| Motiv: Wetlands have been degraded and destroyed for centuries with knock-on effects on ecosystem structure and functioning. Wetlands are now restored to meet environmental objectives and global sustainable development goals. In addition, in the last decades, beavers have repopulated vast areas of their former distribution range. Via dam building, beavers contribute as a nature-based solution (NBS) to wetland restoration. While wetland restoration (either active or NBS) has environmental and ecological benefits, large-scale wetland restoration might harbor potential caveats: risk for outbreaks of vector-borne and zoonotic (animal-spread) diseases. Mosquitoes thrive in wetlands and are important vectors of multiple diseases contracted by humans, and beavers are suspected to either directly (as reservoirs) or indirectly (by creating “risky habitats”) contribute to increased incidence of tularemia (Sw: harpest) among humans.
Mål: In WetZoo, we will study if wetland restoration increases zoonotic risk and examine the following research questions: Do restored wetlands harbor disproportionally high number of vector-borne and zoonotic pathogens and with higher prevalence? Do beaver ponds create favorable conditions for pathogens? Can the increase in human cases of tularemia during the last decades be explained by increased wetland area? A central aim of WetZoo is to identify HOW wetlands can be designed to mitigate potential zoonotic risk.
Metod: In WetZoo, we will combine targeted field studies with experiments. In the field studies, we will examine pathogen prevalence in water, biofilm (incl. mosquito larvae), and wildlife (beavers and small mammals) in different types of wetlands (incl. restored and non-restored ones). In experiments, we will restore 30 wetlands and follow pathogen load in before-after studies.
Varaktighet: WetZoo is designed as a 4-yrs PhD project. With its experimental approach (before-after), WetZoo enables future projects to focus on the long-term effects of wetland restoration since the most critical reference data (situation before restoration) will already be available from WetZoo.
Preliminära resultat: In Sweden, human tularemia cases have increased over the last decades, an increase that temporally and spatially coincides with the recolonization of beavers. In a project focusing small mammal communities in wetlands, communities were species richer and small mammal abundance was higher in beaver systems. As small mammals are important reservoirs of the bacterium causing tularemia, it is likely that beaver wetlands enhance the landscape load of the bacterium.
Anknutning till stitelsens ändamål: WetZoo focuses on water conservation. In the light of the current COVID-19 pandemic, nature restoration is promoted – amongst others by the EU and World Health Organization – as one of the most important tools to mitigate future risk for outbreaks of epidemics and pandemics. We unfortunately see the risk that especially wetland restoration – if done in a wrong way or at the wrong place – might rather trigger pathogen transmission. The results of WetZoo will therefore be pivotal in guiding future restoration projects towards maximizing ecosystem services and minimizing ecosystem disservices, here zoonotic risk. |