Among the tools that European scientists use to understand climate change are the instruments of the Boknis Eck underwater observatory in the Baltic Sea, which measures methane in the seabed, water current flows and other data. Now the undersea installation has given researchers a new puzzle to solve – because it’s gone missing, and no one seems to know why.
The devices stopped their data transmissions at about 8:15 p.m. on August 21, according to Dr. Hermann Bange, a marine scientist with the GEOMAR Helmholtz Centre for Ocean Research in Germany. At first the researchers thought there was a technical error with transmission, but divers sent in early September to check on the marine data system found a more serious situation.
“The devices were gone,” Bange said. “The divers could not find them anymore.”
The only thing that remained was a cut cable, seen above, that was connected to instruments which are about the size of two desks positioned together, one weighing 520 kilograms and the other weighing 220 kg. They were placed there in December 2016 to add new equipment and additional capacity to the sea monitoring system. One works as a miniature power plant and connects to the cable, while the other holds the actual sensors.
The area is restricted, so it’s off-limits to marine traffic, adding to the mystery of what’s become of it.
Now GEOMAR is hoping for clues that will help researchers recover the devices, and more important still, the missing data capacity. In part, that’s because for every month since 1957, environmental information – the temperature, salinity, the concentrations of nutrients, oxygen or chlorophyll – have been collected from the specific geographic location at the outlet of the Eckernförde Bay.
The Boknis Eck installation is part of a system that had provided a significant time series of information, which has helped scientists to draw conclusions about the ecosystem on Germany’s Baltic coastline, at its northern tip where the western edge of the Baltic Sea meets the coasts of Germany and Denmark.
What they can’t answer so far is what happened to it. Bange said the weights make it likely that humans removed them – and to what end? – so local law enforcement agencies are helping with the case. The GEOMAR scientists have considered marine animals or strong, storm-whipped currents that dislodged the devices too, but they are still looking for clues and welcome any information.
“Maybe someone saw something on the morning of 21 August at the Sperrgebiet ‘Hausgarten’ near the Hökholz campsite,” Bange said. “Or someone finds parts of the frames somewhere on the beach.”
The Baltic Sea system cost about €300,000 but that’s not what most concerns the scientists.
“The data that we collect is downright priceless,” Bange said. “They help researchers to register changes in the Baltic Sea and possibly take countermeasures. Therefore, we will try to get the observatory back up and running as soon as possible.”