Although they spend only a brief part of the year along our coast, gray whales are the most frequently sighted of the great whales that live in or travel through the channel. These enormous mammals they may reach lengths of up to 50 feet and-can weigh up to 40 tons - swim an annual marathon of 10,000 miles roundtrip, migrating from their summer feeding grounds in the Bering Sea and West Arctic Ocean to their winter haven in the shallow lagoons of the Baja Peninsula. Their annual journey is the longest known migration conducted by any mammal.
Gray whales travel a well-defined route at about the same time each year. Each fall they leave the icy Arctic waters and head south. Traveling alone or in pods of three to twelve, the whales swim up to 100 miles daily, arriving at Point Conception between early December and January.
At Point Conception, the mainland makes a sharp turn eastward. Many of the whales abandon the curving coastline at this point to ply the open waters of the channel, where they may take one of several routes past the islands.
Six to eight weeks after beginning their journey, the whales arrive in warm Mexican waters, where most of the pregnant cows give birth. In January, the first group to head back northward crosses paths with stragglers who are still on their way south. North bound whales can be spotted in the Santa Barbara Channel from February through April. Solitary whales and mothers with calves may pause in the tranquil kelp beds of the sanctuary to feed.
Whale watchers scanning the channel for a glimpse of migrating grays usually spot their first whale when it comes up for air and blows. Gray whales can stay underwater for up to 20 minutes, although they are probably capable of longer dives when stressed. When they surface and exhale, they produce a vapor cloud typically several feet high. Most whales exhale three to five times, each burst of air several minutes apart, before going back under for a longer dive.
After a series of short dives, a whale may begin a deeper dive by "sounding." The ridge of knuckles across the animal's back appears at the surface and the flukes flip out of the water as they propell the whale downward.
Another clue to a gray whale's whereabouts is its "footprint." A submerged whale often produces circular patterns on the surface of the water as its undulating tail flukes create vertical water currents.
Occasionally, a gray whale will burst out of the water at a 45-degree angle, flip around and then WI back with a dramatic splash. This somewhat mysterious activity is called "breaching." Scientists are not sure why whales do it.
Gray whales can also be seen "pitchpoling" (or "spyhopping") with their heads pushed up through the surface like a periscope. They may stay this way for thirty seconds or more. We are not sure why whales do this, either, though some interesting theories have been offered: Could the whales be looking for land bearings? Conducting celestial navigation? The nature of whale vision tends to discount the latter hypothesis. The eye of a whale is adapted to allow it to see well in its murky underwater environment. Scientists think that whales see less well above water.
Since gray whales probably cannot depend on visual clues for navigation, how do these animals find their way each year? The answer is still a mystery. Perhaps they determine water depth by diving down to touch the bottom; deeper water would be a signal that they have strayed from their coastal path. Maybe water salinity and pressure provide them with bearings. Their habit of traveling in pairs or groups tends to suggest another hypothesis: Following the coastal route may be learned behavior.
Cetaceans are divided into two groups, those with teeth and those with baleen. Gray whales belong to the latter group; in lieu of teeth they have up to 360 fringed plates that grow from either side of the palate. The baleen plates grow in single rows set on edge to the water forming a comb-like construction. The early whalers called the baleen "whalebone" and used them to make such things as corset stays and buggy whips.
Gray whales are dark gray with white scars that may appear as streaks or circular patches. Parts of the body, particularly the head, may be covered with barnacles. Three species of parasitic amphipods, often called whale lice, may also be along for the ride.
Though precise aging of gray whales has never been achieved, scientists have been able to estimate that gray whales reach sexual maturity at an average age of eight years. They reach physical maturity at an estimated average age of forty.
With their predictable itinerary and their habit of traveling close to shore, gray whales are the easiest cetaceans to track through the channel. Other baleen whales that spend time in these waters include fin, blue, minke and humpback whales. Among the toothed whales found here are killer and pilot whales, Risso's dolphins, northern right-whale dolphins, Pacific white-sided dolphins and common dolphins.