King Crab Garden

In the fjords east of Tromsø, red king crabs — introduced from the Barents Sea in the 1960s and now naturalised — have colonised shallow boulder fields in extraordinary numbers. Drysuits and a torch are essential as much of this diving happens in winter darkness, but shining a beam across a 15-metre plateau reveals dozens of crabs spanning a metre tip to tip moving slowly across rocks carpeted in encrusting algae. A completely alien macro experience in a dramatic Arctic setting.