Transcript DATA COLLECTION METHODS FOR NUTRIENTS IN TEXAS …

DATA COLLECTION METHODS FOR
NUTRIENTS IN TEXAS STREAMS
Evaluation of Periphyton Abundance
Joint Project
In cooperation with the TCEQ Water Quality
Standards Program
Project Team
TCEQ
Water Quality
Standards Program
Texas AgriLife Research
PROJECT MANAGER
Contract
Management
Data
Collection
Support
PARSONS PROJECT MANAGER
Water Quality
Monitoring &
Assessment
Support
QAP
Development
Report
Preparation
TIAER PROJECT MANAGER0
GIS & Data
Management
Water Quality
Monitoring &
Assessment
Lead
Laboratory
Analysis
Data
QA/QC
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
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
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
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. 2002. Revised Protocols for Sampling Algal, Invertebrate, and
Fish Communities as Part of the National Water-Quality Assessment
Program. U.S. Geological Survey.
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)
Quantitative Scrape Method
Scrape designated number of samples for
composite based on substrate
Gravel (epilithic habitat)
Cobble (epilithic habitat)
Woody Snag (epidendric habitat)
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
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)
Quantitative Scrape Method
Laboratory Analysis • Ash Free Dry Matter (AFDM) and
Chlorophyll-a (CHLA)
• Results calculated in grams per square
centimeter (g/cm2) based on field
measurements of area and volume sampled
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. 1999. Rapid
Bioassessment Protocols for Use in Streams and Wadeable Rivers:
Periphyton, Benthic Macroinvertebrates and Fish, Second Edition. EPA 841B-99-002. U.S. Environmental Protection Agency; Office of Water;
Washington, D.C.
Viewing Bucket Method
Uses a 5 gallon plastic bucket with a transparent
bottom that contains a fixed grid of 50 dots
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)
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.
2001. Stream Algae, Invertebrate, and Environmental Sampling Associated
with Biological Water Quality Assessments: Field Protocols. Utah State
University.
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
Transect Method
Document:
• Percent coverage of moss
• Percent coverage of macroalgae
• Estimate of micro-algae thickness
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. 1993.
Study of Algae Growth in the Upper Brushy Creek Watershed.
Photo/Grid Method
Photos taken
• Upstream and downstream views
• 5 representative locations with 1 square meter
(m2) grid
Photo/Grid Method
Percent coverage of algae estimated from photos
Thickness and length of algae also recorded
Additional Parameters
• Flow
• Water samples analyzed for:
 CHLA & Pheophytin-a
 Total NO2-N+NO3-N
 Total Phosphorus (TP)
 Total Kjeldahl Nitrogen (TKN)
• Habitat Assessment (year 1)
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 (2001-2007)
Monitoring
Stations
Historical TKN Concentrations
Historical TP Concentrations
Historical CHLA Concentrations
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
Year 1 Results
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
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
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
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
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)
+
Year 1 Results
Transect vs Quantitative Scrape Method
Correlation Analysis
ln(CHLA)
ln(AFDM)
+
+
+
+
ln(Moss)
ln(Macroalgae)
ln(Microalgae)
ln(Moss+Microalgae+
Macroalgae)
Year 1 Results
Photo/Grid vs Quantitative Scrape Method
Correlation Analysis
ln(Trace)
ln(Felt)
ln(Mats)
ln(Trace+Felt+Mats)
ln(CHLA)
ln(AFDM)
Project Objective 1 – Year 2
Evaluate relation of selected SemiQuantitative 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
Project Objective 2 – Year 2
Evaluate relationships of periphyton
abundance to:
• Instream Water Quality
• Habitat Parameters
Year 2 Results
Year 2 - Transect vs Quantitative Scrape
Method
Correlation Analysis
ln(CHLA)
ln(AFDM)
ln(Macroalgae, score)
+
+
ln(Microalgae, score)
+
+
ln(Moss+Microalgae+
Macroalgae, score)
+
+
ln(Maximum Macroalgae
Length, mm)
+
+
ln(Moss, score)
Correlation with Instream Water Quality
Scrape Method
Transect Method
ln(Moss ln(Max+ Micro- imum
ln(Macro ln(Micro
Instream ln(CHLA, ln(AFDM, ln(Moss,
algae + Macro-algae, -algae,
2
2
Water Quality mg/cm ) mg/cm ) score)
Macro- algae
score) score)
algae, Length,
score)
mm)
ln(Stream
CHLA, µg/L)
-
-
ln(TKN, mg/L)
-
-
-
-
-
ln(DO, mg/L)
+
+
+
+
+
pH (standard
units)
-
Scrape Method & Habitat Parameters
Scrape Method
Habitat Parameter
Avg. % of Substrate
Gravel Size or Larger
Transect Method
ln(Moss +
ln(Macro- ln(Microln(Maximum
ln(CHLA, ln(AFDM,
Micro-algae +
algae,
algae,
Macroalgae
mg/cm2) mg/cm2)
Macro-algae,
score)
score)
Length, mm)
score)
+
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)
+
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)
SEM with Scrape Method - CHLA
SEM with Scrape Method - AFDM
SEM with Transect Results - Macroalgae
SEM with Transect Results - Microalgae
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
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
Thank You
Questions?