Arctic marine fungi: from filaments and flagella to operational taxonomic units and beyond

Abstract

AbstractFungi have evolved mechanisms to function in the harsh conditions of the Arctic Ocean and its adjacent seas. Despite the ecological and industrial potential of these fungi and the unique species discovered in the cold seas, Arctic marine fungi remain poorly characterised, with only 33 publications available to date. In this review, we present a list of 100 morphologically identified species of marine fungi detected in the Arctic. Independent molecular studies, applying Sanger or high-throughput sequencing (HTS), have detected hundreds of fungal operational taxonomic units (OTUs) in single substrates, with no evidence for decreased richness of marine fungi towards northern latitudes. The dominant fungal phyla may be substrate-specific, as sea-ice and seawater seem to host more Chytridiomycota and Basidiomycota than Ascomycota-dominated driftwood and sediments. Molecular studies have revealed the presence of the Chytridiomycota and Leotiomycetes in Arctic waters, with mounting evidence suggesting a significant role in nutrient and carbon cycling. The high detection frequency of Leotiomycetes is partly due to OTUs from marine