MECKLENBURG COUNTY STREAM BIOASSESSMENT STANDARD OPERATING PROCEDURES
MECKLENBURGCOUNTY
WATER QUALITY PROGRAM
This report has been approved for release
Anthony J. Roux
Senior Environmental Specialist
Water Quality Program
Date:
Table of Contents
INTRODUCTION…………………………………………………………… 1
BENTHIC MACROINVERTEBRATE BIOASSESSMENT………………. 2
Sampling Methodologies……………………………………………. 2
Field Procedures…………………………………………………..… 4
Sampling Techniques……………………………………………….. 4
Laboratory Techniques and Data Interpretation…………………..… 5
Taxa Richness Criteria……………………………………… 6
Biotic Index Criteria………………………………………… 7
Final Bioclassification for Standard Qualitative Samples…... 7
Quality Assurance and Quality Control…………………………….. 9
FISH BIOASSESSMENTS…………………………………………………10
Sampling Methodologies……………………………………………10
Field Procedures…………………………………………………..…10
Sampling Techniques………………………………………………..11
Laboratory Techniques and Data Interpretation…………………..…11
Young-of-Year Adjustments…………………………………11
North Carolina Index of Biological Integrity………………..12
Fish Tissue Analysis…………………………………….…..15
Quality Assurance and Quality Control……………………………..15
FINAL REPORTS…………………………………………………………..16
Water Quality Status Report…………………………………………16
Fish Tissue Analysis Report…………………………………………16
REFERENCES………………………………………………………………17
APPENDIX I: Bioassessment Sampling Sites………………………………20
APPENDIX II: Bioassessment Equipment and Supplies……………………22
APPENDIX III: Stream Survey Data Sheet…………………………………24
APPENDIX IV: Macroinvertebrate Identification Sheet……………………26
APPENDIX V: Taxonomic References for Benthic Macroinvertebrates……27
Taxonomic References for Fish…………………………….34
APPENDIX VI: Tolerance Values for North Carolina Benthic Macroinvertebrates35
APPENDIX VII: Fish Identification Sheet…………………………………..58
APPENDIX VIII: Tolerance Ratings, Adult Trophic Guild and Young-of-Year
Cut-Off Lengths for Fishes of Mecklenburg County, NC.60
APPENDIX IX: Expectations of the Number of Total Species and Darter Species
Based Upon Drainage Area Size in the Catawba, Broad, New
And Yadkin River Basins……………………………………63
APPENDIX X: MecklenburgCounty Bioassessment Collection Form……...65
APPENDIX XI: Benthic Macroinvertebrate Bioassessment Samples Log…..66
APPENDIX XII: Fish Bioassessment Samples Log………………………….67
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MCWQP Stream Bioassessment Standard Operating ProceduresAugust 2008
MECKLENBURG COUNTY STREAM BIOASSESSMENT OPERATING PROCEDURES
MECKLENBURGCOUNTY
WATER AND LAND RESOURCES
WATER QUALITY PROGRAM
JANUARY 1994
REVISED JULY 2000, 2003, 2005, 2006, 2007, 2008
INTRODUCTION
Stream water quality assessments generally consist of measuring physical and chemical parameters from a single grab sample taken from a specified site on a weekly or monthly basis. The North Carolina Department of Environment and Natural Resources (NCDENR) (1986, 2006a) pointed out that relying strictly on chemical monitoring is not sufficient for detecting trends in water quality. A spill event or small, but significant, changes in water quality may be undetected by either the timing of the sampling or the type of chemical tests conducted. The chemical analysis required to screen for complex pollutants is generally not feasible for ambient monitoring due to costs and manpower. Duda et al. (1982) demonstrated that routine chemical analysis of water samples was not adequate in explaining the serious aquatic biological problems they detected in urban streams.
Several studies have supported the use of benthic macroinvertebrates and fish to monitor the water quality of streams and rivers (Cummins 1977, Penrose et al. 1980, Hocutt 1981, Karr 1981, Weiss et al. 1981, Duda et al. 1982, Hilsenhoff 1982, LaPoint et al. 1984, NCDENR 1986, Schaeffer et al. 1985, Johnson 1986, Karr et al. 1986, Hilsenhoff 1988, Lenat 1988, Waters 1995, Barbour et al. 1999). Changes in the species composition of the fish and benthic macroinvertebrate communities can reflect changes in the watershed upstream, such as recent development, or in water quality brought about by a pollution problem (Cummins 1977, Penrose et al. 1980, Karr 1981, Johnson 1986, Waters 1995, Barbour et al. 1999).
