Ecosystem Penrith Lakes

Transcription

1 Year 11 Biology Ecosystem Penrith Lakes (Population Dynamics - includes depth study modelling) Key Inuiry Question: What effect can one species have on the other species in a community? Students: investigate and determine relationships between biotic and abiotic factors in an ecosystem, including: (ACSBL019) - the impact of abiotic factors (ACSBL021, ACSBL022, ACSBL025) - the impact of biotic factors, including predation, competition and symbiotic relationships (ACSBL024) - the ecological niches occupied by species (ACSBL023) - predicting conseuences for populations in ecosystems due to predation, competition, symbiosis and disease (ACSBL019, ACSBL020) - measuring populations of organisms using sampling techniues (ACSBL003, ACSBL015) explain a recent extinction event (ACSBL024) investigate changes in past ecosystems that may inform our approach to the management of future ecosystems. investigate practices used to restore damaged ecosystems, Country or Place, e.g.: mining sites land degradation from agricultural practices Name Inuiry Question: How healthy is the Ecosystem at Penrith Lakes? Page 1 of 8

2 STATION 1 Abiotic Factors Use water testing kit to collect abiotic data for this site. Site: Final Detention Basin Conditions: Date: Time: Factor Euipment Used / Units Your small group results Average results for your group 1. Phosphate (Nutrient) - Half fill tube. Dissolve tablet. Wait 5 mins. Compare water to chart. 2. ph - (Blue box) Fill tube. 3cm of paper in tube. Wait 1 min. Compare paper to chart. Test tablet kit - ppm (Parts per million) Universal Indicator Paper - a number 3. Turbidity Turbidity Tube - NTU s (Nephelometric Turbidity Units) 4. Temperature Digital Thermometer - o C (Degrees Celsius) 5. Dissolved Oxygen - mg/l is the reading on DO meter. Use conversion chart to get % sat. 6. Conductivity or Total Dissolved Solids (Salts) 7. Light Dissolved Oxygen Meter (Milligrams per Litre) mg/l mg/l Conversion Chart - Temp, mg/l and % % % ( % saturation ) saturation saturation Total Dissolved Solids (TDS) Scan- ppm (Parts per million) Light / Lux Meter - Lux 8. Slope Clinometer - Degrees ( o ) 9. Wind exposure (speed) 10. Depth 11. Visual Pollution Anemometer - kph General knowledge of lakes. Visual Assessment. Use your eyes. 4m Circle the appropriate result: LOW MEDIUM HIGH 12. Source Groundwater and run-off Page 2 of 8

3 STATION 2 bird Observation 1. On your walk - Look at the bird pictures. Once you and the teacher have ID the bird, tick the box. 2. Using column 5, fill in the bird numbers seen today. The teacher will guide you. Use this to work out abundance/distribution and then a habitat/food supply point score. Pelican Little Pied Cormorant Eurasian Coot Australian Wood Duck DIVERS SWIMMERS Australian Grebe Little Black Cormorant Pacific Black Duck Dusky Moorhen Great Egret White-faced Heron WADERS Royal Spoonbill Black Swan Habitat total bird score? 0-10 Poor Fair Purple Swamphen Black winged Stilt Good >25 Excellent bird Counts at 5 survey sites ( Teacher will help you fill this out) Circle Bird Species points for Bird Species / Site No * Abundance Distribution birds seen today 1. Australian Grebe 1 1. Grebe 4 2. Australian Wood Duck Wood Duck 2 3. Black Swan 3. Black Swan 5 4. Blackwinged Stilt 2 4. Stilt 5 5. Dusky Moorhen 5. Dusky Moorhen 3 6..Eurasian Coot 4 6. Eurasian Coot 3 7. Great Egret 7. Great Egret 5 8. Little Black Cormorant 8. Black Cormorant 4 9. Little Pied Cormorant Pied Cormorant 4 10 Pacific Black Duck 8 10.Black Duck 3 11.Pelican Pelican 5 12 Purple Swamphen 4 12.Purple Swamphen Royal Spoonbill 13.Royal Spoonbill 5 14.White-faced Heron 1 14.Heron Other: 15.Other 5 Total Abundance per Site Total point score Total Species per Site TODAY Page 3 of 8

