Aquatic Macroinvertebrates Lab

Using population sizes to assess the health of the environment

Water Stream Trays

BellworkHAVE SLATE, MARKER, & ERASER ON DESK!

1. Draw a simple food chain with a SHARK at the top. Label the producer, primary consumer, secondary consumer, and the tertiary consumer. (at least 4 organisms)

2. If the shark species in your food chain suddenly became endangered, give 3 possible reasons for this?

Why estimate population sizes?• List as many reasons as you can think ofHunting Permits

Endangered Species

Assess impact of Disasters, Disease,

Climate Change

Assess health of environment

To learn!

Why estimate population sizes?

Assess impact of Disasters, Disease,

Climate Change

To learn!

Assess health of environment

…look @ pollution levels using aquatic macroinvertebrates!

Where do we have running water in Arizona?

FWHS

Madera Canyon

Madera Canyon Bugs• May carefully pick up &

observe grasshoppers

• Make observations on slate- why would we use aquatic bugs instead of land bugs to assess health of the environment?

https://www.youtube.com/watch?v=3zivEx4oRQ4

How can you determine the health of an environment using

population numbers?Talk to your neighbor. Be ready to share.

Aquatic Macroinvertebrates & Water Quality Notes

What is an Aquatic Macroinvertebrate?

• Aquatic = live in water• Macro = can see w/out microscope• Invertebrate = no backbone

Why are Aquatic Macroinvertebrates good for

assessing environmental health?

They live near bottom of stream or lake, don’t move far, can’t escape pollution

Aquatic Macroinvertebrates react differently

• Intolerant macroinverts may die in polluted water

• Only see large populations in healthy streams & lakes

• Label these species with a on your sheet (= less pollution)

Mayflies

Stoneflies

Caddisflies

Aquatic Macroinvertebrates react differently

• Tolerant macroinverts inhabit spaces vacated by the others that died

• Large populations in polluted streams & lakes

• Label species these with a on your sheet (= polluted)

Midges

Tubifex Worms

Pouch Snails

Today’s ActivityYou will have 8 seconds at your water station to collect as many aquatic macroinvertebrates as possible (goal = 100+)

Sort bugs as a whole group

Fill in data table for # organisms in each group

Percent composition calculation practice

13 midges7 dobsonflies5 craneflies------Total =

13 / 25 = 0.52 >>> 52%28%20%

Total = 25

At your table• Materials person- clean all petri dishes &

sprinkle new soil on top to hide items

• Jefe- announce stream # & you are the head mathematician

• Recorder- make sure everyone writes down the correct stream # and % on their sheet

• Presenter- be ready to share data

Assess the water quality from your stream Jefe read instructions & get group started on

Data Table 2

6 If my group found 6 stoneflies, is this

what I write in data table 2?

Assess the water quality from your stream Jefe read instructions & get group started on

Data Table 2

2

8

Add all group scores to get

TOTAL

Recorder- Add water quality score

& assessment to board when

finished!

You can double check water quality with EPT/Midge ratio

Generally speaking, the more EPTs you have, the better the water quality

Mayflies (Ephemeroptera)Stoneflies(Plecoptera)Caddisflies (Trichoptera)

Mayflies

Stoneflies

Caddisflies

You can also assess water quality with EPT/Midge ratio

The more midges you have…the lower the water quality

Midges (Chironomidae)

Midges

EPT/Midge Ratio (on back of sheet)Mayflies (Ephemeroptera) = ____Stoneflies(Plecoptera) = ____Caddisflies (Trichoptera) = ____

Total EPT = ____

Ratio: Total EPT / Midges = _____

Higher ratios # = better water quality

Closure- do on backAfter the BP oil spill, many people were concerned about

the extent of the damage done to the Gulf aquatic environment.

1 paragraph w/ at least 3 vocab words from today: If you were asked to determine whether the Gulf has rebounded (i.e. is healthy again), explain what steps you would take & how you would know if the aquatic environment is healthy again.