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��A L A B A M A A & M A N D A U B U R N U N I V E R S I T I E S The Alabama Watershed Demonstration Project: Biotic Indicators ANR-1167 of Water Quality here has been serious con- important sources of water quali- certain water quality conditions. Tcern about declining water ty impairment. It is the primary When conditions change, such quality in streams and rivers source of pollution from logging as when a stream receives signif- since the 1960s. Initially, con- operations in forested water- icant nonpoint source runoff, the cerns were centered on releases sheds in the United States. abundance and distribution of of point source pollutants such animals in the affected site The traditional water quality as heavy metals, sewage, and change as well. monitoring approach has been other chemical wastes from in- to collect stream water samples Although fish and algae have dustrial and municipal origins. and analyze them in a laboratory been used in stream biomonitor- These were harmful both to for suspected physical and ing programs, benthic inverte- human and stream ecosystem chemical pollutants. Unfortun- brates are the most commonly health. For this reason, the Clean ately, because sampling and used organisms. Benthic inverte- Water Act (CWA) was enacted in analysis are expensive and be- brates are widely used as bioin- 1977 to restore and maintain cause concentrations of pollu- dicators because the chemical, physical, and bio- tants vary greatly with time and " They constitute the majority of logical integrity of the Nation s location, physical and chemical species present in streams. waters. In 1987, Section 319 of monitoring alone often cannot an amendment to the CWA detect nonpoint source pollution " The numerous species present created policy to control non- problems. often show a wide range of point source water pollution sensitivity to pollution. A biological approach to pollution that can occur from water quality monitoring bio- " They are relatively easy to sediment and pesticide runoff monitoring incorporates the sample and identify. from farms, residential areas, use of stream organisms them- construction sites, and mines. " The short life cycles and high selves as a basis for pollution High nonpoint source runoff movement of many species detection. Europeans first adopt- may change stream water color may provide reliable and ed this strategy in the early and turbidity (clarity), increase rapid evidence of the return 1900s to identify organic pollu- the amount of organic matter of favorable water quality tion in large rivers. In the United and nutrients (usually nitrogen after a pollution event. States, the use of stream organ- and phosphorus), and increase isms as biological indicators or The combined use of benthic sediment suspended in the sentinels has become wide- invertebrate bioindicators and water. Once in streams, these spread only over the last two traditional stream water quality materials separately or in combi- decades. Several agencies in- monitoring allows a comprehen- nation can seriously degrade cluding the Environmental sive means of assessing water water quality for humans and Protection Agency (EPA), the quality pollution from nonpoint aquatic life. Unlike point source Natural Resources Conservation sources within forested water- pollution, nonpoint source pol- Service (NRCS), and the U.S. sheds. lution is much more difficult to Geological Survey (USGS) now detect and control because employ biologists whose main runoff does not come from a task is to implement biomonitor- few easily identifiable sources, ing in streams and rivers across but instead stems from a number the country. The underlying con- of locations scattered across a cept of biomonitoring is simple: watershed. Nonpoint source pol- certain types of stream animals lution is among the most occur or thrive only under Visit our Web site at: www.aces.edu Mayflies (Order: What Are Benthic Ephemeroptera). These are Invertebrates? aquatic insects whose immature Benthic invertebrates are stages (nymphs) usually have small animals that live on the two or three tails (caudal fila- bottom of a pond, lake, stream, ments), flattened or fingerlike or river for at least part of their gills on the abdomen, and one lives. They inhabit tiny spaces claw at the end of each leg. between submerged stones, Nymphs may be strongly flat- within organic debris, on logs tened (Figure 1) or more cylin- and aquatic plants, or within fine drical (Figure 2). Adults are ter- Figure 3. Perlid stonefly nymph sediments (silt, clay). Techni- (Family: Perlidae). restrial, meaning they live on cally, invertebrates are animals land. that do not have backbones like Damselflies and the larger animals (vertebrates) Dragonflies (Order: Odonata). such as fishes, amphibians, rep- Immature damselflies and drag- tiles, birds, and mammals. onflies (naiads) have a modified Benthic macroinvertebrates lower lip (labium) that is often are bottom-dwelling inverte- strongly toothed and scoop- brates large enough to be seen shaped and is used as a spear with the naked eye. They are for catching prey. Damselflies usually greater than 1 mm or 1D 32 typically are slender, with large, inch long. Most species of thin gills at the end of the ab- stream macroinvertebrates are domen (Figure 4). Dragonflies Figure 1. Flattened mayfly nymph aquatic insects (see below), al- (Family: Heptageniidae). Photo cour- have more husky bodies and no though crustaceans (crayfish, tesy of Howell Daly. external gills on the abdomen sideswimmers, aquatic pillbugs), (Figure 5). Adults of both groups molluscs (snails, mussels, clams), are terrestrial. oligochaetes (earthworms, leech- es), and arachnids (aquatic mites) also occur commonly. General Guide to Aquatic Insects Found in Streams Following is a description of Figure 2. Cylindrical mayfly nymph features that may help you iden- (Family: Leptophlebiidae). Photo cour- Figure 4. Damselfly naiad (Family: tify seven of the groups (orders) tesy of Ralph Charlton. Coenagrionidae). Note the three leaf- of aquatic insects found com- like gills at the end of the abdomen. monly in streams. Consult the Stoneflies (Order: references at the end of this publication for more detailed in- Plecoptera). Stonefly nymphs often are confused with mayflies; formation on identification and they differ in that they always on the biology and ecology of have two caudal filaments (never these or other invertebrates. three), usually lack abdominal gills (some have fingerlike gills on the thorax, or midsection, at the base of each leg), and have two claws at the end of each leg Figure 5. Dragonfly naiad (Family: (Figure 3). Like mayflies, most Aeshnidae). stonefly nymphs are flattened. Adults are terrestrial. 2 Caddisflies (Order: True Flies (Order: Diptera). Beetles (Order: Trichoptera). Caddisfly imma- In terms of species, this is the Coleoptera). Larvae are ex- tures (larvae) are caterpillar-like largest and most widespread tremely variable in form, with with fleshy (whitish) abdomens, group of stream insects. Larvae bodies ranging from a slender, a dark brown head and thorax, lack legs (although they may have crescent shape (such as riffle and three pairs of well- a single, stubby projection, called beetles, Figure 11) to a highly developed legs close to the a proleg, near the head) and flattened form (such as water head. The last abdominal seg- have soft, fleshy bodies; a head pennies, Figure 12). With most ment bears a pair of fleshy ap- may or may not be present. Three aquatic insects only the imma- pendages with hooks. Larvae groups containing larvae common ture stages are aquatic and the may build and live within cases to streams are black flies (Figure adults are terrestrial or capable made from wood, leaf frag- 8), crane flies (Figure 9), and of flight. Adult beetles, however, ments, or inorganic materials midges (Figure 10). Adults are ter- are often as common in streams such as fine sand (Figure 6), or restrial and often resemble mos- as are the larvae. Adults usually they may be free living (Figure quitoes. display the typical beetlelike ap- 7). Adults are terrestrial and re- pearance small, dull-colored semble small moths. with extremely hard bodies. Figure 8. Black fly larva (Family: Simuliidae). Note the brown head and Figure 11. Riffle beetle larva, left, and single fleshy proleg. adult, right, (Family: Elmidae). Photo Figure 6. Overhead view of case- courtesy of Lara Panayotoff. building caddisfly larva inside its stony case (Family: Limnephildae). Note the head and legs emerging from the case on the right side of photograph. Figure 9. Crane fly larva (Family: Tipulidae). The swollen area on the left is a modification of the abdomen Figure 12. Water penny beetle larva that aids in movement. Photo courtesy underside, left, and upperside, right, of Lara Panayotoff. (Family: Psephenidae). Photo courtesy Figure 7. Free-living caddisfly larva of Lara Panayotoff. (Family: Hydropsychidae). Photo cour- tesy of Ken Fritz. Figure 10. Midge larva (Family : Chironomidae). Note the small yel- lowish head and single proleg on the left. 3 Dobsonflies (Order: Importance of Megaloptera). Larvae of this Reference Streams group (hellgrammites) are simi- Because streams differ by lar to caddisflies except that they many natural factors besides have long lateral projections (fil- nonpoint source pollution, it is aments) and/or gills on the ab- critical to establish a baseline or domen, strong heads with large reference condition upon which jaws (mandibles), and are usual- differences or changes in water ly larger (Figure 13). Adults are quality resulting from pollution terrestrial. Figure 14. Use of aquatic dip net to can be judged. Water chemistry collect benthic invertebrates in Coastal (e.g., whether streams drain Plains streams. Flow is from right to left of photograph. chalky limestone or more dense sandstone rocks), the nature of the stream bottom and its slope, flow regimes, amount of light, temperature, and other water- shed features can greatly affect invertebrate communities inde- pendent of human influences. For example, benthic research Figure 13. Dobsonfly larva (hellgram- on undisturbed forested water- mite; Family: Corydalidae). Note the sheds from four different eco- large head and jaws and lateral fila- regions of the southeastern ments on abdomen. Photo courtesy of Figure 15. Use of a Surber quadrat United States (Blue Ridge, George Folkerts. sampler to quantify benthic inverte- Southwestern Appalachians, How Are Benthic brates from a known area of stream Piedmont, and Coastal Plains) re- bottom (1 ft2). Flow is from left to Invertebrates Used vealed that streams from differ- right of photograph. ent ecoregions can show large, in Biomonitoring? natural differences