DBCA's Rivers and Estuaries Science Program has a key role in monitoring, evaluating and reporting on the environmental health of the Swan Canning Estuary and its catchment. Environmental monitoring is focused on biological indicators (seagrass and fish communities), water quality, and contaminants (including plastic).

Monitoring is important. It enables DBCA to:

• recognise changes in seagrass condition, cover, and distribution
• identify priority areas for protection or rehabilitation
• track long term trends in changing climate conditions
• detect early signs of stress from nutrients, turbidity, algal blooms, and pollutants
• evaluate the effectiveness of management interventions over time
• increase public awareness of seagrass values and the importance of estuarine health

Seagrass in the Swan Canning Estuary 

Seagrasses are among the most productive ecosystems on earth, with rates of primary productivity comparable to those of coral reefs and tropical rainforests. Seagrass play vital ecological roles including: 

• maintaining oxygen levels at the sediment/water interface
• supporting diverse and productive faunal assemblages
• carbon sequestration
• providing an important food source for animals such as Western Australia’s iconic black swan
• stabilising the shoreline sediment, helping to prevent erosion and sedimentation
• cycling of nutrients, which helps the water stay clean and reduces the impacts of pollution 

They are also recognised as a bioindicator of ecosystem health due to how they respond to changes in their physical and chemical environment, with a loss of seagrass representing degraded conditions. There are five main species of seagrass in the Swan Canning Riverpark, with paddleweed (Halophila ovalis) being the dominant species. 

Routine seagrass monitoring 

Seagrass has been monitored annually between November and March since 2011 at six locations that represent the niche environmental dynamics of the river. Seagrass parameters measured include presence/absence, percentage of cover, reproduction, total biomass, above/below ground biomass ratio, and leaf density. Seagrass performance is evaluated annually, with an in-depth analyses of seagrass distribution, condition and pressures undertaken every five years.

The monitoring is generously supported by DBCA volunteers.