Monthly Archives: December 2009

Researchers call for orca conservation zone in B.C.

Dec 23 Vancouver Sun article about a forth-coming science paper that proposes a conservation zone that overlaps with the proposed orca sanctuary boundaries:

Wildlife researchers have identified the key feeding area for a critically endangered population of killer whales near Vancouver Island and proposed the creation of a unique, miniature conservation zone for the few square kilometres encompassing the animals’ favourite seafood restaurant.

The international team of scientists, including University of British Columbia biologist Rob Williams and colleagues from Britain and the U.S., spent four months in the summer of 2006 painstakingly monitoring the movements of a three-pod population of killer whales in waters off B.C. and Washington state that numbers just 87 individuals — so few that every animal has been identified from distinctive markings.

The researchers found the whales were about three times more likely to feast on Chinook salmon — their preferred meal — in a narrow coastal strip south of Washington’s San Juan Island than anywhere else in their summer range.

In an article published in the latest issue of the journal Animal Conservation, the scientists propose strict protections on this whale-dining “hot spot,” arguing that the no go zone is small enough to establish a practical system for diverting all boat traffic but large enough to guarantee the whales unfettered feeding.

“Protecting even small patches of water can provide conservation benefits, as long as we choose the spots wisely,” said lead researcher Erin Ashe, a biologist at Scotland’s University of St. Andrews, in a summary of the study.

First outer coast hydrophone nearly live

Neptune hydrophone map

Neptune hydrophone map

On December 8th the NEPTUNE Canada cabled ocean observing system started pouring data on to the Internet.  This opens the door for John Ford and his collaborators to listen for killer whales on the outer coast of southwest Vancouver Island.  The Naxys hydrophone is sensitive to 5Hz-65kHz and is located in Folger Passage at 95m depth (see map at right) just outside Barkley Sound near Bamfield, Canada.

It’s unclear whether or not the audio stream will make it to land in real-time.  There is a comment on the web site that suggests that the hydrophone was to go live on December 8th, but I could find no live or archived data.  The following quote from the associated Coastal Marine Ecosystem project page suggests the signals may initially go only as far as Bamfield Marine Station where vessels might be able to respond to acquire photos for species identification:

“The underwater acoustic signal from the Folger Passage Node will be streamed live to the Bamfield Marine Sciences Centre and hopefully the internet so that students and marine mammal researchers will be able to listen for their species of interest. The archived broadband acoustic signal will also be freely available for more advanced analyses.”

Hydrophones of the VENUS array (Strait of Georgia, east node; 4Hz-100 kHz. ) provided near real-time data for 6 weeks in early 2009, failed, and were replaced on 9/27/09. You can again view spectrograms and listen to mp3 files (lagged ~10 minutes) at this hard-to-find page — in this example from hydrophone 2 at 170m depth — but no archives beyond 1 hour are available on-line (even after registering for data downloads).

[Update 12/17: the fall-winter 2010 VENUS newsletter states that they are providing data from multiple hydrophones that they are comparing.  “Working to improve the VENUS hydrophone system, our team re-configured the 170m-deep array in the Strait of Georgia. We deployed one of our original hydrophones, the Burns CR100, alongside two new ones — a High Tech HTI-99-HF and a Reson 4032T. We are testing the performance of these hydrophones to assess their long-term stability and acoustic character (sensitivity and response). Each hydrophone has its own web page with audio and spectrograms updated every 5 minutes. Already, we have detected hundreds of ships and ferries, and environmental noise associated with wind, rain and even thunder. Check out near real time audio at” Here are direct links to the data archives 3 types of hydrophones: #1: HTI | #2: Burns | #3: Reson.]

[Update 10/12/2010: It appears that the Burns and Reson are still working nicely, while the HTI is functional but generating a signal with interference when the Burns has it’s automatic gain on (noted on June 10, 2010). Also, there is a link to a multimedia archive (download requires registration), but the temporal coverage is very sporadic and generally out-dated.]

[Update 10/03/2011: VENUS has a new hydrophone player that’s pretty cool, but it’s really annoying how their links keep breaking and it’s unclear how often they really have near-real-time data available.  Today I checked again because the southern residents may have gone north last night, but the “most recent” data was from a couple days ago — 10/1/11.  Here’s a bit of info about the hydrophone data processing.]

Paul Macoun, VENUS Project Engineer, with the VENUS SOG East HydrophoneThere is appears to be some history of security concerns voiced by the U.S. and Canadian Navies.  For example, in a November, 2005 IEEE post about Neptune, author Peter Fairley reported:

In the category of unintended consequences are tensions between NEPTUNE and VENUS management and the Canadian and U.S. navies. What concerns the militaries is the possibility that their foes will employ publicly available data from the systems’ sophisticated hydrophones to identify vessels and track their comings and goings. (Canada’s entire Pacific fleet docks at Vancouver Island, just west of Victoria, while a group of U.S. nuclear submarines calls nearby Puget Sound, Wash., home.)

