<i>Malassezia</i> in environmental studies is derived from human inputs

<i>Malassezia</i> is the singular fungus most associated with humans. It colonizes mammalian skin and requires host-derived fatty acids to grow. Widespread sequencing of environmental DNA surprisingly showed that <i>Malassezia</i> is also ubiquitous outside of mammalian hosts. <i>Malassezia</i> is frequently found in marine habitats where it is associated with corals, deep sea vents, diatoms, and more. Given its widespread presence, we reasoned that public metagenomic data could be used to assemble a genome sequence of an uncultured marine <i>Malassezia</i>. However, we found that <i>Malassezia</i> was ubiquitous but never abundant in marine samples and that the few metagenomes we could assemble were consistent with recent human introduction. We also found that the presence of human DNA in sequencing data sets is strongly correlated with the presence of <i>Malassezia</i> DNA, and while not ruling out the growth and survival of <i>Malassezia</i> in marine habitats, they suggest widespread contamination of public data with <i>Malassezia</i>.