Whale sharks can recover from serious injuries at “extraordinary speed,” and even recover partially removed dorsal fins, new research has shown.
Research published in the journal Conservation Physiology shows that the world’s largest fish can recover from lacerations and scratches, often caused by collisions with boats, in a matter of weeks.
Lead author Freya Womersley, a doctoral student at the University of Southampton based at the Marine Biological Association in the UK, said the endangered whale shark, which can reach a length of 18 meters, is facing increased contact with boats as the wildlife tourism sector expands .
She explained that the research used unique sea creature labels to track the speed of healing from injuries through photographs.
She said: “Using our new method, we have been able to determine that these sharks can be cured of very serious injuries over a period of weeks and months.
“That means we now have a better understanding of the dynamics of injuries and healing, which can be very important for protection management.”
The study also highlighted the ability of whale sharks to re-grow a partially amputated first dorsal fin, which, according to the authors, is the first time a shark has ever been scientifically reported to show this phenomenon.
And their markings on previously injured spots have also been observed, suggesting that these are important features for this species and that they persist even after damage.
Ms. Womersley said there could be other less recognizable effects of injuries such as reduced fitness, ability to find food, and altered behavior.
The researchers also found differences in healing rates, with tears typical of propeller injuries, which require longer healing than other types of wounds, highlighting the need for further research to determine the impact of environment and other factors on injury healing.
Recent research has shown that 71% of pelagic sharks have declined over the past 50 years and indicated the need to strengthen protection.
Ms Womersley said: “Whale sharks are globally recording population decline due to various threats as a result of human activity.
“Therefore, it is imperative to minimize human impact on shark whales and protect the species where it is most vulnerable, especially where human-shark interactions are high.
“There is still a long way to go in understanding the healing of whale sharks and shark species in general, but our team hopes that initial studies like this can bring key evidence to decision makers that can be used to protect the future of whale sharks. “