Duda et al. (1982) indicated that benthic macroinvertebrates are useful as biological water quality indicators because they are found in all types of aquatic habitats, less mobile than other groups of aquatic organisms, such as fish, and large enough to be easily collected. Ambient grab sample monitoring may regularly miss slugs of pollutants, while the benthic macroinvertebrates are exposed to everything that enters the surface waters. The benthic macroinvertebrates are sensitive to very subtle changes in water quality and have life cycles of 6 months to 2 years delaying the recovery from short-term pollution events until the next generation appears (NCDENR 1986, Barbour et al. 1999). The benthic macroinvertebrate community structure reflects the effects of pollutants that enter surface waters including any synergistic or antagonistic effects (Penrose et al. 1980, NCDENR 1986, Barbour et al. 1999), thus making them natural indicators of water quality (Duda et al. 1982, Hilsenhoff 1982, Lenat 1988, 1993). Gaufin (1973), along with Duda et al. (1982) and Hilsenhoff (1982) showed that the use of benthic macroinvertebrates provides accurate and reproducible information on the status of a stream's water quality.
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MCWQP Stream Bioassessment Standard Operating ProceduresAugust 2008
Fish communities have been shown to be good indicators of stream water quality (Hocutt 1981, Karr 1981, Fausch 1984, Karr et al. 1985, Karr et al. 1986, Leonard and Orth 1986, Miller et al. 1988, Crumby et al. 1990, Barbour et al. 1999). Like the benthic macroinvertebrates, fish are sensitive to changes in water quality. Fish community structure reflects the impacts of pollutants that enter surface waters including any synergistic or antagonistic effects (Hocutt 1981, Karr 1981, Miller et al. 1988). Also, it may be easier to report the impacts of a pollutant on stream water quality to the general public when talking in terms of fish impact.
MECKLENBURG COUNTY STREAM BIOASSESSMENT PROGRAM
The Mecklenburg County Water and Land Resources, Water Quality Program (MCWQP) (formerly known as Mecklenburg County Department of Environmental Protection (MCDEP)) has developed a STREAM BIOASSESSMENT PROGRAM to enhance the protection of the water quality of streams in the City of Charlotte and MecklenburgCounty by determining the overall water quality of the streams using biological surveys. Sampling site locations are determined by stream size and location. Bioassessment sampling sites are listed in Appendix I. In addition to ambient monitoring, bioassessment surveys can be used as a tool to determine the impact of a spill or test the effectiveness of a storm water BMP.
MCWQP has a Scientific Collection Permit and an Endangered Species Collection Permit issued by the North Carolina Wildlife Resources Commission (NCWRC). These permits, which are renewed annually, authorize MCWQP’s biological survey activities. The Endangered Species Collection Permit requires that permission be obtained from the NCWRC before any sampling be conducted in areas with endangered species. The back of the permit lists all such areas.
All benthic macroinvertebrate samples will be taken during the summer months (May to September). Fish samples may be taken throughout the year (except when the water temperature is <15C). Sampling equipment required for benthic macroinvertebrate and fish sampling is listed in Appendix II.
A.BENTHIC MACROINVERTEBRATE BIOASSESSMENTS
1.Sampling Methodologies
The benthic macroinvertebrate sampling methods to be used have been adapted from those developed by NCDENR (Lenat 1988, NCDENR 2006a). These sampling strategies involve qualitative sampling of benthic macroinvertebrates and are intended for use only in shallow, freshwater streams, usually less than 1.5 meters deep. Turbid and high water stream conditions following a rain event severely impair sampling efficiency by making some critical habitats inaccessible. An underestimation of taxa richness due to turbid high flows may lead to an incorrect assessment of water quality. If high water makes sampling conditions marginal, the sampling event will be canceled and the site will be sampled when the stream flow conditions returns to ambient conditions.
Water quality status is determined by the Taxa Richness of the three sensitive groups, Ephemeroptera, Trichoptera and Plecoptera (EPT) and the North Carolina Biotic Index (NCBI) (NC STANDARD QUALITATIVE METHOD) or by just the EPT Taxa Richness (NC EPT METHOD). A third sampling method, the Qual 4 Method, is an abbreviation of the Standard Method, which is to be used on small streams only.
