Scientists have captured the shocking moment a boat collided with the UK’s largest shark.
Scientists had fitted a ‘shark Fitbit’ with an integrated camera to the endangered shark as it swam off the coast of County Kerry, Ireland.
Just six hours later, the seven metre-long female was struck by a boat passing through an area recently designated as the country’s first Marine National Park.
When the ‘Fitbit’ detached seven hours later the shark had not resumed normal activity – raising concerns that the rare, breeding-age female could have been killed.
Taylor Chapple of Oregon State University, co-lead author of a paper detailing the incident, says: ‘Unlike whales, basking sharks often sink when killed, so it is very hard to gauge mortality rates and even in this case, where the strike wasn’t lethal right away, we’re not sure of the fate of the female that was hit.’
A collaborative team of scientists recorded the footage while trying to gather behavioural and physiological data about the mysterious basking shark.
Basking sharks can grow up to 12m in length and weigh as much as six tonnes, making them the second-biggest fish in the ocean and the UK’s biggest shark.
Scientists fitted a shark with an ‘animal-borne camera and inertial measurement unit’ designed to record its activity levels and movement.
However, what the researchers ultimately ended up recording was the first hard evidence of what happens when a large ocean animal is struck by a boat.
The ‘Fitbit’ recorded as the shark swam along the surface of the water before suddenly attempting an evasive dive as the front of a boat crashed into its side.
Immediately after the boat crashed into the side of the basking shark, it dived directly down to the seafloor and moved to far deeper, offshore water.
The footage shows clear signs of damage to the shark’s skin as well as streaks of paint and abrasion left by the boat.
After the shark dived into deep waters it began to significantly reduce its activity levels until the ‘Fitbit’ detached seven hours later.
Although the collision was initially non-lethal, the final moments of data recorded have left scientists unsure whether the shark survived or later succumbed to her injuries.
The shark was hit by a passing boat despite being within Ireland’s first ever Marine National Park. This area off the coast of County Kerry is known as a location where basking sharks gather to feed and possibly breed.
Despite their size, these monumental sharks are actually gentle giants which feed only on plankton.
Basking sharks endlessly swim in search of plankton-rich waters, using their enormous mouths to filter nutrients from the ocean.
As they feed, basking sharks can filter up to 2,000 tons of water per hour, and extract several hundred pounds of plankton every day.
However, this feeding behaviour may put them at increased risk of being struck by passing boats.
Dr Nick Payne, Assistant Professor in Trinity College Dublin’s School of Natural Sciences, explains: ‘Basking sharks filter feed at the surface, like some whales, and this behaviour makes them similarly susceptible to strikes.’
The sharks are listed by the IUCN red list as endangered and were officially granted protection under the Wildlife Act (1976) in 2022.
Additionally, this year the Irish government created the country’s first National Marine Park.
The coast of Country Kerry is a spot which is frequented by sharks for feeding and, likely, breeding.
Dr Payne continues: ‘Ireland remains one of the only locations worldwide where globally endangered basking sharks continue to aggregate in large numbers.
‘But the fact a shark we fitted our “Fitbit” to was struck in this area within a few hours underlines just how vulnerable they are to boats and highlights the need for greater education in how to mitigate against such strikes.’
In their paper, published in Frontiers in Marine Science, the researchers outline the need for a legally binding code of conduct in areas where basing sharks congregate.
However, in the absence of official guidance, the researchers advise that anyone travelling through an area in which basking sharks are known to surface travel carefully at a slow speed.
Dr Alexandra McInturf, of Oregon State University, says: ‘This incident suggests that much more research is needed on the prevalence of ship strikes on basking sharks in the new National Marine Park and other hotspots along the Irish coastline.
‘Given that Ireland is one of the only locations globally where basking sharks are still observed persistently, addressing such questions will be critical to informing both our ecological understanding and conservation of this globally endangered species.’
This article by William Hunter was first published by The Daily Mail on 24 July 2024. Lead Image: Basking sharks are listed as endangered by the IUCN red list and have been officially protected 2020, however the scientists are calling for legal guidelines to guide boat use in areas where they gather.
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