2012/708 Quantifying physiological and behavioural responses of cultured abalone (molluscs) to stress events

By Andrea Morash et al. 

It is desirable for any primary producer to understand the health and welfare of their stock. This will ultimately enable optimal production and return on investment. The challenge in any aquaculture system is ‘observing’ the physiological and behavioural responses associated with environment, production and other stressors; all factors that impact on the animal health and welfare and so overall production efficiency. Suboptimal health is often associated with culturing conditions, and this is predicted to become more prevalent and unpredictable with a changing climate. There is therefore an immediate and long-term need to overcome the 'observation' challenge.

How do we know if conditions are optimal, and the observed performance efficient and sustainable? Generally for aquaculture species, such as molluscs, it is through measurements of growth rate and survival, equating to biomass produced, rather than on metabolic and behaviour observations on the animal, that are difficult to observe and poorly understood. Therefore there is limited information available for optimising the commercial environment from the animal’s perspective. Sub-optimal conditions lead to stress, and there are multiple (observed and unobserved) stressors or stress events within a commercial growout system, the impact of which on an abalone’s physiology is poorly understood. Measurement of an animal’s response to stress is usually retrospective of the event and via invasive sample collection (an additional stressor).

This project took advantage of the development of a new research tool (“biologger”) for the in-situ measurement of physiological and behavioural parameters to gain an understanding of the response of the abalone to a range of commonly experienced and predicted stressors in a commercial system. This research will provide knowledge for refining farm management protocols, and in the longer-term for developing real-time bio-monitoring of farm management protocols.

This project aimed to:

1. Determine the physiological coping ranges and responses of temperate abalone to various environmental and production stressors measured under controlled laboratory conditions.
2. Attempt to monitor in-situ farmed temperate abalone under commercial conditions to identify and understand the key physiological and behavioural responses to a variety of production stressors.
3. Develop preliminary algorithms to enable interpretation of data from biologgers in the context of physiological and behavioural response to identified stressors.
4. Identify any potential applications of existing biologgers to improve current farm management protocols.