Biodiversity Guide - The Intertwine

egional conservation strategybiodiversity guideChapter 5 Fish and Wildlife of the RegionThe Butterflies of Cascadia: A Field Guide to all theSpecies of Washington, Oregon and SurroundingTerritoriesRobert Michael Pyle. 2002. Seattle AudubonSociety, Seattle.Life Histories of Cascadia ButterfliesDavid G. James and David Nannallee. 2011.Oregon State University Press, Corvallis.Dragonflies and Damselflies of the WestDennis Paulson. 2009. Princeton University Press,Princeton.Freshwater Mussels of the Pacific Northwest (2ndedition)E. Neadeau, A.K. Smith, J. Stone, and S. Jepsenwww.xerces.org/wp-content/uploads/2009/06/pnw_mussel_guide_2nd_edition.pdfWestern Freshwater Musselswww.xerces.org/western-freshwater-mussels/Information on aquatic macroinvertebrate andwater quality monitoring in streams and wetlandswww.xerces.org/aquatic-invertebrates/www.deq.state.or.us/lab/techrpts/docs/DEQ03LAB0036SOP.pdfwww.oweb.state.or.us/OWEB/docs/pubs/wq_mon_guide.pdfPollinator conservation and other invertebrateinformationhttp://www.xerces.orgFishTodd Alsbury and James Byrne, OregonDepartment of Wildlife, and Jeff Azerrad,Washington Department of WildlifeAt least 72 species of fish spend some or all oftheir life history within the greater Portland-Vancouver region (see Appendix E). Of these,47 are native species and 24 are non-native. Onenative species, the Oregon chub, is extirpated inthe region. Many of the region’s fish species spendtheir entire life within a specific home range thatcan vary in size from feet to several miles. Theregion also hosts anadromous species such assalmon, steelhead, sturgeon, Pacific eulachon(smelt) and Pacific lamprey that spend a portionof their life history within the region, as rearingjuveniles and spawning adults, but live the bulkof their lives in the ocean. 1 All native fish speciesin the region are highly dependent on habitat andwater quality conditions at every stage of life inorder to maintain viability or prevent declinesor potential extirpation. Connectivity and accesswithin and among various habitat types withinthe region is critical in maintaining viable populations.Development and the associated streambarriers and road crossings create challenges formany fish species in the region.Conservation Issues and Key Threats to FishFish occupy the following major habitat typeswithin the region:n Estuary (i.e., the Lower Willamette andColumbia River tidally influenced lowlands)n Rivers and streams (e.g., the Willamette,Columbia, Clackamas, Lewis, and Washougalrivers; Tryon, Johnson, Butte, and Boardmancreeks in Oregon; and Mason, Salmon, Gee, andLacamas creeks in Washington)n Lake/wetland (e.g., Smith and Bybee, Beaver,Blue, Fairview, Steigerwald, Vancouver andColumbia River Gorge lakes and wetlands)n Pond (e.g. Salish and Laurelhurst in Oregon;King’s Pond in Washington)n Off-channel/wetland (e.g. Oaks Bottom, theRidgefield and Tualatin National WildlifeRefuges, and Sauvie Island Wildlife Area)Fish occupying every habitat type in the regionface challenges related to management of landand water. More than 160 years of development,particularly in the Portland-Vancouver metropolitanarea, has altered once-important habitatareas in the Lower Willamette River, ColumbiaRiver estuary, and tributaries that supported fishspecies native to the region.The Columbia River estuary (including theLower Willamette below Willamette Falls)provides essential habitat for all native fish species,including juvenile salmon, steelhead, andother anadromous fish as they grow to a size andcondition that increases their survival duringtheir ocean migration. Historically, the estuarycontained substantial amounts of shallow-waterhabitat that provided excellent conditions forgrowth and survival of native fish species. Humanland and water management activities have modifiedthese estuarine habitat conditions, resultingin a loss of habitat complexity and access tooff-channel habitats. Combined with the effectsof the hydropower/flood control system, theprimary activities that have determined currentestuary habitat conditions include riparian habitatloss, channel confinement (primarily via dikingand seawall construction), channel manipulation(e.g., dredging and bank stabilization), floodplaindevelopment, and water withdrawal for urbanizationand agriculture. With the exception ofhigh summer water temperatures, water qualityhas generally improved in the lower WillametteRiver over past decades as a result of pollutantreductions. Yet high pollutant and thermal loadsthat still occur in some areas, during certain timeperiods, may be lethal to fish that spend even alimited amount of time in the area.Tributary stream habitat conditions are alsomoderately to severely degraded within much ofthe region. Widespread development and landuse activity affect habitat quality and complexity,water quality, and watershed processes in lowerWillamette and Columbia tributaries. Streamhabitat degradation is primarily due to past andcurrent land-use practices that have affectedproperly functioning stream channels, riparianareas, and floodplains, as well as watershed processes.The following land management activitiescreate threats and lead to conditions that limitsurvival of native fish species within the region:water temperature, and destabilized streambanks,which has led to increased input of fine sediment.Active removal of large wood contributed significantlyto reductions in the amount of complexinstream habitat. Removal of wood in an attemptto reduce risk and damage from floods continuesto this day but is not as extensive as past effortsto completely remove all wood from the region’sstream systems.n Agricultural development throughout thelowlands in the region. Agricultural developmenthas directly affected riparian areas andfloodplains. Historical floodplain habitats werelost through the filling of wetlands, channelization,and construction of levees and seawalls.Runoff and erosion from agricultural lands wherepesticides, herbicides, and fertilizers are appliedreduce water quality, to the detriment of nativefish and other aquatic species.n Construction of dams, culverts, and otherbarriers. These structures limit access to spawning,rearing, and foraging habitats for nativefish. Dams alter overall flow, reduce high andlow flows, and change temperature patterns andhydrologic and geomorphic processes in waysn Timber harvest and development withinriparian areas. This has reduced stream shade1 “Anadromous” refers to fish that spend most of their adult lives at sea but return to fresh water to spawn.and the input of large woody debris, increased78 79