RESEARCHERS have called for the introduction of a legally-binding code of boating conduct to protect basking sharks in Irish waters from boat strikes.
Ireland is one of the few places in the world where the endangered sharks continue to gather in large numbers.
However, footage from a camera fitted to a shark off the coast of Co. Kerry showed it being struck by a boat just hours later in an area designated as a marine park.
"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," said Alexandra McInturf, co-coordinator of the Irish Basking Shark Group.
Behaviour affected
The collaborative project involving Trinity College Dublin (TCD) and Oregon State University (OSU) saw a camera and monitoring device dubbed a 'shark fitbit' attached to a seven-metre female basking shark.
Its aim was to gather important behavioural and physiological data about the shark but only six hours later she was hit by a boat.
The area where the strike occurred was recently designated Ireland's first National Marine Park.
Data from the recovered the device showed that the shark immediately swam to the seafloor, moved to far deeper, offshore waters and significantly reduced her activity levels.
Basking shark boat strike from Thomas Deane on Vimeo.
The device released around seven hours later, at which point the shark had still not resumed normal behaviour.
While the initial strike was non-lethal, the team is unsure how significant the internal injuries were and whether the shark ultimately survived.
The team recently published their work in the journal Frontiers in Marine Science, outlining the need for a legally-binding code of boating conduct with enforcement power for appropriate authorities.
The Irish Basking Shark Group has also called for boat speed limits during shark season and a confidential boat strike reporting system.
'Critical'
Nick Payne, Assistant Professor in TCD's School of Natural Sciences, said the incident showed how vulnerable basking sharks are to boat strikes and called for greater education in how to mitigate against such incidents.
"Basking sharks filter feed at the surface, like some whales, and this behaviour makes them similarly susceptible to strikes," he said.
Ms McInturf, a Research Associate at the Coastal Oregon Marine Experiment Station (COMES) at OSU, said the incident raises questions about whether and how often sharks occupy such habitats when they are not clearly visible at the surface.
"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," she said.