4 STATION 3 Dipnetting - Invertebrate population sampling - 1. Location: Final Detention Basin 2. Date: 3. Name of Ecosystem : Freshwater Ecosystem (not brackish or marine) 4. Describe the techniue used to sample the abundance of invertebrates: Using a dipnet, sweep the edge of the lake RANDOMLY for mins STATION 4 bug (Invertebrate) I.D. Name, picture & Sensitivity Rating No. Bugs Circle S.R. Back Swimmer 4 Caddisfly Larvae 6 Damselfly Nymph 6 Dragonfly Nymph 6 Freshwater Shrimp 6 Giant Bug 4 Name, picture & Sensitivity Rating No. Bugs Circle S.R. Beetle 3 Boatman 4 Mite 5 Scorpion 3 Spider 4 Treader 4 Interpreting your results using an UNWEIGHTED Signal Score. Step 1 Using your signal score to determine a pollution rating. Use the table below. Signal Score Pollution Rating > 3.5 Healthy Habitat 2.8 to 3.5 Mild 2.1 to 2.7 Moderate < 2.1 Severe Leech 3 Mayfly Nymph 7 Pond Snail 3 Total Bug SPECIES caught = (known as TAXA RICHNESS) Worm Mosuito Fish (vertebrate) Other A Total Sensitivity Rating (S.R.) = This is a POLLUTION INDEX Calculate a SIGNAL SCORE (S.S.). S.S. = Signal Score = Pollution Index (B) / Taxa Richness (A) B 2 1 Step 3 A pollution indicator graph. Use your Signal Score and Taxa Richness to plot a point on the graph below. 5.6 S.S. 2.8 S.S. Quad 3 - Some pollution Quad 4 - Toxic, harsh Ecosystem Quad 1 - Very Good Ecosystem Quad 2 - Fair to good Ecosystem Taxa Richness (A) (Using your bug numbers column you can calculate a WEIGHTED Signal Score. This is a post excursion activity. See your teacher for details on this method.) Page 4 of 8

5 Abiotic Factor Combined Average Today Wrap Up Abiotic Factor Results Your results today (and Rating a glimpse of the past) Tick the correct box Now Turbidity NTU Excellent: <10 Good: Fair: Poor: >30 Light lux Excellent: >15,000 Good: 10,000-15,000 Fair: 5,000-9,999 Poor: < 5,000 Dissolved Oxygen % Excellent: > 60 Good: Fair: Poor: <40 ph Excellent: Good: or Fair: or Poor: < 5.5 or > 9.2 Conductivity ppm Excellent: < 500 Good: Fair: ,500 Poor: >1,500 Phosphate ppm Excellent: 1 or less Good: >1-2 Fair: >2-3 Poor: > 3 Temperature 0 C Good: summer 20-30; Good: autumn/spring 15-25; Good: winter Poor: summer <20 or >30; Poor: autumn/spring <15 or >25; Poor: winter <10 or >20 Past The Past (Farming era) 250 NTU 3800 lux 25% ppm 2.5 Summer average 29 Autumn average 24 Spring average 19 Winter average 15 Page 5 of 8

6 Inuiry Question : How can human activity impact on an ecosystem? Very High Biodiversity Your turn. Write in the space - High or Low Page 6 of 8

7 Your turn. Write in the space Higher or Lower Keystone Species Submerged auatic plants - E.g. Ribbonweed These plants take nutrients out of the water. When they carry out photosynthesis the oxygen goes directly into the water. The plants are a source of food (a producer) and oxygen. A local extinction event - due to predation Mosuito Fish (Gambusia) From Farming to Now! Past farming Now and Future Edge plants dominate Low oxygen waterbugs Wading birds dominate Few Mosuito Fish Food Web - Place the letter of the 3 missing species in the spaces below to complete the diagram Green and Gold Bell Frog Vs Mosuito Fish * Brought in to control. * Eats a range of Decomposers * Responsible for loss (frogs). * Tolerates water uality. * uickly. * DifWicult to. A - Shrimp B -Bass C - Ribbonweed Page 7 of 8

8 Analysis of abiotic and biotic key relationships Turbidity, Light and Dissolved Oxygen The Winal basin has low turbidity (abiotic factor). An h sunlight (abiotic factor) g h auatic plants (biotic factor) g h D.O.(abiotic factor) g h invertebrates/auatic life (biotic factor). Note: a minimum of 60% D.O is essential for gill breathers such as dragonwly nymphs. Farming past : h turbidity gi sunlight gi auatic plants gi D.O. gi invertebrates. Phosphate and Source Phosphate is an essential nutrient for plant growth. It is a plant food. Too much food can cause problems. h urban runoff (main water source for the lakes) g h phosphate levels (>2) g h 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. Farming past : h phosphate levels (>2)gh algae g i auatic plants gi D.O. gi invertebrates. ph and Conductivity/Salinity ph is a measure of the hydrogen ion concentration in water. Most auatic organisms can only survive in the 6-9 ph range. Low ph values are acidic and kill auatic life. Conductivity/Salinity is the amount of dissolved salts present in the water. Higher salt levels g h dehydration of freshwater organisms. Temperature and Light temperature is directly dependent on sunlight availability, air temperature and turbidity. Temperature affects vital biochemical processes within auatic organisms and ultimately their survival. Most organisms can only tolerate a narrow temperature range C = optimal range for macro invertebrates. - In warmer water (20 to 30 C), the rate of photosynthesis and plant growth increases. Animal activity also increases. Farming past : h turbidity gh heat absorption g h water temps gi auatic organisms. Page 8 of 8