In the last 30 years it hasdecreased number of beaches where sea turtles nest, the number of females that come to lay their eggs, the number of eggs that hatch, and the survival rate of the young. According to an investigation by the Higher Council for Scientific Research (CSIC), one of the factors responsible for this situation is agroup of strains of the fungus Fusarium solani.
? Research has revealed that this group of F. solani strains is responsible for themass mortality of loggerhead turtle eggs, Caretta caretta, on the beaches. These strains represent a risk for the survival of these endangered species ?, explains CSIC researcher Jullie Sarmiento-Ramírez, from the Royal Botanical Garden.
Until now, the decline in the number of breeding beaches and egg survival was always attributed to human impact, but this study shows that there are other threats related to the egg-laying period and embryonic development.The fungus found feeds on decomposing organic matterand, under ideal microclimatic conditions, it can affect both immunosuppressed animals, causing nail and eye diseases, as well as some plant species.
75% of the eggs die
The loggerhead sea turtle is in danger of extinction and the number of specimens in the Atlantic is decreasing. “Nest mortality in Cape Verde, where the study was carried out, is very high.Around 75% of the eggs die and most of them are colonized by fungiBut there are other causes of death, such as nest flooding or predation, and it is very difficult to establish the percentage of death caused by each factor, “explains CSIC researcher Adolfo Marco, from the Doñana Biological Station.
“What we do know,” adds Marco, “is that the fungus can massively kill loggerhead turtle eggs and that this fungus is present from the beginning of incubation in the vast majority of nests on the island of Boavista. (Cape Verde), the area where 90% of the eggs in the entire eastern Atlantic are laid “.
A female loggerhead turtle nests every two to three years, but the season that does so she can lay between four and six nests, with an interval of 14 to 16 days between each laying. The number of nests it makes in its lifetime will depend on its survival and longevity.
