Photo by: Corbis/VCG


Unraveling the Mysteries of Basking Sharks

By: Vicky Vásquez

With a scientific name that translates to "large-nosed sea monster," the Basking Shark is an elusive member of the shark family.

June 15, 2021

For being the second largest shark in the world and having a nickname like, basking, it may seem like 50ft-planktivores are easy to study. Even so, scientists have only put a few pieces of the basking shark story together. These peculiar sharks, whose scientific name, Cetorhinus maximus, translates to “large-nosed sea monster”, don’t just float thorough life. They actively navigate surface waters for food in the form of tiny animal plankton (aka zooplankton). With basking shark areas going as long as 20 years between sightings, knowing where to find them can be hard to predict. Still, a single sighting can be immensely valuable, since basking sharks are known to aggregate in large numbers. The most reported in one sighting was a school of over 1,000 basking sharks, and the mingling doesn’t stop there.

REQUIN PELERIN, Cetorhinus maximus, Cetorhinidae, se nourrit de plancton, Ile de Man, Royaume Uni / BASKING SHARK, Cetorhinus maximus, Cetorhinidae, Feeding on plankton, Isle of Man, UK


REQUIN PELERIN, Cetorhinus maximus, Cetorhinidae, se nourrit de plancton, Ile de Man, Royaume Uni / BASKING SHARK, Cetorhinus maximus, Cetorhinidae, Feeding on plankton, Isle of Man, UK

Photo by: Gerard Soury

Gerard Soury

Found in both the Atlantic and Pacific oceans, genetic research shows individuals from either ocean are still part of one big population. To put that into perspective, consider their cousins, the great white sharks (Carcharodon carcharias), who are highly migratory, but genetic research still separates the Pacific and Atlantic great whites into two sub-populations. That is to say, basking sharks are serious jetstream-setters in the shark world. Over in the Atlantic Ocean, satellite tagging data shows transatlantic travel goes both east to west, where the ocean can span 2,060, miles, as well as north to south, which is at least 9,000, miles going just from Iceland to Chile. A testament to basking shark unpredictability is that some of the most stunning footage of their behavior — like the video taken by Chloe Ryan from Kilkee, Ireland during a casual stroll just steps away from her door — comes from citizen scientists.

Photo by: Dr. Dave Ebert

Dr. Dave Ebert

Part of the challenge with understanding basking sharks is certainly due to overfishing. Since the early 1900s, these ocean-surface grazers have been fished all over the world for their livers, meat, and fins. Consequently, in 2019 the IUCN Red List of Threatened Species declared basking sharks to be Endangered. All the same, low numbers may not be the only reason for the mysterious waters still surrounding them. To dive past science’s surface understanding of basking sharks, fisheries scientist Dr. Brittany Finucci from the National Institute of Water and Atmospheric Research (NIWA) dove deeper than the 4,000 feet in the mesopelagic layer, where they also can go for food.

More on Sharks

SHARK WEEK starts July 11 on Discovery and discovery+

Shark Week Is Our Favorite Thing About Summer

Get ready for the best summer yet. This year, SHARK WEEK starts on July 11 with more jawsome shows than ever before on Discovery and discovery+.

Shark Week | The Best Thing About Summer 00:29

Get ready for the best summer yet. Starting July 11 and continuing through July 18th you can see more hours of shark programming than ever before on Discovery and discovery+.

Dr. Finucci, the lead author of a recent publication, was one of eight investigators from four New Zealand institutions that examined 131 years’ worth of data on 401 basking sharks over a 4.2 million km2 aerial-surveyed area within the South Pacific Ocean. The publication focused on what drives these gentle giants to the seas of their choosing so as to better predict the waters that basking sharks will or could use in the future. The biggest takeaway from the New Zealand investigators is that basking sharks are the foodies of the ocean. Where the zooplankton go, the basking sharks will follow, especially when it comes to copepods. Without being able to look up the online reviews for the best and latest basking shark dinner hotspots, the researchers found this out by doing some good ol’ fashion math in the form of correlative statistic models for habitat suitability. Super simple stuff- just kidding, this statistical analysis is complementary to the behemoth size of basking sharks. Thanks to this massive effort, the uncertainty of basking sharks in the South Pacific was analyzed for the first time.

