Orca-damaging SONAR detected….

Here’s more, in a report from Jenny Atkinson at The Whale Museum (and here’s a short review of what SONAR does to whales):

Beginning at approximately 4:30 a.m. PST on February 6, hydrophones operated by The Whale Museum and Beam Reach Marine Science & Sustainability School started detecting SONAR pings.

Hydrophones off the coastline of Lime Kiln State Park, another node about 4 km north (OrcaSound), and one at the Port Townsend Marine Science Center all recorded SONAR pings. Most of the pings were detected at Lime Kiln and were loudest at that node. Recordings of the SONAR continued until approximately 5:10 a.m. PST.

The sounds from these hydrophones stream live via the internet on the public-accessible site www.orcasound.net.  Samples of the recorded sounds are archived there. A 41-minute recording of the event was also made by a regular public listener to the network, who also advised other network listeners via the network email of the SONAR pings.

Preliminary examination of the detected sounds shows that 13 SONAR pings were detected at Lime Kiln, as well as one each at OrcaSound and Port Townsend. This would indicate that the source was closest to Lime Kiln, and likely to the south of Lime Kiln. Examination of the 41-minute recording shows a total of 82 pings occurring roughly every 30 seconds.

The peak power was centered at 7 kHz suggesting it was mid-frequency SONAR. Analyses are ongoing to determine the amplitude of the recorded pings. The Automatic Identification System (AIS) used by marine traffic to broadcast locations of vessels indicated the Canadian Navy frigate HMCS Ottawa was operating in the south end of Haro Strait during this time. It is not known whether other naval vessels were operating in the area without an AIS broadcast.

Examination of the data is ongoing, but results are being posted as they become available to http://www.orcasound.net/wp/2012/02/06/canadian-sonar-in-us-critical-habitat/.

This is the third time naval sonar has been recorded on our hydrophones in Haro Straight. The first was on May 5, 2003 when the USS Shoup, a guided missile destroyer, transited the waters of Haro Strait and activated its sonar while Southern Resident killer whales were in the vicinity.

The second SONAR occurrence took place on April 7, 2009 when the USS San Francisco, a nuclear submarine tested its refurbished sonar in the eastern end of the Strait of Juan de Fuca. The endangered Southern Resident killer whales were not present at that time. It appears that Southern Resident killer whales were not present during this latest incident either, but it is possible that other species of marine mammals were present in Haro Strait during this time.

The Whale Museum has not received reports of stranded or injured marine animals.  If you see an injured or stranded marine mammal, please contact the San Juan County Marine Mammal Stranding Network (800-562-8832).

Posted on February 9, 2012 at 7:11 am by

Categories: Around Here
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