Who Lives in the Water?
Students explore diversity and adaptation to aquatic environments by observing aquatic macroinvertebrates using the Virtual Macroinvertebrates Identification Program.
Purpose: To investigate observe and quantify macroinvertebrates through observation and charting.
Summary:
In this exercise, students will, using, the Virtual Macroinvertebrate Program, observe macroinvertebrates. They will record and summarize and interpret their findings.
Background:
Aquatic macroinvertebrates (insects and other organisms that live in streams and ponds) display a wide range of adaptations to different aquatic conditions. Some types of macroinvertebrates are extremely tolerant of changes in temperature,
flow, food, or even the presence of pollutants, while other types are so sensitive to these changes that they may die or move to other areas. In this activity, students identify the macroinvertebrates in a stream using the Virtual
Macroinvertebrate Identification Program noting which types are most abundant.
Materials:
Macroinvertebrate Tally sheet
Macroinvertebrate Pollution Sensitivities
Guide to Macroinvertebrates
Macroinvertebrate Survey and Assessment
Documents: Biological Monitoring, Stream Side Science User’s Manual
Presentations: Biological Monitoring, Who Lives in the Water.
Introduction:
Macroinvertebrates are organisms that have no backbone and are visible to the naked eye. Macroinvertebrates live their lives mostly in the water. All macroinvertebrates start their lives in the water.
Each macroinvertebrate has its own pollution tolerance. The classes of macroinvertebrates are low pollution tolerant, somewhat pollution tolerant, and high pollution tolerant (Primbas, 2005).
Macroinvertebrates that are low pollution tolerant are caddisflies, water pennies, stoneflies, and mayflies.
Somewhat pollution tolerant macroinvertebrates are dragonflies, craneflies, and damselflies.
High pollution tolerant macroinvertebrates are blackflies, aquatic worms, and midges (Primbas, 2005)
Biotic index values of macroinvertebrates can be used to determine the water quality. The Hillsenhoff’s biotic index scale ranges from one to ten.
An average biotic index values ranges from 1 to 3.75 the water quality is considered excellent.
An average biotic index values from 3.76 to 5 infer good water quality
An average biotic index values from 5.1 to 6.5 infer fair water quality
An average biotic index values from 6.6 to 10.9 infer poor water quality. (Faulds, Murray, & Neville, n.d.)
Macroinvertebrates have different preferred habitats based on the water quality they need to survive:
Riffles
Stagnant
Pools
Undercut Banks