• ESA Endangered: The Southern Resident orcas are endangered, meaning they are at risk of disappearing.
• MMPA Protected: All orcas are protected throughout their range under the Marine Mammal Protection Act.
• MMPA Depleted: The AT1 Transient orcas are considered depleted, meaning there are fewer of them than there should be.
• CITES Appendix II: Orcas are listed under this to help protect them from trade around the world.
• SPAW Annex II: Orcas are also protected in the wider Caribbean region.
Quick Facts About Orcas
• Weight: They can weigh up to 11 tons (as heavy as 5 cars).
• Length: They can grow up to 32 feet (about the length of a bus).
• Lifespan: Orcas can live 30 to 90 years.
• Threats: They face dangers like pollution, boat noise, getting caught in fishing gear, not enough food, and oil spills.
• Region: Orcas can be found in places like Alaska, the Pacific Islands, the West Coast, and more.
Orcas, also known as killer whales, are the biggest members of the dolphin family. They live in every ocean around the world and are easy to recognize because of their black and white bodies. Orcas are top predators in the ocean, meaning no other animal hunts them. They work together to catch food, like a team of hunters.
In the past, people used to hunt orcas and capture them to show in aquariums. While that doesn’t happen anymore in the U.S., it still happens in other places. Today, orcas face other dangers, like pollution, loud noises from boats, and not having enough food.
Some groups of orcas, like the Southern Resident orcas, are endangered, meaning there aren’t many of them left. Special laws protect these orcas, and scientists are working hard to keep them safe by cleaning up the ocean, protecting their food, and making people aware of how to help.
NOAA Fisheries, a group that studies and protects marine animals, is doing a lot to help orcas, especially the endangered ones. They work with other groups and countries to make rules to keep orcas safe and help them recover from the threats they face.
There are many different groups, or populations, of orcas all over the world. Scientists think there are about 50,000 orcas globally. Around 2,500 orcas live in the eastern North Pacific Ocean, where they are studied the most.
Unfortunately, some orca populations have become smaller and even endangered. For example, the AT1 Transient group in the North Pacific was reduced from 22 orcas to just 7 after the 1989 Exxon Valdez oil spill. Because of this, they are considered depleted.
The Southern Resident orcas have also struggled. In the 1960s, many of them were captured to be put in marine parks, which caused their numbers to drop. In 1974, only 71 Southern Residents were left, but the population grew a bit over the next few decades. However, they began to decline again in the late 1990s. By 2020, there were only 72 Southern Residents, but three new calves were born, bringing their total to 75. Scientists and the government are working hard to help this endangered group recover.
Orcas, or killer whales, are mostly black on top with white undersides and white patches near their eyes. They also have a gray or white patch behind their dorsal fin, called a saddle patch. Each orca’s markings can look a little different, making it easy for scientists to tell individuals apart. Male orcas are larger than females and have bigger flippers, dorsal fins, and tails.
Killer whales are highly social, and most live in social groups called pods (groups of maternally related individuals seen together more than half the time). Individual whales tend to stay in their natal pods. Pods typically consist of a few to 20 or more animals, and larger groups sometimes form for temporary social interactions, mating, or seasonal concentrations of prey.
Killer whales rely on underwater sound to feed, communicate, and navigate. Pod members communicate with each other through clicks, whistles, and pulsed calls. Each pod in the eastern North Pacific possesses a unique set of calls that are learned and culturally transmitted among individuals. These calls maintain group cohesion and serve as family badges.
Although the diet of killer whales depends to some extent on what is available where they live, it is primarily determined by the culture (i.e., learned hunting tactics) of each ecotype. For example, one ecotype of killer whales in the U.S. Pacific Northwest (called Residents) exclusively eats fish, mainly salmon, and another ecotype in the same area (Transients or Bigg’s killer whales) primarily eats marine mammals and squid.
Killer whales often use a coordinated hunting strategy and work as a team to catch prey. They are considered an apex predator, eating at the top of the food web.
Orcas live in all the oceans around the world. They are most common in colder places like Antarctica, Norway, and Alaska, but you can also find them in warmer waters. The best-studied groups of orcas are in the eastern North Pacific Ocean.
There are different types of orcas, and they live in different places:
• Resident orcas are found from California to Russia.
• Offshore orcas live far from the coast, usually more than 9 miles out at sea, but they sometimes come closer to shore.
• Transient orcas travel throughout the eastern North Pacific and are often seen near the coast. They sometimes share the same space as Resident and Offshore orcas.
Male orcas usually live about 30 years, but some can live up to 60 years. Female orcas tend to live longer, around 50 years, but some can reach 90 years old.
Female orcas can start having babies when they are 10 to 13 years old. They are pregnant for 15 to 18 months and usually give birth to one baby, called a calf. The calf drinks only its mother’s milk for at least a year and stays close to her for the first two years. Orcas can have babies at any time of the year. In some groups, females have a baby about every 5 years for about 25 years.
Orcas are special because, like humans, they are one of the few animals that go through menopause, meaning they stop having babies later in life.
Entanglement
Orcas face a big danger of getting caught in fishing gear. When this happens, they may get stuck and can’t swim or might drag the gear for long distances. Being trapped like this can make them tired, stop them from eating, or cause serious injuries, which can eventually lead to death.
Overfishing and habitat loss have made it harder for some orcas to find enough food. When there isn’t enough to eat, orcas may have fewer babies and may not survive as long. This is especially a problem for Southern Resident orcas, whose favorite food, Chinook salmon, is also endangered or threatened. Without enough salmon, these orcas struggle to survive.
Pollution from things like wastewater, sewer systems, and pesticides gets into the ocean and builds up in animals. Because orcas live a long time and are at the top of the food chain, harmful chemicals can collect in their bodies, especially in their blubber. These contaminants can damage their immune and reproductive systems, making it harder for them to stay healthy and have babies.
Even though pollution controls help reduce these chemicals, they haven’t completely gotten rid of them. Some chemicals stay in the ocean for many years, continuing to harm orcas and other marine life.
Oil spills, like the 1989 Exxon Valdez spill in Alaska, caused the deaths of many orcas. Oil spills can also hurt orcas by reducing the number of prey they rely on for food. Additionally, harmful chemicals from the oil, like PCBs, can build up in the food chain. These chemicals affect orcas, especially transient populations, since they are at the top of the food chain and eat animals that have already been exposed to the contaminants.
When vessels are present, killer whales hunt less and travel more. Noise interference from vessels, as well as from industrial and military activities, interrupts killer whales’ ability to use sound, which in turn disturbs their feeding, communication, and orientation. Increased vessel noise causes Southern Resident killer whales to call louder, expending more energy in the process.