519029954

Photo by: Corbis/VCG

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

124758496

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 - 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 – 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 - Undiscovered Sharks and the State of the Ocean

Luke Tipple invites “The Lost Shark Guy,” Dr. Dave Ebert, who is personally responsible for finding dozens of shark species that were either previously unknown to science or thought to be extinct. He and Luke discuss why shark populations are a direct indicator of how healthy the ocean is, how to find undiscovered sharks, and why diversity in sharks is essential for marine life.

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 - Why is Tagging Baby Great White Sharks So Important?

Luke Tipple speaks with Dr. Riley Elliott, a marine biologist from New Zealand who recently tagged baby great white sharks, which are rarely seen in the wild. They talk about how climate change is affecting shark pupping grounds, why fishers are wrong to think there are “too many sharks,” and about Dr. Elliott’s Great White App, which allows users to track great white sharks in the ocean.

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 - What is the Status of Sharks in our Oceans?

In this season’s final episode, Luke welcomes Emmy-winning filmmaker and conservationist Shawn Heinrichs to discuss the state of sharks in the ocean. They go over how both legal and illegal fishing operations are decimating the ocean’s wildlife, what it’s like to have a hit put out on you for exposing criminal enterprises to the world, and whether or not NOAA’s data on “sustainable” fishing can really be trusted.

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 - 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: