Few took notice when a 4.2-km subsea cable in the Arctic Ocean vanished without trace back in April 2021, but these days undersea infrastructure security has become a hot topic.
The cable had connected the Norwegian archipelago, Svalbard, to mainland Norway, where data was filtered by Norwegian environmental and defence authorities.
Packed with sensors, the fiberoptic lines measured environmental conditions and fish migration, recording images and sound, and sending all the information back to shore.
They could also be used as drifting hydrophones to listen for passing vessels for security purposes.
The data used to end up on monitors at the Norwegian Institute of Marine Research — but on 3 April 2021 the screens suddenly went blank.
“We lost power and everything died”, recalled Geir Pedersen, the responsible scientist for the Norwegian LoVe project operating the cables.
Inspectors mounted an expensive operation to see what happened. It took them until November 2021 to find a 3-km chunk of severed cable out at sea, some 11km out of position.
“Either a trawl or an anchor grabbed the cable and dragged it. We’re pretty sure about that. When we inspected one of the ends of the cable it was clearly cut with a power tool which means it had been brought on to a vessel and manually cut”, Geir Pedersen told EUobserver.
“It could have been an accident or it could have been sabotage. We don’t know and I think we’ll never find out”, he said.
The severed Svalbard cable is to cost €5.6 million to repair and to be fully operational in 2024, amounting to years of lost scientific data.
Journalists at Norway’s public broadcaster, NRK, also looked into the incident by comparing ship positions using AIS vessel tracking data.
This showed a Russian trawler had crossed over the cable at the time when the ocean researchers received its last signal.
Another cable to Svalbard operated by Space Norway was also damaged on 7 January 2022.
And the NRK journalists again found that a Russian fishing trawler had passed over the cables 20 times in the days before and after the subsea line was damaged.
Crew on the Russian fishing vessel were questioned by local police at the time, but no charges were pressed.
There’s nothing unusual about Russian fishing boats sailing over the cables, which are openly marked on Norwegian sea maps, or calling at Norwegian ports.