Festival celebrates Sitka's winter whales
In the summertime, the humpback whales in the waters near Juneau have spellbound visitors and residents alike. Sightings of feeding whales have even been made in Gastineau Channel to the delight of state workers with waterside windows.
In recent years, however, the humpback whales have been putting on a late fall and early winter show along the outer coast of Baranof Island in Sitka Sound.
In Sitka Sound, the whale numbers are the highest between September and January every year. These whales come to the sound to feed on huge schools of herring that move into deep fjords to spend the fall and winter. Researchers have documented transit times of just over a month between Sitka Sound and Hawaii, thus many of these whales present in January and early February still will migrate to Hawaii in time for the peak of the mating and calving activities.
Since 1997, nine whales have not left Sitka Sound during the winter. Their presence was documented by taking photographs of the unique black-and-white pattern on underside of the tail, or fluke, that identifies each whale. The photographs established sighting histories that showed these whales were present often enough that, given a month transit time each way, they could not have gone to Hawaii and returned to Sitka Sound during the same winter.
It is unknown if these whales were in Alaska waters all year because they were not seen often enough during the spring, summer and fall to document year-round presence. However, it is unlikely they would migrate to tropical waters during months when mating and calving activities are not occurring.
Although a few whales may spend the winter in Alaska, other whales do make the migration across the North Pacific twice a year, with females returning to Alaska with their calves in the spring and early summer.
There are many unknowns about the humpback whale but we do know some things about their life in Alaska waters.
Humpback whales are baleen whales that migrate seasonally to feed in the productive temperate waters of Alaska. Instead of teeth, baleen whales have a row of fringed comb-like plates lined on each side of their upper jaw. When a whale takes a big gulp (15,000 gallons!) of combined water and food, the baleen acts like a strainer to sieve out the food. In Alaska, typical food for humpback whales is a small shrimp-like zooplankton called krill and schooling fish such as herring, sandlance and capelin. Humpback whales can eat about a ton of food a day.
The whales that come to feed in the waters of Southeast Alaska were first brought here by their mothers when they were less than a year old.
These whales continue to return to these same waters every year. This faithfulness makes Southeast Alaska a distinct feeding area for a specific group of individuals. This distinction is further bolstered by the fact that the whales that feed off the coast of California, Oregon, Washington, or in Prince William Sound, are rarely seen in Southeast Alaska.
Humpback whales are found every month of the year in Southeast, with the highest overall numbers in August and the lowest numbers in February. The humpback whales that feed in Southeast generally migrate during the fall and winter for mating and calving to the Hawaiian Islands with a few traveling to western Mexico.
During the first weekend in November, Sitka celebrates the abundance of marine wildlife found in Sitka Sound by hosting the Sitka WhaleFest. This year, researchers will come from Alaska, Canada and Japan to speak about the latest discoveries on humpback and bowhead whales, ice seals, sea lions, sea turtles and even starfish.
This celebration of marine wildlife includes a student art exhibit, sea chantey concert, a market and whale-watching opportunities. University of Alaska credit is available for undergraduates and teachers. For more information on the Sitka WhaleFest contact Phyllis Hackett, director@sitkawhalefest.org, (907) 747-7964, or access the Web site at http://www.sitkawhalefest.org.
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Jan Straley is an assistant professor of marine biology at the University of Alaska Southeast in Sitka. Contact members of Juneau Audubon Society at ckent@alaska.net.