least disturbed streams - tceq...meets temporal requirements of an aquatic life monitoring event...
TRANSCRIPT
Least Disturbed StreamsStephen Curtis, TPWD River Studies
Lauren Pulliam, SWQM Central OfficeRob Cook, EPA Region 6
CWA Section 101 - ObjectiveTo restore & maintain the:
● Chemical ● Physical ● Biological integrityof the nation's waters
Comprehensive information about the biological integrity of aquatic environments needed to:
• complement the established perceptions of physical and chemical integrity
• provide a complete picture of the ecological integrity of the nation's waters.
Section 303 (c) 2 (B):…where numeric criteria are not available, States shall adopt criteria based on biological assessment methods…
Ohio comparison of biosurvey with chemical evaluation
6%
36% 58%
Chemical prediction & biosurvey agree
Chemical evaluation indicates no impairment
Biosurvey shows impairment
Biosurvey showsno impairment
Chemical evaluation indicates impairment
Value of biological information
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• What we are measuring is what we are trying to protect
• More precisely define and measure aquatic life goals
• Better assess current and potential conditions
• Quantify progress towards meeting aquatic life goals
• More effectively communicate the health of the waters to the public
Value of biological information
Strengthen Water Management Programs
Demonstrate environmental outcomes
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Why this works – basic concept
Exposure to Stressors
Biol
ogic
al C
ondi
tion
With increased human disturbance, we see the following widespread changes:
Sensitive organisms: Organisms that are sensitive to pollution are likely to die (esp. sessile).
Tolerant organisms: Organisms that are tolerant to pollution become more abundant.
Diversity: A decrease in the number of species.
Dominance: One or few kinds of organisms make up a large portion of the total.
Where to start?
• Stoddard et al. 2006 defines four types of reference conditions:• Minimally disturbed condition – condition of systems in the absence of
significant human disturbance (e.g. low level atmospheric contaminants only)
• Best attainable condition – condition that today’s sites might achieve if they were better managed
• Historical condition – condition at some point in the past (e.g. pre-intensive agriculture, pre-settlement)
• Least disturbed condition – best of today’s existing conditions (based on a set of explicit criteria defining what is “best”, which vary across regions and time)
Stoddard, J.L., Larsen, D.P., Hawkins, C.P., Johnson, R.K. and Norris, R.H., 2006. Setting expectations for the ecological condition of streams: the concept of reference condition. Ecological Applications, 16(4), pp.1267-1276.
Reference Streams
Factors considered - reference sitesUpstream, Upstream, Upstream and Instream, too• Impoundments, NPDES dischargers, spills or pollution incidents,
human density, agriculture activity, road/highway density, minimal non-point source problems, etc. Instream habitat, flow regime, etc.
Classification• To group similar things together to prevent comparison of apples to
oranges• Reduce the complexity of biological information• Improve resolution or sensitivity of biological surveys to detect impairment
(by accounting for variability among sites) ECOREGIONS
History of the Texas LDS Project• 1989 TX Water Commission publication, An
Assessment of Six Least Disturbed Unclassified Texas Streams
• “Minor water bodies have historically been grouped into a single category (unclassified waters) and provided limited protection under the general criteria of the TSWQS.”
