This project examines food web dynamics and linkages within nearshore reef, seagrass and unvegetated habitats of temperate Western Australia. Our analyses focus on the use of biomarkers (such as stable isotopes and fatty acids) to determine the source of primary production that drives the food web for major consumers, and also examine the spatial and temporal variability of that production. Based in the Jurien Bay region, the field study sites were chosen as representative of different exposure regimes (like inshore versus mid-shelf) and levels of marine park protection (fished versus sanctuary zones).
Stable isotope analyses of seagrass, algae, gastropod and sea urchin samples collected in Autumn (April to May, 2005) from all sites within the study area; values are mean ± s.d. While the seagrass/epiphyte group is isotopically distinct from the red and brown algae, overlap in d13C signatures between the brown and red algae makes differentiation of these primary producers difficult, and highlights the need for alternative biomarkers such as fatty acids.
Dr Christine Hanson
Associate Professor Glenn Hyndes
CSIRO, Mat Vanderklift
CSIRO, Russ Babcock