Between January 9 and February 4 this year, 29 sperm whales got stranded and died on English, German and Dutch beaches. Climate Change Dispatch investigates.
Environmentalists and the news media offered multiple explanations – except the most obvious and likely one: offshore wind farms. Indeed, that area has the world’s biggest concentration of offshore wind turbines, and there is ample evidence that their acoustic pollution can interfere with whale communication and navigation.
However, Britain’s Guardian looked for answers everywhere but in the right place. That’s not surprising, as it tends to support wind energy no matter the cost to people or the environment. After consulting with a marine environmental group, the paper concluded: “The North Sea acts as a trap.… It’s virtually impossible for [whales] to find their way out through the narrow English Channel.”
No it’s not. These intelligent animals would naturally have found their way to and through the Channel by simply following the coast of England or continental Europe. But the author seems determined to pursue his “explanation,” even when it becomes increasingly illogical. “The [trapped] whales become dehydrated because they obtain their water from squid,” he argues, before acknowledging that “the dead Dutch and German animals were well-fed,” and that the North Sea’s squid population has increased in recent years.
The article discards Royal Navy sonar and explosives, because “big naval exercises in UK waters are unusual in midwinter.” Finally, the author concludes with this quote from his purported expert: “When there’s a mass stranding, it’s always wise to look at possible human effects. But, at the moment, I don’t see anything pointing in that direction.”
He should look a bit harder. Not everyone is so blind. Indeed, “researchers at the University of St. Andrews have found that the noise made by offshore wind farms can interfere with a whale’s sonar, and can in tragic cases see them driven onto beaches where they often die,” a UK Daily Mail article observed. It is certainly possible that permanent damage to the cetaceans’ middle and inner ears, and thus to their built-in sonar, can result from large air guns used during seismic surveys and from violent bursts of noise associated with pilings being rammed into the rock bed.
Wind promoters themselves admit that their pile-driving can be heard up to 50 miles (80 kilometers) underwater, and can be harmful to whales that happen to be nearby. But unless these injuries cause external bleeding, they are very difficult to detect. Natural phenomena such as seaquakes, underwater volcanic eruptions and meteorites crashing into the oceans have likely been the cause of whale beachings throughout history, by injuring the animals’ inner ears and sonar organs, frightening and disorienting them, and causing them to seek refuge in shallow waters.
In more recent years, “military exercises using mid-frequency sonar have been linked quite clearly to the disorientation and death of beached whales,” says The Guardian. Low frequency sonar can be even more dangerous, the Natural Resource Defense Council asserts. “Some systems operate at more than 235 decibels,” the NRDC has said, “producing sound waves that can travel across tens or even hundreds of miles of ocean. During testing off the California coast, noise from the Navy’s main low-frequency sonar system was detected across the breadth of the northern Pacific Ocean.”
The U.S. Navy itself has recognized the danger that sonar systems represent for marine mammals. As reported in Science magazine: “In a landmark study, the U.S. Navy has concluded that it killed at least six whales in an accident involving common ship-based sonar. The finding, announced late last month by the Navy and the U.S. National Marine Fisheries Service (NMFS), may complicate Navy plans to field a powerful new sonar system designed to detect enemy submarines at long distances,” despite how important that system and its submarine and surface ship counterparts are for national security. It has been said the “low-frequency active sonar” from this system would be the loudest sound ever put into the seas, The Guardian states.
But wind turbines also emit low frequency noise, including dangerous infrasound. At sea, these vibrations are transmitted via the masts to the water, and via the pilings to the rock bed. They can travel up to 31 miles (50 kilometers). Granted, the acoustic pollution caused by sonar – particularly powerful navy systems – is greater than that from wind turbines. But wind turbine noise and infrasound are nearly constant, last as long as the turbines are in place and come from multiple directions, as in the areas where the whales were recently stranded.
The article continues to a discussion of other problems linked to wind turbines.
Full report: Are wind turbines killing whales? – Climate Dispatch