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The Fraser River – The Study of a Watershed

Dr. Peucker-Ehrenbrink's team samples close to the headwaters of the Fraser, Robson River. The bluish color in the water is caused by 'glacial flour', rocks ground up by the glaciers coming off Mount Robson.The Fraser River watershed, located in the Canadian province of British Columbia, includes the rain-soaked peaks of the Coast Range, the Canadian Rockies, and the dry sagebrush prairie ecosystem in between. The Fraser is unique—it escaped the flurry of dam building that has altered nearly every other large river on the planet. Yet, the Fraser faces other threats. The mountain pine beetle epidemic, which is raging unchecked due to a string of mild winters, may eliminate up to 80% of the native pine forest. As these dead trees are harvested, the exposed soil will receive more of the sun’s heat, which will increase the temperature of the river water. If the water temperature exceeds 20 degrees C, salmon will no longer return to the Fraser—dubbed “the World’s Greatest Salmon River”—to breed. Pollution from logging and pulp mills and excess nutrient input and contamination from mining operations also impact the health of the river.
The Fraser River is fed by a multitude of tributaries. In the Coast Range, streams flow through temperate rainforest.

In the same way a doctor can monitor a patient’s health by analyzing their blood chemistry, scientists can assess the “health” of a river watershed by studying the chemical composition and other properties of the water. Scientists from the Woods Hole Oceanographic Institution, Woods Hole Research Center, and their international colleagues founded the Global Rivers Group to monitor the health of major rivers worldwide, from the Fraser to the Congo.

In May 2011, when the Fraser swelled to overflowing with meltwater and rain, Dr. Bernhard Peucker-Ehrenbrink and graduate students Britta Voss and Sarah Rosengard traveled the length of the river, from the delta to the headwaters, taking samples from both the main stem and critical tributaries along the way. Their data, supplemented by more frequent measurements made by students from the University of the Fraser Valley, will be used to assess how the river and its watershed are changing—for better or worse—over the coming years.

Chris Linder specializes in communicating science to the public using photography and multimedia. Chris holds a Master’s degree from the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution Joint Program and maintains a part-time affiliation with the Woods Hole Oceanographic Institution as a Research Associate.  Since 2002, Chris has focused on communicating the stories of scientists working in the Arctic and Antarctic. His education and training as an oceanographer give him a special insight into photographing marine science. He has spent over a year of his life on expeditions to the polar regions.




  1. Randy Piper
    Lakewood, Colorado
    January 8, 2013, 8:55 pm

    Having lived and played at the headwaters of the Colorado River and watching our forests be decimated in one of the most beautiful environments on earth drove me to extensive research on the issues and impacts of this beetle epidemic. Simply put, we can not stop it – the beetles are now re-generating 2x /year in some areas, and it seems the sciences and forest services agree that we will lose 70-90% of our Pine forests throughout the West over the next decade or two… so the most responsible thing we can do is to create public awareness, put forth a cry for volunteers to help protect our communities, economies, and infrastructure while re-planting in the most critical watershed areas, and utilize the timber removed for lumber and biomass. Go to ChooseOutdoors.com and Beetlekillwood.com for more info on how you can help.

  2. […] National Geographic […]

  3. Bruce Ward
    Pine Colorado
    July 21, 2011, 6:26 pm

    The natural demise of the geriatric trees-50 million acres in the USA and Canada is indeed part of the ecological cycle and if there were no humans on the planet it would not be a concern. However with 1000s of lives at risk due to catastrophic wildfires, water supplies for millions of people at risk and immense carbon emissions real potential outcomes from “letting nature take its course”,

  4. EJ
    July 18, 2011, 10:08 am

    Everything is an ecological cycle and I understand many cycles unseen are progressively being destroyed, which ultimately threatens our lives. We must, be more broad-minded and less ‘instantly gratified”, seriously consider the underlying causes of the deterioration of our eco-systems.