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North America Washington: Columbia River, Chehalis River, Puget Sound Puget Sound. Basin Stream Order Stream Habitat. Community ecology of stream fishes: Patterns and processes in Pacific Northwest species richness. Introduction to the taxa. Fundamental questions:.
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North America Washington: Columbia River, Chehalis River, Puget Sound Puget Sound Basin Stream Order Stream Habitat Community ecology of stream fishes:Patterns and processes in Pacific Northwest species richness Introduction to the taxa
Fundamental questions: • What determines the number of species in a given area or body of water? • Is diversity a function of current or past conditions?
Fish Diversity in the Pacific Northwest Acipenseridae Petromyzontidae White sturgeon Pacific Lamprey Lamprey are typically semelparous and some are anadromous. Sturgeons are very long-lived, large, iteroparous, and often anadromous
Osmeridae Catostomidae common sucker longfin smelt Small, short-lived, often anadromous or lacustrine Intermediate in size, freshwater, rainbow smelt longnose sucker
Cyprinidae (minnows) Peamouth chub (Mylocheilus caurinus) Northern pikeminnow (Ptychocheilus oregonensis) Speckled dace (Rhinichthys osculus) Longnose dace(Rhinichthys cataractae)
Cottidae sculpins
Patterns 5 40 19 Primary freshwater fish species in North America (i.e., those of a freshwater evolutionary lineage) 112 260 110 55
Wisconsin glacial period, about 50,000 to 10,000 years ago McPhail and Lindsey 1970
Patterns North South Source: Hocutt and Wiley 1996
Patterns and Processes • Stikine River 27 spp. • Nass River 27 spp. • Skeena River 32 spp. • Fraser River 39 spp. Colonization: Up from the south (Columbia Refuge) Down from the north (Bering Refuge) Columbia River 45 spp.
Patterns and Processes Pleistocene glaciation 50-10,000 ybp, Lake Missoula, and area it flooded
4 6 8 14 Patterns and Processes Washington Natives: 15 families; 47 spp. Exotics: 9 families; 29 spp. Distribution of primary freshwater species in Washington
Puget Sound and Historic Lake Russell Ice Dam Outflow
Patterns and Processes • Stream Order Traits • Gradient • Habitat volume • Complexity (predator refuge?) • Temperature regime • Disturbance frequency • Prey diversity • Biotic interaction • Sedimentation • Structure
Within a given river system, what determines the: • number of species ? Biotic responses Stream order
Number of Species by Stream Order: Matamek River, Quebec (Morin and Naiman 1990) 20 2 R = 0.77 15 Number of Species 10 5 0 0 5 Stream Order
Within a given river system, what determines the: • number of species • biomass ? Biotic responses Stream order
Within a given river system, what determines the: • number of species • biomass • production ? Biotic responses Stream order
Production and Stream Order: Matamek River Quebec (Morin and Naiman 1990) 60 50 40 Production (kg/ha/yr) 30 20 10 0 0 2 4 6 8 Stream Order
Low Order Streams Life History Patterns short lifespan rapid dispersal high reproductive rate small adult size Community Characteristics Simple trophic links Variable population size High Order Rivers Life History Patterns Long lifespan Dispersal less critical High reproductive rate Large adult size Community Characteristics Complex trophic links Stable population size Diverse reproductive stratagies Stream order and life history and community attributes • Controlled by: • harsh winter conditions • limited summer growth • Controlled by: • Predation and competition
Percent frequencies of 482 fish species by trophic preference and stream size category Goldstein and Meador 2004, Trans. Am. Fish. Soc. 133:971-983
Percent frequencies of 363 classification of species by reproductive strategy and stream size category Goldstein and Meador 2004, Trans. Am. Fish. Soc. 133:971-983
What determines biomass and diversity within a given stream? Habitat features? Habitat Unit Traits Depth, volume, temperature, complexity, disturbance, prey, predators, sedimentation, structure Riffles n = 6 Glides n = 7 Pools n = 11 lamprey trout (YOY) 2% 5% trout (YOY) trout (YOY) 7% cutthroat 3% 10% lamprey Cottus sp. 14% coho 35% 11% coho 6% lamprey 15% Cottus sp. 73% Cottus sp. steelhead 95% 24% Data: David Lonzarich Big Beef Creek
Stream fishes use available habitat selectively. Coho salmon tend to occupy slow, deep water (pools). Healy and Lonzarich 2000
Habitat use patterns vary among salmonids and other fishes, reflecting choice and competition Roni 2002
World-wide, the distribution of stream production for salmonids is very skewed. High production results more from growth than density, and more from chemistry and temperature than habitat and substrate. Coastal NW streams are not highly productive. Bisson and Bilby 1998 Bisson and Bilby 1998
Estimates of biomass and density of trout and char in western Oregon, Washington, and California are generally low. Platts and McHenry 1988
Percent frequencies of substrate by stream category for 426 North American streams Goldstein and Meador 2004, Trans. Am. Fish. Soc. 133:971-983