Sorcha Cronin-O'Reilly

This project focuses on the following needs identified in the Westport Science Strategy:

• “Research to aid prediction of impact of increased turbidity from Westport Project (construction and operation) on seagrass health and hard substrate habitat.”
• “Pressure-response relationships (seagrass and other key benthic species/communities)”
• “Research to determine feasibility of establishing hard substrate/reef on Kwinana Shelf”

Since unvegetated soft-sediment habitats have been identified as key habitat in several Theme workshops, these habitats have been included as key focal habitats, along with hard substrates.

This project has three core components:

1. Surveys of benthic communities in soft-sediment and natural hard habitats.
2. Determination of the pressure-response relationships of key benthic macroalgae and macroinvertebrates to suspended sediment and sedimentation.
3. Small-scale field studies on the feasibility of artificial reefs as a mitigation strategy.

This project is part of the Revitalising Geographe Waterways’ Integrated Ecological Monitoring Study (IEM) which aims to better understand the relationships between water regime, food sources and abundance of benthic macroinvertebrates (> 500 µm), fish and birds utilising the range of habitats (regions) present in the Vasse-Wonnerup.

The benthic macroinvertebrate component is a subset of the larger IEM study and aims to:

1. Determine the characteristics of the benthic macroinvertebrate fauna (i.e. number of species, abundance, diversity and faunal composition), within the six regions of the wetlands at seasonal and annual scales
2. Assess the key environmental drivers (e.g. water quality and depth) that influence invertebrate communities.
3. Investigate the characteristics of the benthic macroinvertebrate fauna at different depths within the most upstream regions of the wetlands (subtidal, intertidal and drying sediments).
4. Help to better understand the potential ecological consequences of changing water regime (water quality and depth) on macroinvertebrate fauna across the different spatial and temporal scales in wetlands.