The VENUS organizers granted the Canadian military the power to squelch VENUS’s acoustic data whenever the navy deems national security to be at risk. That worries some NEPTUNE researchers. “For observatories expecting to have a 24/7 feed, that could be very disruptive to the science,” says Benoît Pirenne, the assistant director of information technology for NEPTUNE Canada, who is designing NEPTUNE’s data and control system.

Such concerns are also alluded to in one slide of a PDF presentation by Svein Vagel (S8_S10_Vagle).  He suggests that the concerns were met by giving the Navy an on/off switch and storing no data locally (presumably because someone might use a sub or dredge to steal the instruments from 170 or 270m depths).  [Update 12/17: see first comment from Dwight Evans, content manager for NEPTUNE Canada web site, confirming that the Navies are filtering the hydrophone signals.]

Other NEPTUNE Canada nodes also have hydrophones.  Pictured at left is the arm of the Canadian remotely operated vehicle ROPOS holding a Naxys hydrophone on a stand that was deployed 10m from the Barkley Head instrument platform (in background).  A instrument spreadsheet indicates another hydrophone was placed 14m from the Barkely Canyon axis node.  These nodes are located on the outer shelf at the latitude of Cape Flattery, so could provide a nice complement to the Neah Bay hydrophone as we try to understand when/how the southern residents leave the Strait of Juan de Fuca and head south down the WA coast.

Locations of hydrophones (m depth, lat, lon):

  • Folger Deep Hydrophone 100 48.8139 -125.2809
  • Barkley Upper Slope Hydrophone 397 48.4275 -126.1747
  • Barkley Axis Hydrophone 982 48.3166 -126.0503

View Salish Sea hydrophone network in a larger map

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+3dB noise reduces ‘effective listening area’ 30% - website of the Acoustic Ecology Institute

Jim Cummings of the Acoustic Ecology Institute has posted another great synopsis of an important new bioacoustics paper that has big implications for southern resident killer whales.  After defining a new bioacoustic metric “effective listening area” (which is MUCH more intuitive than “active space”), the authors clarify how slight increases in ambient noise can have big impacts for animals that need to listen to sounds that are normally barely audible.

The authors note analyses of transportation noise impacts often assert that a 3dB increase in noise – a barely perceptual change – has “negligible” effects, whereas in fact this increased noise reduces the listening area of animals by 30%. A 10dB increase in background noise (likely within a few hundred meters of a road or wind farm, or as a private plane passes nearby) reduces listening area by 90%.

We know that most commercial ships and recreational boats raise the ambient noise levels near killer whales by 20-30dB for periods of ~30 or 3 minutes, respectively, as the vessels and whales pass by each other.  Clearly it is time to articulate in what common situations the southern residents need to perceive barely audible signals — like distant inter-pod communication signals or echolocation returns from prey — and to model the reduction in listening area during typical noise exposures.  This paper suggests the results may be disconcerting even though southern residents are keystone predators (though one has to wonder if transients appreciate the advantage of the acoustic cloak a noisy freighter offers when trying to pick off a resident calf).

Scientific literature reference:
Barber, Crooks, Fristrup. The costs of chronic noise exposure for terrestrial organisms. Trends in Ecology and Evolution, 2010.
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Kalimari for orcas, or another salmon predator

(Chris Henry | Kitsap Sun) Mike Henry of Port Orchard caught this Humboldt squid while fishing for salmon off Sekiu in the Strait of Juan de Fuca.

Ron Hirschi, a local marine naturalist, is reporting Humbolt squid being caught on salmon gear in the central Strait of Juan de Fuca. Will they come all they way in in 2010?


Recreational salmon fishers are now catching them as far east as Sekiu in the Strait of Juan de Fuca. Watch for further reports as they invade the (now officially named) Salish Sea (aka Puget Sound, Hood Canal, Admiralty Inlet, etc).

Catches of the big squid are on standard salmon gear – cut plug and whole herring trolled or mooched. This is all much to the culinary delight of local fishers.

Ron Hirschi
Squid Watcher, Marrowstone Island, Washington State

The photo demonstrates that they are swimming in a habitat where they could decimate orca prey (salmon) or become orca prey themselves. There is some sparse evidence that residents orcas eat eight-armed squid. One squid beak has been observed in the stomach of a stranded transient killer whale. And offshore orcas in the Pacific are thought to feed on squid in addition to sharks.

This article by Chris Dunagan states that the Humbolt squid are known to move with schools of Coho and consume both forage fish and salmon smolts. It will be very interesting to observe the net effect of the squid on the Salish Sea ecosystem.

How NZ orcas hunt sharks

I was most impressed by this underwater photograph taken by Ingrid Visser of a New Zealand killer whale pursuing a mako shark. The associated article from the Daily Mail describes hunting techniques that smack of likely Southern Resident tactics: collaborative herding and stunning blows from the flukes. I wonder: does she have recordings of the vocalization and echolocation that occurs during these attacks? CREDIT: Ingrid Visser / SpecialistStock RIGHTS: Worldwide excluding French territory and UK magazines CAPTION: Orca and Mako shark