Almost 90% of Norway’s mainland kittiwakes have disappeared in the past four decades, as numbers of other seabird species also continue to fall. Between 2005 and 2015, the number of seabirds on the Norwegian mainland dropped by almost a third, according to the Norwegian Environment Agency.

“This is quite dramatic, but it is also one of the bird groups that have done most poorly when you look globally,” says Signe Christensen-Dalsgaard, a seabird ecologist at the Norwegian Institute for Nature Research.

Seabirds are important to life on land: they bring nutrients from the sea to the coast through their guano. They are reliant on the ocean for food, so the fact they are struggling suggests other marine species are in trouble. “It’s a quite strong signal that something is not right in the ocean,” says Christensen-Dalsgaard.