U.S. Navy: Sonar, explosives may damage more than thought
John Van Dame, right, U.S. Pacific Fleet senior environmental planner, and Roy Sokolowski, a U.S. Pacific Fleet sonar modeling expert, speak in Honolulu on Thursday, May 10, 2012 about the Navy's new environmental impact statement for training and testing in Hawaii and California waters. (AP Photo/Audrey McAvoy)
Published Friday, May 11, 2012 8:51AM EDT
HONOLULU - The U.S. Navy may hurt more dolphins and whales by using sonar and explosives in the Pacific Ocean than thought, according to a more thorough analysis that reflects new research and covers naval activities in a wider area than previous studies.
The Navy estimates its use of explosives and sonar may unintentionally cause more than 1,600 instances of hearing loss or other injury to marine mammals each year, according to a draft environmental impact statement that covers training and testing planned from 2014 to 2019. The Navy calculates the explosives could potentially kill more than 200 marine mammals a year.
A notice about the study was due to appear Friday in the Federal Register.
The Navy uses sonar to track enemy submarines, torpedoes, mines and other potential threats underwater. Scientists say the sound may disrupt marine animals' feeding patterns and startle some species of whales, causing them to surface rapidly.
The old Navy analysis, covering 2009-2013, estimated unintentional injury or death to about 100 marine mammals in Hawaii and California, although no deaths have been reported.
The larger numbers are partially the result of the Navy's use of new research on marine mammal behaviour and updated computer models that predict how sonar affects animals.
The Navy also expanded the scope of its study to include things like in-port sonar testing -- something sailors have long done but wasn't analyzed in the Navy's last environmental impact statement. The analysis covers training and testing in waters between Hawaii and California for the first time as well.
"Each time around, each time we swing through this process, we get better, we take a harder look, we become more inclusive," said John Van Name, senior environmental planner at the U.S. Pacific Fleet.
Zak Smith, staff attorney at the Natural Resources Defence Council, said he's encouraged the Navy reduced the threshold for the level of sonar it found to affect beaked whales -- a species that appears to be particularly sensitive to the noise.
"My first glance shows there's positive steps," Smith said after he took a quick look at the 1,800-page document. But he said he would have to look at the details before giving his full assessment.