Year 11 Biology/Senior Science Freshwater Aquatic Ecosystem

Fieldwork Outcomes: 1. Use scientific techniques to investigate how the distribution, diversity and numbers of plants and animals found in ecosystems are determined by biotic and abiotic factors 2. Use appropriate instruments and techniques, such as quadrats and transects to identify how each aquatic ecosystem is unique.

Name ________________________

Regatta Centre Biology Area

Detention Lake

Dipnetting

Bug ID

Plant ID and

Transects

Bird Observation

Regatta Lake

Abiotics

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STATION 1 Abiotic Factors

Factor Equipment used / Units Individual Group Class

1. Water Temperature

2. Turbidity

3. Water pH

4. Conductivity or Total Dissolved Solids (Salts)

5. Dissolved Oxygen mg/L % mg/L % mg/L %

6. Phosphate (Nutrient)

7. Light

8. Slope

9. Wind exposure (speed)

10. Water Depth Depth markers and general knowledge of lakes.

5m

11. Visual Pollution Visual Assessment. Use your eyes. There could be no pollution, a little or a lot.

12. Water Source Groundwater and run-off

Site Description:

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Use test kit to collect abiotic data for this site.

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Waterbird Counts at 10 survey sitesBird Species / Site No. Eg 1 2 3 4 5 6 7 8 9 10* Abundance Distribution

Example: Waterbird 6 2 4 3 15 41. Australian Grebe 6 3 12. Australian Wood Duck 3 8 2 4 123. Blackwinged Stilt 2 24. Dusky Moorhen 1 2 4 35. Eurasian Coot 7 12 4 126. Great Egret 1 17. Little Black Cormorant 3 2 18. Little Pied Cormorant 6 1 29. Masked Lapwing 6 4 710. Pacific Black Duck 8 9 8 611. Pelican 1 112 Purple Swamphen 4 213. White-faced Heron 1 114. Royal Spoonbill 115

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Total Abundance per Site 10

Total Species per Site 3

STATION 2 Bird Observation- Abundance and Distribution

Fill in column 10 for birds found at this site. See grey row and column for an example.

White-faced Heron

Pacific Black Duck

Australian Wood Duck Great Egret

Dusky MoorhenEurasian Coot

Pelican

Little Pied Cormorant

Purple SwamphenLittle Black Cormorant

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STATION 4 Waterbug (Invertebrate) I.D.

Complete the following:

Total number of species identified ______ Dominant species: ________________________

Possible reasons for dominance: _______________________________________________________

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STATION 3 Dipnetting - Invertebrate Data Collection

Name No. Name No. Name No.

Backswimmer

Leech Water Mite

Beetle Larvae

Water Beetle Water Treader

Caddisfly Larvae

Pond Snail Water Scorpion

Damselfly Nymph

Mayfly Nymph

Worm

Dragonfly Nymph

Water Boatman

Water Spider

Freshwater Shrimp

Tadpole Mosquito Fish

Giant Water Bug

Mosquito Larvae

Other

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1. Location: ___________________________________ 2. Date: ________________

3. Name of Ecosystem : ___________________________________________________________

4. Describe the technique used to sample the abundance of invertebrates.

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! Use the colour pictures or specimens to observe the main water plants found in this location.

STATION 5 - Plant ID and Transect

Plant Description Plant Description

A. Common Rush

Small brown flowers, green stem

G. River Clubrush

Tall green reed, bunch of brown flowers

B. Slender Knotweed

Thin leaf, white/pink small flower (all year)

H. Water Lily

The leaves are large pads. Large “pink” flowers in summer

C. Water Primrose

Dark green rounded leaf, yellow flowers (summer)

I.Ribbonweed

A submerged aquatic plant with delicate ribbon-like leaves

D. Water Couch

Similar to green grass but taller

J. Duckweed

Very small free floating oval leaves

E. Tall Spikerush

Thin round large reed with pointy top

K. Salvinia (introduced)

Floating leathery leaves, fibre root system

F. Cumbungi (Bullrush)

Tall flat reed, fairy floss seeds (summer)

L. __________________

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Measuring vegetation distribution and abundance - Belt Transect

Complete transect using plant letters above and depth measurements (use dots and join on graph)

Depth(cm)

0 Water Level

30

60

90

120

0 1 2 3 4 5 6 7 8

Distance from bank in metres (a quadrant is placed at one metre intervals)

Quadrat size ____________ cm Quadrat Interval _________metre/s

Biotic Factor - Vegetation

% of the plant in each quadrat1 2 3 4 5 6 7 8 9 10

A. Common Rush

B. Slender Knotweed

C. Water Primrose

D. Water Couch

E. Tall Spikerush

F. Cumbungi (Bullrush)

G. River Clubrush

H. Water Lily

I. Ribbonweed

J. Duckweed

K. Salvinia (introduced)

L.

