sentence: To date , none of these viruses have been studied in water from Antarctica , where they could point towards contamination of pristine areas by research scientists , or long-distance dispersal.During long-term monitoring surveys , in the Katsura River to the west of Kyoto , Japan , FRNAP-II was shown to have very limited seasonality , with similar levels in the winter and summer months ( Hata et al ., 2016 ) .