Gray whales are remarkable marine mammals that undertake some of the longest migrations of any mammal. Understanding where gray whales live involves exploring their preferred ocean environments and the incredible journeys they undertake annually.
Their Primary Ocean Homes
Gray whales primarily inhabit the North Pacific Ocean, preferring the shallow, coastal waters of continental shelves. Their habitat selection is closely tied to their unique feeding strategy. They are bottom feeders, sifting through marine sediments to consume small invertebrates, such as amphipods and mysid shrimp. This specialized diet means they spend time in waters typically less than 20 meters deep, where these benthic organisms are abundant.
Their feeding grounds feature nutrient-rich muddy or sandy seafloors. While largely coastal, some feeding occurs in slightly deeper shelf areas, especially in their northern summer ranges. This preference for shallower, productive waters distinguishes them from many other large whale species that forage in open ocean environments.
The Epic Migration Journey
The Eastern Pacific gray whale population undertakes an annual migration spanning 16,000 to 22,000 kilometers (10,000 to 14,000 miles) round trip. They transition between their rich Arctic feeding grounds and warmer, protected breeding and calving lagoons.
In October, these whales depart their summer feeding areas in the Bering and Chukchi Seas, heading south along the North American coastline. They travel continuously, averaging 120 kilometers (75 miles) per day at a speed of 8 kilometers per hour (5 miles per hour), reaching the lagoons of Baja California, Mexico, by December and January. In these warmer waters, adult whales mate and females give birth. The northward migration commences from February to May, with mothers and calves often delaying departure until April or May to allow the young to gain strength for the journey back to the Arctic.
Distinct Populations and Their Ranges
Two main populations of gray whales are recognized in the North Pacific Ocean. The Eastern Pacific population, the larger, more well-known group, ranges from the Arctic waters of the Bering and Chukchi Seas to the calving lagoons of Baja California, Mexico. This population has shown significant recovery from past whaling, with numbers reaching 20,000 to 27,000 individuals.
In contrast, the Western Pacific population is smaller and critically endangered, with an estimated 120 to 270 individuals. These whales spend summers feeding off Sakhalin Island and the Kamchatka Peninsula in Russia. Their wintering grounds and migration routes are less understood, though some migrate towards the coasts of Korea, Japan, and China, with some observed migrating to Mexico. Historically, gray whales also inhabited the North Atlantic Ocean, but this population was extirpated, likely due to whaling, by the 18th century. Rare sightings in the Atlantic in recent years are thought to be individual whales wandering from the Eastern Pacific population, possibly facilitated by melting Arctic sea ice, which opens new passages.