In the Philippines this week, over 200 melon-headed whales appeared in near-shore waters across a large bay from Manilla, and appeared confused about how to get out. Initial speculation ran wild, as a Philippine Senator called for an inquiry into whether the US research vessel the R.V. Langseth had created the trouble while doing a seismic survey that has garnered criticism from environmentalists, and was apparently on the Senator’s radar. The inquiry is likely to be brief, as the Langseth is currently over 4000 miles away, working near Fiji. (The surveys in question, which are currently awaiting a permit from the US NMFS, will take place later this spring and summer in various areas between China, Japan, and the Philippines.) While our growing understanding of the impacts of human noise does make it worthwhile to consider whether noise may be implicated in strandings, jumping to ill-considered conclusions serves no one. In this case, there is also speculation about dynamite fishing in the region; according to Environment Minister Jose “Lito” Atienza, he directly questioned the local Governor, who “confirmed it (was taking place). He also said he was battling this illegal activity.” Adding to the mystery is the simultaneous appearance of melon-headed whales in two widely-separated bays (Hawaii and Marianas Islands) in July 2004; these events took place on the same night during a full moon, and there is speculation they were following prey, perhaps squid. In Hawaii, the next morning US Naval forces used mid-frequency active sonar beyond the mouth of the bay, and the whales appeared agitated, and perhaps were driven into shallower waters, in the Marianas the animals were apparently less disturbed, and “interacting with humans.” This points to the possibility that noise can become an aggravating or additional factor in some situations, even if not the primary causative factor in bringing the whales into a dangerous situation. The moon is again bright this week, though certainly the dynamite fishing deserves continued diligent scrutiny.
Press coverage of this incident: Senator blames Langseth, Dynamite fishing considered
US Navy description of earlier full-moon incidents