Daily Archives: March 3, 2010

Fulbright talk on marine conservation in the Pacific Northwest

Dr. Rob Williams

Dr. Rob Williams

Notes from an annual lecture at the University of Washington, March 3, 2010, at 7pm:

“Marine conservation in the Pacific Northwest: Whales, Salmon, and Sound” by

Rob Williams, 2009-2010 Canada-US Fulbright Visiting Chair

“A scientist is someone who asks ‘what if’ questions.” — Margaret Atwood

“If you want to study whales, you should put yourself in path of the whales.” — Alexandra Morton  (Her advice inspired Rob to settle on Pearse Island in Johnstone Strait.)

When I was a kid in the 1970s growing up on Vancouver Island, a great success was the ‘save the whales’ movement.  It was successful in that we gave it a name and a voice (Roger Payne), e.g. the Sound of the Earth LP vinyl record.  Such recordings helped us understand that sound and hearing is as important to whales as light and vision are to us.  Acoustic space is as important for our local whales as the coastal rainforest habitat is to B.C. bears.

Abundance estimates of local whales were rare historically in western Canada.  It is a complex region, there was no whaling, and Canada had left the IWC in the 1980s.  More recently, the Species at Risk Act made abundance estimates more important.

In the U.S., the Marine Mammal Protection Act outlines management objectives.  A key element of the Act is that Potential Biological Removal (PBR) limits annual anthropogenic mortality while meeting the management objectives.   Thus, it demands abundance estimates, e.g. PBR = Nmin * 0.5 (Rmax) * Fr

In Canada, the Species at Risk Act dictates that best available information must be used (whether from science, first nations, etc).  No quantitative abundance estimate is required, but filling in such data gaps was likely to be helpful.

So, I went off to Britain to get a PhD in abundance estimation.  Once back in Canada, I worked with a non-profit using line transects to estimate average number of cetaceans (6 species) on the B.C. coast within the gap between U.S. survey areas. We estimated populations of: 15,000 (?) harbor porpoises; 26,000 Pacific white-side dolphins (possibly moving into inshore waters of WA); 496 fin whales (all inside Queen Charlotte Island, ship strike risk), 1,300 humpback whales (density highest at S end of Queen Charlottes where shipping density is at a minimum);

Juxtaposing species density surfaces and shipping density creates a map of ship strike “risk” for that species.  Similar maps could be made for oilspill likelihood.  At the least, such maps can help us know where to pay attention and maybe where to focus conservation actions.

Acoustic habitat quality: does anthropogenic noise mask cetacean signals? Working with Chris Clark we tried to use noise to quantify acoustic habitat quality (masking metric).  The lowest 5% of sound levels characterizes the “ancient ambient” conditions.  Pop-ups were deployed in Prince Rupert, Caamano Sound, Johnstone Strait, Vancouver and Haro Strait.  Johnstone Strait had highest sound pressure levels, possibly due to a local bottleneck of shipping.

Williams talks in Kane Hall

Williams talks in Kane Hall

Chronic ocean noise is an insidious problem that’s received less attention than military sonar.  Amazingly, the International Maritime Organization and IWC have resolved to reduce shipping noise 50% in this decade.  Technological solutions exist; we just need an incentive.  It seems there is an opportunity to lead on this issue.

There are many short-term effects of ship noise decreasing the active space of cetaceans that may be biologically meaningful: masking of communication, prey sounds, predator sounds, etc.  When Erin recently began her PhD, we observed a few hundred Pacific white-sided dolphins in Knight Inlet, we noticed many of them breaching and then porpoising away.  Transients chased them into a bay and attacked.  Acoustic detection of the incoming transients had life or death consequences for some of those dolphins!

How many salmon do killer whales need?  I participated in a UW workshop to analyse data from SeaWorld, IWC, and wild KWs.  Main result was that nursing costs mums ~40% extra energy.  It’s clear that SRKWS need hundreds of thousands of salmon.  Whose salmon?  Whales don’t see or hear the boundary, so there is a profound need for transboundary research.

Next: 2 year Marie Curie Fellowship starting this fall at St. Andrew to study masking effects of shipping with mathematics collaborators.

Scott’s favorite quote from Rob’s talk: “Whales need a quiet ocean with fish in it.”