Water Quality and

Aquatic Macroinvertebrate Diversity

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After successfully participating in this lab, you will be able to:

• Thoroughly describe a macroinvertebrate.• Understand a watershed.• Explain why bio-monitoring is important.• Describe the fluctuations in dissolved

oxygen in two different waterways.• Differentiate between photosynthesis and

cellular respiration.

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What is an Aquatic Macroinvertebrate?

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What is an Aquatic Macroinvertebrate?

• Insects, worms, snails, crayfish, other arthropods

• Live in all types of water habitats• Most have gills for absorbing oxygen• Cannot escape pollution events• Certain species are more or less tolerant of

pollution

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Many aquatic macroinverts are larval stages of terrestrial adults

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How do we collect aquatic macroinvertebrates?

Kick-seining – stretching a large net across a stream and kicking up sediments, where macroinverts live.

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Biomonitoring

• Stream biomonitoring is the study of the biological organisms present in a stream. 

• Based on what organisms are present, you can get an idea of what the water quality is like.– Species dependent – depends on number of

species of different sensitivities to pollution

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What is a Watershed?

• A watershed is the area of land where all of the water that is under it or drains off of it goes into the same place.

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CuyahogaWatershed

•Land area draining into one water body•Cuyahoga Watershed drains into Lake Erie

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Bath Nature Preserve

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Bath Creek

Lots of sunlight

Abundant plant growth

Warmer water

Mud bottom

Slow water flow

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North Fork of Yellow Creek

Shaded

Cooler water

Few aquatic plants

Fast flowing water

Rocky bottom

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Did you know?• Photosynthesis – happens during the day, and

only in plants• Cellular Respiration – happens all the time, in

ALL living things (including green plants!)

• In streams with lots of plants, the amount of oxygen increases during the day, but may drop very low at night. This means some organisms may not be able to survive in the water

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Photosynthesis

6CO2 + 6H2O + sunlight → C6H12O6 + 6O2Carbon dioxide + water + sun → organic matter + oxygen

Cellular Respiration C6H12O6 + 6O2 → 6CO2 + 6H2O + energyGlucose + oxygen → carbon dioxide + water + energy

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Which stream would have more dissolved oxygen?

Bath Creek Yellow Creek

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Which is Bath Creek?

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