Effects of anthropause on tardigrade urban communities during COVID-19 pandemic restrictions in Salta, Argentina

GRABOSKY, A; ANDREA X, GONZÁLEZ REYES; ROCHA, ALEJANDRA MARIANA; RODRÍGUEZ ARTIGAS SANDRA; BALLARDINI F; OSTERTAG, B; DOMA, IRENE; CORRONCA JA

Simposio; 15th International Symposium on Tardigrada; 2022

Background: To manage and prevent coronavirus illness (COVID-19), restriction measuresthat heavily affected social activities were implemented. This period of restricted humanmovement, or anthropause, ensured an unprecedented reduction of anthropogenicemissions, resulting in a significant improvement in air quality in many cities.Methods: We use the reduction of vehicular traffic in Salta as a reference for evaluating theimpact of the anthropause on tardigrade populations. We used samples taken during the 2019winter season with high (H) and low (L) vehicular traffic, as well as those collected during the2020 winter season under the restrictions (HC and LC). The samples were processed like theusual methodology. The programmes PAST, iNEXT, SPADE, and R were used to analyse thedata.Results: A total of 1,887 specimens were collected, representing 13 species. Habitat H had thehighest number of individuals (N = 1086), although habitat L was 1.34, 1.20, and 1.13 times morediverse than communities H, LC, and HC, respectively. In addition, habitat HC was found tobe 1.19 times more varied than habitat H (prior to the restrictions). The Whittaker curvesreveal that all urban communities are dominated by Macrobiotus sp. nov., Milnesium quiranae,and Viridiscus rufoviridis. Doryphoribius was only found in H and L, and Mesobiotus was onlyfound in HC and LC. Mesobiotus sp. nov. 1 is a new species for science. The beta diversitypartition indicated that species turnover was higher than nesting. The ordination (CCA)explained 64% of the total variance (Axis 1), distinguishing the L community from the H, HC,and LC communities, showing increasing similarities across the habitats during therestrictions.Conclusions: We infer that limits on vehicular traffic during the COVID-19 pandemicmitigated the previously observed consequences of species extinction due to biotichomogeneity, allowing the colonisation of novel species such as Mesobiotus sp. nov. 1. Nestedurban patterns of diversity could be reversible gradients over time. To summarise, we stressedthat the diversity of tardigrades in Salta and a variety of variables, the most important of whichis vehicular activity, influence their assemblages.