Presentation on theme: "1 -Reclamation in Hong KongReclamation in Hong Kong -DredgingDredging -Simulation of dredgingSimulation of dredging -Introduction to brine shrimpIntroduction."— Presentation transcript:
1 -Reclamation in Hong KongReclamation in Hong Kong -DredgingDredging -Simulation of dredgingSimulation of dredging -Introduction to brine shrimpIntroduction to brine shrimp -Effect of dredging to brine shrimp (Q1 – Q2)Effect of dredging to brine shrimp (Q1 – Q2) -Pollutants in the sediment (Q3)Pollutants in the sediment (Q3) -NOS: Scientists often make hypotheses based on careful observations (Q4)NOS: Scientists often make hypotheses based on careful observations (Q4) -Limitations of the set-upLimitations of the set-up -Needs for different types of data in EIANeeds for different types of data in EIA -Extension activity: Pollution indicatorExtension activity: Pollution indicator -Extension activity: Other impact of reclamationExtension activity: Other impact of reclamation Disneyland development: Benefit or loss Activity 2 Click the links below to access the slides:
Impact of reclamation on marine life forms When did the earliest reclamation in Hong Kong begin? 1850s Where was it? In Sheung Wan, HK Island (Around Bonham Strand, Morrison Street) (The present tram line was sea before 1850)
3 Earliest reclamation in HK
Can you name some places that are reclaimed land? Is your school and home built on reclaimed land? Check it out! Check it out!
Dredging ( 挖泥 ) is often involved in reclamation Dredging is the process of excavating or moving sand / rock underwater. What is dredging?
How does dredging affect the environment? Disneyland construction commenced without permission Evacuation of sand harnesses coral reefs in Po Toi Island Dredging in East Lamma Channel threatens Lamma fish culture zone
Investigation: Simulation of dredging
Simulation of dredging Try it yourself! Seawater with 30 live brine shrimps Tank A no dredging Start day No. surviving Day 1 No. surviving Day 2 No. surviving Tank B with “dredging” Start day No. surviving Day 1 No. surviving Day 2 No. surviving “Dredging”: Removal of 40 ml sand per day
Brine shrimp is used to represent the marine organisms FemaleMale Larvae 1 cm 1 mm
Dredge sand from the sea! Is the survival of brine shrimp affected by dredging? How? What are the differences between the water with or without dredging?
11 Did you notice the blue particles (copper sulphate) after dredging? They represent some particles that are normally separated from the environment by sediment. Once the sediment is removed, they are exposed to the environment …
12 What might happen when these particles are released into the environment?
13 How can the observations in Q2 and Q3 help you to explain the impact of dredging? Scientists use their imagination in making a hypothesis! A hypothesis is based on careful observations.
14 What are the limitations of the set- up compared with the real situation? Discuss!
15 Prediction about the impact of dredging in the real world The EIA involves simulation modeling by computer to determine effects caused by dredging. What kinds of data would be needed in the model to predict reliably the impact of dredging?
16 What kinds of data would be needed? Which factors affect the dispersal of suspended solids? Do wave and tidal actions affect the distance traveled by the sediment stirred up? How does the type of dredger used affect the amount of suspended solids?
17 Collaboration is common between scientists in different fields
18 Extension activity: Pollution indicators The abundance of an organism or evidence of changes in its physiological processes can indicate the degree of pollution Can you name an example? Organisms showing great changes may be called pollution indicators What might be the criteria for choosing a species to indicate the degree of pollution?
19 Extension Activity 1: Other impacts of reclamation Try to identify other possible evidence of environmental impact in the drawing!
20 What features should the seawall have in order to minimize the impact of reclamation and to withstand wave action? A seawall is built before reclamation to withstand wave action and to minimize the effect of reclamation on the environment.
21 Compare these seawalls Old style seawall Seawall built recently
22 How did the development of scientific knowledge contribute to the improvement of seawall design? Advances in science and engineering enable better design of seawalls which might reduce loss of microhabitats In designing the seawall, scientists in different fields collaborate.