Conservationists in Mexico are warning of the dangers to the migrating Gray Whale. <br /><br />Hundreds of the giant mammals are preparing their journey back to their summer feeding grounds in the far North. <br /><br />Their annual trip of 18,500 kilometres takes them from the Bering Sea between Russia and Alaska, all the way down to Mexico's western coast.<br /><br />And in a few weeks, back again. It is the longest migration made by any mammal on earth. And their entire trip is spent just kilometres off the coastline.<br /><br />Al Jazeera's Franc Contreras reports.
