Mayo Whale Beaching: Possible Acoustic Trauma Link
Acoustic Trauma Suspected in Strandings of Rare Whale and Calf in ireland
The recent stranding and subsequent deaths of a True’s beaked whale and her calf in County Mayo, Ireland, have sparked concerns about the potential role of “acoustic trauma” caused by human-generated ocean noise. Experts believe loud underwater sounds, notably from naval exercises utilizing active sonar, may be responsible for the tragic event.
What Happened in County Mayo?
On July 27th, a True’s beaked whale and her calf were discovered stranded on Kilcummin Back Strand in County Mayo. Despite efforts, both whales died. This event coincided with similar strandings reported in the Netherlands and Orkney, Scotland, raising questions about a potential wider issue. The stranding is particularly noteworthy as True’s beaked whales are rarely sighted in Irish waters - this was only the second confirmed sighting and the 20th stranding recorded since 1899.
The Link Between Acoustic Trauma and Whale Strandings
Dr. Simon Berrow, CEO of the Irish Whale and Dolphin Group (IWDG) and lecturer at Atlantic Technical University Galway, believes acoustic trauma is a leading possibility. Deep-diving species like the True’s beaked whale are especially vulnerable.
How Does Acoustic Trauma Affect Whales?
These whales routinely dive to depths of 1,000 to 2,000 meters. When exposed to intense underwater noise, such as that produced by active sonar, they can experience a range of physiological problems.Active sonar emits sound waves at frequencies similar to those used by whales for dialogue. This can cause:
Disorientation: The intense noise can disrupt a whale’s ability to navigate and communicate.
Panic and Rapid Ascent: Disturbance can trigger a panicked reaction, causing the whale to surface too quickly.
decompression Sickness (“The Bends”): Rapid ascents can lead to the formation of nitrogen bubbles in the whale’s tissues,similar to decompression sickness in human divers. The whales washed ashore exhibited signs consistent with this condition.
Auditory Damage: Prolonged or intense exposure can cause permanent hearing damage.
Dr. Berrow explained that the whales often strand with signs of the bends, an unusual occurrence that frequently points to acoustic trauma as the underlying cause.
The primary source of concern is the use of “active sonar” by navies (not the Irish Navy, specifically).This technology uses powerful sound pulses to detect submarines.The frequencies used can overlap with those used by whales for communication and echolocation, causing significant disruption and potential harm. While the connection isn’t definitively proven in this case, the timing of the strandings alongside potential naval activity raises serious questions.
Examination and Challenges
An investigation is currently underway to determine the exact cause of the strandings. However, Dr. Berrow expressed concerns about the ability to reach a conclusive answer. conducting a thorough post-mortem examination on whales is complex, and Ireland currently lacks the specialized expertise needed for a comprehensive analysis.
What could Have Been Done?
unfortunately, Dr. Berrow stated that little could have been done to save the stranded whales. Refloating these large marine mammals is a challenging and hazardous operation, requiring trained personnel and significant logistical support. While the calf initially refloated on its own, it was found dead a few days later, likely due to starvation following the death of its mother.
The Bigger Picture: Protecting Marine Life from Noise Pollution
this incident highlights the growing threat of noise pollution in the ocean and its impact on marine life. Increased shipping traffic, seismic surveys, and naval activities all contribute to the problem. Further research and mitigation strategies are crucial to protect vulnerable species like the True’s beaked whale. These strategies could include:
Establishing Marine Protected Areas: Creating zones where noise-generating activities are restricted.
Developing Quieter Technologies: Investing in technologies that reduce underwater noise emissions.
Implementing Stricter Regulations: enforcing regulations on noise levels from ships and other sources.
Increased Monitoring: Expanding monitoring programs to track noise levels and whale behaviour.(Image: A view of a whale stranded on a beach in Co Mayo – Photo: Cathy and Angela Kelly via IWDG)