Vessel Slowdown Trial in Haro Strait

Discussion in 'General Open Forum' started by agentaqua, Aug 28, 2017.

  1. agentaqua

    agentaqua Well-Known Member

    Vessel Slowdown Trial in Haro Strait
    Between August 7th and October 6th, 2017, all piloted commercial vessels transiting Haro Strait
    are requested to reduce their speed to 11 knots (speed through the water) between Discovery
    Island at the southern end, and Henry Island at the northern end. Average vessel speeds
    through this area range from 18 knots for containers to 13 knots for bulkers.
    https://www.portvancouver.com/envir...program/vessel-slowdown-trial-in-haro-strait/

    [​IMG]
     
  2. Cool study, hopefully a large majority of vessels choose to participate by slowing down. Is there any way to impose a mandatory speed through that stretch?
     
  3. agentaqua

    agentaqua Well-Known Member

    Might be - not sure if the shipping companies would want a mandatory one. Maybe through the Oceans Act or SARA...
     
  4. Tugcapitan

    Tugcapitan Well-Known Member

    I'm curious about a few things surrounding this study.

    - How can a lay person access the hydrophone data from the existing ECHO project in Georgia Strait measuring vessel noise? (I've seen all of the participation percentage numbers, but none of the measurements themselves...)

    - Since the physical experiment part of this study is now a few weeks old, why does the literature already state that underwater noise is a "key threat" to the recovery of Southern Resident population? (Chinook salmon numbers? Water acidity? PCBs?)

    -Where can one look at the scientific results linking ship noise and Orca behavior? (YouTube "surfing orcas" to see how they react in a massive ships wake. I was told the orcas in this video were surrounded by whale watching vessels minutes before this video was taken)

    -How do these same scientists feel about the constant following of the orcas by ambitious and ever bigger whale watching vessels? Is it really necessary to harass them all day in the name of educating the public?

    -As the vessel slow downs are not stated to reduce whale strikes as that doesn't seem to be a problem in that specific area, who decided it was beneficial to have the ships make less noise but thus spend more time in their habitat by slowing down?

    -Who are the scientists making these recommendations and where can we read their research / conclusions?

    -How will "they" determine the effects of the slowdown on Orca behavior?

    -what about the vessels that are going flat out to make 11 kts?

    I fully support the slow down if it helps the Orcas, I'm just having trouble finding scientific research results from known experts correlating vessel noise and whale behavior. It seems weird to me that we are supporting vessels that actively search the whales out and hang around in very close proximity to them all day long, but are targeting vessels that pass through the general area to make changes to help them. Although I've only had Orcas in my wake a couple of times, I can't count how many times I've been in the middle of nowhere when Pacific White Sided Dolphins have actively searched me out to hang out in my bow wave or wake for a considerable amount of time with my throttles pinned. I hate to think I've been negatively impacting their behavior. Have I? Says who? (I am genuinely not trying to stir the pot here, I want to know.)
    I would understand the reasoning if we were trying to reduce whale and whale calf strikes like they are on the East Coast, Los Angeles, Australia ect.
    I just feel like "they" could do a better job of convincing us that there is sound reasoning (pun only sort of intended) that these slow down measures will help, and are not just a distraction to prove that we are actually doing something helpful while ignoring the very real problems with much more difficult solutions.
     
  5. agentaqua

    agentaqua Well-Known Member

    Good points/questions, TC - and as I posted on the Sailing soon: an Orca-friendly, all-electric car ferry thread:

    My question(s) would be:
    1/ if we reduce "acoustic disturbance" will we increase ship/whale collisions?
    2/ what frequencies are whales most attuned to? Which ones the least? What frequencies do ship's props and engines noises operate on? Is there a frequency like a deer whistle that would assist with collision avoidance by whales?
     
  6. Tugcapitan

    Tugcapitan Well-Known Member

    Yes those are also interesting questions.

    Would a whale whistle alerting greys or humpbacks ect also then disturb Orcas trying to feed?
     
  7. GLG

    GLG Well-Known Member

    There are links inside this pdf that point to some of the studies that you asked about.
    https://www.portvancouver.com/wp-co...ter-Noise-Infographic-Footnote-References.pdf
    Have a listen to this sound file to hear what the orca hear when a ship passes. It seems that prop cavitation is the prime suspect and reducing speed would play an important part in that.
    https://www.portvancouver.com/wp-co...oat-noise-Hanson-Island-BC-Orcalab-credit.mp3

    More info can be found here.
    https://www.portvancouver.com/environment/water-land-wildlife/marine-mammals/echo-program/
     
    agentaqua likes this.
  8. Tugcapitan

    Tugcapitan Well-Known Member

    Thanks GLG, I'll take some time to read all that before responding further.
     
  9. GLG

    GLG Well-Known Member

    You welcome Tugcaptian, I look forward to you input as you have a perspective that is valuable to our community.
     
  10. agentaqua

    agentaqua Well-Known Member

    Thanks for all your sleuthing, GLG!
     
