SU Report Title: Physical, Chemical, and Biological

1. ACFB-EUSE Project Overview SU Report Title: Physical, Chemical, and Biological Responses of Streams to Increasing Watershed Urbanization in the Piedmont Ecoregion of Georgia and Alabama, 2003 • Authors: • Brian Gregory • Dan Calhoun Status: Supervisor review complete; out to colleague this month Mary Freeeman, USGS-BRD, David Walters, USEPA-NERL • Project support: • Brian Hughes-management • Gary Buell-GIS • Evelyn Hopkins-GIS (retired) • Wade Bryant-field/data support • UGA- fish taxonomy, field support • Tenn WSC-mobile lab, technicians • GA WSC-field support, data management

2. ACFB Study Unit Objectives: “to describe the physical, chemical and biological responses to increasing urbanization on streams in the southern Piedmont region of the southeastern US, in the vicinity of Metropolitan Atlanta, Georgia.” “Specifically, this study investigated changes in the biological communities using a metric and multivariate ordination approach”

3. Study Design • 4 Major river basins • 2 level 4 Ecoregions • Past landuse -highly productive ag • Currently – forested outside ATL • Site Selection • 20-60 sq mile basins (217) • Site selection UII composed of 19 variables (|ρ|≥0.5) • 1997 population data • 1990 land-use data • Selected more sites in low to mid range • Consistent riparian vegetation/cover (reach level) • Most highly urban of basins outside older urban core • Sample snags since riffle habitat available at only about 1/3 final sites

4. Study Design Data analysis UII 5variables (|ρ|≥0.95) 2000 pop density • Housing density • Road Density • % Developed in watershed • % Developed in buffer • % Forest

5. Study Design

6. Study Design -Cluster analysis of sites -components of Data Analysis UII -4 groups + 1 outlier -provided groups based only on landuse -used to conduct tests on biotic response -graphical aid in presenting scatter plots

7. Study Design

8. Study Design

9. Data analysis strategy Environmental Data -landuse -stage -temp -habitat -QW Environmental Metrics - hydro (by season) - fragstats - HDAS - SPMD assays - QW (sums) Spearman correlations -env. metrics X UII, comp, imperv. -bio. metrics X UII, comp, imperv. -bio. metrics X env. metrics Raw Data -landuse -temp -QW -SPMD -stage -invert -algae -fish -habitat Biological Metrics -inverts-IDAS(SE) -algae-ADAS (v7) -fish-EPA/G&M/ GaDNR Ordination (NMDS) based community analysis -ordination diagrams -ANOSIM -Multivariate dispersion -SIMPER Multivariate regression -RELATE -IMS -BEST Biological Data -algae -inverts -fish

10. Top Science Findings • 5. Habitat • RTH habitat types may not be richest -- at least in Southern Piedmont • -Invertebrate abundances higher on riffles but overall species richness higher • on snags (based on 10 site comparison) • Episamic diatom communities higher species richness than snags (based on 30 site • comparison) • -Habitat differences not related to urbanization • 4. Water quality: • Anthropogenic chemical signature apparent at low levels of urbanization UII = 20 • -Very little initial resistance • -Insecticides more highly correlated than herbicides with UII • -SC and SPMD chemistry and bioassays strongly respond to increasing • urbanization • -Nutrient and herbicides generally elevated in the middle of gradient • 3. Hydrology • Urbanization effects on hydrology most pronounced during the fall – least during the winter • -flashiness metrics dominated

11. Top Science Findings • 2. Biological Communities • Homogenization of community composition (within groups) observed in algal, invertebrate and fish communities in response to urbanization • Changes in communities across the gradient most pronounced in invertebrate (rth), least pronounced in algae 1. Biological Communities Invertebrate communities responded most significantly to urbanization -Invert response appears to be mainly related to changes in water chemistry (pesticides/SPMD chemistry and not hydrology) [rth abundance>>8 parameters including DO,Σherbicides, diazinon and fipronil] -Fish response to urbanization less pronounced than inverts but also related to changes in water quality (field parameters/SPMD) [relative abundance>>turbidity, specific conductance] -Algae response to urbanization poor – strongly related to hydrology during the spring, significant response to nutrient chemistry

12. Key Synthesis Questions • How do we deal with the influence of agriculture on the urban gradient design? • How do we deal with issues of watershed scale on the responses to the urban gradient? • How do we compare changes in biological communities across different regions of country ? • -are they the same for algae, inverts, fish? • -do we need “common threads” at least for community reports

13. Follow-up EUSE Study? Objectives • More focused efforts based on current findings • Partner with municipalities to study effects of BMPs especially related to flow alteration, flashy stream flow, or extended low-flow duration on streams • Investigate cummulative effects of urbanization on larger river systems • Water availability for human use and ecology • Partner with universities to conduct controlled laboratory studies including use of artificial streams, in situ experimentation, or lab studies to investigate hypotheses generated by our field studies