Arctic benthic ecosystems under change: the impact of deglaciation and boreal species transportation by macroplastic

Photo by Michał Łepecki The Arctic is the region hardest hit by global climate change; its effects can be observed not only as an increase in air and sea water temperatures, but also as the rapid meltdown of Arctic ice (glaciers and sea ice), which has, until recently, defined the most characteristic features of the Arctic ecosystem. These “natural” changes are now being exacerbated by a new phenomenon related to anthropogenic activity, i.e. plastic garbage floating on the surface of the ocean.

In the past, only wood would drift all the way from the estuaries of Siberian rivers to the coasts of the European Arctic. Accumulating on polar shores over centuries, these wood piles did not modify the local ecosystem in any novel way (all they did, after all, was drift over from another part of the Arctic). For centuries, Atlantic waters flowing up north along European coastlines carried larvae and adult animals, but only a small proportion of these made it all the way to the farthest north. In the 1970s, however, fisheries began to use plastic nets and boxes, and the industry started to inundate Europe with plastic packaging and containers. These almost indestructible, floating pieces of waste now serve as rafts on which adult animals of various southern species embark on a voyage across the ocean.

Photo by Michał Łepecki The ADAMANT project sets out to show how the plastic waste that lands on its shores affects the ice cover of Spitsbergen and to determine which species most commonly use this form of transport (bivalves, crustaceans, polychaetes). Genetic studies suggest that  incoming species arrive on Spitsbergen from different corners of Europe, including Iceland, Denmark and Scotland, and not only nearby Norway. The importation of southern species increases species diversity and the genetic diversity of local fauna. By comparing the earliest available satellite photos of the region (from the 1990s) with contemporary images, we also distinguished the sites where sea ice disappears from the coast completely from those where its retention period has just shortened. Thanks to the fact that our voyage on IOPAN OCEANIA in 1990 had allowed us to collect data on the benthic fauna of two bays located near glaciers, we were able to compare data from 30 years ago with new samples from the same sites. It turns out that the bay from which the glacier is slowly retreating has undergone significant changes over these past 30 years; both the quantity and diversity of its fauna has increased, while the other bay, which has experienced no such changes in ice cover (there was no ice there 30 years ago either), has remained almost completely unchanged.

Our research is still in progress; the project was prolonged because of the pandemic, but we have already broadcast a movie to show our field work in the Arctic, and the results of our last publication have made the cut for a prestigious scientific press review.