Fluorescence spectroscopy lights the way to better aquaculture
Aquaculture plays an important role in sustainable international food production, providing more than 50 % of the world's fish stocks in 2012. However, aquaculture in coastal waters can generate large amounts of organic waste due to the inherent density of fish within these systems. Recirculating aquaculture systems (RASs) are closed-loop systems in which fish stocks can be grown and harvested away from natural marine environments. These systems have significant benefits over harvesting wild stocks: increased food safety, source traceability and sustainability, and decreased environmental impact. The EU-funded FAMORAS (Fluorescence analysis and monitoring of recirculating aquaculture systems) initiative worked to optimise RASs using fluorescence spectroscopy. The researchers wanted to greatly improve the productivity of EU fish farming industries. Researchers sampled RASs to establish typical fluorescence signatures during normal operation. They sampled and analysed RAS water over extended periods to capture variability and directional changes in water quality. The team used fluorescence data and statistical tests to identify subtle changes in RAS water quality. They then designed, constructed and tested an online, real-time fluorescence sensor for RAS water quality monitoring. The researchers found differences in organic matter character due to changes in feeding strategies. These small changes are likely very important in managing RAS water quality and subsequent treatment requirements. According to FAMORAS' findings, these changes in organic matter character occurred during the start-up/build-up phase of a freshwater RAS. The researchers found out how each organic matter component comes to equilibrium with the biological treatment systems and how each component behaves once at equilibrium. Project results show the potential of fluorescence spectroscopy as a viable way to monitor organic matter within RASs. There are also potential benefits for EU aquaculture industries to further develop an online sensor to optimise the management and operation of aquaculture facilities.
Keywords
Fluorescence spectroscopy, water quality, fish farms, recirculating aquaculture systems, FAMORAS
