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DATA COLLECTION METHODS FOR NUTRIENTS IN TEXAS STREAMS Evaluation of Periphyton Abundance Joint Project In cooperation with the TCEQ Water Quality Standards.

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Presentation on theme: "DATA COLLECTION METHODS FOR NUTRIENTS IN TEXAS STREAMS Evaluation of Periphyton Abundance Joint Project In cooperation with the TCEQ Water Quality Standards."— Presentation transcript:

1 DATA COLLECTION METHODS FOR NUTRIENTS IN TEXAS STREAMS Evaluation of Periphyton Abundance Joint Project In cooperation with the TCEQ Water Quality Standards Program

2 Project Team

3 Problem - Development of Nutrient Criteria for Streams Chlorophyll-a Measures suspended algae in the water column Often included as part of routine monitoring Good indicator of nutrient enrichment in lakes and reservoirs but generally not in streams

4 Problem - Development of Nutrient Criteria for Streams Periphyton - attached macro- and micro-algae Often a better response variable to nutrient enrichment in streams than chlorophyll-a Historical data on periphyton abundance are sparse

5 Project Purpose To evaluate four field methods for monitoring attached macroalgae and microalgae in wadeable streams Quantitative  Scrape Method Semi-Quantitative or Qualitative  Viewing Bucket Method  Transect Method  Photo/Grid Method

6 Quantitative Scrape Method Source: Derived from the USGS National Water-Quality Assessment Program (Moulton II et al., 2002) Moulton II, Stephen R., Jonathan G. Kennen, Robert M. Goldstein, and Julie A. Hambrook Revised Protocols for Sampling Algal, Invertebrate, and Fish Communities as Part of the National Water-Quality Assessment Program. U.S. Geological Survey.

7 Quantitative Scrape Method Obtain a composite sample from the richest target habitat (RTH) defined in descending priority: 1)Cobble (epilithic habitat) 2)Gravel (epilithic habitat) 3)Woody snags (epidendric habitat) 4)Macrophyte beds (epiphytic habitat)

8 Quantitative Scrape Method Scrape designated number of samples for composite based on substrate Woody Snag (epidendric habitat) Gravel (epilithic habitat) Cobble (epilithic habitat)

9 Quantitative Scrape Method Measure in the Field - Area of substrate sampled Volume of rinse water used Volume of each of two subsamples to be submitted for laboratory analysis

10 Quantitative Scrape Method Subsample Preservation - Field filtered through a 0.7 micrometer (μm) glass fiber filter Filter placed in labeled Ziploc bag and stored frozen (on dry ice)

11 Quantitative Scrape Method Laboratory Analysis - Ash Free Dry Matter (AFDM) and Chlorophyll-a (CHLA) Results calculated in grams per square centimeter (g/cm 2 ) based on field measurements of area and volume sampled

12 Viewing Bucket Method Source: Derived from the Rapid Bioassessment Protocol developed by USEPA (Barbour et al., 1999) Barbour, M.T., J. Gerritsen, B.D. Snyder, and J.B. Stribling Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers: Periphyton, Benthic Macroinvertebrates and Fish, Second Edition. EPA 841- B U.S. Environmental Protection Agency; Office of Water; Washington, D.C.

13 Viewing Bucket Method Uses a 5 gallon plastic bucket with a transparent bottom that contains a fixed grid of 50 dots

14 Viewing Bucket Method Dots characterized as: Macroalgae Microalgae Bare Also measured - Maximum length of macroalgae Thickness of microalgae (6 transects with 3 locations each totaling 18 locations per station)

15 Transect Method Source: Derived from field protocols developed by Utah State University (Hawkins, et al. 2001) Hawkins, Charles, Jeff Ostermiller, Mark Vinson, and R. Jan Stevenson Stream Algae, Invertebrate, and Environmental Sampling Associated with Biological Water Quality Assessments: Field Protocols. Utah State University.

16 Transect Method 3 diagonal transects uniformly subdivided into 6 sampling locations (total 18 locations) At each sampling point, pick up the nearest piece of substrate

17 Transect Method Document: Percent coverage of moss Percent coverage of macroalgae Estimate of micro-algae thickness

18 Photo/Grid Method Source: Derived from an algae growth study performed by Paul Price Associates, Inc. and Alan Plummer and Associates, Inc. Paul Price Associates, Inc. and Alan Plummer and Associates, Inc Study of Algae Growth in the Upper Brushy Creek Watershed.

