San Juan Watershed MONITORING PROGRAM FLOW ' TRANSECT SAMPLES (1 per [junmet) ^ Surripimg puirtl ut uiich Siunaucl ueteoitxi systamiititully uftoi random start Sarripfcng points proceed iri L, C. R pattern upstream Modified D-frame kick not 1 square foot Quadrat sampled for 30 MoondB COMPOSITE SAMPLES FROM ALL TRANSECTS Serve bucket or other bucket!*) COMPOSITE AND PRESERVE SAMPLE 1 liter bottlers) (max of 4 bottles >1 pass/Ob) Fil no more than 50% with sample PrfiSHfVfi with -95% Rthanol (or h final con- cenUatoon of at least 70% :Q WHY DO WE CONDUCT BENTHIC MACROINVERTEBRATE ASSESSMENTS?1 Benthie (or "bottom-dwelling") macroinvertebrates are-small aquatic animals and larvae, including mayfly, caddis, and stonefly larvae;, as well as snails, worms, and beetles. They can be seen without a microscope- and are often found attached to rocks, vegetation, logs, and sticks or burrowed into sand and sediments- The diversity and assemblage of benthie macroinvertebrate communities can be an important indicator of health in aquatic communities, and the health of macroinvertebrate communities is strongly correlated to water quality, water chemistry, and more-. Macroinvertebrate assess- ments can also help identify important environmental stress- ors and trends in ecosystems. Macroinvertebrates tolerate Certain stressors better than others. Therefore, the make-up of the benthie community (that is, the presence or absence of certain species) can provide valuable clues about pollutants in the water. Macroinvertebrate orders including Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies) are especially sensitive to pollutants and can be important indicators of water quality. MACROINVERTEBRATE COMMUNITY STRESSORS Figure 1. Transect sample design for collecting benthie macroinvertebrates at wadeable sites. Biological condition is the most comprehensive indicator of waterbody health. Human activity or natural events can compromise waterbody health. Generally, healthy waterbodi-es can support a wide variety and high number of macroinvertebrates, including many that cannot tolerate pollution. When the biology of a waterbody is healthy, the chemical and physical components of the waterbody are also usually in good condition. However, if samples show only pollution-tolerant species, or little diversity or abundance, that may be an indicator of a less healthy waterbody. This information can be used similarly to fish populations in understanding of the biological condition of a waterbody. I Ccwntani! ALL kirA ritil wartpltm cxrflitctacl from ALL biinsnctn ------- COLLECTING SAMPLES2 Because macroinvertebrates typically live on the bottom of a river, we must first disturb them, usually by "kicking" the substrate surface upstream of our collection net. The current of the water then pushes the macroinvertebrates into the net. Under this approach, we place the mouth of the net in the same area that we disturb with the "kicking" technique. Disturbing a defined area (1 meter2) for a pre-defined period of time allows us to estimate the population of macroinvertebrates in that area. To create a composite sample, we combine samples at each transect (see Figure 1). We sample the first transect at a randomly selected left, right, or center point, then alternate the positions for the remainder of the transects. Samples are combined in a 1-liter bottle and preserved with 95 percent ethanol, which eutha- nizes the- macroinvertebrates. This eliminates the potential for larger, predatory macroinvertebrates to eat the smaller ones and affect the sample composition. SAMPLING EQUIPMENT Collecting Modified kick net :(D-frame with 500 |im Smal l spatula, spOiOn,, or scoop to transfer sample Samples mesh) and 52" handle Sample;jars, 1L HDPE plastic suitableTor use with Watch with timer or stopwatch ethanol Sieve bucket with 500 urn mesh openings 95% ethanol, in a' proper container (U.S. Sitd No:, 35) Cottjtf (with absorbent material) for transporting 5-gallon bucket ethanol and samples Watchmakers' forceps Electrical tapฎ Was:h bottle, 1L capacity labeled "STREAM Scissors WATER" Field Operations Manual or laminated Quick Funnel with large Pore spout Reference Guide Recording Composite benthic sample labels with and Soft (#2) lead pencils Measurements without preprinted sample ID numbers Fine-tip indelible markers Blank labels on waterproof paper tor Clear tape strips inside of jars Sample Gellegtipn form To learn more about benthic macroinvertebrate sampling, visit https://www.epa.gov/national-aquatic- resource-survevs/indicators-benthic-imacroinvertebrates, * LM EF'4, National Aquatic Resource Surveys, IncliHHKTS: BenthlEftlKi CTBrttfeMtes. flMHltflBlle at national-aquatic-resource-surveys/indicators-benthic-macroinvertebrates; Mountain Studies Institute. December 2017. Animas River 2017 Macroinvertebrate Assessment. Available at https://static1.squarespace.eom/static/53bc5871e4b095b6a42949b4A/5 ad4e5$98d922deflt5939dc/1523902l)fi2738/MSI &TifmssBMLfeparLJ?0'1SQ417 pdf fllS M-31*'I fetorฉ I Ftveis sgl 8tf$png A$efaSSftR?fTti fita Field Opeiatiofr$ Manufel watiesbls vetsidfi 15 Available at F iction/files/2019-05/clocuments/ri'sa_l6l9_fom_wadeable_version_1.2_0.pdf. 4>EPA EPA 841-F-21-006 United States APRIL 2021 Environmental Protection , Agency https://www.epa.gov/saniuanwatershed ------- |