Endangered whales are to be given right of way in North Atlantic waters after collisions with ships became the primary cause of their death.

The International Maritime Organisation has given Canada permission to re-route shipping lanes in the Bay of Fundy, off the coast of Nova Scotia, which is a haven for migrating North Atlantic right whales.

Collisions are now responsible for half of whale deaths

Transport Minister David Collenette said: "The government of Canada has created new, safe and effective shipping lanes which will reduce the likelihood of a right whale suffering a ship strike in the Bay of Fundy by up to 80%."

The slow-moving mammals are the most endangered large whales on Earth.

There are just 350 worldwide and they have been on the list of protected species since 1936.

Exclusion zone

Every year, the whales migrate from the eastern coast of the United States to the Bay of Fundy, and current shipping lanes cut across their summering waters.

Earlier this year, the Canadian Government asked the International Maritime Organisation to modify shipping routes in the area to reduce the risk of collision between ships and whales.

After the new rules go into effect on 1 July, ships will have to divert several kilometres around a special zone.

Experts who track the whales say ship collisions are their biggest threat, followed by entanglement and hunting.

A little over a third of all right whales deaths from 1970 to 1991 were attributed to collisions with ships. Since 1991, that figure has risen to more than 50%.