Mining, pulp mills, agriculture, forestry, roads and other development in the Fraser River watershed all cause water pollution and regular violations of water quality standards for copper, zinc, lead, cadmium, chromium and many other pollutants toxic to salmon.
Live blog of a talk by Joseph Graber on “Land-based Infrared Imagery for Marine Mammal Detection” at UW/APL on March 10, 2011.
Admiralty Inlet tidal currents can exceed 3 m/s and is therefore a valuable prospect for tidal power generation. The Inlet is also a migration corridor for marine mammals, most importantly southern resident killer whales.
Infrared radiation has a range of bands from about 1-10 micrometers. In July 2010 at Lime Kiln State Park, we tested a FLIR A40 IR camera, as well as Canon VB-C50FSi and Flea B/W digital cameras. On July 7 we imaged 84 surfacing whales.
The key to detecting marine mammals is to detect the change in the temperature (T) contrast between the sea and the dorsal fin when a killer whale surfaces. The mean temperature difference was about 2 oC.
How does it work? “Increased sky reflectivity at high incident angles lowers the apparent sea surface T and enhances detection.”
At 182m the camera only yielded one pixel to represent an orca which makes detection difficult beyond ~75m. At greater ranges, detection can be assisted by blows which are sometimes discernible at ranges >100m when dorsal fins are hard to resolve.
For clear conditions, T sky < T sea (about 4.3-7.3 oC vs 10.1 oC for the sea from a nearby buoy).
Ambient light, fog, and sea state can affect detection distance and reliability for visual and IR cameras.
Automated detection for IR could be accomplished by monitoring thermal gradients. Joe used thresholds (area, orientation, perimeter, and eccentricity) and frame-to-frame comparisons (to remove sporadic detections). This simple algorithm produced hits for 85% of a subset of the killer whales imaged in the Lime Kiln tests.
Today Tacoma’s News Tribune offers a story about the imminent issuing of new rules for watching southern resident killer whales. This story confirms Donna Darm’s recent mention of the regulations being currently under review at OMB. It remains to be seen whether the rules will be issued in time for the whale watching industry and killer whale researchers to plan accordingly for the upcoming season.
Underwater noise pollution affects calls but not clicks (yet)
The article states that “Research shows engine noise can interfere with the whales’ ability to find food.” That’s a little unclear. What has been shown for southern residents (Holt, et al., 2009) is that underwater noise from nearby boats makes killer whales call louder. If those calls are important for foraging, then the boat noise could affect the whales’ ability to find food. The greater potential impact of vessel noise on their ability to forage is masking of the echolocation clicks they use to target salmon. That is a focus of on-going observational and modeling efforts.
Ruckelshaus pwns Aggergaard
My favorite quote is from Bill because it suggests that the whale watching industry should take a broader, longer view of conservation science and policies:
Anytime you have an endangered species you always have somebody who is adversely impacted by the efforts to save the species, and they are very skeptical about the science that shows what they’re doing is causing any harm. The whale watch boats are equally dependent on the health of the orcas as are people who are concerned about them as a species.
He didn’t quite deliver the punch line for which I was hoping: a sustainable whale watching industry would lead in the reduction of all risks identified in the recovery plan — not just donating time and money to save Pacific salmon or working to clean up persistent pollutants, but proactively reducing potential vessel effects in accordance with all available science and the precautionary principle. Why not support the proposed vessel regulations — even propose to strengthen them (e.g. by adding a 7 knot speed limit within 400 yards throughout their critical habitat despite enforcement logistics), enjoy the short-term PR benefits of setting a stellar example, invest in binoculars and range finders, and then work with NOAA to abate the economic impacts (relax the rules, re-hire workers, grow the fleet) later if recovery occurs and new research justifies being less conservative?
“the equation seems simple as too few fish, likely means too few whales” [pg. 3 of 250 pg PDF]
“So let’s get effective Killer Whale Viewing Regulations in place and let’s put all of our collective energies
into the really important steps of Salmon Stock Restoration and Pollution Clean-up and Prevention. All the
houses around us are burning and we are keeping our house safe by spraying the roof and walls with a
garden hose.” [pg. 6]