La loggerhead turtle (Caretta caretta) is gaining ground on the Spanish Mediterranean coast with an increase in spawnings and births that reinforces a trend already visible in recent years. This summer’s most emblematic landmarks, the Delta of the Ebro has established itself as a key nesting area, while in Mojacar The first offspring have already appeared after continued technical management and monitoring.
The phenomenon is attributed to a combination of warmer waters for climate change, the quality of natural spaces, and the improvement of protocols and the citizen involvementThe laying usually starts at midle June and, with a few incubations of about 50 days, births can last well into autumn.
The Ebro Delta is consolidating itself as a key laying area
So far this season, six of the ten sets confirmed on Catalan beaches are concentrated in the Delta of the Ebro, an enclave that specialists already describe as one of the major of the Mediterranean coast for the species. The concentration of nests in this area is approximately equivalent to one in four nests recorded throughout Spain (usually between 20 and 30 per year), while the rest of the Catalan nests have been located in the Costa Brava.
The 2025 calendar illustrates the rhythm of the season: 20 June, first nest in the Delta with 119 eggs ; the 25 June Two new cases are detected in Sant Feliu de GuÃxols and again in the Delta (With 101 y 90 eggs); the 6, 16 and 17 for July More bets are added in the Delta (with 100, 101 y 93 eggs); the July 19th a nest appears in Platja d'Aro 74 non-viable eggs; the July 24th another spawning is recorded 113 in the Delta; the July 27th, 63 en l'Escala, as well as the July 30th, 105 en l'EstartitThe balance sheet speaks of 885 viable eggs.
The regional administration believes that the curve will continue to rise: the season it is not closed and new clutches could be confirmed or nests that have gone unnoticed until now could appear. Given that births can extend beyond September, the possibility of nesting is not ruled out. hatchings until October; in fact, in the Delta the first offspring this week.
This boom confirms a change in behavior compared to previous decades: in Catalonia they were mainly documented juveniles and subadults feeding on the coast, and it was not until 2006 (Premià de Mar) and 2011 (Malgrat de Mar) when the first eggs were found. The expansion in the western Mediterranean is reminiscent of what happened in Italy, where it went from barely 2-5 nests in the late 90s to figures that today are around 700-800 annually.
Births in Mojácar and nest management
En Mojácar (AlmerÃa), the first hatchling emerged in the Rumina beach after 55 days since the setting made on 22 June, made of 99 eggs To minimize the impact of storms, the nest is relocated near the original point following the inter-administrative protocol, moving 20 eggs al Oasys Minihollywood in Tabernas and staying 79 on the same beach with protection and thermal control measures.
In the days before birth the following was observed: characteristic sinking of the sand that announces the hatching. The surveillance has been uninterrupted, with Environmental Agents, staff of the Ministry, Local police and volunteering of the association SERBA, an entity recognized in 2024 with the Andalusian Environmental Award.
The offspring will be derived al Andalusian Marine Environment Management Center, a Algeciras, for a program of headstarting which keeps them for approximately one year until reaching around 700 grams and harden the shell. This initial reinforcement increases the supervivencia against predators in a species in which, despite hatching rates of 70-90%, just around the 1% reaches reproductive maturity.
AlmerÃa adds nesting history in Vera (2001), Pulpà (2015) y Mojácar (2021 and 2023), along with attempts without a nest in Bitter Water (2014), Almanzora Caves (2016) y Mojácar (2024)The presence of nests on Spanish beaches is increasingly common, a pattern associated with Mediterranean thermal rise and more active social surveillance and awareness.
Causes of change and conservation challenges
Factors explaining this shift include the water heating, the existence of well-preserved natural spaces, the low Light pollution in stretches of coast and collaboration between administrations, entities such as CRAM Foundation y Beta-University of Vic, and the fishing sector itself, returns juveniles accidentally caught. The marine environment of the Delta of the Ebro It also acts as a feeding area for juveniles from the western Atlantic and the eastern Mediterranean.
The biology of the species determines its vulnerability: females reach sexual maturity between the 15 and 30 years, can overcome the meter of shell and 200 kilos, and bury the eggs 35-50 cm on the sand before returning to the sea. Although the season coexists with crowded beaches and temporary, the technicians are confident of beating record bets if the trend continues.
The scientific community is investigating why the spawnings in the eastern Mediterranean usually occur around 70-90 eggs and in the West they sometimes reach until 130With the season still underway and an increasingly normal presence on Spanish beaches, forecasts point to a sustained expansion of the number of nests in the coming years.
The map they draw Delta of the Ebro y Mojacar It is that of a species that is adapted to a changing Mediterranean, supported by management protocols, science and citizenship: more nests, better data and a window of opportunity to ensure their campaigns long term.