Assessment of Aquatic Biological Communities Along a Gradient of Urbanization in the Willamette Valley Ecoregion, Oregon and Washington Ian Waite, Kurt Carpenter, Andrew Arnsberg, Frank Rinella, Steve Sobieszczyk, Ian Wigger, Curt Hughes and Mike Sarantou National Water-Quality Assessment (NAWQA) Program

Seattle Sacramento Raleigh Atlanta Portland Denver Dallas-Ft. Worth Milwaukee- Green Bay Salt Lake City Boston Birmingham NAWQA Urban Gradient Studies

Oregon Willamette River Valley Willamette River Valley, Oregon

Willamette Urban Intensity Index Urban Index Population Density per sq mile

Willamette Urban and Ag Willamette Valley Ecoregion

Tickle Creek near Boring, Oregon Urban Index = 32

Urban Streams Claggett Creek Amazon Creek Pringle Creek Urban Index =

Water chemistry Habitat Algal Invertebrate Fish assemblages

Y-Axis Invertebrate Tolerance (Weighted Abundance) Y-Axis % Ephemeroptera Plecoptera Trichoptera Richness

nMDS Ordination of Invertebrate Density (Log X+1) w/ overlay of Population Density AXIS 1 AXIS 2

What variables are related to the Ordination Axis 1?

Plot of Population Density vs. % AG+Urban Land Use (% disturbance) Transition High Pop.Den Med/High AG+Urb Low/Med Pop.Den High AG+Urb Low AG+Urb

Multivariate Regression Tree (MRT: Primer) Linking Inverts to Environmental Data (coded by %AG+Urban) A: DO > 3.4 (< 2.5) TEQ 1120) A B C H D TEQ, DO and Sum_PEST B: Sum_PEST 0.087) % AG+Ur Categories < 15 % 15 – – 69 > 69 %

Nonparametric Regression Tree Linking Inverts to Environmental Data (coded by %AG+Urban) nC: TEQ n D & E: DO n F & G: Sum_PEST B G F E C I H J K L D A  H: TEQ  I: DO  J: Sum_PEST  K: TEQ  L: Sum_PEST

% Fish Metric Includes 4 Metrics n % Salmonids % Native (other species) n % Reticulate Sculpin n % Introduced or Exotic poor condition poor condition % Fish Metric Includes 4 Metrics n % Salmonids % Native (other species) n % Reticulate Sculpin n % Introduced or Exotic

“What do you mean cooties, no cooties on me.” FZ Exotic Species

nMDS Ordination of Fish Abundance (Log X+1) with overlay of Population Density per sq mile

Preliminary CONCLUSIONS  Fish showed a linear response as urban intensity increases based on individual metrics % EPT Richness  Invertebrates showed a smooth threshold for some metrics at Urban Index values of ~25 or < 5-10% Impervious

Preliminary CONCLUSIONS  Flashiness of urban stream flows usually related to % impervious does not seem to be the dominate factor affecting the biological assemblages in the Willamette Valley  Biotic assemblages were strongly related to differences in WQ among sites (e.g., TEQ, Pesticides, DO, and Water Temp.) likely due to Urban and AG land use disturbances – either singularly or in combination.

High Pop.Den & High AG+Urb High AG+Urb & Low/Med Pop.Den Low Pop.Den & Low AG+Urb  Little difference found in fish and inverts between High AG+Urban (% disturbance) and High Population Density sites Preliminary CONCLUSIONS

 Prediction of invertebrate metrics at unsampled sites using the urban index will be attempted using EPA and/or ODEQ sites in Willamette Valley – still amassing the data % EPT Richness

Evaluating the Effects of Urbanization on Water Quality I – II Concurrent Session F & G: Tues. 1 – 5 pm Panel Discussion Effects of Urbanization on Streams Tuesday 7:00-9:00 pm Meeting Room A8, SJ Convention Center Contact Info: Ian Waite

nMDS Ordination of Invertebrate Density Sites coded by %AG+Urban %AG+Ur Categories < 15 % 15 – – 69 > 69 % AXIS 1 AXIS 2

Hypothetical response to increasing urban intensity…..threshold or linear or none? Minimum threshold Maximum threshold Resistance

Population Density % Impervious 0.98 % Urban 0.98 Road Den Urban Index 0.98 Mean Watershed Elev Watershed Slope Flow Stats 0.73 DOC 0.70, SO TN 0.81, TP 0.73 Pest. Tox. Index_Summer 0.70 Sum_Insecticide 0.70 TEQ 0.79 Environmental Variables usually surrogates for many processes