NSW Water Bug Survey

Gunnedah High SchoolYear 8

Science 1 & 2 withMiss Scholberg & Miss Feodoroff

Warrumbungle EEC On behalf of the year 8 group that went down to the Namoi river on the 26th of October 2011, we would like to thank Meg Leathart; who is the principal of the Warrumbungle Environmental Education Centre. We could not have done it without her generosity with lending us her equipment and her insight on the bugs at the river.

Our Aim

-To survey the amount of bugs and what type of bug they were.-To compare the Namoi river now, to past surveys and -expeditions.-To take a sample of the pollution in the water and compare it to past tests.

Study Site

• The location of this expedition was at the Namoi River, Cohen’s Bridge, Gunnedah NSW

Equipment

• Bucket• Net• Sorting tray• Magnifying

glass• Water bug

detective guide• Field record

sheet

Personal Protection

• Gum boots or in-closed shoes

• Hat• Sunscreen• Long pants

Collecting Samples• We used the bug

detective guide to identify collected bugs.

• Then we recorded the information on the field record sheet.

Pools and runs

• Fast moving water• currents that went in

most directions• strong water flow. • The water was calmer

underneath trees and near the water banks.

Water Types and Methods• RIFFLES – Cool shallow areas of

water that have a rocky bottom with fast flowing water and multiple currents with high oxygen levels.

• METHOD – Shuffle feet into the bottom of the river and catch the bugs that come out of the dirt or place net in the flow of the fast running water and catch the bugs that follow the water.

• EDGEWATER – Emergent plants with overhanging branches, (which slightly enter the water) and roots in and around the water banks.

Identifying & Counting Samples

• To identify the bugs, use the Bug Detective Guide.

• We counted our bugs and tallied them.

• From this we went to the Pollution Index.

Results

Pollution Tolerance Bug TypeSensitivity

Rating(SR)

Number ofbugs found

(#)

WeightFactor(WF)

SR x WF

Very sensitive Mayfly nymph 9 14 4 36

Tolerant

Beetle larva 5 1 1 5

Dragonfly nymph 4 1 1 4

Water strider 4 1 1 4

Whirligig beetle & larva 4 16 4 16

Damselfly nymph 3 1 1 3

Fly larva & pupa 3 1 1 3

Freshwater mussel 3 3 2 6

Freshwater shrimp 3 12 4 12

Very tolerant

Diving beetle 2 6 3 6

Water boatman 2 44 5 10

Freshwater worm 2 1 1 2

Bloodworm 1 1 1 1

TOTALS: 102 29 108

Stream Pollution Index

What the SPI score means:

SPI Stream Quality Rating

<3 Poor

3 to 4 Fair

4 to 6 Good

>6 Excellent

We calculate the stream pollution index by Total (SR x WF)

Total WF

SPI = 108 29 = 3.7