John Huisman

Anaerobic digestion piggery effluent (ADPE) has high ammonium content (toxic to most organisms) and is very turbid. The environmental consequences of high productivity piggeries is significant and can result in negative environmental impacts, hence bioremediation techniques (in particular using macroalgae) are therefore of great interest. In this study, we evaluated the growth potential of several locally isolated macroalgae in ADPE under outdoor climatic conditions and investigated their nutrient removal rates and biochemical composition. A consortium of two macroalgae, Rhizoclonium sp. and Ulothrix sp. was isolated and could efficiently grow in the ADPE with concentration of up to 248.4 mg NH3. N L-1. Macroalgal consortium growth could not be maintained at higher ADPE concentration. Maximum ammonium removal rate (30.6 ± 6.50 mg NH4+-NL-1d-1) was achieved at ADPE concentration equivalent to 248.4 mgNH4+-NL-1. Mean biomass productivity of 31.1 ± 1.14 g AFDW m-2d-1 was attained. Total carbohydrate and protein contents ranged from between 42.8-54.8 and 43.4-45.0% (ash-free dry weight), respectively, while total lipid content was very low. Our findings highlight the potential use and promise of Rhizoclonium and Ulothrix sp. consortium for the bioremediation of ADPE and biomass production. To the best of author’s knowledge, this is the first study evaluating the potential of using macroalgae to treat ADPE. While there is a need for further optimisation, successful macro algae growth on ADPE indicates the potential of using these organisms for not only treating ADPE but also as a potential source of animal feed or bioenergy production.

The Rowley Shoals are comprised of three emergent reefs - Mermaid, Clerke and Imperieuse - located approximately 300 km west-northwest of Broome along the edge of the continental shelf. Due to their isolation and protection from most human impacts, the Rowley Shoals are likely to be amongst the most pristine coral reef environments remaining in the world (Bellwood et al. 2003; Gilmour et al. 2007). As coral reefs continue to degrade worldwide, careful management of the Rowley Shoals will be required to establish and maintain them as regional and potentially global benchmarks for coral reef biodiversity conservation. However, successful management requires informed decision-making. Although all three shoals are managed by State or Commonwealth departments as marine protected areas, information about trends in marine biodiversity over time is essential for comparison and assessment of the effectiveness of the different management regimes in effect across the three shoals.

Benthic plants (algae and seagrasses) are a dominant component of most inshore marine ecosystems in Western Australia, and several CSIRO projects presently underway incorporate macroalgal surveys to establish baseline community structure. One of SRFME’s core research projects, Coastal Ecosystem and Biodiversity in Western Australia has as a primary objective the ‘provision of representative baseline assessments’. It is imperative that these surveys be based on reliable and consistent taxonomic information if they are to provide meaningful habitat and community characterizations. This project uses the taxonomic expertise of John Huisman to ensure consistent and accurate identifications of the macroalgae. In addition to the benefits to CSIRO core research, this project will contribute to ‘FloraBase’, a CALM endeavour to document information regarding Western Australia’s plant life. This information is web-based and, in part, made available to the public.