FRDC has approved a three-year, $900,000 project to assess the impact of sediments from Tasmanian salmon farms on adjacent or nearby rocky reef systems and the potential for interactions with other marine industries. The study will provide information to help managers provide for the sustainability and future expansion of fish farming, and will describe existing impacts on other commercial and recreational users.
For many months now commercial and recreational fishers and farmers have complained publicly about sediments, referred to as dust, which they believe have come from salmon farms impacting important productive reef systems in southern Tasmania. Tasmania's coastal reef systems support significant fisheries for a range of species that include trumpeters, morwongs, wrasse, rock lobster and abalone.
A key concern is whether there may be adverse effects on reef health (i.e. off-site interactions) as a result of increased aquaculture activities. Therefore a key element of the main FRDC study will be to provide a better assessment of the potential risk to reef systems from sediment deposition and nutrient dispersion from fish farms directly. Whilst the study will use modelling to predict the risk associated with the deposition of farm derived sediments to the ecology of reef habitats in new farming regions, and will seek to identify cost-effective and risk appropriate approaches for assessment of reef health, it is not within the scope of the study to evaluate effects on abalone directly. Consequently, this PhD project is proposed in association with the main study to provide a better understanding using biomarker accumulation rates of how waste feed/ faeces from salmon farming might directly influence abalone, and to what extent abalone might take up nutrients resulting from fish farming. The study will also compare these laboratory derived accumulation rates with loadings in fish collected from the wild (FRDC study areas) to assess natural loadings and the influence of trophic interactions.