"We have seen an improvement in some areas and it has coincided with the spread of theAmerican polychaete worm Marenzelleria, which is now one of the most common benthicspecies in the northern Baltic Sea. It made us wonder what effects the worm have on theecosystem, 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 centre partner Baltic Nest Institute.The study, which was highlighted in the 2011 October issue of Nature Geoscience, is part of the wider HYPER project (Hypoxia mitigation for Baltic Sea Ecosystem Restoration).
Positive effects twice as great
The modeling study shows that these 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.
"According to our calculations, the positive effect of the worms can be twice as great as
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, explains.
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 reduce 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.
For more information, contact:
Joanna Norkko
joanna.norkko@helsinki.fi
Tel. +358-400-419021
Bo Gustafsson
bo.gustafsson@stockholmresilience.su.se
Tel. +46 73 707 86 03
A brief summary of the article (in English) is available on the Baltic Nest
Institute website
Download Swedish version of press release here
(pdf, 410 kB)