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MCWQP Stream Bioassessment Standard Operating ProceduresAugust 2008
The STANDARD QUALITATIVE METHOD collection technique consists of 2 kick net samples, 3 sweep-net samples, 1 leaf-pack sample, 2 rock and/or log wash samples, 1 sand sample (using the sweep net) and visual collections. Benthic macroinvertebrates are sorted in the field using forceps and white trays, and preserved in glass vials containing 95% ethanol. The organisms are picked roughly in proportion to their abundance. It is not necessary to remove all individual specimens. Some organisms are not picked, even if found in the samples. These include colonial species (Bryozoa, Porifera), Nematoda, Collembola, semiaquatic Coleoptera, and all Hemiptera except Naucoridae, Belostomatidae, Corixidae and Nepidae. These are not picked either because abundance is difficult to quantify or because they are most often found on the water surface or on the banks and are not truly benthic. If time prohibits the sorting of samples in the field, the debris collected will be placed in vials containing 95% ethanol and sorted at a later date in the lab. The Standard Qualitative Method is used on large streams and streams impacted by a known point source, such as a wastewater treatment plant discharge.
The QUAL-4 SAMPLING METHODcollection technique is a modified version of the Standard Qualitative Method, where all organisms are picked. This method was designed to be used only in small streams, which have a Drainage Area 3 square miles. With the Qual 4 method, four samples are collected rather than ten: one kick net sample, one sweep net sample, one leaf-pack, and visuals. All benthic macroinvertebrates are sorted and preserved from the samples in the same manner as the Standard Qualitative Method. The time required for this technique is usually 2½ to 3 hours. The Qual 4 Method is more appropriate for small 1st and 2nd order streams than the Standard Qualitative Method (NCDENR 2001, 2006a), although a bioclassification cannot be assigned from Qual 4 samples.
The EPT METHOD is a further modification of the Standard Qualitative Method. Only organisms belonging to the Ephemeroptera, Trichoptera and Plecoptera groups are collected. The EPT Method collections consist of 1 kick net, 1 sweep-net, 1 leaf-pack and 1 visual sample. Field notes are made concerning the abundance of other groups, especially any pollution indicator species. The EPT Method will be used on small streams and larger streams not impacted by a known point source.
A clean, unpolluted stream, such as Gar Creek (Catawba River Basin) in northeast and Clear Creek (Yadkin River Basin) in southeast Mecklenburg County, are used as reference streams and are sampled at the same time as the other sites each year. The Standard Method is used for collecting benthic macroinvertebrates from these reference sites.
2.Field Procedures
At each sampling site a STREAM SURVEY DATA SHEET (Appendix III) is filled out. On this sheet is recorded relevant data pertaining to the sampling site, field parameters, and notes on taxa abundance, in-stream habitat, and general stream appearance. The field measurements, Conductivity, Dissolved Oxygen, Temperature and pH, are taken prior to sampling the macroinvertebrates. A photograph will be taken of the site if one is currently not on file.
All samples are labeled with the collection site name and location, date of collection and initials of collectors. The labels are placed inside each sample vial.
3.Sampling Techniques
Macroinvertebrate sampling consists of kick net, sweep-net, leaf-pack, rock/log wash, sand, and visual samples. Sampling techniques for each of these samples is described below.
Kick Net. The Kick Net is a sampling tool consisting of a double layer of flexible nylon door or window screening material between 2 poles. The kick net is generally used to sample riffle areas. At a stream site lacking riffles, kicks are taken from bank areas, macrophyte beds and root snags. Species preferring faster current velocities are collected from the riffles.
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MCWQP Stream Bioassessment Standard Operating ProceduresAugust 2008
The kick net is positioned upright on the stream bed while the area upstream is vigorously disturbed by kicking or hand stirring and scraping the substrate. The debris and organisms in the kick net are then washed down into a sieve bucket with a US Standard No. 30 mesh bottom, from which the large debris (leaves, sticks and rocks) is removed. Two kicks are taken from riffle areas. These samples will be taken from areas of differing current speeds.
Sweep Net. The Sweep Net is a long-handled triangular net. The sweep net is generally used to sample bank areas, root masses, macrophyte beds and sandy/silty areas where species that prefer lower current velocities can be found. Three samples are taken by physically disturbing an area and then passing the net through the disturbed area. The sweep net is used also used to collect macroinvertebrates such as Oligochaeta and Chironomidae from SANDY habitats. To sample sandy habitats, the sweep net is placed just downstream of the sandy habitat, which is then vigorously disturbed.
Leaf-Pack Samples. Leaf-packs are collections of leaves and sticks that can be found piled up behind rocks, woody snags or other obstructions in the stream. Three or four leaf-packs are collected and washed down into a sieve bucket and then discarded. The best leaf-packs generally consist of older leaves that have begun to break down and decay. Leaves in pool areas should not be collected.
