About the Species
Once common throughout the Northern Hemisphere, gray whales are now only found in the North Pacific Ocean where there are two extant populations in the eastern and western North Pacific.
Gray whales earned the nickname “devil fish” because of their aggressive reactions when harpooned. Commercial whaling rapidly brought both Pacific populations to near extinction. International conservation measures were enacted in the 1930s and 1940s to protect whales from over exploitation and in the mid-1980s the International Whaling Commission instituted a moratorium on commercial whaling.
The eastern population was once listed as endangered under the Endangered Species Act but successfully recovered and was delisted in 1994. The western population remains very low, around 200 individuals, and is listed as endangered under the ESA and depleted under the Marine Mammal Protection Act.
Gray whales are known for their curiosity toward boats and are the focus of whale watching and ecotourism along the west coast of North America. They thus face threats from vessel strikes and disturbance on their migration route. Gray whales make one of the longest annual migrations of any mammal, traveling about 10,000 miles round-trip.
NOAA Fisheries works to conserve gray whales through collaborative management, integrated science, partnerships, and outreach. Our scientists use a variety of innovative techniques to study, protect, and rescue gray whales in distress (e.g., disentanglement and stranding response). We strive to reduce the harmful effects of human activities such as fisheries interactions, noise, and pollution, through management actions based on sound science, public input, and public outreach.
NOAA Fisheries estimates the population size (also called a stock) for gray whales in its stock assessment reports. A stock is a group of animals that occupy the same area and interbreed. Shore-based observers have conducted systematic counts of eastern North Pacific gray whales migrating south along the central California coast in most years since 1967. The eastern North Pacific population was once listed as endangered under the ESA but has successfully recovered and was delisted in 1994. The western North Pacific population remains low, and its continued survival is questionable. This population is estimated to include fewer than 200 individuals.
ESA Endangered - Foreign
- Western North Pacific DPS
CITES Appendix I
- Throughout Its Range
- Throughout Its Range
- Western North Pacific DPS
These large whales can grow to about 49 feet long and weigh approximately 90,000 pounds. Females are slightly larger than males. Gray whales have a mottled gray body with small eyes located just above the corners of the mouth. Their pectoral flippers are broad, paddle-shaped, and pointed at the tips. Lacking a dorsal fin, they instead have a dorsal hump about two-thirds of the way back on the body, and a series of 6 to 12 small bumps, called “knuckles”, between the dorsal hump and the tail flukes. The tail flukes are nearly 10 feet wide with S-shaped trailing edges and a deep median notch.
Calves are typically born dark gray and lighten as they age to brownish-gray or light gray. All gray whales are mottled with lighter patches. They have barnacles and whale lice on their bodies, with higher concentrations found on the head and tail.
Behavior and Diet
Gray whales are frequently observed traveling alone or in small, unstable groups, although large aggregations may be seen in feeding and breeding grounds. Like other baleen whales, long-term bonds between individuals are thought to be rare.
They are primarily bottom feeders that consume a wide range of benthic (sea floor) and epibenthic (above the sea floor) invertebrates, such as amphipods. Gray whales suck sediment and food from the sea floor by rolling on their sides and swimming slowly along, filtering their food through 130 to 180 coarse baleen plates on each side of their upper jaw. In doing so, they often leave long trails of mud behind them and "feeding pits" in the sea floor.
Killer whales prey upon gray whales.
Where They Live
Gray whales are found mainly in shallow coastal waters in the North Pacific Ocean. There are two geographic distributions of gray whales in the North Pacific: the eastern North Pacific stock, found along the west coast of North America, and the western North Pacific stock, found along the coast of eastern Asia. Most of the eastern North Pacific stock spends the summer feeding in the northern Bering and Chukchi Seas, but some gray whales have also been reported feeding along the Pacific coast during the summer, in waters off of Southeast Alaska, British Columbia, Washington, Oregon, and northern California. In the fall, gray whales migrate from their summer feeding grounds, heading south along the coast of North America to spend the winter in their wintering and calving areas off the coast of Baja California, Mexico. Calves are born during migration or in the shallow lagoons and bays of Mexico from early January to mid-February. From mid-February to May, eastern North Pacific gray whales can be seen migrating northward along the U.S. west coast. Photo-identification studies indicate that gray whales in this stock move widely within and between areas on the Pacific coast. They are not always observed in the same area each year, and there may be gaps of several years between repeat sightings. Although western and eastern DPS gray were thought to be relatively isolated from each other, recent satellite tagging data have shown that at least some western North Pacific DPS gray whales migrate across the northern Gulf of Alaska, and along the west coast of British Columbia, the United States, and Mexico.
Lifespan & Reproduction
Gray whales become sexually mature between 6 and 12 years, at an average of about 8 to 9 years old. After 12 to 13 months of gestation, females give birth to a single calf. Newborn calves are approximately 14 to 16 feet long and weigh about 2,000 pounds. The average and maximum lifespan of gray whales is unknown, although one female was estimated at 75 to 80 years old after death.
Entanglement in Fishing Gear
Gray whales are at high risk of becoming entangled in fishing gear, either swimming off with the gear attached or becoming anchored. Once entangled, whales may drag and swim with attached gear for long distances. This can result in fatigue, compromised feeding ability, or severe injury, which may ultimately lead to death.
Collisions with all sizes and types of vessels are one of the primary threats to marine mammals, particularly large whales. Gray whales are one of the most vulnerable species to vessel strikes because they feed and migrate along the U.S. west coast, which has some of the world’s heaviest vessel traffic associated with some of the largest ports in the country. Gray whales may also be vulnerable to vessel strikes in the inland waters of Washington and in feeding areas along the Pacific coast.
Disturbance from Whale Watching Activities
Whale watching has become an important recreational industry in several communities along the North American coast from British Columbia, Canada, to the gray whale wintering lagoons of Baja California, Mexico. Whale watching along this route may affect gray whale migration.
Underwater noise threatens whale populations, interrupting their normal behavior and driving them away from areas important to their survival. Increasing evidence suggests that exposure to intense underwater sound in some settings may cause some whales to strand and ultimately die.
Like all marine mammals, gray whales are protected under the Marine Mammal Protection Act. The western North Pacific distinct population segment is listed as endangered under the Endangered Species Act and depleted under the MMPA. NOAA Fisheries is working to help conserve this population and to ensure its continued survival and continued recovery.
Reducing Entanglement in Fishing Gear
Gray whales are incidentally caught as bycatch and entangled in fishing gear, leading to deaths and serious injuries. We work with fishermen, industry, non-government organizations, and academia to find approaches and strategies for reducing bycatch in U.S. fisheries.
Reducing Vessel Strikes
Collisions between whales and large vessels often go unnoticed and unreported, even though whales can be injured or killed, and ships can sustain damage. We have taken steps to reduce the threat of vessel collisions to gray whales. For example, NOAA Fisheries has collaborated with NOAA Sanctuaries and the U.S. Coast Guard to effect changes in shipping lanes that should help reduce the risk of ships striking large whales.
NOAA Fisheries has also worked with the Southern California Marine Exchange to coordinate meetings with shipping industry leaders to discuss the issue of large whale ship strikes. NOAA works with the USCG, industry representatives, and the NOAA Weather Service prevent strikes by alerting mariners of the presence of large whales to raise awareness and help prevent strikes.
We recommend that operators of large vessels do the following to help reduce the risk of ship strikes:
Learn when the seasonal abundance of large whales is in your shipping lanes.
Listen for and heed advisories.
Consult the Local Notice to Mariners in your area or Coast Pilot for more information.
Keep a sharp look-out for whales; post extra crew on the bow to watch, if possible.
Reduce speeds while in the advisory zones or in areas of high seasonal or local whale abundance.
If practicable, re-route the vessel to avoid areas of high whale abundance.
Minimizing Whale Watching Harassment
Admiring whales from a distance is the safest and most responsible way to view them in their natural habitat. NOAA Fisheries supports responsible viewing of marine mammals in the wild and has adopted a guideline to observe all large whales from a safe distance of at least 100 yards by sea or land. NOAA Fisheries’ West Coast Region encourages the public to be “whale wise” and has also published its own safe viewing guidelines and outreach materials for boaters, paddlers, and drone operators on the west coast.
Overseeing Marine Mammal Health and Stranding Response
We work with volunteer networks in all coastal states to respond to marine mammal strandings. When stranded animals are found alive, NOAA Fisheries and its partners assess the animal’s health and try to return it to the water. When stranded animals are found dead, our scientists work to understand and investigate the cause of death. Although the cause often remains unknown, scientists can sometimes identify strandings due to disease, harmful algal blooms, vessel strikes, fishing gear entanglements, pollution exposure, and underwater noise. Some strandings can serve as indicators of ocean health, giving insight into larger environmental issues that can have implications for human health and welfare.
