Global warming tragedy: Fraser River salmon dying as climate change heats up waters
Global warming has already significantly changed our Fraser River. Its waters are warming and its flows are shifting to earlier in the year. By summer when the legendary salmon runs surge into the river to spawn, the river is more often becoming too warm and low for their survival. Already more and more salmon are dying en route to the spawning grounds. Fishing quotas are being cut back to make up for it.
Experts predict far more "dramatic changes" lie ahead unless humans switch away from climate polluting energy sources. They say our salmon will be hard pressed to survive and thrive in the new overheated Fraser River we are creating.
The Fraser River drains a watershed larger than the state of Washington. The CO2 from the burning of oil, coal and natural gas has changed the climate significantly in this huge watershed. Average air temperatures are rising, average snowpack is declining and rainfall has changed throughout of the year. The river that drains his huge changing landscape is being changed as a result.
Changing flows
Water is now coming down the Fraser River earlier and earlier as the climate warms.
The mid-point of the annual flow now happens much earlier on average than in 1950.
For example, my chart below shows the percentage of annual flow each year that already passed Hope by July 1st. The trend towards more and more of the annual flow passing before summer starts is clear.
Fisheries and Oceans Canada (DFO) expect this trend to continue as long as global warming keeps getting worse. Their climate models show "dramatic changes in the flow of the Fraser River" as more and more of the flow shifts away from summer and into the winter and early spring. The lower the summer flow the warmer the water.
The cause of this shift in flow away from summer is the decline in our late-season snow pack as BC's climate heats up. The Fraser River is a "typical snow melt dominated river". That means flows are lower in winter while snow is accumulating, followed by rapidly rising flows in spring as snows melt and rains start. But now snowfall is decreasing and rising temperatures are melting it sooner. Less and less snow remains by summer.
Overheating
Global warming is causing the Fraser River, like the air around it, to get warmer. The BC Ministry of the Environment's climate change website states: "The average summer temperature of the Fraser River increased by 1.1°C between 1953 and 1998." Here is their chart:
This warming appears to have increased significantly in recent decades.
A technical report for the Cohen Commission -- A Review of Potential Climate Change Effects on Survival of Fraser River Sockeye Salmon (CCCC) -- states that the Fraser has now warmed by 2.0 C in the last sixty years, with 0.7 C of that occurring in the last two decades.
Fisheries and Oceans Canada also expect this heating trend to get much worse as long as global warming continues:
"By the end of this century, throughout all of July and August, the average daily temperature will exceed the highest average daily temperature (see dashed line) that was observed during the normal period."
Here is their chart:
Rising temperatures are very bad news for salmon. The CCCC report summarized 64 scientific studies trying to understand the impact of just 0.7 C warming over the last two decades. It found "survival of returning adults has very likely decreased" and "the cumulative impacts of climate change on survival across life stages could have been substantial."
Both this CCCC report and the DFO predict an increasingly hostile and tenuous future for Fraser River salmon if we allow global warming to continue.
Struggling Salmon
The Fraser is the largest salmon producing river in Canada. And it is heating up relentlessly...
Temperature is the "master environmental factor" for salmon, as it is for almost all fish. As the graphic at the top of this article illustrates, warmer river temperatures stress adult salmon in many ways, causing more to die before spawning. Females with their extra energy needs are even more susceptible than males. The DFO is blunt about what is coming if we don't switch away from dirty energy...
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(5) Comments
Nice article and the conclusions seem valid.
One comment though. You need to be careful when you talk about "average snowpack is declining" due to global warming. While it is clear average temperatures are increasing, that warming also leads to increased precipitation in some regions - and therefore snowpack up high. BC Hydro data ("Hydrologic Impacts of Climate Change, April 2012") shows that there has certainly been a substantial decrease of average snowpack between 1956-2005 (18% on average, but variable between none-to-47%, depending on the region). However, their modellers can attribute the vast majority of that change to ENSO variations. Once you take that out, the remaining signal leaves only about a 4% average decrease in snowpack (probably in the noise). Just wanted to point that out for clarity/accuracy.
The key thing is, what you pointed out clearly, that there is earlier melting of the snowpack - and as a result, the measurements of warmer temperatures in the rivers that affect those fish that spawn in the late spring and summer.
Barry, you write on the subject of dying salmon on the Fraser and not once mention any of the evidence that shows one of the other major sources of high mortality rates ( and we could argue the only source of the decline). This evidence is what the DFO is trying so desperately to hide. Without even mentioning there is a large body of experts who disagree with the DFO "findings" shows your lack of journalistic skill - or is it journalistic integrity?
Did you forget your only information source is the same scientists who have been told they are not allowed to speak to reporters without Harper’s communications staff approval? The only information that is allowed to be released is what Harper wants released? Have you not noticed that Harper only uses “science” when it’s convenient to his needs and when science doesn’t suit his needs, science is discredited and mocked? Why would you not look for other sources of scientific opinion and research knowing any information coming out of a Harper approved piece of information is probably extremely biased and politically motivated?
You can't think that anyone reading this article, who doesn't have their job and livelihood based on the success of fish farming, could read this and not question your motives for missing the obvious.
I'm sure you will have many of the "industry farmers" on here thanking you for your "highly researched" piece of journalism. The shame of it is you know what you have done here and so does everyone else.
You are the Bagdad Bob of the Wild fish wars. When the last wild salmon drifts down the river what will your legacy read like?
A study done by Michael Kent DFO in the early 90's showed that healthy salmon could withstand increases in water temperature quite remarkably.
However, the virus or bacteria he was studying at the time became more active with increases in temperature.
I think global warming is all the more reason to get those disease-incubating fish farms out of the oceans, and to stop the dirty oil of the tarsands and the burning of coal - whether in Canada or China.
Wild salmon may be the "canary in the coal mine" so we should be putting all of our best efforts into saving these aquatic canaries.
Afterall, we are ALL in the same coal mine.
The reference for increased water temeprature is Patterson et al, 2007a.
How old was the data?
BC has cooled .8C since then.