Abiotic - Water Depth (cm)

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Trophic Orders - Name the order and the examples show.

Adaptations  Fill in the missing words to complete the plants and animal adaptations:

Tall   Spike   Rush   is   hollow   and   uses   _____________________   to   in/late   its  stem   and   remain   upright.   This   provides   maximum   surface   area   for  sunlight   absorption/   photosynthesis   and   /lotation.   Its   /lower   and    _______________________  is  right  at  the  top  so  it  has  maximum  exposure  to  wind  and  open  water.  It  also  clumps  to  aid  in  protection  from  wind  and  currents.    

 

Dragon6ly    Nymph • Has  an  extendable   lower  __________  to  grasp  its  prey  at  a  (200th  of  a      second  –  fastest  of  any  living  thing.)    • Strong  legs  for  grasping  reeds  and  assisting  in  swimming.    • Internal   ___________   that   double   as   a   form   of   locomotion   when  required  (acts  like  a  jet  propulsion).    • Compound  ___________________  for  better  /ield  of  view.    • Colouration/camou/lage   to   disguise   themselves   amongst   the  detritus.  

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             CONCLUSION/WRAP  UP

Key  Points  &  Relationships:    

Temperature  and  Light • Temperature  affects  vital  biochemical  processes  within  aquatic  organisms  and  ultimately  their  survival.    

• Most  organisms  can  only  tolerate  a  narrow  temperature  range.    •  E.g.  10  -­‐  30°C  =  optimal  range  for  macro  invertebrates.    • In  warmer  water  (up  to  30°C),  the  rate  of  photosynthesis  and  plant  growth  increases.    

• Water  temperature  is  directly  dependent  on  sunlight  availability,  air  temperature  and  turbidity.    

Turbidity,  Light  and  D.O   • The   /inal   basin   has   low   turbidity   (abiotic   factor)   =   more   sunlight   (abiotic   factor)   =   more  aquatic   plants   (biotic   factor)   =   more   D.O   (abiotic   factor)   =   more   invertebrates/aquatic   life  (biotic  factor).

Note:  a  minimum  of  60%  D.O  is  essential  for  gill  breathers  such  as  dragon/ly  nymphs.  

pH    and  Conductivity/Salinity   • pH  is  a  measure  of  the  hydrogen  ion  concentration  in  water.    • Most  aquatic  organisms  can  only  survive  in  the  6-­‐9  pH  range.    

• One  water  source  is  groundwater  which  is  salty  =  higher  pH  and  conductivity.  • Conductivity/Salinity  is  the  amount  of  dissolved  salts  present  in  the  water.    • Higher  levels  =  dehydration  of  freshwater  organisms.    

Phosphate  and  Water  Source  • Phosphate  is  an  essential  nutrient  for  plant  growth.  •      More  urban  runoff  (main  water  source  for  the  lakes)  =  higher  phosphate  levels  (2+)  =  greater  risk  of  blue  green  algae  outbreaks.

Note:  A  series  of  large  detention  basins/lakes  has  been  constructed  upstream  so  that  the  plants  in   those  can  remove  excess  phosphate  (and  other   impurities)   from  the  water  prior   to   it  being  allowed  into  the  main  lakes.    

Additional  Notes:   ______________________________________________________________________________________________

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Additional  Notes:   ______________________________________________________________________________________________

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Group Average

Water Rating

Temperature O C Good: summer 20-30; autumn/spring 15-25; winter 10-20

Poor: summer >30; autumn and spring <15 or >25; winter >20

Turbidity NTU Excellent: <10

Fair: 21-30

Good: 11-20

Poor: >30

pH Excellent: 6.5 - 8.5 Good: 5.0 - 6.4 OR 8.6 - 9.0

Poor: < 5 (acidic) OR >9 (alkaline)

Conductivity ppm Excellent: < 500

Fair: 501 - 1,500

Good: 500 - 1000

Poor: >1,500

Dissolved Oxygen

%Good: >65 Poor: <65

Phosphate ppm Excellent: < 1

Fair: 3

Good: 1 - 2

Poor: 4

Light luxGood: 10,000+ Poor: <3,000

Depth 5 m Temperature and DO levels decrease with depth

Water Source Groundwater + run-off Groundwater brings salts and minerals

Run off brings pollution and nutrients (PO)

Abiotic Factor Results