Aquatic Macroinvertebrates as Indicators of Water Quality in the Salt and Verde Rivers

Aquatic Macroinvertebrates as Indicators of Water Quality in the Salt and Verde Rivers

Biocriteria and Bioassessment Bioassessments provide integrated evaluations of water quality. They can identify impairments of aquatic life from contamination of the water column and sediments from known or unregulated chemicals, non-chemical impacts, and altered physical habitat.

Resident biota can function as continual monitors of biological integrity, increasing the likelihood of detecting the effects of episodic events, toxic non-point source pollution, cumulative pollution, or other impacts that chemical monitoring alone is unlikely to detect.

Biocriteria can be used to assess to what extent current regulations are protecting designated and/or existing aquatic life uses.

Multimetric Indices to Prepare and Analyze Biological Data Multimetric indices combine indicators, or metrics, into a single index value. Each metric is tested and calibrated to a scale and transformed into a unitless score prior to being aggregated into a multimetric index. Both the index, and the scale, are useful in diagnosing ecological condition.

Indices of Biotic Integrity Calculated for Arizona s perennial, wadeable streams (Patti Spindler, ADEQ). Clustered into cold and warm water designations instead of ecoregions.

Warmwater metrics for Arizona as derived from reference streams. Metric Total taxa Trichoptera taxa Ephemeroptera taxa Diptera taxa Scraper taxa % Scraper % Ephemeroptera % Dominant taxa Hilsenhoff Biotic Index Metric Threshold Value 34 8.0 7.0 9.0 7.0 25.1 70.8 20.9 4.9

Index of Biotic Integrity assessment scores (warmwater) Exceptional Good Fair/Impaired Poor/Very Impaired 73-100 53-72` 27-52 0-26

Site Scores Salt1 (Salta bove Roosevelt): 60 good Salt2 (Salt below Stewart Mtn. Dam): 22 very impaired Salt3 (Salt at Phon D. Sutton): 29 impaired V1 (Verde at Sheep Bridge): 88 exceptional V2 (Verde below Horseshoe): 41 fair impaired V3 (Verde below Bartlett Dam): 25 poor very impaired V4 (Verde at Beeline Hwy.): 34 fair impaired

Reservoir Effect on Stream Biota Mean(IBI Score) 80 70 60 50 40 30 20 10 0 Above Below

Why? Regulated flows below the reservoirs lack of the right type and amount of disturbance needed for diversity.

Intermediate Disturbance Hypothesis Suggests that the greatest biodiversity is maintained by disturbances of intermediate severity or frequency. Very mild or rare disturbances allow competitive exclusion and produce low species diversity. Very frequent or catastrophic disturbances cause local mass extinction and again, produce low species diversity.

Intermediate disturbance, as is typically seen in unregulated streams/rivers, neither cause extinction or allow competitive exclusion. They do prevent dominant competitors from increasing to shutout levels. Thus, intermediate disturbances tend to maintain species diversity.

Oneway Analysis of Tolerance By Site 11 9 Tolerance 7 5 3 1-1 SALT1 SALT2 SALT3 V1 V2 V3 V4 Site Oneway Anova Analysis of Variance Source DF Sum of Squares Mean Square F Ratio Prob > F Site 6 43.76029 7.29338 2.9548 0.0079 Error 364 898.46074 2.46830 C. Total 370 942.22102 Means for Oneway Anova Level Number Mean Std Error Lower 95% SALT1 SALT2 SALT3 V1 V2 V3 V4 74 69 53 42 35 46 52 6.50000 6.97101 7.09434 5.95238 6.42857 6.60870 6.86538 0.18263 0.18914 0.21580 0.24242 0.26556 0.23164 0.21787 6.1408 6.5991 6.6700 5.4757 5.9063 6.1532 6.4369 Std Error uses a pooled estimate of error variance Upper 95% 6.8592 7.3430 7.5187 6.4291 6.9508 7.0642 7.2938

------ Ancylidae Astacidae Baetidae Belostomatidae Calopterygidae Candoniidae Capniidae Carabidae Centropagidae Ceratopogonidae Chironomidae Coenagrionidae Corbiculidae Corixidae Corydalidae Curculionidae Cypridae Cypridopsidae Daphniidae Dolichopodidae Dorylaimidae Dryopidae Dytiscidae Elmidae Empididae Eremaeidae Erpobdellidae Eylaidae Gerridae Glossosomatidae Gomphidae Haliplidae Helicopsychidae Hydrachnidae Hydridae Hydrobiidae Hydrodromidae Hydrophilidae Hydropsychidae Hydroptilidae Hydroscaphidae Hypogastruridae Leptoceridae Leptophlebiidae Libellulidae Libertiidae Limnaeidae Limnocharidae Lumbriculidae Lymnaeidae Macroveliidae Naucoridae Nemouridae Stratiomyidae Sysiridae Tabanidae Talitridae Tanyderidae Temoridae Tipulidae Tricorythidae Tubificidae Veliidae cyclorrhaphous brachycera 20 40 60 Invert Family Distributions Odontoceridae Philopotamidae Physidae Planariidae Planorbidae Psychodidae Pyralidae Simuliidae Sperchontidae Sphaeridae

Questions?