This morning at around 8:30, Lon Brocklehurst texted that he was hearing orcas on the Bush Point hydrophone. Though it was all ship noise by the time we tuned in, we’ve pulled the recording from the public Amazon cloud-storage and confirmed he heard the calls and whistles of SRKWs, including some S16 calls that are commonly used by K pod!
Here’s a ~16 minute clip:
You can hear the SRKW signals, despite the substantial low-frequency noise. (Lon drove up to Bush Point today to try to figure out the source of the noise which just started up recently!)
Lon runs Labcore Systems, a firm down in Tumwater, Washington that makes some of the most resilient hydrophones we’ve ever tested. Along with his ex-Navy buddy, Ken Balcomb of the Center for Whale Research, Lon designed and built the hydrophone system that was deployed at Bush Point — the latest location added to the Orcasound hydrophone network, thanks to the hosts — Susan and Howie of Orca Network.
Because Lon has worked hard on the Bush Point hydrophones, including diligent maintenance when anything breaks, he also is one of the citizen scientists who listens most-closely to the Bush Point live stream. He even has the feed hooked up to some custom C++ software called Spectrogram Lab that helps him visualize the audio data as a 3D spectrogram and keep track of band levels (relative to a local background he defines). Here’s a screenshot of his real-time display:
(frequency across the bottom, back in time up and to the right, warmer colors indicate higher acoustic intensity)
Congratulations, Lon, on being first to detect the SRKWs entering Puget Sound for the 5th time this fall. This was an exciting observation because the previous sighting of J+K pods was by the Salish Sea Orca Squad way up in the Strait of Georgia. The pods were heard off of East Point on Saturna Island around 18:30 on 11/10/2020, a ~100 kilometer swim from Bush Point (via Rosario Strait or San Juan Channel).
The two detections 14 hours apart allow us to measure the mean swim speed of the SRKWs around or through the San Juan Islands: 7.15 kph or 3.85 knots! They probably had ~1 knot help from the ebb tide in Rosario, but may have fought the last of it as they came into Admiralty Inlet. http://www.dairiki.org/tides/daily.php/ros
All I can say is Wow !!! Its amazing How much large Vessel noise there is for the Orcas to live & Deal with ! 😢😢
I am new to listening to the hydrophones. Tonight at approx. 10:25 PM, Bush Point, I heard what sounded to me like a bird chirping (not an Orca sound). Can bird sounds from land be heard? Is it rare to hear orca activity at night? Thank you for your dedication
Great question, Megan. Yes, birds can sometimes be heard on Orcasound hydrophones. Even though the hydrophones are usually at least a few meters under water, they are also quite sensitive. So if there isn’t a lot of ambient noise, you can sometimes hear animals splashing or vocalizing on the sea surface just above the hydrophone.
Of course, it’s also possible that you heard a marine mammal that sounds like bird. Also, there’s not much known about how sea birds use sound underwater in the Salish Sea…