WAMSI 2 - Kimberley Node - Project 2.2.4 Benthic primary productivity

Primary producers play significant roles in coastal processes and ecological function. These roles include provision of habitat, stabilising substrates and provision of a food source to fauna. Currently, there are very few studies on primary producers in the Kimberley region, contributing to the poor understanding of processes and adaptive mechanisms under extreme environmental conditions. The project has focussed on the data deficient components of benthic primary producers: seagrasses, macroalgae and sediment microalgae and bacterial communities. The objectives of the project were to (a) understand the temporal and spatial variations in biomass and productivity of seagrasses, macroalgae and benthic microalgae (b) investigate the rates and magnitude of microbial carbon and nitrogen cycling processes, and how they influence primary production and (c) to investigate the rates and net effect of herbivory on seagrasses, macroalgae and benthic microalgae.
The seasonal and spatial variability in biomass and growth of selected species of seagrasses and seaweeds was measured during 5 surveys at 5 sites in the Bardi Jawi Indigenous Protected Area (on dates during 2013-2015). The productivity, carbon processes and nutrient cycling of microalgae and bacteria in intertidal and shallow subtidal sediment was also measured. Rates of herbivory were measured at 3 sites during 4 surveys. Stable isotope ratios of the major primary producers were measured at 5 sites.