Linking physiology, nutrition and environment research to potential impacts of climate change: case-study on Tasmanian Atlantic salmon aquaculture
Carter, CG and Katersky Barnes, RS and MacLeod, C and King, HR and Battaglene, SC, Linking physiology, nutrition and environment research to potential impacts of climate change: case-study on Tasmanian Atlantic salmon aquaculture, Programme and Abstracts,3rd International symposium on Cage Aquaculture in Asia 2011 (CAA3), 16-19 November 2011, Kuala Lumpur, Malaysia, pp. 88-89. (2011) [Conference Extract]
Atlantic salmon (Salmo salar) is Australiaís largest and most valuable farmed
seafood and makes a significant contribution to the rural economy in the state of Tasmania.
It is based around transfer from freshwater hatcheries to marine cage farms and, although it
accounts for a small part of global salmon production, it is noteworthy for several reasons.
Industry is innovative and has developed many technological solutions. There is also a
highly active research community which has collaborated widely with industry and other
stake holders across ecosystem effects, genetics, health, nutrition, physiology and
reproduction. Of particular interest is the relative closeness of Tasmania to the equator
which, along with local conditions, means that average water temperatures sometimes
approach the upper thermal limits for salmon production. Historically, high water
temperatures have been advantageous in promoting high growth, the industry is now
managing for potential impacts of climate change.
With increasing water temperature metabolic rate increases and dissolved oxygen (DO)
decreases so that salmon are more likely to experience hypoxic conditions. Salmon have
been considered hypoxia sensitive, however some Tasmanian salmon are able to regulate
their metabolic rate and show a level of robustness to their environment. Furthermore,
salmon perform optimally over a wide temperature range and maintain high levels of growth
performance outside the optimum temperature range. Protein, lipid and mineral nutrition
under sub-optimum conditions will be discussed. For example, sub-optimum temperature
and DO impacted increased protein and energy requirements. Increasing water
temperatures also influences the interaction between aquaculture operations and the
environment. Changes in feeds and in husbandry practices such as feeding and stocking
regimes will affect the overall nature of the environmental impact, whilst broader ecosystem
processes (e.g. seasonal nutrient inputs, current regimes, biogenic processes in the
sediment and water column) will be influenced by climate change and may in turn affect the
systemís capacity of to assimilate nutrients, both at a local and a system wide scale.
Whilst limiting environmental conditions test respiratory physiology, adequacy of nutrient
supply and growth, Atlantic salmon have robust physiological systems for maintaining