Habitat and Biota
Habitat quality, macroinvertebrates, birds, and amphibians are also used to provide indicators of the health of the stream. Students evaluate thet quality of the habitat and collect and identify invertebrates in the spring, summer, and fall. Students survey birds and amphibians with the help of their teachers and volunteer experts in the spring or early summer. The data, including graphed summaries, is available as excel spreadsheets.
Riparian Habitat
Based on the EPA’s Stream Habitat Walk, the Lower Fox River Watershed Monitoring Program employs an easy-to-use approach for identifying the elements of a stream's habitat. Primarily a qualitative visual assessment, the habitat walk identifies potential water quality issues and allows observers to quickly become acquainted with their stream.
For the habitat walk, the stream is evaluated by its physical in-stream characteristics, local watershed integrity, visual biological observations, and an optional macroinvertebrate survey. Assessed in-stream characteristics include substrate composition, water appearance and odor, channel morphology, vegetation, and bank conditions. The local watershed is examined for types of land use present, and whether particular uses are impacting the stream water quality. Biological characterization includes the stream’s wildlife, fish, aquatic plants, and algae growth. Finally, an optional macroinvertebrate survey identifies basic invertebrates present and their relative abundance.
Benthic Macroinvertebrates
The benthic (bottom-dwelling) macroinvertebrates supported by a stream are a great indicator of overall stream health due to their variable tolerance of pollution. Generally speaking, mayflies (Ephemeroptera), stoneflies (Plecoptera), caddisflies (Trichoptera), and riffle beetle larvae (Coleoptera) require a relatively pristine environment. Macroinvertebrates highly tolerant of pollution include midge larvae (Diptera), snails (Gastropoda), leeches (Hirundinea), and aquatic worms (Oligochaeta). Organisms such as scuds (Amphipoda), clams (Bivalvia), crayfish (Decapoda), cranefly larvae (Diptera), and aquatic sowbugs (Isopoda), are somewhat tolerant, and are found in a wide variety of water conditions.
Because macroinvertebrates are relatively immobile as compared to other aquatic organisms, they provide a quick snapshot of the condition of their surrounding habitat and the state of the stream’s food web. Macroinvertebrate samples are best taken from within a riffle because the increased level of dissolved oxygen available generally provides the most diverse population of the stream organisms. High diversity and numbers of macroinvertebrates indicate good water quality conditions, whereas presence of only pollution tolerant species or absence of macroinvertebrates suggests a degraded environment. Because naturally occurring coldwater and warmwater streams support different species of macroinvertebrates, researchers should not attempt to compare data from these two types of streams to each other in determining stream health.
Birds and Amphibians
In order to assess the biodiversity of the riparian community, bird and amphibian surveys are being performed as part of the LFRWMP. At a minimum of 10 stations along the riparian corridor, 10-minute bird counts are conducted on June mornings at daybreak to determine what species are using the habitat. Amphibian surveys are planned for three occasions in the spring as determined by overnight temperatures. Survey one occurs when overnight temperatures reach 41°F, survey two at 50°F, and survey three at 63°F. The time frame for amphibian surveys is from one-half hour after sunset to midnight. Audio CDs with detailed species’ calls provide the training for both the bird and amphibian assessments.