Boat collides with massive 23-foot shark in rare video footage

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Rare footage captured by a camera attached to the back of an endangered shark shows the shocking moment the shark was struck by a boat, after which the animal plunged into deep water and rested for hours.

It is unclear whether the enormous, 7-metre-long animal, a basking shark, ultimately survived the collision.

However, researchers say the incident is a sign that such encounters are quite common for ocean-dwelling species.

The video — which could be one of the first of its kind ever recorded — highlights the need to better protect and understand these sharks, said Dr. Alexandra McInturf, a research associate at Oregon State University who co-authored a study on the incident. The findings appear in a paper published Wednesday in the journal Frontiers in Marine Science.

“We are calling for a legally enforceable code of conduct in this area, particularly with speed limits,” McInturf said, referring to the waters around the Blasket Islands, off the coast of Ireland, where the basking shark incident occurred and one of the few places in the world where the animals are known to congregate. “What I hope most comes out of this is more research into this species.”

Big and elusive

The basking shark is a relatively gentle species, known for skimming the ocean surface with its jaws spread open in search of small planktonic crustaceans. It also filters its food in a manner similar to that of its relatives, the whale shark and megamouth shark.

The basking shark is a huge animal that can grow up to 12 meters long. It is one of the largest fish in the world, after the whale shark.

Basking sharks are also endangered. The International Union for Conservation of Nature estimates that there are only about 20,000 left in the world.

To gather more data on the creatures’ food and feeding habits, McInturf and her research partners have fitted about 20 basking sharks with tags and cameras.

On April 24, one of the cameras captured something unexpected: footage of a basking shark feeding just below the surface of the water before suddenly crashing hard into the hull of a boat.

The footage also shows the aftermath of the encounter, including a large scratch on the shark’s back, near its dorsal fin, and some of the blue antifouling paint (a type of coating used on boat bottoms to prevent barnacles from forming) that has corroded the animal’s mottled skin.

Maritime traffic and endangered species

Researchers have long known that boats and other shipping traffic can pose a danger to marine animals.

While the problem for whales is fairly well documented, there is less data indicating how serious the problem is for sharks.

But the video and research findings that emerged from the incident are timely for the shark research community, noted Dr. Christopher Lowe, director of the Shark Lab at California State University, Long Beach. In his work studying sharks of all species off Southern California, he said, about 1 in 10 he encounters shows signs of a dangerous encounter with a ship.

Basking sharks, which are more susceptible to collisions with boats because of their habit of feeding near the surface, have often been spotted with paint or scars on their fins or backs — likely the marks from collisions with ship propellers and hulls, McInturf said.

While it can be difficult to determine whether the markings are the result of accidents or whether the sharks are simply rubbing against parked vehicles, the researchers’ video provides clear evidence: this basking shark suddenly and unexpectedly collided with a moving boat.

The footage also shows the shark quickly escaping into the ocean depths. The animal remained there, barely moving, until the camera stopped recording about 7 ½ hours later. The device, McInturf noted, which includes the camera and a fitness tracker-like instrument that records the shark’s movements, was designed to stop collecting data and release the shark so researchers could retrieve the data.

It’s nearly impossible to say whether the shark survived after the tracking device stopped collecting data, McInturf adds. However, she cautions that even if the shark is still alive, the injuries could have lasting effects.

Protection of basking sharks

McInturf stressed that Ireland and the UK have already taken important steps to help protect the endangered basking sharks.

Incidentally, the shark was also hit by a boat that was in waters that Ireland had recently designated as a national marine park.

However, there are no enforceable rules attached to the park yet. And that’s something McInturf hopes will change as more policymakers and boaters recognize the importance of creating a lasting harmony between shipping and endangered wildlife.

But McInturf said she doesn’t plan to place blame on anyone.

“One thing I think about a lot is the fact that these basking sharks are very hard to see when they’re not at the surface,” McInturf said, stressing that these incidents are likely accidental. “I’m not trying to paint the ship as a bad guy.”

Lowe added that even where there are rules, they can be difficult to enforce. But he does see value in spreading the message to boaters, hoping they will voluntarily slow down and watch for marine life.

Boats can also be seriously damaged by a collision with a shark.

“I think the first step is education – just training skippers,” Lowe said.

He added that while it is encouraging to see some shark species starting to stabilize or recover from severe population losses, he questions how quickly they would recover if boat strikes were not a threat.

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