About the Species
The fin whale is the second-largest whale species on earth, second only to the blue whale. It is found throughout the world’s oceans. It gets its name from an easy-to-spot fin on its back, near its tail.
Like all large whales, fin whales were hunted by commercial whalers, which severely lowered their populations. Whalers did not target them at first, because they were fast swimmers and lived in open ocean habitats. But, as whaling methods modernized with steam-powered ships and explosive harpoons, and whalers decimated other easy-to-catch species, whaling turned to fin whales. This industry killed a huge number during the mid-1900s—nearly 725,000 in the Southern Hemisphere alone.
Whaling is no longer a threat for fin whales (commercial whaling ended in the 1970s and 1980s, though some subsistence hunting continues today in Greenland under sustainable quotas allowed by the International Whaling Commission). Currently, the major threat to this species comes from vessel strikes. The fin whale is listed as endangered under the Endangered Species Act and depleted under the Marine Mammal Protection Act.
NOAA Fisheries and its partners are dedicated to conserving and rebuilding fin whale populations. We use innovative techniques to study, protect, and rescue these endangered whales. We engage our partners as we develop regulations and management plans that foster healthy fisheries and reduce the risk of entanglements, create whale-safe shipping practices, and reduce ocean noise.
For management purposes, we divide fin whales in U.S. into four stocks:
- Alaska (Northeast Pacific)
- Western North Atlantic
We determine the number of fin whales through counting stocks, however, not all stocks have accurate information. Reliable, recent estimates are available for much of the North Atlantic Ocean, but not for most of the North Pacific or the Southern Oceans. We do not know how populations in those ocean basins have changed, relative to their pre-whaling size. The most recent population assessments can be found in stock assessment reports.
Fin whales have sleek, streamlined bodies with V-shaped heads. They have a tall, hooked dorsal fin, about two-thirds of the way back on the body, that rises at a shallow angle from the back. Fin whales have distinctive coloration—black or dark brownish-gray on the back and sides and white on the underside. Head coloring is asymmetrical—dark on the left side of the lower jaw, white on the right-side lower jaw, and the reverse on the tongue. Many fin whales have several light-gray, V-shaped “chevrons” behind their heads; on many of them, the underside of the tail flukes is white with a gray border. These markings are unique and can be used to identify Individual fin whales.
Behavior and Diet
Fin whales are fast swimmers and are often found in social groups of two to seven individuals. In the North Atlantic, they are often seen feeding in large groups that include humpback whales, minke whales, and Atlantic white-sided dolphins.
During the summer, fin whales feed on krill, small schooling fish (including herring, capelin, and sand lance), and squid by lunging into schools of prey with their mouth open, using their 50 to 100 accordion-like throat pleats to gulp large amounts of food and water. They then filter the food particles from the water, using the 260 to 480 baleen plates (long, flat plates made of fingernail-like material called keratin) that they have in place of teeth on each side of the mouth. Fin whales fast in the winter while they migrate to warmer waters.
Like other baleen whales, fin whales also skim the water, taking in huge volumes of water. When they close their mouths, the water is pushed out through the baleen and the prey is caught on the inside of the baleen. A fin whale eats up to 2 tons of food daily.
Where They Live
Fin whales are typically found in deep, offshore waters of all major oceans, primarily in temperate to polar latitudes. They are less common in the tropics. They occur year-round in a wide range of locations, but the density of individuals in any one area changes seasonally. Most migrate from the Arctic and Antarctic feeding areas in the summer to tropical breeding and calving areas in the winter. The location of winter breeding grounds is not known. Fin whales travel in the open seas, away from the coast, so they are difficult to track. There are three named subspecies of fin whale:
- B. physalus physalus in the North Atlantic and North Pacific
- B. physalus quoyi in the Southern Ocean
- B. physalus patachonica in the mid-latitude Southern Ocean
In fact, most experts consider the B. physalus physalus in the North Atlantic and the North Pacific to be separate subspecies. The two populations rarely (if ever) mix, and there are geographical stocks within these ocean basins. Fin whales are migratory, moving seasonally into and out of feeding areas near the poles, but the overall migration pattern is complex and likely varies by region, and specific routes have been documented for some populations. Acoustic recordings from passive-listening hydrophone arrays indicate a southward “flow pattern” in the fall from the Labrador-Newfoundland region, past Bermuda, and into the West Indies. There may be resident groups of fin whales in some areas, such as the Gulf of California, the East China Sea, and the Mediterranean Sea.
Lifespan & Reproduction
Little is known about the social and mating systems of fin whales. As with other baleen whales, long-term bonds between individuals are rare.
Fin whales have long lives—they reach physical maturity at about 25 years, and their maximum lifespan is about 90 years. Males become sexually mature at 6 to 10 years of age and females at 7 to 12 years of age. After 11 to 12 months of gestation, a pregnant female gives birth to a single calf in tropical and subtropical areas during midwinter. Newborn calves are about 18 feet long, and weigh 4,000 to 6,000 pounds.
Fin whales sometimes mate with blue whales and hybrids have been documented.
Vessel strikes can injure or kill fin whales. Fin whales are probably the most vulnerable species to ship strikes after North Atlantic Right Whales. The projected increase in ship traffic arising from the opening of trans-polar shipping routes (as arctic sea ice continues to decline) will increase the risk of vessel strike and also increase ambient noise and pollution.
Entanglement in Fishing Gear
Fin whales can become entangled in fishing gear, either swimming off with the gear attached or becoming anchored. They can become entangled in many different gear types, including traps, pots, or gillnets. Once entangled, whales may drag and swim with attached gear for long distances, ultimately resulting in fatigue, compromised feeding ability, or severe injury, which may lead to reduced reproductive success or death.
Underwater noise negatively affects 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.
The impacts of climate change on baleen whales may result from altered oceanographic conditions, as well as the timing and distribution of sea ice coverage. Changes in prey distribution could lead to changes in foraging behavior, nutritional stress, and diminished reproduction for fin whales. Additionally, changing water temperature and currents could impact the timing of environmental cues important for navigation and foraging.
In the Spotlight
The fin whale is listed as endangered throughout its range under the Endangered Species Act and as depleted throughout its range under the Marine Mammal Protection Act. This means that it is in danger of extinction throughout all or much of its range. NOAA is working to protect this species in many ways, with the goal to protect them from threat and increase their population size.
Recovery Planning and Implementation
Under the ESA, NOAA Fisheries is required to develop and implement recovery plans for the conservation and survival of listed species.
The recovery plan for the fin whale was published in July 2010. Its goal is to recover the species, with an interim goal of down-listing its status from endangered to threatened.
The major actions recommended in the plan are:
- Reduce or eliminate injury or death caused by ship collision
- Reduce or eliminate injury or death caused by fisheries and fishing gear
- Protect habitats essential to the survival and recovery of the species
- Minimize effects of vessel disturbance
- Continue the international ban on hunting and other directed take
- Monitor the population size and trends in abundance of the species
- Maximize efforts to free entangled or stranded fin whales and get scientific information from dead specimens
NOAA Fisheries is working to minimize effects from human activities that hinder the recovery of fin whale populations in the United States and internationally. Along with our partners, we work to:
- Reduce entanglement in fishing gear
- Respond to stranded and entangled fin whales
- Rescue collision risk to fin whales
Reducing Entanglement in Fishing Gear
Entanglement in fishing gear is a primary cause of serious injury and death for many whale species, including fin whales.
In the Atlantic, we implemented the Atlantic Large Whale Take Reduction Plan to reduce the incidental mortality and serious injury of right whales, humpback whales, and fin whales in gillnets and trap/pot fisheries along the East Coast.
Reducing Vessel Strikes
Collisions between whales and large vessels can injure or kill the whales and damage the vessels, but they often go unnoticed and unreported. The most effective way to reduce collision risk is to keep whales and vessels apart. If this is not possible, second best is for vessels to slow down and keep a lookout.
Addressing Ocean Noise
Underwater noise threatens whale populations, disrupting 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. 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 mammals’ hearing.
Overseeing Marine Mammal Health and Stranding Response
We work with volunteer networks in all coastal states to respond to marine mammal strandings including all whales. When stranded animals are found alive, NOAA Fisheries and our partners assess the animal’s health and determine the best course of action. 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 attribute strandings 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 may also have implications for human health and welfare.
Marine Mammal Unusual Mortality Events
Fin whales have been part of a declared unusual mortality event in the past. Under the Marine Mammal Protection Act, an unusual mortality event is defined as "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response." To understand the health of marine mammal populations, scientists study unusual mortality events.
Educating the Public
NOAA Fisheries aims to increase public awareness and support for fin whale conservation through education, outreach, and public participation. We regularly share information with the public about the status of fin whales, as well as our research and efforts to promote their recovery.
Within the United States, the fin whale is listed as endangered throughout its range under the Endangered Species Act of 1973 and is listed as depleted throughout its range under the Marine Mammal Protection Act of 1972.
Key Actions and Documents
Incidental Take Authorization: U.S. Navy Hawaii-Southern California Training and Testing (HSTT) (2018-2025)
- Proposed Rule (2023)
- Notice of Receipt of Application for Revision to 7-Year Rule and LOAs
- Final 7-Year Rule (2020)
- Proposed 7-Year Rule (2019)
- Notice of Receipt of Application for 7-Year LOAs
Incidental Take Authorization: Lamont-Doherty Earth Observatory's Marine Geophysical Survey in the Puerto Rico Trench and slope of Puerto Rico
Incidental Take Authorization: Alaska Department of Transportation and Public Facilities' Tongass Narrows Project (2023)
Incidental Take Authorization: Atlantic Shores Offshore Wind Bight, LLC's Marine Site Characterization Surveys off New Jersey and New York
NOAA Fisheries researches the biology, behavior, and ecology of the fin whale. We use the results to inform management decisions and recovery efforts for this endangered species.
Determining the number of fin whales in each population—and whether a stock is growing or shrinking over time—helps resource managers assess the success of conservation measures. Our scientists collect information and present these data in annual stock assessment reports.
Other research focuses on the acoustic environment of cetaceans, including fin whales. (Acoustics is the science of how sound is transmitted.) We study the basic acoustic behavior of whales, dolphins, and fish; map the acoustic environment; and develop better ways to find cetaceans using autonomous gliders and passive acoustic arrays.
Acoustics can reveal differences between fin whale populations and monitor hearing levels and feeding behavior. We also study how underwater noise affects the way fin whales behave, eat, interact with each other, and move within their habitat.
Recent Science Blogs
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Opinion on the effects of tugs towing a jack-up rig on the endangered fin whale, threatened Mexican…
Endangered Species Act (ESA) Section 7(a)(2) Biological Opinion Office of Naval Research (ONR)…