• Of the six streams studied: 1 exceptional ALU, 4 high ALU, 1 limited ALU
History of the Texas LDS Project• 1992 TX Water Commission, TPWD, and EPA Region 6
publication, Texas Aquatic Ecoregion Project: An Assessment of Least Disturbed Streams
• Goals of the project:• Determine if significant aquatic life uses existed in small
unclassified streams• Determine if regional patterns in physical, chemical, or biological
attributes exist• Define and verify TX Ecoregions• Develop procedures for assessing aquatic life uses in Texas streams
Current LDS Project Goals• Compile all data on LDS ecoregion reference streams
• Evaluate historical LDS sites to determine if still suitable
• Evaluate candidate LDS sites to determine if they should be added to the LDS database
• Field sampling in 60-75 historical and/or candidate LDS site• Sampling complete at ~50 sites
• Sample a subset of streams more than once to provide data that meets temporal requirements of an Aquatic Life Monitoring event
Least Disturbed Ecoregion Reference Streams…
• Have little or no urban development in the watershed
• Have no major point sources of pollution
• Have no atypical sources of non-point source pollution
• Are not channelized, or have not had major physical habitat modifications
Benthic Macroinvertebrate Collection Methods
• Historical methods:• Riffles with 1 ft2 surber
sampler • Ekman grab samples of
soft bottom substrate at sites with no riffles
• Collected three replicates per site
• Mean Point Score
• Current methods:• 5 minute kicknet - RBP• Snag sampling at sites
with no riffles• Minimum of ~200
individuals collected• Index of Biotic Integrity
ER 33/35 Benthic IBI Calibration Using LDS Data
• Taxa and Composition Measures• Functional Composition• Tolerance Measures
Determine scoring criteria range for each metric using raw data percentiles
ER 33/35 Benthic IBI Calibration Using LDS Data
Physical Habitat Data Collection Methods
• Historical methods:• Watershed area and stream gradient• Flow• Instream and riparian characteristics at 5 transects along 0.5 to 1.0 km reach
• Stream width and depth• Instream cover• Substrate composition• Tree canopy• Stream bank slope, stability, vegetative cover
• Current methods:• Instream and riparian characteristics at 5-6 transects along 150-500 m reach
Fish Collection Methods• SWQM Procedures, Volume II
• Seining: minimum of 6 effective hauls• Electrofishing: minimum of 900 seconds• All available habitat within study reach• Field/lab processed specimens
Fish: Regionalized IBI AssessmentCatfish Creek @ Engling WMA, Anderson Co.Collector: Kleinsasser & Crowe August-88Metric Category Intermediate Totals for Metrics Metric Name Raw Value IBI Score
Drainage Basin Size (km2) 554Number of Fish Species 24 Number of Fish Species 24 5Number of Native Cyprinid Species 5 Number of Native Cyprinid Species 5 5Number of Benthic Invertivore Species 5 Number of Benthic Invertivore Species 5 5Number of Sunfish Species 6 Number of Sunfish Species 6 5Number of Intolerant Species 2 Number of Intolerant Species 2 3Number of Individuals as Tolerantsa 14 % of Individuals as Tolerant Speciesa 7.4 5Number of Individuals as Omnivores 4 % of Individuals as Omnivores 2.1 5Number of Individuals as Invertivores 167 % of Individuals as Invertivores 88.8 5Number of Individuals as Piscivores 17 % of Individuals as Piscivores 9.0 3Number of Individuals (Seine) 128 Number of Individuals in Sample 3Number of Individuals (Shock) 60 Number of Individuals/seine haul 14.2 3Number of Individuals in Sample 188 Number of Individuals/min electrofishing 3.85 3# of Individuals as Non-native species 0 % of Individuals as Non-native Species 0.0 5# of Individuals With Disease/Anomaly 3 % of Individuals With Disease/Anomaly 1.6 1
Index of Biotic Integrity Numeric Score: 50Aquatic Life Use: High
a Excluding Western MosquitofishThis data should be incorporated with water quality, habitat, and other available biological data to assign an overall stream score.
Ecoregions 33 & 35
Species Richness and Composition
Trophic Composition
Fish Abundance and Condition
• Calculated an IBI for each sampling event –> 7 regionalized IBIs• Compare overall IBI scores• Assess and refine individual metrics
Linam et al. 2002
Fish: Status of Reference Streams
IMPROVING
DEGRADING
Supplemental Data Analysis
• GIS Data• Land-Use Land-Cover• Point/NP Sources• Instream Barriers
• Multivariate Analyses• Benthic Macroinvertebrates• Fish Community
• Microplastics
mdpi.com
Future Plans
• A lot left to do…• Supplemental field sampling• Sample processing• Data analysis• Report writing
• Least Disturbed Streams Report• Tentative due date: August 2018• Committee meeting – develop an outline & action items
Thank You!!