911: superpod northbound at Orcasound Lab on a smokey night

After not being present in the Salish Sea throughout August, the Southern Resident Killer Whales have visited Haro Strait this month — often in a “super-pod” combination of the J, K, and L pods. Although I missed listening live to them this evening, an entourage of more than 60 simultaneous listening citizen scientists enjoyed the live “concert.” This is a 30-second clips that shows what it sounded like at its apex:

30-s ogg sample
30-s mp3 sample

Not only did the community set a record this summer for simultaneous listeners (even without a notification email going out!), but also they collaborated to do a great job of tagging the live stream in real-time. At their peak, they generated this “candidate” event — or likely “acoustic bout” — while listening to the Orcasound Lab hydrophone (near Roche Harbor on the west side of San Juan Island).

Screengrab of recent candidate detections generated by the citizen scientists listening to the live audio stream at live.orcasound.net

You can see that over a period of 10 minutes, the number of listeners grew from 29 to 63, and a total of 10 labels were added, almost all of them indicating the presence of valuable signals, and in some cases specifically indicating the presence of particular SRKW pods. These labels helped me prioritize which period of the archived Orcasound data to download from the Amazon S3 bucket associated with the Orcasound Lab audio stream for further analysis and sharing. Examining a couple hours on either side of the candidate event, I found about 25 minutes where the SRKW signals were audible over intermittent boat and ship noise — from about 21:45-22:10 (the Raspberry Pi4 started this streaming/recording session at 18:30).

Audacity waveform and spectrogram showing about 25 minutes of SRKW signals.

Based on sightings earlier in the day, as well as the labels, this recording likely includes calls from all three pods (J, K, and L). Overall, the density of calls is very high; in the ~7-minute section from ~21:49-21:56 the calls are nearly continuous!

A couple minutes where the calls are nearly continuous.
Zoomed in on a 30-second clip (the one embedded at the top of this post).

Here is that 7-minute period in two HTML5-compliant formats:

7-minutes in .ogg format
7-minutes in .mp3 format

And here is the whole 25-minute bout:

25-minute .ogg recording

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