Evaluating the performance of freshwater macroalgae in the bioremediation of nutrient-enriched water in temperate environments
Algal bioremediation can significantly improve the quality of wastewater by assimilating nutrients. However, the efficiency and stability of this approach depends on identifying suitable algae based on their biomass productivity and ability to outcompete less desirable algae. Here, we compare the productivity and competitive ability of three taxa of filamentous macroalgae under the seasonal light and temperature conditions experienced in temperate environments, including extremes of heat and cold. Specific growth rate was greatest for the tropical isolate of Oedogonium under summer conditions (36–40%; P < 0.05); however, it had lower growth under cooler (autumn, winter) conditions than the temperate algae of Stigeoclonium and Hyalotheca. Overall, Stigeoclonium and Hyalotheca had the most stable production across all treatments. A 5-week competition experiment found that each algae grew fastest in monoculture compared with bi-culture and poly-culture treatments. While all three genera showed a considerable level of competitive dominance depending on algae composition and environmental conditions, no single genus outperformed all others under all conditions. Oedogonium was dominant in warmer conditions, Stigeoclonium in cooler conditions (> 90% for both) and, in its absence, Hyalotheca also dominate over Oedogonium. Our results suggest that rather than finding an optimal taxon for all four seasons, the best decision for maximising stable biomass production will require either seasonal rotation of algae, or bi-cultures of the most dominant ones. Further, prioritising competition over production when selecting freshwater algae for wastewater bioremediation is likely to prove the most successful strategy.
KeywordsAlgae Biomass Competition Growth Species dominance Oedogonium
We thank Maria Martínez, Rebecca Lawton and Tine Carl for their assistance with experiments and Melbourne Water and Melbourne City Council for allowing collection of algae from their ponds. This research is part of the Pacific Biotechnology (previously MBD Industries Ltd) Research and Development program for the Integrated Production of Macroalgae.
Funding was provided by the Australian Research Council through a Future Fellowship (TD) and by the Victorian Goverment through the Port Phillip Bay fund (SS).
- Balina K, Romagnoli F, Pastare L, Blumberga D (2017) Use of macroalgae for bioenergy production in Latvia: review on potential availability of marine coastline species. Energy Procedia 113:403–410Google Scholar
- Cole AJ, Mata L, Paul NA, de Nys R (2014b) Using CO2 to enhance carbon capture and biomass applications of freshwater macroalgae. GCB Bioenergy 6:637–645Google Scholar
- Cole A, Dinburg Y, Haynes BS, He Y, Herskowitz M, Jazrawi C, Landau M, Liang X, Magnusson M, Maschmeyer T, Masters AF, Meiri N, Neveux N, de Nys R, Paul NA, Rabaev M, Vidruk-Nehemyab R, Yuen AKL (2016a) From macroalgae to liquid fuel via waste-water remediation, hydrothermal upgrading, carbon dioxide hydrogenation and hydrotreating. Energy Environ Sci 9:1828–1840CrossRefGoogle Scholar
- Creel L (2003) Ripple effects: population and coastal regions. Population Reference Bureau Washington, DC: Population Reference Bureau and Measure Communication:1–7Google Scholar
- Day SA, Wickham R, Entwisle TJ, Tyler P (1995) Bibliographic checklist of non-marine algae in Australia. vol 4. CSIRO, CanberraGoogle Scholar
- Entwisle TJ, Sonneman JA, Lewis SH (1997) Freshwater algae in Australia. Sainty & Associates, SydneyGoogle Scholar
- Hughes AD, Kelly MS, Black KD, Stanley MS (2012) Biogas from Macroalgae: is it time to revisit the idea? Biotechnol Biofuels 5:86Google Scholar
- Lu QM, Knudsen JF, Eskesen SK, Powers JT, Shremp F, Segar DA, Stamman E, Yucheng Z (2012) Wastewater management for coastal cities: the ocean disposal option. Springer, BerlinGoogle Scholar
- Martine G, Marshall A (2007) State of world population 2007: unleashing the potential of urban growth. UNFPAGoogle Scholar
- Pelling M, Blackburn S (2014) Megacities and the coast. Earthscan from Routledge, OxfordGoogle Scholar
- Priyadarshani I, Sahu D, Rath B (2012) Algae in aquaculture. IJHS 2:108–114Google Scholar
- Wett B, Buchauer K, Fimml C (2007) Energy self-sufficiency as a feasible concept for wastewater treatment systems. In: IWA Leading Edge Technology Conference. Singapore: Asian Water, pp 21–24Google Scholar
- Wiencke C, Fischer G (1990) Growth and stable carbon isotope composition of cold-water macroalgae in relation to light and temperature. Mar Ecol Prog Ser :283-292Google Scholar