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Home My WebLink AboutUSGS(Mary Freeman)Information for EFSAB: •Stream-ecology and flow relationships based on our ACF research • Transferability of species preferences • Defensibility of ACF work in context of controversy Mary Freeman USGS Patuxent Wildlife Research Center 110 Riverbend Rd, Room 101 Athens GA 30602 mcfreeman@usgs.gov USGS Science Thrust Project: Water Availability for Ecological Needs Goal: develop a scientific basis for predicting ecological consequences of water-supply development in a river system Reservoirs Intakes GA Piedmont study: 3 year study, fishes living downstream of 27 municipal withdrawals Habitat generalist species richness not related to • Withdrawal size • Withdrawal type Freeman, M. C. and P. A. Marcinek. 2006. Fish assemblage responses to water withdrawals and water supply reservoirs in Piedmont streams. Environmental Management 38: 435-450. Permitted withdrawal (mgd) as proportion of 7Q10 flow (ln transform) Reservoirs Intakes Stream-dependent species richness declines: • With increasing withdrawal size • Below storage reservoirs Freeman, M. C. and P. A. Marcinek. 2006. Fish assemblage responses to water withdrawals and water supply reservoirs in Piedmont streams. Environmental Management 38: 435-450. Permitted withdrawal (mgd) as proportion of 7Q10 flow (ln transform) GA Piedmont study: 3 year study, fishes living downstream of 27 municipal withdrawals Lower Flint study *: Strong geomorphic effects on response of fishes to variation in base flows •Geology (Ocala limestone vs. Fall-line Hills) •Channel morphology (confined vs. unconfined) Confined Unconfined Larger streams Smaller streams Peterson et al. 2009 McCargo and Peterson 2010 * Ecological responses to changes in flow regimes? Aquatic Biota Base flowsLarge floods High-flow pulsesSmall floods Extreme low flows Flow regime components ? Aquatic Biota How do flow regime components affect biota? Variables in “flow-ecological response relations” Base flowsLarge floods High-flow pulsesSmall floods Extreme low flows Channel Condition Water quality: temperature, DO, contaminants Population processes: Survival (Persistence) Reproduction Colonization Flow regimes affect: •Transport of materials •Processes •Habitat structure, dynamics •Disturbance Historic land use, channel modification Runoff/Wastewater discharge Aquatic Biota Channel Condition Historic land use, channel modification Runoff/Wastewater discharge Flow regimes affect: •Transport of materials •Processes •Habitat structure, dynamics •Disturbance Nutrient availability Water quality: temperature, DO, contaminants Base flowsLarge floods High-flow pulsesSmall floods Extreme low flows Organic matter transport Sediment, wood delivery and transport Aquatic Biota Channel Condition Historic land use, channel modification Runoff/Wastewater discharge Flow regimes affect: •Transport of materials •Processes •Habitat structure, dynamics •Disturbance Nutrient availability Water quality: temperature, DO, contaminants Base flowsLarge floods High-flow pulsesSmall floods Extreme low flows Organic matter transport Sediment, wood delivery and transport Spawning/ Migration cues Riparian condition/ processes Biological productivity Aquatic Biota Channel Condition Historic land use, channel modification Runoff/Wastewater discharge Flow regimes affect: •Transport of materials •Processes •Habitat structure, dynamics •Disturbance Nutrient availability Water quality: temperature, DO, contaminants Base flowsLarge floods High-flow pulsesSmall floods Extreme low flows Sediment, wood delivery and transport Riparian condition/ processes Biological productivityHabitat volume, depth, velocity Spawning/ Migration cues Organic matter transport Aquatic Biota Channel Condition Historic land use, channel modification Runoff/Wastewater discharge Flow regimes affect: •Transport of materials •Processes •Habitat structure, dynamics •Disturbance Nutrient availability Water quality: temperature, DO, contaminants Base flowsLarge floods High-flow pulsesSmall floods Extreme low flows Sediment, wood delivery and transport Riparian condition/ processes Biological productivityHabitat volume, depth, velocity Organic matter transportSpawning/ Migration cues Stream Impoundment Water Withdrawal Aquatic Biota Channel Condition Historic