Mink (Neovison vison) as a natural vector in the dispersal of the diatom Didymosphenia geminata

Considerable resources have been invested worldwide in response to the spread of the diatom Didymosphenia geminata in rivers and streams. Considering the very low possibility of elimination of an invasive microbe, management has focused on biosecurity protocols, addressed exclusively toward the human role in dispersal (e.g. ‘check, clean dry’ campaigns and gear-washing stations for recreational users). Natural dispersal by wildlife vectors may also play an important role in the spread of D. geminata and other algal species, potentially limiting or negating the efficacy of biosecurity measures. We investigated the possibility that introduced mink (Neovison vison) may be a potential dispersal agent for D. geminata and other stream diatoms in Chilean Patagonia. Neovison were trapped near a zone of strong and persistent D. geminata blooms in the fifth order Rio Simpson, and also in a fourth order upstream tributary, Rio Huemules, the latter with smaller, more incipient blooms. Epibiotic D. geminata cells were...