Human Impacts on the Intertidal Wetlands of

Homebush Bay

1. Lithosphere

2. Atmosphere

3. Hydrosphere

4. Biosphere

Human impacts and the four components of the biophysical

environmentAtmosphere

• Changing of wind patterns caused by inappropriate location and design of buildings (wind channelling effects)

• Hydrogen sulphide produced by waterlogged soils is a feature of this ecosystem. Processes within the soil may be disrupted by construction activities

Hydrosphere• Modifications to the hydrosphere e.g.

straightening of Powells Creek alters levels of dissolved oxygen.

• Increased levels of turbidity and toxic chemicals because of urban and industrial landuses

• Oil spills from vessels in Sydney Harbour

Lithosphere• Construction of bund walls changed

the hydrology of the site by reducing and redirecting the flow of water, thereby affecting soil moisture for the mangroves.

• This affects the health of the mangroves and the decomposer organisms that recycle minerals essential for the ecosystem functioning

Biosphere• Atmospheric gases necessary for plant

and animal growth may be altered by pollution

• The death of marine organisms due to dumping of toxic chemicals

• Construction of rock and dirt bund walls introduces weeds into the ecosystem

An example of bund walls

Activities

1. Answer questions 1-3, p105.

2. Explain how the use of intertidal wetland ecosystems by humans can be describes by degrees of modification to natural vegetation

3. Identify the five management issues affecting the Bicentennial Park intertidal wetlands