Macroinvertebrates

1
Macroinvertebrates

• Why study macroinvertebrates?

2
Macroinvertebrates

• Small animals without a backbone that can be seen
  with the naked eye. They live in and around
  aquatic environments.
• Include all life stages (e.g. larvae)
• Biodeverse e.g., snails, worms, leeches used
  to determine biodiversity

3
Define Habitats

• Map your site
• Define types of macroinvertebrate habitats
• Streams Pools, riffles, runs snags
• Ponds/lakes substrates, shade
• Determine protocol based on habitat
• Rocky substrates in running water
• Multi habitat submersed vegetation, vegetated
  banks/snags, muddy bottoms, gravel and sand

4
Types of sampling habitats
Running water pools, runs and riffles Submersed
vegetation Vegetated Banks, snags, logs and
roots Muddy Bottom Gravel and sand
5
Riffles, Runs Pools
Pool deeper and slow moving water
Run between pool and riffle
Riffle shallow area with fast moving water
6
Different substrates
Sand and gravel
Muddy bottom
Rocky
Vegetated banks
7
Emergent Vegetation
Snag
Emergent vegetation
8
When How to sample

• Only sample every 6 months
• Sampling moves the substrate around disturbs
  the area. Site recovery after sampling is gt 2
  months
• Replace rocks, etc. so minimal site disturbance
  (particularly in semi-arid environments)

9
Equipment
Quadrat PVC square
1 m
Kick net
1 m
D-net
10
Rocky substrates in running water

• Select 3 sites riffles preferred
• Collect water sample, sieve through 0.5 mm net.
• Wash net off discard water downstream of site
• Place 1 m x 1m quadrat on bottom, alligned with
  flow 2 students hold kick net on downstream
  site
• Students overturn rocks substrates inside
  quadrat scrape
• Students then disturb sample area for 3 min.
• Rinse organisms from net to bucket

11
Vegetated Banks

• Submerge D-net into water, move into vegetation
  or around snags and logs heading towards the
  bottom
• Bounce net on sediments twice
• Lift up net
• Put sample into a bucket in the shade

12
Muddy Bottom

• Place quadrat into sediments
• Place D-net along one side of the quadrat
  (downstream side). Lower it 4 cm into sediments.
• Move the net over the entire 1x1 m square
• Squish net in water to remove sediments
• Put sample into bucket
• For gravel and sand use a shovel to put 4 cm
  of substrate into net

13
Multi-Habitat

• Pick sampling sites logs, sand, vegetation
• Collect a total of 20 samples moving upstream as
  sample
• Use quadrat for sampling mud, sand, gravel
• Sort

14
Sorting, Identifying and Counting
Pick out organisms from bucket place in tray If
water is clear, pour sample directly into
tray Wash off sticks discard Sort into taxon
using identification key count
15
Sub-Sampling gt 100 individuals
4 cm x 4 cm
Determine number of squares to sample 4 x 7 28
squares 20 x 28 5.6 count number in 6
random squares Multiply number by 5 to obtain
total number