Photo by: Dr. Dave Ebert

Dr. Dave Ebert

When it came to the observations the investigators reviewed, sightings trended in the summer months as well as locations closest to the presence of humans. The biggest message from this data doesn’t reflect basking shark behavior, but rather that of citizen scientists. The work of people around the world reporting what they see on the water is incredibly valuable to scientific knowledge. Citizen scientists can be anyone, like the readers of this very article. If you or someone you know observe basking sharks out in the wild, report these sightings to groups like the Spot a Basking Shark Project in the eastern North Pacific, Shark Trust’s Basking Shark Project in the United Kingdom or the Irish Basking Shark Group.

Next Up

Shark Week: The Podcast – Kinga Philipps on Massive Tiger Sharks in French Polynesia

Luke Tipple is joined by shark conservationist and star of Discovery’s Shark Week Special Sharks in Paradise, Kinga Philipps, to discuss massive tiger sharks in French Polynesia.

Shark Week: The Podcast - How Shark Fishing Funds Human Trafficking

Luke Tipple is joined by Pulitzer Prize-winning journalist and author of the Outlaw Ocean Ian Urbina, who has dedicated his life to chronicling crime on the high seas. They discuss the state of our world’s oceans, how nearly 20% of your seafood was likely caught illegally, and the surprising link between modern slavery and the killing of sharks.

Shark Week: The Podcast - Superstar Kesha Lifts the Gag Order on Saving Sharks

Pop superstar Kesha joins Shark Week’s Luke Tipple on the podcast to discuss her love of sharks, how her music funds her addiction to diving, and how you can find inner peace while under the water. And at the end, our researcher Sierra drops in to tell us that some sharks have teeth in their eyes.

Shark Week: The Podcast - Do Scientists Need to Kill Sharks?

Host Luke Tipple welcomes two guests to discuss how researchers can kill sharks in the name of science – and whether they need to at all. The first is Dr. Neil Hammerschlag, shark researcher and founder of Atlantic Shark Expeditions, and an expert on data-gathering in the field. He’s followed by explorer Fred Buyle, a world-record-breaking freediver whose innovative methods of shark tagging are explored. Plus, our researcher Sierra tells us about how a 50-year study changed our understanding of tiger sharks – and much of the work wasn’t even done by scientists.

Shark Week: The Podcast - How Smart Are Sharks?

The discussion turns this week to sharks’ intelligence, and how it varies among species. Host Luke Tipple is joined by Dr. Tristan Guttridge, a behavioral ecologist and veteran of Shark Week whose research has tackled the social smarts, and even personalities, of different kinds of sharks. He sheds light on why we shouldn’t just think of them as dumb fish with rows of razor-sharp teeth. And at the end, our researcher Sierra Kehoe tells us about shark hypnosis.

Shark Week: The Podcast - How Many Sharks Are Yet to Be Discovered?

Luke Tipple is joined by Shark Week host and all-around adventurer Forrest Galante. They discuss his upcoming special Alien Sharks: South Africa, Forrest’s remarkable talent for finding creatures once believed to be extinct, and how many shark species may still be unknown. Then, our researcher Sierra stops by to tell us about the world’s most prehistoric shark.

New Walking Shark Species Discovered

A shark that walks, evolutionary conundrums, temperature changes, and tectonic shifts lead scientists to discover four new species of sharks.Watch Island of the Walking Sharks on Wednesday, July 27 at 8:00pm ET/PT on Discovery and stream it on discovery+.

Shark Week: The Podcast - How To Have A Career in Shark Science

Shark Week’s Luke Tipple tackles the question “How can I work with sharks?” alongside two experts in the field – and their answers are not always the obvious ones. Luke is joined first by Kelly Link, Associate Curator of the Georgia Aquarium who talks about what it’s like to be an aquarist, how it differs from field work, and how to get yourself noticed. The second guest is Dr. Neil Hammerschlag who goes into detail on what it takes to become a prominent scientist, and what other paths you can take if a PhD isn’t for you. And at the end, researcher Sierra stops by to tell us about the world’s smallest shark.

Shark Week: The Podcast – Madison Stewart Discusses Helping Shark Fishermen Transition into Tourism

Luke Tipple is joined by Madison Stewart aka “Shark Girl”, filmmaker, shark conservationist and founder of Project Hiu.

Shark Week: The Podcast - Lights! Camera! TEETH! Making Shark Docs

Shark Week’s Luke Tipple is joined by longtime filmmaker and Emmy-award-winner Andy Casagrande. He’s filmed and appeared in dozens of shark documentaries, and might just be the most prolific shark cinematographer in history. He talks with Luke about his career, the contentious term “shark porn,” and the future of the industry. And at the end, our researcher Sierra talks about the unprecedented ways that sharks are currently endangered.

Related To: