Algal bioproducts derived from suspended solids in intensive land-based aquaculture

Land-based aquaculture produces suspended solids in culture pond and settlement pond waters that could be harvested as a bioresource. Suspended solids were quantified, characterised and harvested from these two sources to assess their suitability for conversion to bioproducts. The suspended solids of settlement ponds were less concentrated (87.6 ± 24.7 mg L−1) than those of culture ponds (131.8 ± 8.8 mg L−1), but had a higher concentration of microalgae (27.5 ± 4.0%) and consequently higher particulate organic carbon (24.8 ± 4.7%) and particulate nitrogen (4.0 ± 0.8%). The microalgal community also differed between sources with a higher concentration of fatty acids in the biomass from settlement ponds. Consequently, biochar produced from biomass harvested from settlement ponds was higher in organic carbon and nitrogen, with a lower cation exchange capacity. In conclusion, we characterised a renewable and potentially valuable bioresource for algal bioproducts derived from suspended solids in intensive land-based aquaculture.