HUMPBACK AND BLUE WHALE PHOTO

HUMPBACK AND BLUE WHALE PHOTO-ID RESEARCH

U.S. West Coast (California, Oregon, and Washington)

Each year hundreds of humpback and blue whales come to California coastal waters to feed. Unlike the gray whales that migrate along the California coast, these two species feed offshore in deeper waters. Their populations were decimated by commercial whaling and many scientists feared that blue whales may have been reduced to the point where they were doomed to extinction. Blue whales were a prime target of commercial whaling because they were the largest whale (and the largest animal that has ever lived). Recent research has revealed that a surprisingly large number of both blue and humpback whales feed on krill in California waters. The concentration of blue whales off California is higher than in any other location in the world.

PURPOSES OF THE RESEARCH

The objectives of our research include:

Determine the abundance of humpback and blue whales off California.
Determine trends in these populations.
Identify critical feeding habitats that need protection, and monitor potential human-caused threats to large whale populations off California.

ACCOMPLISHMENTS OF THE RESEARCH

Cascadia has individually identified more than 1,600 blue whales and more than 1,500 humpback whales along the California coast. Our research has revealed that these whales appear to be a distinct sub-population separate from those in Alaska. Most of these whales migrate to waters off Mexico to mate and calve in the winter. A few humpback whales seen along the California coast have been identified as far south as Costa Rica and as far west as Hawaii.

The identification of individual whales has also revealed far larger populations than were thought to exist in these waters. We now estimate that about 2,000 blue whales and just over 1,000 humpback whales use California coastal waters. Though this is far more than previously thought, this emphasizes the importance of these waters to both of these species. we have also found very low reproductive rates of humpback whales off California and are exploring the potential causes for this troubling finding. Of critical importance is determining whether these populations are increasing or decreasing.