Taken as a longitudinal, in situ experiment, these coinciding occurrences seem beyond chance and should inform decision-making about military sonar worldwide. 4 And, as it bears repeating, t here have been zero mass odontoceti strandings in the sonar-ban zone since the policy was implemented. With the public's attention, two years later the European Parliament passed a moratorium on high-intensity naval sonar, and the Spanish Ministry of Defense prohibited all active sonar training near Canary Islands. between NATO exercises and the stranding of beaked whales" since 1985.
Additionally, according to Michel Andre, a veterinary scientist who lead investigations into the deaths, this was "the seventh time there a coincidence.
Biological tests showed that the animals hadn't been sick, but had suffered injuries now linked to sonar, such as "severe, diffuse congestion and hemorrhage" and embolisms in various organs. Over the next three days, four more whales were found lifeless. Half of the animals died, while the other half were returned to the ocean. 2Ĭoinciding with the exercise, fourteen beaked whales were found stranded ashore Fuerteventura and Lanzarote, two of the Canary Islands. Designed as a mock operation to secure the Strait of Gibraltar, the Spanish-hosted drill involved 30 NATO ships and submarines that used mid-range sonar. The catalyzing event for these developments occurred in late September 2002, when ten NATO countries gathered in the Atlantic to conduct a multinational military exercise called Neo Tapon. Without delving into the pathology here, I think this news coming out of the Canary Islands, when considered as historical evidence, represents a convincing argument of the damage sonar can do. Sonar comprises only a part of all marine noise, but new Scitable blogger Sara Mynott points out that it may contribute to decompression sickness in whales. As one of Scitable's new, exciting blogs, Saltwater Science, just discussed, a controversy exists concerning the impact of noise pollution on ocean life.
These signals vary in frequency and loudness, and undersea acoustics are complicated, but it seems that sonar may harm marine mammals. Similarly with active sonar, undersea vessels make pulses of sound called pings with electric signal generators and discern important data from the sound waves' reflections. With echolocation, odontoceti like porpoises, dolphins, and non-baleen whales produce a focused beam of clicks from specialized organs in their heads and perceive essential information from the echo. 1Īs these marine mammals echolocate to detect objects and orient themselves, submerged military previously tested their "sound navigation and ranging" or sonar in these waters to find other forms and move. Luckily, a team of Spanish scientists recently made exceptions to the rules by suggesting a cause for a happy non-event: since a moratorium on sonar was passed in 2004 for the Canary Islands, no mass strandings of whales or dolphins have happened there. They typically also don't make announcements that certain incidents have not occurred. Good conservationists, like all good scientists, know that correlation doesn't mean causation.