This year, earlier than other years, spawning for the Caretta sea turtles and the effects of the climate crisis on the oceans are troubling.

For the first time, in the 40 years of records of ARCHELON, on May 10 the first one was found nest Caretta sea turtle in the Gulf Slowly Zakythos.

According to a related announcement by the Environmental Organization, the scientific predictions of moving the spawning season earlier in the spring, due to climate change, are confirmed.

In detail, as ARCHELON underlines, as every May since 1984, the researchers and volunteers started their mission in Zakynthos, the Peloponnese and Crete this year.

But on their first visit to the spawning beaches on May 11, three members of the Zakynthos Program were in for a surprise: the first nest of the season had already taken place the night before in Sekania, the Area of ​​Absolute Nature Protection of the Zakynthos National Marine Park. .

“Reviewing time series data from previous years confirmed that for the first time a nest was found so early in May in Laganas Bay”, says Aliki Panagopoulou PhD, Head of Research Issues at ARCHELON. Meanwhile, her morning May 15th the first Carretta nests were also recorded in its Nature Protection Area Kyparissiakou Gulf and in the north Cretein Rethymnon, and earlier than usual.

But why do sea turtles start laying their eggs earlier?

According to ARCHELON, scientists as early as 2016 predicted that the spawning season would move earlier in the season due to climate change! This is because sea turtles are vulnerable to the effects of climate change both on land and in the sea. Especially the temperature plays an important role throughout the life cycle of the specific animals, significantly influencing their reproduction. Starting egg laying earlier in the year may act as an adaptation mechanism for turtles to avoid very high summer temperatures (Patel et al., 2016).

The recent State of Europe’s Climate 2023 report published by the European Commission states that during the whole year 2023, the average sea surface temperature in all of Europe’s seas was the warmest ever recorded. Parts of the Mediterranean and Atlantic recorded the highest average sea surface temperature values ​​on record there. In the Mediterranean, sea heatwaves were recorded in July and August with sea surface temperatures reaching 5.5 degrees Celsius above average in some areas. The oceans are an important heat store for our planet’s climate system, as they cover 2/3 of the earth’s surface and have absorbed 90% of the excess heat caused by anthropogenic emissions of greenhouse gases. Changes in ocean temperature can lead to habitat changes and mass die-offs of marine species.

“But even if moving nesting to cooler days may provide some relief for turtles, climate change may negatively affect them in other ways. For example, the increase in temperatures prevailing inside the nest during incubation can affect the sex of the hatching turtles. High temperatures lead to the birth of more female than male turtles, which can affect the populations and their survival”, warns Aliki Panagopoulou.