The interaction between bacterial abundance and selected pollutants concentration levels in an arctic catchment (southwest Spitsbergen, Svalbard)

Highlights: • The Arctic is no longer considered as a highly pristine environment. • The purpose of the research was to study interactions between pollutants and bacteria. • Freshwater samples were manually collected from the Revelva catchment. • The analytical procedures have been validated against certified reference materials. • The biggest number of bacteria were detected at the estuary and in the Revvatnet lake. Persistent organic pollutants (POPs) have been a topic of interest in environmental sciences for > 60 years. POPs in the Arctic have been investigated since the 1970s, when first atmospheric measurements revealed the presence of these pollutants in the polar regions. Major contaminant transport routes to the Arctic include atmospheric and oceanic transport, as well as inflow from rivers and sea ice. The sources of pollutants, such as industry, power generators, vehicle and ship exhausts, introduce the PAHs, phenols, formaldehyde or metals into the Arctic. Transport via sea currents, however, can take several years. The highest concentration levels of total PAHs were observed in two samples from the tributaries in July 2015 and were 1069 ng L^{− 1} and 3141 ng L^{− 1} and in September 2015, the highest concentrations were observed in samples collected from Revvatnet lake and were 978 ng L^{− 1} and 1823 ng L^{− 1}. The highest concentrations of trace elements in both months were 41 μg L^{− 1} in the sample from the highest tributary (July 2015) and 79 μg L^{− 1} in the same sample (September 2015). The purpose of this study was also to determine abundance of bacteria in the Arctic freshwater of different types. Microbes are omnipresent and represent diverse biological communities. In the freshwater ecosystems, microorganisms form the base of the food chain supporting higher trophic levels. Although microbes are generally thought to live in the warm regions of Earth, many of them develop in cold climates. In the Revelva catchment, the biggest number of bacteria were detected at the river estuary in July 2015 and at the sampling point located in the Revvatnet lake in September 2015. Generally, the bacterial abundance indices depended on nutrient levels to a small extent, showing the environment of the Revelva catchment not to be nutrient limited, which is in accordance with its rich biological life also in macroscale.