Salmon Leaks Part 5: Expert Reports on Climate Change and Habitat

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At the very least, Judge Cohen’s sockeye inquiry has proven so far to be a window into the behind the scenes workings of Fisheries and Oceans Canada. In addition, because of the requirement of witnesses to testify under oath, independent scientists have an unprecedented opportunity to tell it like it is. During the aforementioned sessions, contracted researchers had just such an opportunity.

The inquiry commissioned a number of researchers to complete expert reports on various topics of concern and two reports were presented in the hearings recently.  Drs. Scott Hinch from the University of British Columbia and Eduardo Martins from Carleton University presented their report on the potential climate change effects on sockeye and trends in en route loss and pre-spawn mortality in the Fraser River.

See transcripts for testimony on climate change report:


On Mar 8 counsel brought up recent Fraser River extreme water temperature trends in relation to climate change (starts on page 7, line 36)  and questioned Dr. Hinch about them. Hinch replied, “we have more extreme years, recently. So as I said, 13 out of the past 20 years were record temperatures in the historical context.” Hinch went on to discuss the negative effects of warming water on sockeye (page 9, line 45) and referred to temperature “as the master biological factor controlling for fish.”

Also on Mar 8, Dr. Hinch discussed the developing phenomena of pre-spawn mortality and en route loss in returning Fraser sockeye (page 62, line 3). Hinch stated,

“yes, starting in 1992 en route loss really starts being reported by the management agencies. In 1996 we start seeing a real large or an abrupt change in the late run sockeye en route loss values where prior to ’96 it was minimal and after then it was very large, owing to the early migration phenomenon. Prior to ’92 en route loss wasn’t really recorded or reported much, although it likely occurred in some years, but it likely occurred in a much smaller context.”

Counsel continued on this interesting vein (starts on page 63, line 24) and the topic moved towards the significance and magnitude of pre-spawn and en route mortality. Counsel asked,

“This might be the single greatest causative factor we have to look at?”

Dr. Hinch replied, “Yes. For—again, for a group of—for those particular group of stocks that are affected by en route loss.”

Counsel commented on the actual numbers of sockeye this could translate into “we could be looking at losses of over three million fish in some years?”

Hinch replied, “Yes.”

The conversation between counsel and Hinch moved towards establishing the link between en route mortality of late run sockeye and the phenomenon of early entry into the River (page 65, line 44). Counsel asked, “am I correct that this early migration pattern…for Late Runs is a significant factor in the pre-spawn mortality and en route loss?”

Dr. Hinch replied, “For Late Runs, yes.”

Counsel continued, “There’s a direct correlation between those?”

Dr. Hinch replied, “Yes.”

Counsel then asked about the cause of early migration. Dr. Hinch explained that “It hadn’t happened prior to ’96 and suddenly this is occurring in large segments of the Late Runs.” The discussion continued and climate change was eliminated as a likely cause of the early migration phenomenon in late run sockeye. Another published study which was reported in the Globe and Mail recently was brought into the discussion because Hinch was an author. The study’s lead author—Kristi Miller of DFO—hypothesized that a virus may be linked to the early entry behaviour and early mortality of some Fraser sockeye stocks. Hinch acknowledged that he agreed with the concluding statement of that study:“Our hypothesis is that the genomic signal associated with elevated mortality is in response to a virus infecting fish before river entry and that persists to the spawning areas.” This interesting exchange went further into the details of this purported virus (see page 70, line 39).

Dr. Hinch mentioned that Kristi Miller offered up a name for the disease associated with the purported virus—“salmon leukemia”—and it was suggested that it may be caused by a retrovirus with immune suppression capabilities like the AIDS virus. Hence, it could compromise a salmon’s ability to fight off other diseases and parasites. Counsel added that “chinook farms in 1992 experienced an outbreak of salmon leukemia” and subsequently asked Hinch whether “In the course of your research have you looked at whether there’s any evidence of this viral signature in fish farms?”

Hinch replied, “I personally haven’t. I’m not sure what DFO has done.” He also agreed the purported virus in sockeye and its potential linkage to the salmon farming industry is an important line of research that should be addressed.

The second expert report was written by Marc Nelitz, Katherine Wieckowski and others from ESSA technologies on the role of fresh water ecology on the decline of Fraser sockeye.

See transcripts for testimony on fresh water ecology expert report:


On Mar 10 counsel engaged in a somewhat lengthy and heated cross-examination of Marc Nelitz (starts on page 85, line 21) on the subject of the effects of recreational activities on sockeye, using Cultus Lake as an example, and why this factor was not included in his report.

For more information see:


One Response to Salmon Leaks Part 5: Expert Reports on Climate Change and Habitat

  1. d says:

    Thank you for helping the public to make sense of this information flowing from this critically important inquiry.

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