Mar 25, 2026
Just two decades ago, the appearance of a sea turtle nest on the Spanish coast was considered a rarity. Today, however, this is an increasingly evident trend, confirmed by scientists and environmental agencies.
This is the loggerhead turtle (Caretta caretta), one of the oldest and most iconic marine animals on the planet, capable of living between 50 and 70 years, or even longer.
This species, considered rare and vulnerable, is listed on the IUCN Red List with a status of āVulnerableāĀ and is protected by international agreements on the conservation of marine fauna in the Mediterranean.
Although they are widely distributed, their populations have declined in many regions, making every new nesting site a particularly significant development.
How the situation has changed
According to data from scientific studies, monitoring programmes and environmental agencies in Spain (including the Valencian Regional Government):
Until the early 2000s, nesting was very rare and sporadic
From the 2010s onwards, there began to be reports of regular cases
In recent years, the number of nests has increased significantly
For example:
2019ā2021 ā several confirmed nests each year
2022ā2024 ā already dozens of cases across the country
The Valencian Community (including Alicante) has become one of the key areas
It is important to understand that this is not a case of āmass colonisationā, but rather a process that is expanding; it is still limited but growing.
Why do turtles come to Spain?
The main cause is the change in temperature in the Mediterranean and in coastal areas.
Sea turtles have a unique characteristic: the sex of their offspring depends on the temperature of the sand:
below ~27Ā°C ā males predominate
above ~29Ā°C ā mostly females are born
In traditional nesting areas (Greece, Turkey), the temperature of the sand is rising, causing an imbalance in the sex ratio.
The western Mediterranean, including Spain, still has more balanced conditions, making it a potential new breeding ground.
It is not a āreturnā, but an expansion
Genetic studies indicate that turtles that nest in Spain:
come from different towns
including the Atlantic and the eastern Mediterranean
do not belong to a local historical population
In other words, what we are seeing is an expansion of the range, not a return.
Where nests are being found
The main areas are:
Comunidad ValencianaĀ (Denia, El Campello, Orihuela Costa)
CataluƱaĀ (Delta del Ebro, costa de Barcelona)
Balearic Islands
specific cases in Andalucia
This is particularly relevant for this area: the province of Alicante is already one of the key observation points in Spain.
Torrevieja: a local example that confirms the trend
This phenomenon is no longer merely a scientific hypothesis, but a reality that can be observed on the Costa Blanca.
In the summer of 2024, a female loggerhead turtle (Caretta caretta) laid a clutch of eggs on the beach at Los Locos, Torrevieja. Following its discovery, specialist teams activated the protection protocol: the area was cordoned off and some of the eggs were moved to a safer location, including a protected area on the beach at La MataĀ and the facilities of the OceanogrĆ fic in Valencia, where controlled incubation took place.
Months later, in 2025, the hatchlings were born. Some of them took part in the conservation programme known as āhead startingā, whereby they are reared under supervision to increase their chances of survival. In autumn, several of these turtles were released into the sea from the beach at La Mata, in a public event attended by local residents and visitors.
This case is not merely anecdotal: it shows that the entire life cycleāfrom hatching to releaseāis already taking place in Torrevieja, establishing the area as an active part of the speciesā new breeding range.
How nesting occurs
The process remains the same:
A female turtle goes to the beach at night
Lays between 80 and 120 eggs
After 45ā60 days, the young are born
However, the survival rate is extremely low: only about 1 in 1,000 reaches adulthood.
What threatens turtles?
The main risks are caused by human factors:
Artificial lighting disorients the young
cleaning machinery can destroy the nests
the presence of people
coastal development
Therefore, if you spot a turtle, the advice is clear: do not approach it, do not touch it, and contact the emergency services.
What does this mean from a scientific point of view?
Experts interpret this phenomenon as:
a shift in the range
adaptation to climate change
an attempt to maintain reproductive balance
It is not a āmedia sensationā, but a significant biological indicator.
The essentials
Spain is becoming a new nesting areaĀ for sea turtles.
Pero esto no significa:
a mass migration
not a permanent change of habitat, but rather a process of adaptation that is currently underway.
Conclusion
The appearance of sea turtle nests on the Costa Blanca is, at the same time:
Some good news ā the species is adapting
and a warning sign ā the environment is changing rapidly
The big question remains: will the western Mediterranean become a new, stable home for these long-time seafarers, or are we witnessing a temporary phase within a much broader global process?