Improving the health status of fish and crustacean larvae by combining microbial & stress management  

To establish a more sustainable fish and crustacean production, there is a need for new microbial management strategies that focus on 'join them' and not the traditional 'beat them' approaches. To efficiently manage the microbiota in the system to minimize disease risk, a lot can be learned from research on intensive larviculture of several fish species where detrimental host-pathogen interactions are a normal phenomenon. It is argued that ecological theory could serve as a foundation for developing sustainable microbial management methods that prevent pathogenic disease in larviculture (De Schryver and Vadstein, 2014).

Management of the water microbiota in larviculture systems according to ecological selection principles has been shown to decrease opportunistic pathogen pressure and to result in an improved performance of the cultured animals. We hypothesize that such an approach will proof its value for the shrimp culture business in the context of AHPND as well.

Improving robustness of organisms is a more holistic approach to tackle the many infectious and non-infectious disease problems encountered in aquaculture.  It encompasses improving the energetic and nutritional reserves, homeostatic capacities (osmotic regulation etc.), defense and immune systems, as well as the microbial flora in and on the animals. All of these levels have an additional/synergistic effect on how well the cultured organisms can fight off pathogens and deal with environmental stress.  One of the central concepts in this kind of stress management is (xeno)hormesis (Calabrese and Baldwin, 2002). It is characterized by a low dose stressor inducing a response in an organism of which the net outcome is favorable for the organism. The search for products which allow animals to better deal with stress is one of the most obvious avenues to obtain improved production in a short term.

References

Calabrese, E.J. and Baldwin, L.A. (2002). Defining hormesis. Hum Exp Toxicol., 21(2):91-7.

De Schryver, P. and O. Vadstein (2014). Ecological theory as a foundation to control pathogenic invasion in aquaculture. The ISME Journal (2014), 1-9