Rock / LogWash Technique. This technique is designed to sample smaller invertebrates such as the Chironomidae. Rocks that have visible growths of periphyton, Podostemum, or moss, and logs and sticks are washed in a large plastic tub partially filled with water. A single composite sample can be made from approximately 10-15 rocks and/or logs. The wash material in the tub is poured through a fine-mesh sampler (300 micron nitex mesh placed between four or five inch PVC pipe fittings screwed together, the NCDWQ Chironomid-getter) and the water allowed to drain out. The residue is preserved in 95% ethanol by placing the fine mesh sampler into another larger container, which is half filled with ethanol.
The sample is allowed to sit for several minutes and then backwashed into a picking tray. The sampler is rinsed between sites. This field preservation method makes small chironomids and oligochaetes, as well as fast moving organisms such as baetid mayflies, more visible and easier to pick up with forceps.
Visual Search. The Visual Search is an inspection of large rocks and logs for attached macroinvertebrates. Rocks and logs in all habitats ranging from riffles to pools need to be inspected. The tops of both rocks and logs serve as specialized microhabitats for many species. Several species of caddisflies and the lepidoptera family Pyralidae build retreats in crevices on the top of rocks and logs. Stone cased caddisflies can be found on the top and sides of rocks. Decaying wood should be picked apart and inspected for macroinvertebrates. The area under loose bark will also be inspected for macroinvertebrates. The visual search should be limited to 10 minutes.
4.Laboratory Techniques and Data Interpretation
All benthic macroinvertebrates in the sample are identified to the lowest possible taxonomic level, recorded on a MACROINVERTEBRATE IDENTIFICATION SHEET (Appendix IV), and tabulated as RARE (1-2 specimens), COMMON (3-9 specimens) or ABUNDANT (10 specimens). Most organisms can be identified using a dissecting microscope, but Oligochaeta and Chironomidae must be mounted on glass slides and identified with a high-powered compound microscope. When making Chironomidae slides, no more than 4 organisms are to be placed under the same cover slip (22x22 mm size), with a maximum of 8 specimens per slide. Fewer organisms are to be mounted per cover slip if smaller cover slips are used or if large specimens are mounted. Following identification, samples are labeled and stored for future reference.
All data collected from a site (Stream Survey Data Card and macroinvertebrate identifications) are entered into a bioassessment database. Any species, such as the clam Corbicula fluminea and the Megalopteran Corydalus cornutus, that are identified and left in the field are to be noted on the laboratory bench sheet has having been identified In Situ. The following statistics are calculated for each Standard Qualitative Method sample following the procedures and criteria developed by NCDENR (Lenat 1988, Eaton and Lenat 1991, Lenat 1993, NCDENR 2006a): Total Taxa Richness, EPT Taxa Richness, Biotic Index Value (Total Sample), EPT Biotic Index Value and EPT Abundance. The Total Taxa Richness and Biotic Index value statistics will not be generated for EPT Method samples.
The Qual 4 method is used only for very small streams. NCDWQ has not developed criteria for these small streams. Only EPT taxa richness values are used to determine biological impairment. A Not Impaired rating is given if the stream would receive a bioclassification of Good-Fair or better using NCDWQ EPT criteria developed for larger streams (Table 1). Small streams that would have a minimum bioclassification of Fair or Poor continue to be Not Rated.
Note that prior to the year 2000, Chironomidae were collected but not identified. Therefore, Total Taxa Richness and Biotic Index Value (Total Sample) were not calculated prior to the year 2000. Beginning with samples collected in the year 2000, all Chironomidae will be identified and all statistics will then be calculated.
a.Taxa Richness Criteria
Taxa richness is the simplest measure of diversity. The NCDENR taxa richness criteria are based on the association of good water quality with high taxa richness. The more sensitive species are gradually eliminated with increasing levels of pollution resulting in decreasing taxa richness values.
Total taxa richness (ST) and taxa richness for Ephemeroptera + Trichoptera + Plecoptera (SEPT) are calculated and the SEPT is used to assign a biological classification to each sample (Excellent, Good, Good/Fair, Fair and Poor). Bioclassification criteria developed by NCDENR (2006a) for EPT taxa richness values for the North Carolina Piedmont for the EPT sampling method is listed in Table 1. For Standard Qualitative samples, the EPT criteria are not directly used to assign bioclassifications because new criteria using borderline criteria were developed by NCDENR (2006a) (see Table 2). EPT Method samples are scored solely on EPT taxa richness.