Impact of global change on the remobilization and Bioaccumulation of organic Pollutants in PolAr aquatic food webs

Europe’s scientists have explored the impact of climate warming and permafrost melting on persistent organic pollutants (POPs) in polar food webs.

The EU-funded BioPollAr project has studied the effect of climate change on the availability of contaminants in Arctic and Antarctic ecosystems and food webs. European and international researchers involved in this project have also focused their research on the investigation of the presence of emerging pollutants such as organophosphate esters (OPEs) and perfluoroalkyl substances (PFASs) in Arctic and Antarctic biota, terrestrial and marine ecosystems.

The study involved the analyses of temporal series of POPs (from legacy, such as polychlorinated biphenyls (PCBs)), organochlorine pesticides, recently regulated flame retardants, polybrominated diphenyl ethers (PBDEs) and emerging POPs (such as PFASs and OPEs) in more than 1 000 samples from fish, plankton, water, soil, vegetation and atmospheric samples taken from 2015 to 2017 together with archived samples from biota taken yearly since the 90’s.

Some of the results found, revealed a positive correlation, over the last two decades, between the concentration of POPs in Arctic char (Salvelinus alpinus) from four lakes in the Canadian High Arctic, and the interannual variations of the North Atlantic Oscillation (NAO). “This fact together with increasing Arctic temperatures could increase POPs concentrations in char over the following decades, particularly if there are nearby secondary sources,” says Dr Ana Cabrerizo, a Marie Skłodowska-Curie research fellow.

Long range transport of pollutants

Another key result developed during the EU-Project revealed, for the first time, that permafrost melting, due to warming in the Arctic, is releasing a large amount of stored POPs bound to organic matter into aquatic systems. “This is having a significant impact on Arctic lakes and their simplistic food webs,” notes Dr. Cabrerizo.

This important result was observed on lakes on Melville Island, in the Canadian High Arctic at Cape Bounty Arctic Watershed Observatory (CBAWO). CBAWO is a remote and uninhabited location, 400 km from the nearest Arctic community and represents an environment largely unimpacted by direct human activity. “Due to its remoteness and absence of anthropogenic activities, all pollutants found in freshwater and terrestrial compartments have been introduced through long range atmospheric transport. This area therefore is of great value for studies on POPs and climate change,” Dr. Cabrerizo explains.

Freshwater environments such as lakes and rivers and marine environments are major ecosystem features of the Arctic region, providing important sources of food like Arctic char, and seals as well as drinking water. “Alteration of organic carbon sources such as soil, sediments due to accelerated warming, that have been noticed in our study area, will reduce food quality and make it more contaminated, especially with legacy PCBs and DDTs, as already shown in Cabrerizo’s studies,” she warns.

New threats identified

Work carried out on recently regulated pollutants like BDEs and emerging OPEs and PFASs provided novel insight. The findings of the project proved that not only legacy POPs are transported to the most remote places of the world, but also ‘new’ chemicals are being detected in the most pristine regions of the world, which effects on polar food webs and ecosystems are still unknown, explains Dr Cabrerizo. She also states that international policies should take this fact into a serious consideration.

The outcomes of BioPollAr will support national and international policies on chemical management and be of special interest for local Inuit communities who live in the Arctic.

Reference source: Impact of global change on the remobilization and Bioaccumulation of organic Pollutants in PolAr aquatic food webs