in inverte- Invertebrates may be quanti- Typically, benthic inverte- brate communities. Total inverte- fied by species richness (number brates are sampled from streams brate and EPT richness often of unique types of invertebrates using dip nets or kick screens for may be higher in upland streams present in a sample), abundance qualitative collections (Figure 14) of the Blue Ridge or Southwest (total number of invertebrates in or quadrat samplers such as a Appalachians than in lowland a sample), relative abundance Surber or Hess sampler for more Piedmont or Coastal Plains (number of invertebrates in the precise, quantitative collections streams. This demonstrates that sample from one species relative (Figure 15). After collection, the stream invertebrates can vary ge- to another), and species diversity samples are examined either in ographically according to differ- (distribution of total individuals the field or in the laboratory. ences in natural watershed at- across species in the sample). The invertebrates are removed tributes, and measures such as One very popular biomoni- from stones and organic debris, the EPT index are useful in identified as belonging to a par- toring metric is the EPT index. recording such natural variation. This is a measure of the total ticular taxonomic group, and Thus, some measure of refer- counted. Once counted, inverte- number of species within the ence conditions that incorporates brates can be compared to sam- three most pollution-sensitive natural variation must be estab- aquatic insect orders: ples taken in the same stream lished if biomonitoring is useful but at different times, such as Ephemeroptera (mayflies), in pinpointing changes resulting before and after a suspected pol- from nonpoint source impacts in Plecoptera (stoneflies), and lutant has entered a stream. They streams. also can be compared to sam- Trichoptera (caddisflies). ples taken from two or more This index assumes that streams at approximately the streams showing high EPT rich- same time, such as from a stream ness are less likely to be polluted suspected of receiving a pollu- than are streams showing rela- tant and a nearby undisturbed tively low EPT richness in the reference stream. same region. 4 Application of References Kellogg, L. L. 1992. Save our Biomonitoring in streams monitor s guide to aquatic Alabama Streams macronivertebrates. Izaak Walton The biomonitoring approach League of America, Arlington, Virginia. described in this publication is currently being used with con- Klemm, D.J., P.A. Lewis, F. Fulk, and J.M. Lazorchak. 1990. ventional water quality sampling Macroinvertebrate field and labora- in the Alabama Watershed tory methods for evaluating the bio- Demonstration Project (AWDP). logical integrity of surface waters. This project is centered within EPA/600/4-90/030. U.S. the Sepulga River Basin (Butler, Environmental Protection Agency, Crenshaw, and Conecuh coun- Office of Modeling, Monitoring ties) in south-central Alabama. Systems, and Quality Assurance. The main objective of the AWDP Washington, D.C. is to examine if nonpoint source McCafferty, W.P. 1983. Aquatic physical, chemical, and biologi- entomology. Jones and Bartlett cal measures of water quality are Publishers, Boston, Massachusetts. related to a mixture of human Merritt, R.W. and K.W. activities within the Sepulga Cummins, editors. 1996. An intro- Basin. The biomonitoring aspect duction to the aquatic insects of of AWDP is specifically designed North America. 3rd edition. Kendall- to evaluate whether stream ben- Hunt Publishers, Dubuque, Iowa. thic invertebrate communities Resh, V.H., J.W. Feminella, and differ in watersheds showing dis- E.P. McElravy. 1990. Sampling aquatic insects. Department of similar amounts of silvicultural, Entomological Sciences and Office agricultural, or residential land of Media Services, University of use and, in turn, assess if inver- California, Berkeley, California. tebrate-based measures of water Rosenberg, D.M. and V.H. Resh, quality are useful in describing editors. 1993. Freshwater biomoni- differences in land use within toring and benthic macroinverte- watersheds of the Gulf Coastal brates. Chapman and Hall, New Plain. York, New York. Thorp, J.H., and A.P. Covich, editors. 1991. Ecology and classifica- tion of North American freshwater invertebrates. Academic Press, San Diego, California. U.S. Department of Agriculture, Soil Conservation Service (Now NRCS). 1988. Water quality indica- tors guide: surface waters. NRCS- TP-161. Washington, D.C. 5 Jack W. Feminella, Associate Professor, Biological Sciences, and Kathryn M. Flynn, Extension Forester and Coordinator, Associate Professor, Forestry, both with Auburn University For more information, call your county Extension office. Look in your telephone di- rectory under your county s name to find the number. Issued in furtherance of Cooperative Extension work in agriculture and home economics, Acts of May 8 and June 30, 1914, and other related acts, in cooperation with the U.S. Department of Agriculture. The Alabama Cooperative Extension System (Alabama A&M University and Auburn University) offers educational programs, materials, and equal opportunity employment to all people without regard to race, color, national origin, religion, ANR-1167 sex, age, veteran status, or disability. UPS, 6.5M30, New Dec 1999, ANR-1167

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