Humpback Whale Population Doubles off Canada Coast

Between 2004 and 2011 the population of humpback whales present in the coastal fjords of British Colombia doubled, according to research published in in the journal PLOS One.

Scientists studied whale populations on the western Canada coast using photo-identification surveillance of identifiable adult humpback whales, noting that the number of whales in the water increased each year of the study, effectively doubling in seven years of research.

When the research began in 2004 about 68 humpback whales were accounted for. By 2011 researchers were able to identify 137 of the whales.

Erin Ashe from the Sea Mammal Research Unit at the University of St. Andrews in the UK, and her colleagues from other institutions, conducted the survey year-round, but abundance of whales was only estimated in the summer months of July and September, when the the migrating whale population is the largest.

The coastal fjords off the British Colombia coast were ideal as a study location because they serve as a sort of "pit stop" for whales in the middle of migration, allowing them the feed and refuel upon the abundance of marine life in the fjords.

Humpback whales migrations cover vast amounts of territory. Whales along the Canada coast may travel as far away as Hawaii or Japan during their migration. They may go several months without feeding.

Ashe and her colleagues estimate that the humpback whale's survivorship rate -- or the average probability of an adult whale surviving to the next year -- is higher in the coastal fjords off British Colombia than it is for the species anywhere else in the world.

However, during their time in the Canadian fjords, the whales face increased environmental stressors, particularly from whale watching expeditions which capitalize on the whales' presence.