Science Editorial.- A group of scientists has recorded, for the first time, the impact of a boat with a basking shark, an endangered species, which suffered injuries after the incident and displayed abnormal behaviour during the time that the experts were monitoring it.
A study led by Oregon State University and published in Frontiers in Marine Science reports andThe incident, which was recorded on video and which, according to researchers, would be the first record of such an impact against a large marine animal that they have evidence of.
The researchers followed the incident because hours earlier they had tagged the animal, a female basking shark measuring about seven metres, with a device similar to an activity bracelet and a camera, programmed to be released, which happened seven hours later and was then recovered.
The team therefore does not know whether the shark, which showed visible skin damage, paint marks and a red abrasion but no apparent bleeding or open wound, survived the impact.
Boat collisions are not always immediately fatal, but these injuries can have short- and long-term consequences.
The data indicate that for several hours after tagging the animal, it spent most of its time at the surface, continuing its normal feeding behavior, with an occasional dive.
Suddenly, he tried to make a quick, evasive move, when the keel of a boat pierced his back, just behind his dorsal fin.
The animal immediately increased its heart rate and headed offshore toward the seafloor, a markedly different behavior than before the blow, according to Taylor Chapple of Oregon State University and one of the study’s co-authors.
Data taken by the device showed the shark did not resume feeding or behaving normally while under surveillance.
The basking shark is the second largest known fish, often reaching more than eight metres in length, and Ireland, where the incident occurred, is one of the few known places where they still gather in large numbers.
These sharks are surface-filter feeders, similar to some whales, which makes them more susceptible to collisions with ships.
Unlike whales, basking sharks typically sink when they die, making it difficult to measure mortality rates.
The fact that a shark was hit in that area within a few hours underlines “how vulnerable these animals are to boats and highlights the need for greater education on how to mitigate such attacks,” said Nicholas Payne, from Trinity College Dublin, who also signed the study.
Ireland’s basking sharks have been protected since 2022 under the Wildlife Act and earlier this year the Irish government announced the creation of the country’s first National Marine Park, protecting 28,328 hectares of land and sea off the coast of County Kerry, where they often gather to feed and, potentially, mate.