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Basking Sharks: The Vulnerable Gentle Giant

The Basking Shark (Cetorhinus maximus), is the second-largest species of shark and also the second-largest species of fish in the world’s oceans. You can often see these sharks along the west coast of the UK.

It is one of only three plankton-eating species of sharks, along with the Whale Shark and the Megamouth Shark.

Statistical Information

Dusky Whaler Shark underwater
  • A basking shark may grow up to 35 feet (10.6 m) in length and weigh up to 10,000 pounds (4.5 metric tons). The biggest basking shark ever recorded was a hefty 40.3 feet long.
  • These critters have enormous livers that account for 25% of their total weight. While filter eating, basking sharks may purify up to 4,000,000 pounds (1814 metric tons) of water per hour.
  • They often swim in duos or groups with up to 100 others.
  • The gestation time for female basking sharks is at least three years. Basking sharks are thought to live for roughly 50 years.

Description

Basking Sharks

Over time, people have called basking sharks by many different names. The basking shark scientific name is “Cetorhinus maximus,” dubbed so in 1765 by Johan Ernst Gunnerus, a bishop and botanist from Norway.

Basking Shark Appearance and Anatomy

Basking Sharks Appearance

The basking shark has a big, light-grey body. The top is darker in tone, while the bottom is lighter. It has a big triangle-shaped black dorsal fin on its back.

The basking shark’s mouth is very wide, and the inside of its gaping mouth is white. On the other hand, the gill rakers are black (finger-like structures that prevent food from escaping through the gills). There are many rows of small teeth in the basking shark’s mouth.

Apart from its size and enormous mouth, the basking shark is instantly recognizable from its long “nose!”

Basking Shark Location

Why care for Shark

Basking sharks can be found in almost all of the seas along the UK’s coast in the summer. There have been more reports of sightings in the southwest corner of England, along Scotland’s west coast, and the coast of Wales. They’ve also been seen around the Scottish Hebrides (specifically the Isle of Skye and the Isle of Mull).

A study done in 2009 found that many basking sharks were seen off the Atlantic coast of North America during the warmer months of the year.

Since they like water between 8 and 15 degrees Celsius, you rarely see them in tropical waters like the Indian Ocean.

Basking Sharks Habitat

basking shark with their group

A common question about these gentle giants is, where do basking sharks live? The basking shark is a deep-sea creature that inhabits coastal and oceanic seas between 200 and 2,000 m deep. However, it often ventures closer to land. It is often seen near the water’s edge in the spring and early summer. It is often found offshore in places with temperatures between 7 and 16 degrees Celsius close to ocean fronts.

Basking sharks can be commonly found up to the Arctic Circle in the northern hemisphere but can be found worldwide. They are a species that moves around a lot.

They go hundreds of miles yearly to find plankton blooms in the world’s oceans. They have been known to swim across the equator to get to the best places.

See Related: Great White Shark

Basking Sharks Feeding/Hunting/Eating

Basking Shark is roaming around in the sea

Basking sharks, like whale sharks, are filter-feeders. This means they swim slowly around the ocean with their mouths wide open and use organs called “gill-rakers” to filter plankton from the water. People call this way of eating “ram feeding.”

But unlike whale sharks, basking sharks are “obligate ram feeders.” This means that the shark must swim all the time to get food to its mouth. Even when they are not swimming, whale sharks can move water over their gill rakers. This is called “pumping the buccal glands.”

Basking Shark Habits

Leopard sharks feeding on kelp
PixilRay / Adobe Stock

For most of the summer, basking sharks stay near the surface of the water and move very slowly. They got the name “basking” shark because this “lazy” form of swimming makes it look like they are relaxing in the sun.

Even though basking sharks usually live alone, groups of the same gender have been seen swimming together. Most of the time, there aren’t more than a few of these giant fish in these shoals.

Between babies, they take a break. Because of this, they don’t reproduce very often, making them more likely to become extinct than species that reproduce more often.

They have been seen swimming out of the water, which might be a parasite-elimination technique.

See Related: Dusky Shark

Basking Sharks Life Cycle

Deep sea fish Greenland shark

Even though not much is known about the basking shark’s lifespan, it is thought that they may live up to 50 years.

Males reach sexual maturity between 12 and 16 years old, while females do so between 16 and 20. After about two to three years of pregnancy, females give birth to live babies. When born, babies are between 1.5 and 2 meters long and swim to the surface to eat out of instinct.

Basking Sharks’ Role in the Ecosystem

Angel Shark swimming

The species eats plankton by filtering it through its body and moving it near the surface with large amounts of plankton. When they eat, they spread their giant mouths and move slowly through the plankton clouds, grabbing the tiny plankton with their gill rakers. A basking shark can filter thousands of tons of water every hour.

