A person sampling sediment on an Arctic shore. 
Teppo Rämä/UiT The Arctic University of Norway

Human activities alter ecosystems and in most cases lead to biodiversity loss. Animals, plants and fungi are responsible for the processes and services the ecosystems provide. The loss of species threatens the ability of ecosystems to provide these services and to remain stable over time. 
Scientists have raised awareness of this threat for decades and in response, policy has established biomonitoring programs that help to assess change in ecosystem status and biodiversity over time and space. However, despite their importance for ecosystems, no monitoring program yet includes aquatic fungi, i.e. fungi living in freshwater and marine ecosystems. 

Aquatic fungi (AF) are crucial in ecosystems as resources for higher trophic levels, as parasites that control animal and plant populations, and as decomposers and pathogens that control carbon and nutrient cycling. AF thereby contribute to all four categories of ecosystem services: i) regulating services, like leaf litter decomposition and the self-cleaning capacity of ecosystems; ii) supporting services, like nutrient cycling and bioindicators of environmental conditions; iii) provisioning services, notably metabolites and clean water; and iv) cultural services, particularly educational and inspirational values. 

The new European project MoSTFun aims at reducing our knowledge gap on AF by adding these vital organisms to biodiversity monitoring programs.