In connection with the update of the management plan for the Barents Sea, the politicians are discussing how to define the ice edge zone. We always know where the ice edge zone is at any given time. But how do we indicate that on the map?
The ice edge zone is the belt between ice-covered and open sea. A rich and productive ecosystem thrives here when warm water from the Atlantic meets the cold water from the Arctic Ocean, particularly in the spring.
The ice edge zone is a dynamic observable phenomenon that moves several hundred kilometres during the course of a year. Nevertheless, the administrative boundary must be defined as a line on the map. Within this line, the area will be defined as SVO – particularly valuable and vulnerable areas. Where should the boundary run? That is a question for the Government and the politicians in the Storting.
The definition of the ice edge zone is where more than 15% of the sea surface is covered by ice. The current management plan defines the zone as where there is more than a 30% likelihood of ice during the month of April over the course of a period of 30 years.
The most conservative proposal calls for a definition of the zone as where there is more than a 0.5% likelihood of ice in the month of April during the course of 30 years. For the last 30 years, such a conservative proposal means that ice has been observed there for a total of 4-5 days, or just a few hours per year.
In this video, marine toxicologist Axel Kelley explains what the ice edge zone is, and how it is managed.