Stream Quality Assessment Biological Monitoring
WHY Monitor Stream Quality? To determine if problems exist in our streams and rivers.
HOW do we Monitor Stream Quality? • Stream quality can be assessed by determining the kinds of animals that live within the stream (Biotic Assessment) • Other indicators may be stream odor, appearance, and surroundings (Abiotic Assessment)
Biotic Assessment • Seines may be used to collect stream inhabitants • Group members can help to dig up critters to be caught in the seine, by scraping rocks or shuffling their feet
What kind of critters do we look for? Macroinvertebrates • “Macro”= large enough to be seen with the naked eye • “Invertebrate” = without a backbone • Aquatic macroinvertebrates can be indicators of water quality
There are 3 groups of Macroinvertebrates: • Group One Taxa – pollution sensitive organisms; if these critters are present, you have little pollution in the water • Group Two Taxa – moderate pollution-tolerant; these guys may indicate that the water has some pollution, but not a lot of pollution. • Group Three Taxa – heavy pollution-tolerant; these critters may indicate very heavy pollution
Group One Taxa Pollution sensitive organisms found only in high quality water
Stonefly Nymph • 1/2” - 1 1/2” in length • 6 legs with hooked tips • Long antennae • 2 hair like tails
Mayfly Nymph • 1/4”-1” in length • 6 large hooked legs • Plate-like gills on sides of body • Many long feelers on lower half of body • Antennae • 2 to 3 long, hair-like tails
Water Penny Beetle Larvae • 1/4” in length • 6 tiny legs on bottom side of body • Flat, saucer-shaped body with raised bumps on top side of body
Gilled Snail • Shell opens on the right • Opening covered by thin plate called operculum
Caddisfly Larvae • Up to 1/2” in length • 6 hooked legs on upper third of body • 2 hooks at back end • May be found in rock, stick, or leaf case • Typically greenish colored body with dark head
Dobsonfly Larvae (Hellgrammite) • 3/4” - 4” in length • 6 legs • Many feelers on lower half of body • 4 hooks at back end • Fan shaped gill tufts on sides • Short antennae
Riffle Beetle • 1/4” in length • Oval body covered with tiny hairs • 6 legs • Antennae • Both larva and adult are commonly found in the water Adult Larva
Group Two Taxa Somewhat pollution tolerant organisms that can live in moderate quality water.
Crayfish • 1/2” - 6” in length • 8 legs • 2 large claws • Resemble small lobsters
Dragonfly Nymph • 1/2” - 2” in length • 6 hooked legs • Large eyes • Usually buried in mud or found clinging to root masses
Damselfly Nymph • 1/2” - 1” in length • 6 thin hooked legs • 3 broad oar shaped tails • Large eyes
Crane Fly Larvae • 1/3” - 2” in length • Plump caterpillar-like segmented body • Finger-like lobes at back end • Typically white in color, can be green or brown
Clam • Clams in Ohio streams come in variety of sizes, shapes, and colors according to the species.
Group Three Taxa Pollution tolerant organisms that can handle poorer water quality.
Leech • 1/4” - 2” in length • Ends with suction pads
Aquatic Worm • 1/4” - 1” in length • Look like earthworms • Can be very thin
Midge Larvae • Up to 1/4” in length • 2 legs on each side • Worm-like segmented body • Rapid squirming movement
Black Fly Larvae • Up to 1/4” in length • One end of body wider • Suction pad on larger end • Black head
Pouch Snail • Shell opens on the left • No operculum • Breathe air
HabitatWhere do you find macroinvertebrates? • Under rocks • Around tree roots • Around beds of vegetation • Around litter or other debris • In riffle zones
Streamside Habitat • Tree overhang • Roots and logs jutting into the stream • Rocks and boulders along the stream edge • Provide homes and shelter for animals
Riffle Zones • Areas where water is visibly flowing over rocks and stream bottom • Look like small rapids • The movement over the rocks allows oxygen to enter the water
pH • Indicates whether the stream is basic, acidic, or neutral • Acidic: 0-6.9 • Neutral: 7.0 • Basic: 7.1-14 • Most macroinvertebrates live best in a slightly basic pH (approx. 8) • What sorts of things can change the pH of a stream to dangerous levels?
Alkalinity • Indicates the stream’s ability to neutralize acids • If a lot of acid is needed to cause the stream’s pH, it can neutralize well. It has high alkalinity. (Good) • If the pH drops with just a little acid, the alkalinity is low. (Bad)
Dissolved Oxygen • Indicates the amount of oxygen that is dissolved in the water…necessary for plants and animals! • How does the water replenish its oxygen?
Nitrates • Form of Nitrogen (NO3) that is essential to life. • High levels of nitrates can be toxic! • Try not cleaning your fish tank for a year… • Why? Nitrogen combines with Oxygen to form nitrate (NO3). Too much Nitrogen removes too much oxygen and causes the fishies to suffocate. • Healthy Levels – 1 mg/L • Toxic Levels – 10 mg/L • Water treatment plant – 30 mg/L
Phosphates • Essential for life • Phosphorus can be dissolved or suspended • Similar to Nitrates: • High levels – toxic • Low levels – toxic • Moderate levels - healthy
Stream Flow • Choose a section of the creek. • Use a tape measure to find the width and depth of a 100 foot area. • Float a rubber ducky from one end to the other and time its flow. 100 ft. area Speed of Ducky: 100 ft. / _____sec. = _______ ft./sec. Avg. Width x Avg. Depth x ______ ft./sec. = _________ ft.3/sec. **Stream Flow**
Turbidity • Clearness or cloudiness of water. • The deeper you can see (clearer), the healthier the stream. • Equipment: Turbidity Tube
Other Stream Quality Indicators • Water appearance • Water odor • Stream bank shape • Stream bottom cover • Streamside vegetation • Land uses within the watershed • Pipes entering the stream • This is called the Qualitative Habitat Evaluation Index (QHEI)
Riparian Corridor • Streamside forests • Protects streambanks from erosion • Protects water quality by filtering out pollutants • Provides wildlife habitat
Point Source Discharges • Discharge entering a stream or river from a pipe or tile, i.e. • Agricultural field tile • Storm drains • Factory outputs • Water treatment plant outlets
Need More Information ? • Check with Ohio EPA for more specific information and expertise on setting up a water quality monitoring program, especially for chemical monitoring • Both ODNR and Ohio EPA can assist with Quality Habitat Environmental Index (QHEI)