PhD Thesis MJProl .pdf - digital-csic Digital CSIC - Consejo Superior ...

New strategies for the control of bacterial infections in marine fish larval rearing 7
larvae. A high residence time is accomplished by the use of large containers in
combination with low inflow/outflow rates.
Figure 1.1. Application of new strategies for the control of bacterial infections in marine fish larval
rearing.
A basic principle involved in the use of matured seawater is that, as nonopportunistic
and less harmful bacteria species are at increased level in inflow seawater,
they will prevent the proliferation of harmful opportunistic species. Slow-growing
bacteria will thereby be present in high numbers during the first days after hatching and
may have a competitive advantage over opportunistic bacteria, which proliferate at later
stages of the rearing. So called “pioneer species” will colonize first various parts of the
developing gut, and occupy adhesion sites.
Matured seawater has been successfully applied in several experiments with
marine fish larvae, as in the case of incubation of Atlantic halibut yolk-sac larvae
(Skjermo et al., 1997) and with first feeding of turbot larvae (Salvesen et al., 1999). It
should be noted that in Recirculating Aquaculture Systems (RAS), there is an analogy