19 Photo/Grid Method Photos taken Upstream and downstream views 5 representative locations with 1 square meter (m 2 ) grid

20 Photo/Grid Method Percent coverage of algae estimated from photos Thickness and length of algae also recorded

21 Additional Parameters Flow Water samples analyzed for:  CHLA & Pheophytin-a  Total NO 2 -N+NO 3 -N  Total Phosphorus (TP)  Total Kjeldahl Nitrogen (TKN) Habitat Assessment (year 1)

22 Project Sampling Stations 30 stations – Lower Brazos & Colorado River Basins Selected to represent a variety of water quality & substrate conditions All existing TCEQ SWQM Stations with biological data within the last assessment period ( )

23 Monitoring Stations

24 Historical TKN Concentrations

25 Historical TP Concentrations

26 Historical CHLA Concentrations

27 Project Objective – Year 1 To identify which Semi-Quantitative or Qualitative Method was best related to the Quantitative method Quantitative  Scrape Method Semi-Quantitative or Qualitative  Viewing Bucket Method  Transect Method  Photo/Grid Method

28 Year 1 Results

29 General Assessment – Scrape Method Sampling biased to RTH Can be performed in most water depths and turbidities Lots of small gear needed, onsite filtration, requires dry ice for freezing filters Gravel substrates include lots of sediment Very time intensive, needs lots of attention to detail to properly sample, field filter and record all needed information Lab analysis of samples required

30 General Assessment – Viewing Bucket Method Transects random Requires decent visibility to substrate Needs limited equipment Fairly easy and relatively quick to implement with little training Sometimes difficult keeping count of dots

31 General Assessment – Transect Method Transects random Can be performed in most water depths and turbidities Needs only a tag line for transect Simplest of 4 methods to implement

32 General Assessment – Photo/Grid Method Biased toward observed algae Requires good visibility to substrate Equipment limited, construction of PVC frame simple, camera generally standard equipment Very simple to implement, but requires documenting several photos per station and post-processing With grid, % cover might be better estimated in the field than from photos

33 Year 1 Results Viewing Bucket vs Quantitative Scrape Method Correlation Analysis ln(CHLA)ln(AFDM) ln(Macroalgae) ln(Microalgae) ln(Micro+ Macroalgae) + ln(Maximum Length Macroalgae)

34 Year 1 Results Transect vs Quantitative Scrape Method Correlation Analysis ln(CHLA)ln(AFDM) ln(Moss) ln(Macroalgae)++ ln(Microalgae) ln(Moss+Microalgae+ Macroalgae) ++

35 Year 1 Results Photo/Grid vs Quantitative Scrape Method Correlation Analysis ln(CHLA)ln(AFDM) ln(Trace) ln(Felt) ln(Mats) ln(Trace+Felt+Mats)

36 Project Objective 1 – Year 2 Evaluate relation of selected Semi- Quantitative with Qualitative Method with 2 years of data Quantitative  Scrape Method Semi-Quantitative or Qualitative  Transect Method (selected) – modified to include length of longest macroalgae

37 Project Objective 2 – Year 2 Evaluate relationships of periphyton abundance to: Instream Water Quality Habitat Parameters

38 Year 2 Results

39 Year 2 - Transect vs Quantitative Scrape Method Correlation Analysis ln(CHLA)ln(AFDM) ln(Moss, score) ln(Macroalgae, score)++ ln(Microalgae, score)++ ln(Moss+Microalgae+ Macroalgae, score) ++ ln(Maximum Macroalgae Length, mm) ++

40 Correlation with Instream Water Quality Scrape MethodTransect Method Instream Water Quality ln(CHLA, mg/cm 2 ) ln(AFDM, mg/cm 2 ) ln(Moss, score) ln(Macro -algae, score) ln(Micro -algae, score) ln(Moss + Micro- algae + Macro- algae, score) ln(Max- imum Macro- algae Length, mm) ln(Stream CHLA, µg/L) - - ln(TKN, mg/L) ln(DO, mg/L) pH (standard units) -

41 Scrape Method & Habitat Parameters Scrape MethodTransect Method Habitat Parameter ln(CHLA, mg/cm 2 ) ln(AFDM, mg/cm 2 ) ln(Macro- algae, score) ln(Micro- algae, score) ln(Moss + Micro-algae + Macro-algae, score) ln(Maximum Macroalgae Length, mm) Avg. % of Substrate Gravel Size or Larger Avg. % Instream Cover Dominant Substrate (1=clay, 2=silt, 3=sand, 4=gravel, 5=cobble, 6=boulder, 7=bedrock and 8=other) Riffles (#) Available Instream Cover (%) ++++ Bottom Substrate Stability - score 1 (unstable) to 4 (stable) +++++

42 Structural Equation Modeling (SEM) Multivariate analysis technique that includes specialized versions of other analysis methods Can be used for confirmatory or exploratory evaluation of model structure (i.e., the nature of processes potentially affecting a phenomenon)

43 SEM with Scrape Method - CHLA

44 SEM with Scrape Method - AFDM

45 SEM with Transect Results - Macroalgae

46 SEM with Transect Results - Microalgae

47 Conclusions Scrape & Transect Methods Worked well on most substrates Some problems on gravel with scrape method (Large amounts of sediment collected & high AFDM) Both methods have issues if streams are not wadeable Scrape and Transect methods positively correlated for general algal abundance

48 Conclusions Scrape & Transect Methods Algal abundance measures were more highly correlated to habitat than water quality parameters SEM implied that substrate size and light were the most influential factors on periphyton growth

49 Thank You Questions?


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