Invasive Species: The Case of Didymosphenia geminata in Neuquén, Argentina

BEAMUD G.; LAFFITTE L; MUÑIZ SAAVEDRA, JULIETA; BAFFICO G; LAURENZANO B; DIAZ M; PEDROZO, F.L.

FRESHWATERS AND WETLANDS OF PATAGONIA. ECOSYSTEMS AND SOCIOECOLOGICAL ASPECTS

springer

Año: 2022; p. 100 - 120

 The diatom Didymosphenia geminata (D. geminata) is an invasive periphyticspecies from the Northern Hemisphere. This organism presents an ecologicalparadox since it has the apparently unique ability to rapidly produce largedevelopments of algal biomass in oligotrophic environments. The explanation forthis paradox is unclear, but it likely includes aspects of ecology, hydrology,biogeochemistry, and geomorphology. D.geminata occurrence and mat formation in Patagonia date from 2010,spreading throughout Argentinean Patagonia (provinces of Chubut, Neuquén, RíoNegro and Santa Cruz) by 2018. Since the appearance of the alga, the GeneralDirectorate of Aquatic Biology and the Provincial Directorate of Water Controlof the Neuquén Province have worked to establish surveillance guidelines and toidentify the presence of D. geminata inaquatic environments to set up protected areas free of the alga, as well as todefine the actions to be taken in the provincial territory. In 2012, theSurveillance and Monitoring Program was implemented. In this chapter we discussthe results of the program related to the dispersion and ecology of the algaand its effects on periphytic communities. Historically, D. geminata habitat preferences have been related topristine-oligotrophic conditions. At present, the alga is expanding itsecological spectrum, showing a wider tolerance to environmental conditionsparticularly for nutrients such as phosphorus and nitrogen, some ions such asmagnesium, and even temperature. Range expansion and environmental preferencesof D. geminata could modify the stateof susceptibility to invasion in numerous waterbodies. Efforts by stateagencies have not been able to prevent the spread of this invasive exoticorganism within Neuquén, and between other Argentinean provinces. For themanagement and control actions of invasive species to be effective, it isparamount to quickly respond to alerts, without administrative delays.