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

DAINA – Polish-Lithuanian Funding Initiative, NCN 2017/27/L/NZ8/03331

The melting and retreat of Arctic tidal glaciers and ice disappearance from the coast (fast ice, ice foot) are the two most conspicuous effects of climate warming on Spitsbergen, the European Arctic. The ice-free seabed is released at a speed of 500 m per year, and the coastal ice that use to cover shores for 7-9 months, is now reduced to the late winter 2-3 months. The deglaciation of Spitsbergen cause formation of new habitats, not available before. The observed changes are increase of biomass and biodiversity and emergence of sublittoral communities to shallower waters, where ice scouring was a controlling factor.
At the same time, the boreal flora and fauna comes to Spitsbergen with Atlantic waters from the Western Europe UK area. The distance of over 1000 km that separates Spitsbergen from the Europe is a challenge for the larvae of benthic organisms, that use to live in the water column few weeks only. The new way of migration emerged with the macroplastic litter, that drifts massively on ocean currents. The large plastic boxes, barrels, nets are easily colonised by adult organisms, that may travel for years on the sea surface, before stranding on the new coast. The aim of the project is to describe the processes of arctic coast colonisation by boreal organisms. Does it follow the principle of island biogeography theory – with random colonisation of the islands, where the species richness, stability of population and structure of communities depends on the island size and distance to the continent? Or we have the scenario of the boreal biogeographical province shift North? In the second case the populations would be similar to source area, communities are rich and stable, and structure similar to those from the boreal sites. In the first case scenario, drift on the macroplastic litter is very important for the islands colonisation, in the second scenario is of no importance, as the whole province shifts anyway. The way to understand which scenario most likely happens, is the comparison of recently ice free areas, those that are still partly iced and the same habitats still frozen.
The most suitable area of study is the Isfjorden complex on the West Spitsbergen, where the sequence from boreal to arctic conditions can be observed on relatively short distance. The area is feasible for study due to the best available logistics, and opportunity to work in adverse weather conditions, that reduce the risk of field work substantially.
In addition, we will study the most likely source areas – coastal habitats of Fareo- Shetland islands, to compare the genetics of species that are found on Spitsbergen as well. Such study will give us the answer if the Svalbard populations are in contact with the source areas on the continent, or colonization is irregular and random. Planned research will enrich the knowledge on the pace and direction of Arctic change – specifically to the dispute about “tipping point” or “regime shift”. As the planned natural science studies are associated with ecosystem goods and services analysis – that covers the field of socio economy and natural economy, the outcome of the project will expand beyond the natural sciences domain. Cooperation between Lithuanian and Polish researchers will enrich both sides. The Polish project partners have long tradition and experience in Svalbard research, as well as the infrastructure (polar station and research vessel). Their recently completed projects substantially advanced our knowledge on ecosystem processes in the warming environments of European Arctic. The Lithuanian partners have good knowledge and long-term practical experience in marine invasion biology research, mapping and sensitivity analysis of seabed habitats, remote sensing and environmental genetics. Both research teams were working in cooperative projects before in the Baltic Sea research and in European projects on marine biodiversity. The Polish team will introduce Lithuanian researchers to the Arctic research, opening new opportunities for future cooperation.
The aim of planned research is to describe the mechanism and patterns of the colonization of the deglaciated arctic coasts.