A humpback whale was spotted by the crew of a Port of Vancouver patrol boat Friday morning (May 22), according to a post on the port authority's Twitter account.
Although the pictures only show a whale's tail, or "flukes", rising above the water, humpback tails have a distinct shape and are often presented to view at the water's surface when diving for food.
Because the tails are one of the easiest humpback features to photograph, and because they feature distinctive colour patterns and scars that are unique to each whale, such photos are often used by conservationists and marine biologists worldwide to identify individual humpbacks.
Humpbacks, grey whales, and orcas have been seen in increasing numbers in and around Vancouver Harbour, Indian Arm, English Bay, and Howe Sound in recent years.
There have been several sightings of humpbacks and orcas (which are often called "killer whales" but are actually the largest member of the dolphin family) in Burrard Inlet, off West Vancouver, and in the Howe Sound area during the past 10 or 11 days.
Male humpbacks typically grow to a length of about 14 metres, the size of a city bus, while females often attain a length of up to 16 meters (52 feet). According to the Encyclopedia of Marine Mammals, one modern female humpback stretched to 19 metres (62 feet), the size of an articulated city bus.
The longest whale ever recorded is the blue whale (up to 33.5 meters, or 110 feet), with fin whales and humpbacks vying for the title of the second-longest (the fin whale just beats out the humpback by a third of a metre, 27.3 metres to 27 metres (89.5 feet to 89 feet).
That female humpback length of 27 metres, although it came from detailed Caribbean whaling accounts from the mid-1800s, is regarded by some researchere as less reliable than modern records, though the species was hunted to near-extinction before international conservation efforts were put in place in the 1960s. Today's usual humpback lengths would put it closer to fifth place in world cetacean size charts, slightly behind the blue, fin, right, and sperm whales.
Whale watchers and photographers are fond of seeking out humpbacks because of their habit of "breaching", or throwing themselves vertically out of the water (for up to two-thirds of their body length) and crashing back down on their sides or backs, often accompanied by a large splash.
Humpbacks are also recognizable because of their extremely long pectoral fins, which some whale watchers say give them the appearance of a jet plane. These pectoral fins are the longest, proportionately, of any cetacean (aquatic mammals that include the toothed and baleen whales), often reaching lengths of about five metres (16 feet), a third of their body length.
Conservationists estimate the North Pacific humpback population to be between 18,000 and 20,000. Because of steady population growth of about four percent per year for almost two decades, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) downgraded its 2003 "threatened" status of the North Pacific humpback to the lower-risk category of "special concern" in 2011.
North Pacific humpacks, like the grey whales often seen off the B.C. coast, give birth in tropical or subtropical seas and migrate north to feed in the spring and summer in cold northern or polar waters, where there is an abundance of the krill (small crustaceans) and small fish (such as herring and juvenile salmon) they feed on. The whales almost never eat in the winter, surviving off stored body fat built up during the spring and summer feeding.
Some humpbacks migrate about 15,000 kilometres every year (round trip), and individual whales have travelled the almost 5,000 kilometres between Alaska and Hawaii in 36 days. Some humpbacks that feed in southern B.C. winter in shallow waters off Mexico.