The rorqual whale in Ystad becomes an object of research

The rorqual whale that was found in the Baltic Sea and then was submerged a few miles off the coast of Ystad has now become an object of unique research.

Securing the whale cadaver and then transporting it out into open water was no easy task. The whale was in a stage of putrefaction, and its size meant that dealing with it posed a great challenge. The submersion was a complex operation. But at the end of August this year, the rorqual whale was sunk 3.5 nautical miles off the coast of Ystad next to a shipwreck.

‘Submerging a nine-metre-long whale is never easy, of course’, says Department of Marine Sciences researcher Thomas Dahlgren. ‘This one was incredibly buoyant, and a large measure of both cunning and scrap iron was required to get it down on the bottom. In nature, a dead whale drifts around for a long time before it eventually sinks.’

Together with Björn Källström, a research colleague at the same department, Dahlgren will follow the whale’s decomposition process in the sea.
’Since trawlers at the beginning of the 20th century brought up whale bones from the seabed, we have known that there are animals that are found only on dead whales, such as clams and snails’, says Källström, who was present when the whale was sunk.
‘We’re following the process for some time through amateur divers who visit the site’, Dahlgren says. ‘In the summer we will go down there ourselves and take samples and document it.’

Eutrophication of the seas is a major environmental problem. What animals are naturally capable of living in eutrophicated environments and converting the nutrients is less well known, particularly in the Baltic Sea. The whale cadaver naturally is very rich in nutrients.
‘We will make use of “citizen science” to get data from the whale. We are collaborating with Pdyk, the company that submerged the whale for us. It was Pdyk that found it floating in the sea and towed it in. We also are working with Ystad municipality to inform divers who dive at the wreck where the whale was sunk.’

The researchers will ask the divers to collect information about the temperature and salinity by the whale and ask them to photograph and film the site if they have cameras with them. This will allow the collection of a lot more data while also involving the public.
’We are happy and grateful for the positive response and the interest which residents and authorities have shown in the whale and our research. It will be fun to continue working on this project’, says Dahlgren, from the Department of Marine Sciences.