Unusual SRKW calls at 2 a.m. in Haro Strait, and then ship noise (again)

I couldn’t sleep last night and ended up in front of the computer. Wondering whether to read about the Muller report or watch more DIY shower tiling videos, I randomly decided to check on the live-streaming Orcasound hydrophones — just to see if the nodes were operating normally. I really hadn’t listened for more than a few minutes to the Orcasound Lab before my ears perked up.

First I heard a few faint, barely-discernible single and widely spaces calls, but I wasn’t sure what I was hearing. Then, at 1:53:43 local time, I heard Southern Resident Killer Whales on the Orcasound Lab hydrophone! An unusual pattern of two calls (S22 and S42) was repeated three times. There was consistently a gap of 3 seconds between the S22 and S42 calls, and then a pause of 4 seconds before the S22/42 pair was repeated.

Here’s a spectrogram and compressed audio clip:

Spectrogram of the ~30 second clip containing repeated S22 and S42 calls.

And here’s what the full hour looked like, with lots of ship noise before and after the brief period of SRKW calls (within the narrow vertical blue/green strip).

Note the Lloyd’s mirror effect during the passing of the latter (cargo) ship…

(Note: for playback using the original HLS segments, here is the URL of the .m3u8 file:

https://s3-us-west-2.amazonaws.com/streaming-orcasound-net/rpi_orcasound_lab/hls/1553329934/live.m3u8

Copy/paste it into an HLS reference player like this one and you’ll be able to scrub back and forth in the raw compressed data.)

Of course, I didn’t recognize the call types immediately — though I was confident they were SRKW calls that I’d heard before. I had to go through the latest draft of the Ford/Osborne online call catalog to figure out what I was hearing. I think the main reason they sounded familiar to me is because the S42 call is what J1/Ruffles made over and over the last time I heard him (back in January, 2010, interspersed with a few S10 calls, not S22s).

One inference we can make from this observation of these two call types being used together is that they were most likely made by J pod. Thanks to this nice figure from Monika Wieland’s 2007 undergraduate thesis in which pod associations were made with each SRKW call type, we can surmise that S22 was made recently (2005-6) by J pod and L pod, but S42 was not made recently by L pod.

Pondering the shipping industry & the abatement of its ponderous noise

Shortly after the call sequence, the noise from a cargo ship in Haro Strait became audible and slowly rose as the ship proceeded south from Turn Point. Within about 10 minutes, the ship noise had drowned out any subsequent calls (or maybe the whales stopped calling) and remained audible for a about an hour.

I jumped over to marinetraffic.com and discovered that only one ship was near the Orcasound Lab location in Haro Strait. The ship was the Aurora SB, outbound from the Port of Vancouver at 13.3 knots (190 meters long, built in 2009, currently sailing under the flag of Cyprus).

Screenshot of the Aurora SB cargo ship passing the Orcasound Lab hydrophones.

So, I found myself again waiting ship noise to stop. I was still excited about hearing the orcas with so little effort (and so much luck). That made me eager to listen for whales again, so I decided to stay up. To kill time — and because listening to ship noise is boring and the shipping industry in general is annoyingly hard to understand — I recreationally started researching the cargo ship and posting to Facebook thoughts like:

What did they bring to Canada? Who shipped it on that particular ship? Who in Canada bought the bulk material?

What did they export from Canada? Who in Canada is shipping it? Who will buy it?

Who was the Captain? Who was the Canadian Pilot?

All these humans are responsible for the noise pollution the endangered orcas experienced tonight.

It’s remarkably hard to find the answers to any of these questions. I thoguht about just asking the Port of Vancouver for the answers, but it was the middle of the night and the start of the weekend. So, I started digging for anything I could find on the interwebs…

Flag :Cyprus 
Port of Registry :Limassol 
Registered Owner 1 :YOUNG AURORA SHIPPING LIMITED
Management Company 1 :A.E. NOMIKOS SHIPPING INV. LTD.

Eventually, I found an “email” contact form on the Mitsui site. After feeling the normal frustration about the shipping industry — how opaque and anonymous it is — it felt good to be able to write to someone related to the ship. This is what I submitted (in <500 letter chunks via their web form!):

Hello,

Tonight a cargo ship that you built made a lot of noise underwater as it left the Port of Vancouver in Canada. Just before the ship was heard on our live hydrophones, we were listening to the calls of an endangered species of killer whales. Sadly, the noise from the ship made it impossible to hear the whales, or the whales stopped calling during the noise.

We are worried that the noise also made it more difficult for the whales to hunt for the salmon that they like to eat. They love their salmon, eat it raw (like sushi!), and find it by making bursts of sound and listening for the faint echoes, just like bats hunt for moths.

This leads me to suggest a few improvements to your web page about environmental sustainability. Perhaps you should consider adding underwater noise pollution to the concerns you have about the marine environment?

Also, you could discuss any underwater noise quieting technologies you may incorporate into your ships (like optimal wake flow and propellers, resilient mounts for hull-mounted machinery, quieter bearings and engines, sound-absorbing engine room paints, etc.)

Best regards, 
Scott in Seattle

References:

Wieland, M., 2007. Repertoire Usage of the Southern Resident Community of Killer Whales (Orcinus orca) (Bachelor of Arts). Reed College.

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