River’s Day Reflections
Contributed by Dr. John Richardson, University of British Columbia Department of Forest and Conservation Sciences / SCCP Steering Committee Chair.
A lot of attention is paid to large rivers, as we use those for a variety of ecosystem services, and we all fret about the reduction in their quality. However, we rarely think about the sources of water, all those little trickles of streams draining from forests, alpine areas and grasslands that come together to form our majestic rivers.
When we do not think about small streams as the source of water, it is very easy to remove the forest around them, build next to them, let livestock graze beside and in them, and even bury them in the ground in storm-water drains (most of Vancouver’s streams are buried).
However, the lack of protection leads to more erosion of sediments because there are no plants to hold banks together, flows of nutrients that are not taken up by vegetation, no shading so water heats up, and no inputs of leaves and other organic materials that fuel freshwater food webs. Once the source streams are degraded, no amount of protection or “restoration” downstream is going to make a major reversal. All that warm, sediment and nutrient-laden water is coming.
Small streams in BC provide habitats to many species at risk, including tailed frogs, Pacific water shrews, bull trout, coastal giant salamanders and others that live nowhere else in our river networks. There are also hosts of species of invertebrates, algae and other groups that are poorly known, but some of which are also at risk.
British Columbia is like many places in the world, offering little protection of source streams. Washington State and others have recognized the importance of these headwaters and protects them, at least more than we do in BC. One of our projects called “Source Stream Protection” is trying to quantify the ecological benefits of protecting headwaters versus the economic returns of harvesting away all the trees. When we look at the large rivers and comment on whether they are endangered or not on Rivers Day, remember the source of the sediment, nutrients and warm water that contribute to their degradation.
Look towards the source streams!
Here is a sample of further links on organizations or programs working on river conservation and restoration: Fraser Valley Watersheds Coalition, Canadian Rivers Institute / BCIT Rivers Institute, https://freshwater-science.org/https://freshwater-science.org/, Trout Unlimited Canada, Society for Ecological Restoration (SER) Western Canada
Image Credit: Pamela Zevit. Top, Coquitlam River, middle, degraded stream impacted by upland stormwater runoff and loss of intact riparian vegetation in the Fraser Valley, bottom, Byrne Creek in Burnaby 'foaming' after a rain event.