land use, channel modification Runoff/Wastewater discharge Nutrient availability Water quality: temperature, DO, contaminants Base flowsLarge floods High-flow pulsesSmall floods Extreme low flows Sediment, wood delivery and transport Riparian condition/ processes Biological productivityHabitat volume, depth, velocity Organic matter transportSpawning/ Migration cues Land Cover Dynamics Stream Impoundment Water Withdrawal Aquatic Biota Channel Condition Historic land use, channel modification Runoff/Wastewater discharge Nutrient availability Water quality: temperature, DO, contaminants Base flowsLarge floods High-flow pulsesSmall floods Extreme low flows Sediment, wood delivery and transport Riparian condition/ processes Biological productivityHabitat volume, depth, velocity Organic matter transportSpawning/ Migration cues Reach isolation Land Cover Dynamics Climate Change Stream Impoundment Water Withdrawal Aquatic Biota Channel Condition Historic land use, channel modification Runoff/Wastewater discharge Nutrient availability Water quality: temperature, DO, contaminants Base flowsLarge floods High-flow pulsesSmall floods Extreme low flows Sediment, wood delivery and transport Riparian condition/ processes Biological productivityHabitat volume, depth, velocity Organic matter transportSpawning/ Migration cues Reach isolation Land Cover Dynamics Discharge Geomorphic channel type (habitat template) Probability a species persists, reproduces, or colonizes In a given year depends on: • Species traits • Channel type and stream size • Location in the drainage network (connectivity) • The seasonal flow regime in that year J. T. Peterson, USGS OR-CRU USGS Water Availability for Ecosystems Metapopulation response to flow variation: occupancy of stream segments Modeling results 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 Extinction Colonization ReproductionFlow characteristic Re l a t i v e s u p p o r t Median Q 10 day low Q 10 day high Q SD Q Spawning Rearing J. T. Peterson, USGS OR-CRU Seasonal time-step, metapopulation simulation of changes in fish species richness in relation to flow Flow statistics • Median seasonal Q • CV seasonal Q • Seasonal 10-d min Q • Seasonal 10-max Q • Min 10-d SD of flow -20% -18% -16% -14% -12% -10% -8% -6% -4% -2% 0% 0 10203040 Ch a n g e i n o c c u p a n c y r a t e ( % ) Daily water withdrawal (MGD) Mosquitofish Pirate perch Redbreast sunfish Grayfin redhorse Blackbanded darter Change in species-specific occupancy with increasing withdrawal levels J. T. Peterson, USGS OR-CRU Simulated stream fish responses to withdrawals in Potato Creek basin Can evaluate model outcomes sensitivity to assumptions regarding mechanisms Stream fish metapopulation model Change in species richness with increasing withdrawal levels J. T. Peterson, USGS OR-CRU -18% -16% -14% -12% -10% -8% -6% -4% -2% 0% 0 1020304050 Ch a n g e i n f i s h s p e c i e s r i c h n e s s (% ) Daily water withdrawal (MGD) Extinction: 10-d min flow Reproduction: SD of flow 10-d max flow Can evaluate model outcomes sensitivity to assumptions regarding mechanisms -18% -16% -14% -12% -10% -8% -6% -4% -2% 0% 0 1020304050 Ch a n g e i n f i s h s p e c i e s r i c h n e s s (% ) Daily water withdrawal (MGD) J. T. Peterson, USGS OR-CRU Stream fish metapopulation model Change in species richness with increasing withdrawal levels Extinction: 10-d min flow Reproduction: SD of flow 10-d max flow Extinction: Median flow Reproduction: SD of flow 10-d max flow Apalachicola-Chattahoochee-Flint basin (ACF) • 51,000 sq km • Blue Ridge, Piedmont, Coastal Plain • ca. 110 fish species (10 endemic species) • ca. 27 extant freshwater mussel species (6 federally listed) • Fine-resolution PRMS models for 6 sub-basins in 3 physiographic regions • WaterSMART activities: • Current conditions flow model • Sample fishes and mussels to estimate meta/population dynamics in differing physiographies • Update model parameters • Simulate biota responses to flow alteration scenarios WaterSMART ACF – Environmental Flows Component Fluvial- specialist species Generalist species All species Change in species richness with increasing withdrawal levels J. T. Peterson, USGS OR-CRU Simulated stream fish responses to withdrawals in Potato Creek basin Guidance for ‘environmental flows’? We can use existing data & knowledge to