Whale advocates concerned about sonar in Strait
April 8, 2009 · Updated 2:51 PM
Orca advocate Jeanne Hyde reports on her blog, whale-of-a-porpoise.blogspot.com, that loud pings believed to be from a ship's sonar were recorded over an eight-hour period in Haro Strait Tuesday and today.
The pings were recorded over hydrophones stationed at Lime Kiln State Park and about three miles north of Lime Kiln. Hyde reported she was told by the U.S. Coast Guard that the sounds came from a U.S. Navy submarine.
"Unfortunately for all those marine mammals nearby and their inner ears it seems that a vessel came through using its sonar several times as it passed by in the inland waters," Hyde reported. "I'm assuming it was the Navy as there was this electronic sounding voice ... sounded like it was counting down ... I could hear the number 9 and the number 6 clearly within the 'counting' or whatever it was doing ... then there would be no more electronic sounding voice ... then it would start again ... it was difficult to tell if it was repeating the same thing over and over or not ... but several times I heard the 9 and the 6 clearly ... then ... then ... SONAR."
Hyde said the sonar "actually hurt my ears as I heard it over my computer speaker ... I can't imagine what it was like to any marine mammal that may have been near."
"The first sonar that I heard was on the Lime Kiln (hydrophones) — loud," she reported. "(T)he next sonar that I heard was softer and more like a drawn out ping again ... but then I heard from someone else that it was louder on Orca Sound (hydrophones) which are a few miles to the north ... so I switched to (Orca Sound hydrophones) and the next sonar was loud ... then the next time it got softer ... so I thought they were going north through Haro ... but then ... really loud sonar with a long long lasting ping."
Hyde reported "three loud, high-pitched beeps" at 12:24 a.m., followed by a series of countdowns and other pings. She reported "hurt my ear" kind of pings at 12:43, 12:48, 12:59, 1:11, 1:31, 1:41, 1:57, and 2:01 a.m. Sonar pings continued until about 3:12 a.m., she reported.
Whale advocates and scientists believe sonar pings can be harmful to the endangered killer whale population and other marine mammals in the inland waters.
On May 5, 2003, the Center for Whale Research observed porpoises, killer whales and a minke whale seemingly attempting to flee from sonar pings from the USS Shoup (DDG-86); the pings were measured at 230+dB 3kHz.
Two dead porpoises were found immediately following the sonar incident on shores adjacent to the destroyer's path, and a total of at least 10 porpoises died in the approximate time-frame of the incident.
At a necropsy at the National Marine Mammal Laboratory, a porpoise, as well as a Baird's beaked whale that died following a naval exercise near the Olympic National Marine Sanctuary, showed evidence on CT scan consistent with hemorrhagic trauma that could be due to sonic pressure that would disorient and incapacitate the animals.
The Navy is taking public comment until April 13 on possible expansion of the use of sonar in the Northwest.
In a letter to the Navy, the Whale Museum board of directors asked that the Navy "incorporate better techniques to improve their detection rates of marine mammals, extend their exclusion zones around detected marine mammals, and utilize exclusion zones based on specific areas and times in their mitigation strategies."
"The Navy can and should do better at knowing where marine mammals are within the Navy’s training region. It would be preferable that a third party organization conduct this monitoring and that the sightings be reported and made available to the scientific and management communities," the letter states.
"If marine mammals are sighted or detected within acoustic range, then exercises should be shut down if in progress, and postponed or moved elsewhere if the exercises have not yet started ... Exercises that generate loud noise (active sonar, explosions) should not be conducted at night because visual detections of Southern Resident orcas or other marine mammals are not usually possible.
"Exercises that generate loud noise (active sonar, explosions) should not be conducted in the inland waters (including the Strait of Juan de Fuca) because these form critical habitat for endangered Southern Resident killer whales and because this area already has so many anthropogenic noise sources."