Rearing of flounder (Platichthys
flesus) juveniles in semiextensive systems
K. Engell-Sørensen, J.G. Støttrup, M.
Holmstrup-2004
Aquaculture, 230(1-4): 475-491
Abstract:
A low-technology rearing system was implemented for
rearing juvenile flounder for stock enhancement in a Danish fjord, the
Limfjord. Each year during 1996–2002, between 13,000 and 153,000 juveniles
were reared from the yolk-sac stage until metamorphosis in outdoor ponds
relying on phyto- and zooplankton blooms as their main food source. In
contrast to other similar systems, the blooms in this system are closely
monitored and, to a certain extent, regulated. The zooplankton blooms
consisted mainly of calanoid copepods, dominated by the species Temora
longicornis and Centropages hamatus. Most juveniles produced
(>99.5%) were normally pigmented with average yearly survival rates from
hatch to metamorphosis varying from 7±9% to 48±18%, lowest in the first
years of production
(Department
of Plankton Ecology, Bio/consult as, Johs. Ewalds Vej 42-44, DK-8320 Åbyhøj,
Denmark, e-mail: kes@bioconsult.dk)