What are macroinvertebrates and why should we care?
A macroinvertebrate is an insect that lives in water for part or all of its life. Did you know that the black fly, dragonfly, and crane fly begin their lives in the stream? You may also recognize the names of other residents- mayflies, caddisflies, and crayfish. Macroinvertebrates are important in understanding a complete picture of the health of a stream. Certain critters can live only in healthy water, others in water that’s ‘not bad’ to ‘meh’, and others that do not mind the living in the equivalent of a rundown motel. Things like pollution and the presence or absence of trees and shrubs affect the health of a stream.
Macroinvertebrates that need simply the best: Mayflies, caddisflies, stoneflies, dobsonflies, water pennies
Macroinvertebrates that can hang in a wide range of conditions: crayfish, craneflies, scuds, sowbugs, dragonflies
Macros that do not mind much: midges, aquatic worms, blackflies
This November, the Senior Environment Corps (SEC) sampled Phipps Run and Panther Hollow Run in Schenley Park to check out their macroinvertebrate communities. SEC volunteers have been monitoring the chemical and physical stream conditions in Schenley Park these past few months, but Fall calls for taking a closer look at stream dwelling critters.
Sampling for these stream dwelling insects in spring and autumn is critical for understanding stream health. While chemical sampling is a very important part of monitoring, it only provides a snapshot of stream conditions. Macroinvertebrates are surrounded by water day and night, and do not move very much. Their presence is much more telling of longer-term water health.
What did the SEC find? Nuthin but scuds. A scud is a macroinvertebrate related to crayfish and shrimps. It is easy to identify these little buggers after you have seen them a few times because of their classic side swimming moves.
Scuds can be found in a range of water quality conditions, including polluted waters. The biggest problem in finding so many scuds is not necessarily their stream health status, but the fact that they are the only ones living in these streams. Variety is the spice of life, and having stream critter community with one type of critter is bad news. This shows that conditions might not be so great for other critters to thrive, or that there is a lack of access/conductivity to these streams. All of the streams in Allegheny County have been impacted by development activities- roads, houses, businesses, pollution- and macroinvertebrates help to tell the story of these impacts.
What can be done?
Everyone plays a part in improving water quality
Do not dump anything down storm drains
Clean up pet waste
Do not litter
Plant trees and shrubs
Make a change in your personal care products (shampoo, hand soap)
Join a watershed group or start your own
Properly dispose of household waste and pharmaceuticals
Spread the good word!