Basking Sharks Fun Facts Recap

basking shark with their group

Here are some facts about basking sharks:

  • Although an adult basking shark size can reach a length of over 40 feet and a weight of 10,000 pounds when fully grown, the basking shark length when newborns are typically between 5 and 6 feet long. The basking shark mass is unmatchable to any other shark species.
  • The hundreds of tiny teeth basking sharks have are not used to catch prey any larger than plankton.
  • They only consume plankton, a microscopic creature. The plankton is sent to the shark’s stomach as the water is poured into their mouths and filtered out by the gills.
  • They are one of the very few sharks on the planet that swims with their mouth open is the basking shark. They swim for 30 to 120 seconds with their mouths open to gulp down plankton before closing them. They often turn their bodies around as they move through the water to eat. Sometimes, they even roll all the way around.
  • Basking sharks can live for up to 50 years.
  • Basking sharks are not friendly creatures; in a few rare instances, they are often seen swimming alone in the ocean.
  • Basking sharks are not harmful to people.

The basking shark is usually a solitary animal that swims around the oceans looking for tasty plankton blooms. No one knows where they go when they don’t have to eat. Still, it seems like they like to get together with other animals at certain times of the year to socialize or find a mate.

Scientists from the University of Aberdeen in Scotland and the Queen’s University in Belfast found in 2020 that basking sharks always go back to their favorite places to eat throughout the year. Their DNA also found that many of the animals surveyed there were related to each other.

So, it turns out Basking sharks spend most of the year alone, but they like to spend time with their families when they get the chance!

It is thought that these family groups help younger members of the species learn how to migrate and find the best places to eat. But no matter what the reason is, it is clear that the basking sharks’ annual gathering is the biggest and best event!

See Related: Types of Sharks Around the World

Conservation

Front view of Angel shark

A recent study says that the number of basking sharks has dropped by as much as 71% in the last 50 years. Between 1946 and 1997, up to 100,000 adult basking sharks were caught in the northeastern Atlantic Ocean alone, where they had been fair game for hundreds of years.

It can take a female basking shark up to 18 years to reach sexual maturity, and they can carry their young for up to three years. This means that basking sharks have one of the lowest birth rates among all shark species. Even though they are one of the most protected shark species in European waters, they are also on the verge of extinction due to their low birth rate.

Threats

Even though hunting this species is illegal in many countries, there is still a thriving black market for basking shark components. Fins alone, worth up to $57,000, are traded in Hong Kong, Japan, and the US.

Because basking sharks like to eat and hang out near the shore, they are still at risk of getting caught in fishing gear, hit by ships, bothered by tour boats, and damaged their habitats by coastal projects.

Basking Sharks Hunting

People used to hunt the basking shark for its liver oil, which was used to make vitamin A, lamp oil, and tan leather. There is also a chemical in the oil called squalene, used in medicine and cosmetics. Also, basking sharks were killed for their huge fins, which are very popular in Asia’s shark fin market.

Extracts From Basking Sharks

The basking shark population has been overfished in the past for its liver oil, skin, meat, and fins. The oil from basking shark livers is significant since it is utilized in pharmaceutical and cosmetic applications.

When used as storefront advertising for a Chinese restaurant serving the delicacies of shark fin soup, a single, gigantic basking shark fin can bring in tens of thousands of dollars.

See Related: Killer Whale: Is This Animal Endangered?

Basking Sharks Food Competition

Are Basking Sharks Dangerous

Both whale sharks and basking sharks funnel vast amounts of seawater through their mouths to consume floating plankton. These sharks, consume both zooplankton and fishes as well as invertebrates. The only competitors for the basking shark’s favorite food are plankton-eating whales and whale sharks.

Conservation Efforts

Men on a boat fishing on the sea

Basking sharks are currently listed as “Endangered” on the International Union of Conservation of Nature (IUCN) Red List of Endangered Species. The basking shark went from “Vulnerable” to “Endangered‘ in 2018 because their populations are still declining. The shark, which can live for at least 50 years and has a meager reproduction rate, is very vulnerable to being eaten.

Organizations

whale swimming in the ocean with a lot of fish around it's neck and head, with a lot of fish around it's neck
Anna / Adobe Stock

The Marine Conservation Society in the UK and some local groups, like the Manx Basking Shark Watch, are working to protect basking sharks and ensure they stay around.

The good news is that these animals are now well protected in most of their natural habitat, including in the UK and the European Union. As a result, their numbers seem to have stabilized.

See Related: Great Hammerhead Shark

Final Thoughts

Basking sharks swim slowly like the whale shark, but they never stop swimming. The basking shark (also known as the elephant shark) tail is all muscle, and you don’t want to annoy a 10-meter-long shark and get hit by what would feel like a shark-skinned tree trunk!

Basking sharks usually don’t care about divers or swimmers and mind their own business. You won’t witness any basking sharks displaying a dangerous attitude. But half of their body is a powerful tail which is very big, so even though they swim slowly, they can still do a lot of damage if they whack you.

You certainly don’t have to worry about one taking a chunk out of you or eating you whole. Basking sharks have no interest in eating anything more prominent than plankton.

Related Resources:

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