Biological Properties • Biological attributes of a waterway can be important indicators of water quality. Biological attributes refer to the number and types of organisms that inhabit a waterway. The poorer the quality of water, the fewer the number and types of organisms that can live in it.
Benthic Macroinvertebrates (bottom-dwelling)(animals w/o backbones visible to naked eye) Hydropsyche sp. (Caddisfly larva) Heptageniidae sp. (Mayfly larva) Perlodidae sp. (Stonefly larva) • Great candidates for biological monitoring…
Macroinvertebrates as Indicators • Limited migration patterns–good indicators of localized conditions and site-specific impacts Easy to sample and identify • Broad range of habitat requirements and sensitivities to pollution
The Tolerance Index0 - 10 0 10 most pollution sensitive e.g. Stoneflies most pollution tolerant e.g. Midges & Leeches contain hemoglobin, tolerate lower DO, prefer soft substrate, less sensitive to toxins require high DO, clear water, rocky cobble substrate
Stonefly Water Penny Beetle Mayfly Dobsonfly Alderfly Mussel Snipe Fly Riffle Beetle Macroinvertebrates as Indicators Pollution Sensitive (“Clean Water”) Benthos
Macroinvertebrates as Indicators Blackfly Caddisfly Isopod Cranefly Somewhat Pollution Tolerant Benthos Damselfly Dragonfly Crayfish Amphipod
Macroinvertebrates as Indicators Pollution Tolerant (“Polluted Water”) Benthos Pouch Snail Midgefly Worm Leech