identify predictable ecological responses to flow alteration ◦Provide a scientific basis for developing regional environmental flow standards Arthington et al., 2006, “The challenge of providing environmental flow rules to sustain river ecosystems”, Ecological Applications 16(4), 1311-1318. Poff et al., 2010, “The ecological limits of hydrologic alteration (ELOHA): a new framework for developing regional environmental flow standards”, Freshwater Biology 55, 147-170. Start with regional hydrologic models Identify stream types expected to respond differently to flow alteration Model ecological responses to flow alteration for each stream type Use ecological models with socially-determined objectives to decide on flow requirements Monitor outcomes, improve models, repeat ◦Recent review* 165 studies, response to flow alteration 92% -> “negative ecological changes” with flow alteration But, robust, transferable quantitative relationships lacking * Poff and Zimmerman, 2010. Ecological responses to altered flow regimes: a literature review to inform the science and management of environmental flows. Freshwater Biology 55:194-205. Challenge! • Flow regime is one of many factors influencing ecological condition at a point in time • Communities are dynamic Result: Noisy “flow-ecology” data Konrad et al. 2008. Assessing streamflow characteristics as limiting factors on benthic invertebrate assemblages in streams across the western United States. Freshwater Biology 53: 1983-1998 Ephemeroptera, Plecoptera, & Trichoptera ses richness vs. CV of annual min flows Sites from 11 Western US states Challenge! Potential product of empirically-based simulation studies: • Simulated flow-ecological response curves for species groups & stream types, based on flow effects on underlying processes • Guidance for monitoring to reduce uncertainties % Change in flow component (e.g., summer minimum, spring maximum) % Change in species occurrence Environmental Management 2011 Survival negatively related to 10-d high flows during summer Recruitment positively related to spring and summer flow 5-year mark-recapture study, Sawhatchee Crk GA 3 listed mussel species Environmental Management 2011 Transferability? Question often asked in relation to flow-habitat models. 0 10 20 30 40 50 60 70 80 90 100 0 50 100 150 200 250 300 Flow, cfs 2-Dimensional model Model depth, velocity in relation to flow Do species use the same habitats in different rivers? Alabama stream fish study*: Depth/velocity/ substrate criteria transferability for fishes in Piedmont and Coastal Plain streams •Good transferability: fish species that consistently use fast-water habitats - “riffle species” e.g., Bronze darter, lipstick darter, greenbreast darter •Poor transferability: fish species not restricted to shallow, fast habitats – “pool and riffle species” e.g., Alabama shiner, speckled darter * Freeman, Bowen, Crance 1997. Transferability of habitat suitability criteria for fishes in warmwater streams. NAJFM 17:20-31. Similarly: good transferability of near-substrate hydraulic criteria for some macroinvertebrates From review by Lamaroux et al. 2010, River Research and Applications Macroinvertebrate diversity in relation to velocity, Gore et al. 2001, Regulated Rivers, Research and Management Transferability? Question also applies to estimated flow effects on populations & population processes •Hypothesized variation in flow-ecology relations among stream “types” is the basis for classification in ELOHA •Testing context-dependence* of flow-population dynamics in WaterSMART and other research System fragmentation Reach isolation Channel confinement and bed sediments Water quality * “Defensibility of the ACF work given the high degree of controversy?” • Conceptual basis supported in best scientific understanding (flow regimes influence population processes via multiple mechanisms; species persistence an outcome of local survival, reproduction, dispersal dynamics) • ELOHA and supporting studies • Metapopulation dynamics • Population viability theory • Approach allows explicit evaluation of alternative hypotheses and propagation of uncertainty in outcomes • Potential applications: • Analysis of management alternatives in specific stream systems • Derivations of relations between water management actions and biological outcomes, for differing contexts