Tidal wetlands and macrophytes beds

Wetlands are vegetated areas that are regularly covered by standing water. Many different types of plants and animals are attracted to the water and plant life in wetlands, including birds, platypus, frogs and snakes. Wetlands also acts as natural sponges, absorbing and stilling flood waters and filtering out sediments, nutrients and other pollutants.

A conceptual diagram illustrating some typical plants and animals often found in Derwent estuary wetlands and seagrass beds is provided here.

A century ago, wetlands were found in most of the bays and coves up and down the Derwent. Most of these wetlands were filled in over time, to make way for buildings, factories, parks and even tips. Today, only a few of these wetlands remain - for example at Goulds Lagoon and Risdon Cove. The Habitat Atlas indicates that there are 1.3 square kilometres of tidal wetlands remaining in the Derwent estuary, particularly in the area between Bridgewater and New Norfolk, where large areas of marshes, reed beds and tidal flats can still be seen.

Did you know?

  • Many of the sporting fields along the Derwent foreshore were once wetlands, including at Cornelian Bay, Geilston Bay and Wentworth Park.

Things to explore

  • Visit a wetland as part of a school trip, for example at Goulds Lagoon, Risdon Cove, or the man-made Kingston stormwater treatment wetland.
  • Download the Wetland Communities E-Set from the Parks & Wildlife website for information and activities.

Community types

Plants and animal species of tidal wetlands and macrophytes beds occur in a range of different community types, largely distinguished by the vegetation types.

Key threats

Wetlands are among the world's most productive environments yet their continuing loss and degradation is a major global problem. A century ago, wetlands were found in most of the bays and coves up and down the Derwent. Most of these wetlands were filled in over time, to make way for buildings, factories, parks and even tips. Today, only a few of these wetlands remain - for example at Goulds Lagoon and Risdon Cove. The Habitat Atlas indicates that there are 1.3 square kilometres of tidal wetlands remaining in the Derwent estuary, particularly in the area between Bridgewater and New Norfolk, where large areas of marshes, reed beds and tidal flats can still be seen.

There are many threats to tidal and lagoon wetlands of the Derwent estuary, which are common to most wetlands. These include:

  • direct damage or loss from land clearing and urban development;
  • introduction and spread of weeds and pests;
  • alterations to natural water patterns and flows (due to water extraction, barriers, and changing weather patterns);
  • local sources of pollution and pollution within the greater catchment (upstream); and
  • altered fire regimes.

Macrophytes beds have also been considerably influenced by human actions. Major impacts include:

  • impaired hydrology due to reduced river flow rates;
  • altered nutrients;
  • altered sediment budgets;
  • dredging, and
  • anchor drag.

While a range of legal, policy and other mechanisms are already in place to deal with these threats, there is a need for a special focus on the management needs of wetlands and macrophytes beds.

Educational resources and excursions

Wetland and macrophyte education resources and activities for teachers and students

Metallic Skink (Niveoscincus metallicus) by Alex Dudley

Restoring and promoting the Derwent estuary