  11. ziggy

    ziggy Well-Known Member

    If cavitation is the major contributor then slowing to a speed below vessel cavitation speed makes sense. Cavitation is the forming of bubbles around the face of the propellor if I remember correctly. As such cavitation speed varies from vessel to vessel and depends on factors such as wheel design, maintenance of the wheel, and depth. For example most modern warships have a much higher cavitation speed than does the average merchant vessel, through prop design.A loaded vessel is likely quieter than an empty vessel, because bubbles form easier at the surface.Hit something with your prop and you become much noisier, anyone who has ever done this can attest to the feeling and sound. So it may not be a one speed fits all

    Looking at the participants in this program, I'm surprised to not see DND involved. As you can imagine our Navy ( and everyone else's) spends a lot of money researching sound signatures and how to avoid producing them. They have the people who specialize in analyzing ships noise, so one would hope prior to determining whether it's cavitation, or machinery noise that is causing problems, they will share their data.
     
    agentaqua likes this.
  12. agentaqua

    agentaqua Well-Known Member

  13. agentaqua

    agentaqua Well-Known Member

  14. agentaqua

    agentaqua Well-Known Member

  15. Tugcapitan

    Tugcapitan Well-Known Member

    So I did some reading. A lot.

    It seems most scientists agree that there are "inherent difficulties in quantifying the potential effects" of vessel noise on whales. Almost all of the research available from our port and government surrounding this vessel slow down in Haro Strait was developed on the East coast for Fin, Humpback and Right whales which communicate on different frequencies to Orcas. Even for those whales the scientists themselves admit "Very little is known about the actual range of communication between whales, so assumptions have to be made".

    I tried hard to find studies linking vessel noise to Orcas behaviour without much luck. It seems the best sources right now are from the University of Washington. Hopefully the Data collected from this latest slowdown experiment will shed some light on the SRKW (Southern Resident Killer Whale) populations behaviour as it relates to noise, but I find that unlikely. I still believe the Clearseas organization's agenda is based more on political maneuvering than on real science, but if that leads to changes that actually help our Orcas then I guess it doesn't really matter if they were made for politicians to wave over their heads or not. Our government is desperate to convince the public they've done something to make a difference. We'll see.

    I must admit that most of the scientific data I came across required an education different than mine to understand properly. But again, it was centred around whales that communicate on totally different frequencies to the whales this project is meant to help. If anything, I was left with more questions than answers after I'd read all I could.

    I found a couple of things very interesting.

    There isn't as big a difference between commercial traffic noise and pleasure craft as I imagined. The averages were listed as 162 decibels for pleasure craft, and 178 decibels for Container ships (Container ships are generally accepted as the noisiest of all commercial traffic) Although on very different frequencies.
    One study opined that Orcas would be able to hear most vessels from a distance as far as 10km!!!! That made me think again about the whale watchers. We are asking ships to slow down in an area where Orcas "might" be present, but as a society are endorsing high speed vessels to seek them out and surround them? How could this not be more detrimental than a passing ship? Not only that, but ships transmit noise at a frequency well below that of normal Orca communications, where as outboards are right in their communication frequency. In fact, the ONLY piece of evidence I could find amongst all of those "studies" linking Orcas and ship noise referred to whale watchers....

    "There is some evidence that whales can, but sometimes do not, compensate for such changes in their ambient noise environment. For example, killer whales increase the amplitudes of their calls with increasing noise in the 1-40kHz frequency band" (Holt et al. 2009)
    "For example, SKRW's produced longer calls in the presence of vessel noise following a large increase in whale-watching boats" (Foote et al., 2004)

    After reading this and realizing ship's frequencies are different to Orcas communications I was ready to call BS on the vessel slowdown until I read about how ships frequencies could easily mess with the Orcas echo clicks and the locating of prey. One scientist cited a lack of Chinook salmon as their biggest threat, I agree, but the same scientist said thats why its especially important now to make sure we don't interfere with their locating of prey as there is so little around. Finally I felt like I could get onboard with the slowdown.

    And then there has been Sandheads over the last couple of weeks. So much Orca activity in the miles around the Fraser. Its easy to find them, they are literally surrounded. The viewing "rules" for whale watchers are out the window. The time limit is especially meaningless as there are one or two vessels joining the group every time one leaves, same as in Boundary and Haro. However I really started to question my own impact on them as well. Here I was making traffic arraignments so as accommodate 5 different commercial vessels including ships travelling in different directions but all right around the South arm of the Fraser. The whales had already been split into two groups by another tug and tow, 8 whale watching vessels (man they are building some big ones now), 50 recreational "kickers" fishing away, and another ship and pusher tug exiting the river.

    I couldn't see a "way out" for the whales and it must have been deafening under the water. I have to admit I felt bad for them trying to catch their fish amongst all of that.
     
    bigdogeh and agentaqua like this.
  16. agentaqua

    agentaqua Well-Known Member

    Thanks for sharing what you learned, TC! Excellent post. I wonder how they will determine if the slow-down zone has been "successful"? Maybe they'll key-in on the large release of farmed fish instead of Chinook???
     
    Tugcapitan likes this.
  17. agentaqua

    agentaqua Well-Known Member

  18. agentaqua

    agentaqua Well-Known Member

  19. agentaqua

    agentaqua Well-Known Member

  20. agentaqua

    agentaqua Well-Known Member

Share This Page