument developed.

What's Being Done and What's Next?

The annual control campaign in Navarra is a crucial step in managing the invasive turtle population. However, eradication is challenging. The traps catch turtles weekly, but the species reproduces quickly, and new individuals may be introduced through illegal releases. A closer look at the same subject appears in Stranded Ships in Hormuz Risk Spreading Invasive Species Globally. Anyone following the wider picture can start with Sea Turtle Rescue Network Saves Hundreds on Cape Cod. The same theme surfaces in Olive Ridley Turtles Nest on California Beaches in Historic First, which takes a different angle.

Authorities emphasize the importance of not releasing pets into the wild. Education and awareness campaigns aim to prevent future introductions. The situation in Mendillorri lake serves as a case study for other regions facing similar invasions. Context on how this played out before sits in Invasive Species in Spain: Why the Guadalquivir Is a Hotspot. A companion piece, Invasive Species Cost Australia Billions: How to Respond, approaches the same subject from another angle.

• Current population: Approximately 100 Florida turtles in Mendillorri lake.
• Historic high: Nearly 300 turtles found during the 2016 draining.
• Control method: Weekly trapping using sunbathing traps.
• Legal status: Listed as an invasive species in Spain since 2013.
• Campaign start: Annual control efforts begin in June.

Comparison of Invasive Species in Mendillorri Lake

FAQ

The situation in Pamplona's Mendillorri lake is a reminder of the lasting impact of invasive species. While control efforts have reduced the turtle population from its peak, ongoing vigilance is necessary to protect native ecosystems.