The Navy has acknowledgedthat vessels on maneuver off Hawaii last month used their sonarperiodically in the 20 hours before a large pod of melon-headed whalesunexpectedly came to shore in the area. The acknowledgment added to analready contentious debate over whetherthe sound from sonar has beencausing marine mammals to strand.
Navy officials said that a review of the July 3incident indicates that two ships turned on their sonar between 6:45and 7:10 a.m., by most accounts just before the unusual movement ofalmost 200 deep-water whales to the shoreline of a Kauai bay. The Navyhad said earlier that no sonar was used until more than 90 minuteslater, well after the animals came ashore.
Lt. Cmdr. Greg Geisen, the Navy spokesman responsiblefor information about the maneuver, said a Navy review of the incidentstill concluded that the ships were either too far from the whales orwere using the sonar at the wrong time to cause the mass movement.
"There is no evidence of a relationship here between thesonar use and the whale behavior," he said.
But the newly released information from Geisen andother Navy officials -- that the ships were testing their sonar inpreparation for the maneuver on the day before the whales came ashore,and early on the morning of the near-stranding -- has caused someobservers to question that conclusion.
"Every time the Navy changes its story, it reducesits credibility onthis issue," said Cara Horowitz, a lawyer with theNatural Resources Defense Council, which has sued the Navy over arelated sonar issue. "The Navy would be better off spending more timedeveloping commonsense ways to protect whales from sonar and less timedenying a connection that is unfortunately been repeatedly shown."
Officials at the National Oceanographic andAtmospheric Administration (NOAA), which is looking into the incident,said it remains uncertain what caused the near-stranding.
"At this point, we still know very little about whatmight have made those whales behave so unusually," said Donna Wieting,chief of the Marine Mammal Conservation Division of NOAA's NationalMarine Fisheries Service.
"But saying that sonar played no role might be apremature determination," she said. "Even if we can't establish a clearcause and effect, we're having these coincidences [of unusual andsometimes deadly] marine mammal behavior around sonar, and we have toask why."
Some marine mammals come to shore naturally, becausethey are following a sick lead animal or trying to avoid predators andsuch natural occurrences as potentially harmful red tides. Melon-headedwhales are relatively small and highly social animals that normallylive in deep waters, at least 15 miles from shore. Wildlife officialssaid it is highly unusual for such a large number of them to come toshore as they did on July 3, although there is one report of a similarmass movement in the 1850s.
The new Navy information about when the sonar wasused off Hawaii was first made public in late July, at a meeting of thefederal Marine Mammal Commission focused on how to limit the effects ofocean noise on whales and other sea creatures. Rear Adm. StevenTomaszeski updated the information then, and said the Navy hadconcluded there was no connection between the sonar use and the unusualwhale behavior.
He and Geisen said the July 2 sonar use could nothave caused the whales to head into Hanalei Bay because the ships --four Japanese and two American -- were too far away when the equipmentwas used. Geisen also said the Navy first learned of the stranding fromthe National Marine Fisheries Service (NMFS) at 5:30 a.m. on July 3,and not between 7 and 7:30 a.m., as earlier reported, making itimpossible for the 6:45 to 7:10 a.m. sonar usage to have harmed thewhales.
Wieting of NMFS said, however, that her office hasreceived no reports of a 5:30 sighting, and still believes the whaleswere first seen after 7 a.m.
Navy officials are adamant aboutthe need for sonartraining. They say there is a substantialand growing threat from"quiet" diesel submarines that could menace the United States fromcoastal waters, andthat only active sonar use candetect them. TheNavy is planning a sonar training ground in the Atlantic Ocean, off theCarolinas.
Residents and government officials worked throughoutJuly 3 to steer the whales back to open water, and all made it exceptone newborn calf that died of starvation. Officials say that some ofthe animals may have died at sea without a trace.
The Hawaii incident is the third significant oneinvolving sonar and marine mammal strandings near the United Statessince 2000. The stranding of 17 whales of various kinds off the Bahamasin 2000, which resulted in the death of at least six of them, occurredduring a major Navy maneuver. Navy officials at first said there was noconnection between their exercise and the stranding, but lateracknowledged that the loud sound from the sonar had caused the animalsto flee ashore.
Another incident occurred off the coast of Washingtonstate last year, where harbor porpoises unexpectedlycame ashore aftera sonar exercise. The Navy concluded that there was no connectionbetween the two, but NOAA is still reviewing the incident.
The International Whaling Commissionsaid in a report last month that there is "compelling evidence" thatNavy sonar is harming some species of whales, but Navy officialsdismissed the conclusion as "unscientific."
contentious [con'ten·tious || -??s](形)好争吵的, 有异议的, 爱争论的
strand [strænd]n.fibers or filaments twisted together to form a rope(or thread, yarn, etc.); string of pearls or beads; single fiber orfilament; lock of hair; shore, beach, land alongside a body of water
v.drive up onto the shore; be driven onto the shore;leave someone in a difficult situation; be stuck in a difficultsituation
was adamant was decisive, did not give up
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adamant [ad·a·mant || 'æd?m?nt]adj.unyielding, firm, immovable; hard
porpoise [por·poise || 'p?rp?s /'p??-]n. species of dolphin, type of marine
