Department of Parks adn Wildlife
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lake benger
Lake Benger - Photo © J Lawn/ Parks and Wildlife

Many wetlands in Western Australia have been destroyed or degraded since European settlement.

More detailed information about threats to wetlands and how to manage them can be found in:

Alteration of natural water regimes

The normal patter of water flow in a wetlands can be affected by activities such as:

Plants and animals that inhabit wetlands are often dependent on a particular water regime, and may be affected by changes in water levels and flow.

Loss of vegetation

The vegetation that occurs in wetlands is an important component of the ecosystem.

Vegetation:

Loss of vegetation can have serious effects an ecosystem.

Introduction of invasive species

Weeds invade and compete with native plant species for resources.

Feral animals are known for their destructive impact on wetland areas, and can disrupt the intricate food chains that exist within the ecosystem.

Invasive species introduced into wetlands include:

Effect of salinity on wetlands
(note intrusion of samphire as a result of
clearing) - Photo © M Rogers/ Parks and Wildlife

Salinity

Salinisation and related changes to hydrological processes (e.g. inundation or flooding) are widespread issues in agricultural areas.

Some mining activities, such as brine discharge, can also cause salination in wetlands. 

Changes to water quality

Variations to water quality including acidification and salinisation can harm wetland environments.

Waterlogging

Waterlogging occurs when the soil is so wet that there is insufficient oxygen in the soil for plant roots to respire (breathe). Waterlogging can originate from:

If the period of waterlogging is too long, many plants will drown.

Surface water erosion and sedimentation

Changes in the way water behaves in the landscape can also impact on the soils in the catchment.

Changes to wetland hydroperiod

Hydroperiod refers to the length of time that wetlands are influenced by water (surface and/or groundwater).

As a consequence of the clearing of native vegetation, there has been a substantial increase in the volume of surface water runoff and the volume of groundwater discharge in the catchments. In many catchments, this has substantially altered the timing and area of inundation of many wetlands. This can cause negative environmental impacts regardless of water quality.

Water pollution

Bulrush weed invasion of wetland
- Photo © M Rogers/ Parks and Wildlife

Wetland water bodies can be contaminated by various activities, including:

Some pollutants can be harmful to wildlife and can greatly reduce the water quality of the wetland.

The use of fertilisers in the wetlands catchment can cause nutrient enrichment in the wetland.

Natural processes

Fire, floods, cyclones and drought are all naturally-occurring processes that have the potential to alter and damage wetland environments.

Fire can remove or change habitat available for wildlife around wetlands.

Maintaining and improving habitat for nature conservation, including through revegetation, can protect and improve wetlands and assist in conserving biodiversity.