Everyone who understands our Noosa River knows what happens to the colour of the water during floods. And we know it’s caused by soil erosion in the catchment.

What we don’t know is how much of the sediment ends up staying in the system, or its distribution within the estuary.

Excess fine sediment in an estuary can smother important habitats such as seagrass and shellfish beds. The breakdown of nutrients and organic matter can result in a lack of oxygen on the bottom, creating a dead zone.

Knowing how much fine sediment is deposited in the system and where it accumulates will help target restoration campaigns, contributing to protecting and enhancing our unique and valuable estuarine ecosystems.

Filling this knowledge gap is the goal of the Noosa Sediment Accumulation Study, a community-science collaboration funded by the Nature Conservancy, the private firm Ecological Service Professionals (ESP), and Noosa Parks Association. 

Sediment catchers were designed by Dr Simon Walker of ESP, and assembled with the assistance of the Noosa Mens Shed and NPA members.

Samples from the catchers will be collected every couple of months for about 12 months, giving data about settlement rates in different parts of the system.

Samples using a “bottom grab” have already been collected from the entire system and sent for analysis by ESP.

This project will directly contribute to understanding how our Noosa River estuary works and the pressures it faces now. It will inform restoration and protection measures to support a resilient ecosystem into the future.

If this sounds like a project you would like to be involved in, email Bryan Walsh at office@noosaparks.org.au.

Bryan Walsh. Noosa Parks Association Project Officer.