The Xiamen Symposium on Marine Environmental Sciences (XMAS 2025)

Conservation efforts for sea turtles have primarily aimed at safeguarding nesting sites from human disturbances such as habitat destruction and poaching. However, emerging threats, including fungal infections like Sea Turtle Egg Fusariosis (STEF), have become a significant concern, contributing to a growing number of unhatched eggs. This study investigates the fungal species affecting sea turtle nests in Peninsular Malaysia, focusing on green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata). Samples were collected from infected eggs, surrounding sand, and debris from nesting sites in Melaka, Pahang, and Terengganu. Fungi were grown on Potato Dextrose Agar (PDA), pentachloronitrobenzene (PCNB) agar and Carnation Leaf Agar (CLA). The pure cultures were obtained and gene sequencing by using the translation elongation factor 1-alpha gene (TEF-1α) and Internal Transcribed Spacer(ITS) for species identity confirmation. The analysis revealed that Fusarium species were the dominant fungal invaders, with Fusarium falciforme being the most prevalent (48%). Other identified Fusarium species included F. lichenicola, F. keratoplasticum, F. suttonianum, F. proliferatum, F. oxysporum, and F. neocosmosporiellum. Additionally, Aspergillus species, mainly A. fijiensis followed by A. niger, A. ustus and A. niveus were also detected, though they played a secondary role in infection. The results highlight the urgent need to monitor fungal dispersal in sea turtle nesting areas, as Fusarium colonization may be a major cause of hatchling failure. Addressing fungal threats is critical for enhancing sea turtle conservation efforts, ensuring the long-term survival of these endangered species.

Fusarium, sea turtle, hatchlings and conservation