Nest microbiota and pathogen abundance in sea turtle hatcheries

Hatchery practices are pivotal to conservation success. In sea turtle hatcheries, reusing sand is a norm, but it remains unclear whether such an approach increases the risk of Fusarium solani species complex (FSSC) infection and mortality in sea turtle eggs. We employed 16S and ITS amplicon sequencing in sands and isolated Fusarium strains from diseased eggs across seven turtle hatcheries and their neighbouring beaches in Malaysia. FSSC was isolated from all sampled hatcheries, and Fusarium falciforme was the predominant species (82.9%). All but one hatchery had a distinct microbiota and higher abundance of FSSC (mean = 5.2%) than the nesting beaches (mean = 1.3%). The hatchery that maintained the most stringent practice by not reusing sand had a microbiota resembling that of nesting beaches, and the lowest FSSC abundance. The results of the current study imply that sand should not be reused in sea turtle hatcheries.