The humpbacks are back, and even if we don’t know the reason, it’s a cause for celebration. Humpback whales were hunted almost to extinction, but the population has been recovering. This summer, whale watchers, who in the past almost never saw one of the 40-tonne creatures in the Salish Sea, are seeing groups of 15 to 20 in the waters off Victoria.
“We’ve never seen anything like this,” said Michael Harris, executive director of the Pacific Whale Watch Association. The organization represents 38 whale-watching companies in B.C. and Washington, and works with whale researchers.
“We’re seeing all sorts of behaviours: breaching, pec-slapping, vocalizations above water.”
Humpbacks are magnificent animals, noted for their aerial leaps in breaching and for their vocalizations. They migrate farther than any other mammal, the longest recorded journey being 8,300 kilometres.
Like many whales, humpbacks were hunted for their blubber to make oil and other products, beginning in the 1800s and as late as 1967. Place names such as Whaling Station Bay on Hornby Island are reminders of the industry that existed on the West Coast for decades.
More than 25,000 were killed in B.C. waters between 1905 and 1967. By the time they were declared protected in 1965, only 1,600 remained. They are still listed as a species at risk.
However, the humpbacks have been recovering. Their population has been increasing by about six per cent a year, and in the 1990s, they started returning to the Salish Sea. Harris estimates there are 21,000 in the area.
The history and the numbers are easy questions to answer. The harder question is why. Why are they coming to the Salish Sea in such numbers?
Food and safety are two likely explanations. They might have figured out that this area is relatively free of dangers.
But food has to be a big factor. Humpbacks, which weigh a tonne even as newborns, eat as much as 1,300 kilograms a day. Small fish, plankton and crustaceans such as krill are the foods of choice.
During the summer, they go on a feeding spree to build up blubber for the winter. While they prefer warm, shallow waters for calving, they like cold and productive waters for feeding. That might help to explain the attraction of the Salish Sea.
The questions affect more than just the humpbacks.
“These are large-bodied consumers with high metabolic demands. It’s critical to find out what they’re eating,” said Rhonda Reidy, a naturalist and University of Victoria doctoral student.
If they are eating the food that is needed by salmon and herring, their rising numbers could affect those species. Managing the humpback’s recovery and the commercial fisheries could be a more difficult balancing act than it is already.
Reidy, quite rightly, intends to focus her research on answering the food question.
The precarious numbers of killer whales in our region are a constant source of concern, so it’s refreshing to find that at least one species devastated by human activity has rebounded. Even if we don’t yet understand all the factors involved, it gives us hope for the future.
We have to explore the reasons for the recovery and for the whales’ movement into our waters. The things we learn could help not only the humpbacks, but other species, as well.
