“We have seen an improvement in some areas and it has coincided with the spread of the American polychaete worm Marenzelleria, which is now one of the most common benthic species in the northern Baltic Sea. It made us wonder what effects the worms have on the ecosystem, and if they could have contributed to the improved oxygen conditions, “ says Daniel Reed, one of the main authors behind the new study. Daniel Reed is a researcher at the Baltic Nest Institute and Utrecht University. Baltic Nest Institute is a part of the Stockholm Resilience Centre at Stockholm University.
Nature Geoscience highlight
The modeling study shows that the invasive worms can contribute to the binding of phosphorus in the sediments, reducing the eutrophication of the Baltic Sea and the risk of algal blooms. The study was also highlighted in the October issue of Nature Geoscience.
“According to our calculations, the positive effect of the worms can be twice as great as the enhanced wastewater treatment, for example in the Stockholm area. This way, these worms provide us humans with a very important ecosystem service, one of the study's first authors Joanna Norkko from Åbo Akademi University,” explains.
Alien species and a healthy Baltic Sea
Healthy sea bottoms are important both because they are crucial food resources for fish and birds, but also because they regulate the flow of nutrients in the sea. If emissions are reduced under the Baltic Sea Action Plan, the conditions for life on the bottoms may be improved to the extent that animals themselves can help to improve the situation further, the researchers write. As for the role of non-native species, science may be forced to rethink and consider possible positive effects rather than just the negative ones.
The new study is part of the HYPER project, where BNI together with an international consortium carries out research on issues related to hypoxia.
Further information
Download the press releases in Swedish
(pdf, 400 kB) and English. (pdf, 390 kB)
Contacts:
Joanna Norkko (joanna.norkko@helsinki.fi), Phone: +358 400 419 021 or
Bo Gustafsson (bo.gustafsson@stockholmresilience.su.se), Phone: +46 73 707 86 03
Reference:
A welcome can of worms? Hypoxia mitigation by an invasive species. Global Change Biology (2011), Joanna Norkko, Daniel C. Reed, Karen Timmermann, Alf Norkko, Bo G. Gustafsson, Erik Bonsdorff, Caroline P. Slomp, Jacob Carstensen and Daniel J. Conley.
Links:
Link to article in Global Change Biology.
Link to the article in the October issue of Nature Geoscience.
Link to an interview with BNI researcher Bo Gustafsson about the research in Swedish Radio.
A brief summary of the article (in English) is available on the website of the Baltic Nest Institute.
