Maritime authorities in Sweden and Denmark have proposed a rerouting of the main shipping routes into the Baltic, scheduled to be effectuated in 2020. Roughly 80,000 ships pass through Kattegat each year, roughly half of them in the deep water route T through the Great Belt, the other half through the Sound (route D). The rerouting will move the split between the two routes about 100 km to the north, creating a new route S parallel to the Swedish coast and about 20 km east of the existing route T. This creates a unique opportunity to study effects of heavy ship traffic in a shallow sea. A range of parameters will be measured in the existing shipping lane, the new shipping lane and reference areas away from the shipping lanes. This will be done for at least a full year prior to rerouting, to establish a baseline, and at least one full year after the change.
A number of work packages are planned. Primary goal will be to describe changes to the soundscape (by sound recorders) in ecological important areas and quantify effects on harbour porpoise abundance (by passive acoustic monitoring). Secondary goals will be to study other ecosystem components: birds (by aerial surveys), fish (by eDNA) and benthic invertebrates (by surveys and sampling).