Isotopic tools for better management of aquatic environment and resources

Water is a vital resource that is under ever-increasing demand from population and industry growth, agricultural development, and environmental allocations that are crucial to sustain the natural ecosystems upon which we all rely. Analysis of naturally-occurring stable isotopes (d13C and d15N) have emerged as powerful techniques for addressing research and management-related questions in ecology and aquaculture. Our work on coastal wetlands has identified carbon and nutrient dynamics, the sequestration potential of saltmarsh and mangrove systems, and anthropogenic impacts on aquatic food chains. We compared trophic position and dietary sources in freshwater wetlands during a severe El Nino drought (2007) and following a subsequent series of wetter than average La Nina years (2013), and identified that food chains expand and contract with oscillations in climate phase in the absence of new sources of carbon. We applied isotopic tools in aquaculture, which is the fastest growing food-producing sector in Australia and around the world and accounts for one-third of global fish production. However, production and profitability from inland and coastal aquaculture are often low due to environmental constraints and the increasing cost of production. Our work to develop low-cost feeding strategies for PNG fish farmers suggests operational costs can be reduced by carefully utilising production inputs or changing the ingredients used in feed formulations. These results provide insights for further applications of stable isotopes in the aquatic ecosystem studies.

Keywords

Water, Ecosystems, Populations, Stable isotopes, Ecology, Agriculture, Southern Oscillation

Citation

Mazumder, D., Saintilan, N., Kobayashi, T., Wen, L., Rogers, K., Hollins, S., Johansen, M., Walsh, C., Narimbi, J., & Sammut, J. (2015). Isotopic tools for better management of aquatic environment and resources. Presentation to the 13th Australasian Environmental Isotope Conference, Sydney, Australia, 8-10th July 2015. In 13th Australasian Environmental Isotope Conference, Sydney, Australia, 8-10th July 2015, Programme and Abstracts, (pp. 28.)