Every year, Gray whales make a 10,000 mile long migration from bays off the coast of Baja California up into the high north within the Arctic Circle. In the summer months once the ice in the Arctic has melted, the whales reach rich feeding grounds in which they gorge themselves on small invertebrates called amphipods. Gray whales are baleen whales, meaning they have plates made of carotene that hangs from their upper jaw. Gray whales use their baleen in a unique way compared to most whales. Unlike other baleen whales which primarily feed on krill, gray whales feed on amphipods which live in the thick Arctic mud. To feed on them, the whales dive down to the ocean floor and scoop up the mud into their mouths. The mud is then filtered, leaving the amphipods caught in their baleen. They then use their huge tongues to scrape the amphipods off the sides of their mouths and into their stomachs. Grey whales will feed continuously all summer long until the ice begins to freeze again; then they will make there long journey south to their breeding grounds in Baja.
Gray whales are local visitors to San Diego that migrate past our coast from early December to late in April. Usually the whales are seen traveling by themselves or in small groups of two or three. In December they are on their southern migration down to bays in Mexico such as San Ignacio where they will give birth and mate. During the months they spend traveling past San Diego, we can observe many different behaviors from them. Although gray whales are not as active at the surface as other large whales, every now and then they can exhibit some pretty exciting behaviors. They can be seen breaching, where the whale launches itself more than two thirds of the way out the water and then lands in a large splash. They can also be seen fluking, where an observer can see an exposed tail fluke when a whale goes down on a deep dive after it takes a breath. The arch of its back at the surface causes its fluke to come up and out of the water.
Written by: Bryant Grady