Microbiota in fungal-infected sea turtle nest. Sea turtle nest sand

Hatchery practices influence the outcome of conservation success. In sea turtle hatchery, reusing sand is believed to associate with microbe or pathogen accumulation which affects hatching success. It is unclear whether such approach increases the risk of Fusarium solani species complex (FSSC) infection, which caused huge mortality in sea turtle eggs worldwide. We employed 16S and ITS amplicon sequencing in 123 nest sand samples and isolated fungal strains from diseased eggshells across seven hatcheries in Malaysia. FSSC was isolated from all sampled hatcheries which F. falciforme was the predominant species. A distinct microbial composition and higher abundance of FSSC (mean 5.2 %) were found in used-sand of hatchery. Furthermore, we revealed another fungus Pseudallescheria boydii consistently appeared in higher abundance (mean 11.4 %) in FSSC-infected nest and associated with lower hatching success. An apparent exception was found in one hatchery that maintains more stringent practice by changing the hatchery location (i.e. sand) every nesting season. The microbiota of nest sand from this hatchery is similar to natural environment. Moreover, the FSSC abundance of this hatchery was also the lowest when compared to other sites. This study may help suggest practices that reduce fungal infection on turtle eggs in hatchery setting.