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Delve into the physical features and habitats of the Columbia River estuary. Learn why it is crucial to be concerned about its wetland habitat and how it influences fish distribution and survival. Explore the regional setting, salinity, temperature, and tidal influences. Discover the importance of wetland restoration activities for sustaining the estuarine ecosystem.
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Columbia River estuary – overview of physical features and habitats Colin Levings ISAB Thanks owing to Jen Burke UW and Chris Hathaway LCREP for graphics
What is an estuary? -a semi-enclosed body of water where freshwater and saltwater mix (common usage) -the entire portion of a river that is influenced by ocean tides (Williams et al 2006 for the Columbia River estuary)
Why should we concerned about physical features of the estuary ? -interacting with biological factors (competition, predation) physical factors influence the distribution, abundance, and survival of fish. John Ferguson and Don Lyons will discuss. Examples -temperature influences growth and food requirements -salinity influences the smolting process when salmon migrate from fresh to salt water -currents and water depth can affect distribution
Regional setting for the Columbia River estuary -water from the largest watershed on the northeast Pacific coast drains through this drowned river valley (map from Emmett et al 2000)
Temperatureat Warrendale (from Fuhrer et al 1996) Flow at The Dalles 1901-1950 and 1980-2003 (from Naik and Jay 2005)
Why should we be concerned about wetland habitat in the estuary? Dan Bottom will discuss. -detritus (complex of decaying vegetation and microbes) is recognized as a main source of energy for invertebrates (fish food) supporting estuarine food webs -vegetation area can be measured and used as a surrogate for fish habitat because vegetation is also influenced by physical factors
Video inventory of shoreline to help plan restoration Wetland Loss – Grays River