The 12,000 mile round trip gray whale migration begins in November or December when the 28,000 whales begin to leave their summer feeding grounds in the Bering and Chuckchi Seas and head south to their birthing and breeding grounds in Baja. San Ignacio Lagoon is one of the best places to see the mothers and babies each spring. Ecotour operators give people access to the lagoon and bring them out in boats to meet the whales. Whale watchers on the coast spot the 12-15 foot spouts of the gray whales as they surface for air on their travels. In April the whales begin their trip north.
About Gray Whales
These are large mammals: 50 feet long, 36 tons. Yet they feed on plankton, the smallest creatures in the ocean. Gray whales are filter feeders; they scoop up sediment from the ocean floor by rolling on their sides. The amphipods (krill, tube worms, mollusks) stick to the baleen that lines their mouths and filters out the water and sand. Then they use their tongues to collect the food stuck on the baleen. They feed during the summer months in the north.
Predators and Protection
Human hunters almost wiped out the gray whale population. The whales were killed for meat, oil and baleen. Since 1947 the gray whales have been protected by the International Whaling Commission (IWC).
Killer whales (orcas) are a danger to the gray whale calves as they swim north with their mothers in the spring. The gray whale mothers swim closer to the shore during this direction of the migration to protect their young from orcas who are waiting from them to arrive on their way north. Whale watchers in boats off the California coast often witness the gruesome sight when a killer whale catches a young gray whale. NOAA Fisheries Service (National Oceanographic and Atmospheric Administration) is studying the effect of killer whale predation on the gray whale population.
Migration Change Due to Warming Oceans
Warming oceans are causing the gray whales to behave differently. The arctic ice is melting due to global warming, changing the feeding patterns of many marine species. As other species move north to the whales' feeding grounds, competition increases for food and whales go farther north to prepare for the migration south. The gray whales are arriving in Baja 7-10 days later than they did a few years ago as their migration path lengthens.
Some gray whales are staying in Washington and Oregon in the winter months and returning to the north from there rather than going down to Baja. They are referred to as "resident whales" by some. The Monterey Bay Aquarium marine biologists studying climate change believe that whales that travel farther north to feed have changed their migration pattern by not continuing south to Baja.
More evidence of climate change is the melting ice in the Northwest Passage. This is the most probable explanation for the sighting of a gray whale in the Mediterranean Sea in May 2010. Gray whales that lived in the Atlantic were wiped out by commercial whalers in the early 1900s. Discovery of the whale on "the wrong side of the world" is best explained by the melting of the arctic ice allowing the whale to make its way from the north Atlantic down to the Mediterranean, the same direction it would swim in the Pacific. Scientists assume the whale did not realize that it was in the wrong ocean.
Satellite imagery is used to track whales in the Pacific ocean. Information about feeding areas and migratory paths help determine the health of the gray whale population and of the ocean.
Kathleen Sonntag - A native Californian, I now live in Carmel on the central coast. Having escaped from Silicon Valley where I managed engineering projects, ...