Addressing Ocean Noise
Increasing evidence suggests that exposure to intense underwater sound may cause some whales to strand and ultimately die. NOAA Fisheries is investigating all aspects of acoustic communication and hearing in marine animals, as well as the effects of sound on whale behavior and hearing. In 2016, we issued technical guidance for assessing the effects of anthropogenic sound on marine mammal hearing.
Beginning in the mid-1930s, gray whales were protected under a commercial hunting ban adopted by the League of Nations. This ban (which also included right whales) was the first international agreement to protect a whale species from commercial whaling operations. The ban on commercial gray whale catches has continued since the late 1940s under the International Whaling Commission. Gray whales are still hunted by native people of Chukotka, Russia, and Washington State and are subject to catch limits under the International Whaling Commission's aboriginal subsistence whaling scheme.
Today, gray whales are protected under the MMPA. The eastern North Pacific stock was once listed as endangered under the Endangered Species Act, but was delisted in 1994 based on evidence that the population had nearly recovered to its estimated original population size and was not in danger of extinction throughout all or a significant portion of its range. In 1999, NOAA Fisheries conducted a review of the status of the eastern North Pacific stock of gray whales (PDF, 106 pages) and recommended the continuation of its classification as non-threatened based on the continued growth of the population (approximately 27,000 individuals in 2016). We continue to monitor the abundance and calf production of the stock, especially in light of recent climatic changes occuring in their arctic feeding grounds. The western North Pacific stock of gray whales has not recovered. It is listed as endangered under the ESA and depleted under the MMPA.
Regulatory Actions & Documents
Initiation of 5-Year Reviews for the Endangered Fin Whale, Endangered Gray Whale Western North Pacific Distinct Population Segment, and Endangered Sei...
- Final Rule to Delist the Eastern North Pacific Population (59 FR 31094)
- Notice of Determination to Delist the Eastern North Pacific Stock (58 FR 3121)
- Original Listing Rule (35 FR 18319)
NOAA Fisheries conducts research on the biology, behavior, and ecology of the gray whale. The results are used to inform management decisions and enhance recovery efforts for this species.
Determining the size of gray whale populations helps resource managers gauge the success of NOAA Fisheries’ conservation measures. Our scientists collect and present these data in annual stock assessment reports.
Strandings and Unusual Mortality Events
To understand the health of whale populations, scientists work with our stranding network partners to collect data on all marine mammal strandings and investigate unusual mortality events. Scientists study UMEs such as the 1999–2000 eastern North Pacific gray whale UME, in which an unusually large number of dead gray whales stranded along the west coast of North America, from Mexico to Alaska. To fully understand the causes of these events, interdisciplinary teams of scientists study interdependent factors that may contribute to whale deaths.
Eastern North Pacific gray whales migrate annually between winter breeding grounds in the lagoons of Baja California, Mexico, and summer feeding grounds in the Arctic. This migration follows the coast of North America and overlaps with areas of heavy coastal shipping, fisheries, and resource exploration. Evaluating risk from these activities requires fine-scale data on precise migration routes. In March 2012, scientists from NOAA Fisheries Southwest Fisheries Science Center and Mexican collaborators deployed small satellite dart tags on adult gray whales to monitor their fine-scale migration route through the coastal waters off Baja California, Mexico, and southern California.
NOAA Fisheries’ West Coast Regional Office and National Marine Mammal Laboratory fund photo-identification studies to better understand the gray whale stock structure and behavior. This information allows us to follow the animals over time and learn about their use of habitat and their feeding patterns. It can also shed light on the relationship between the eastern and western populations.
Gray Whales in Alaska
Our research on the population dynamics, diet and foraging behavior, distribution, and movement patterns of gray whales provides information crucial for understanding and protecting gray whale populations in Alaska.
This report provides a summary of large whale entanglements that occurred in U.S. waters in 2017 including...
Gray whales Eschrichtius robustus, while engaged in underwater signaling, circumvented noise in their...
NOAA Fisheries Protected Resources Division biologists conducted six survey flights of the shifting sand...
Data & Maps
Marine Mammal Laboratory Cetacean Assessment & Ecology Program. A full report for the full 2017 survey...
This report describes field activities of the Aerial Surveys of Arctic Marine Mammals (ASAMM) project...
Spacial data and maps of critical habitat and Endangered Species Act (ESA) threatened and endangered...