Abstract—In Croatia, the majority of cultured marine fish species
are reared in net cages. The intensive production of the fish in net
cages may generate the considerable amount of bio waste and change
water quality especially in enclosed and semi-enclosed coastal areas.
The aim of this paper is to assess the potential impact of sea bass
(Dicentrarchus labrax L.) cage farm on water quality. The weak
relationship between food supply and water quality parameters
(nutrient content and phytoplankton biomass) was found, but
significant changes in oxygen saturation was observed in the cages
during the warmer period of a year especially in the morning
(occasionally it dropped below 70 %). Despite of, satisfactory results
of water quality parameters, it is necessary to establish
comprehensive monitoring process, especially to include quality
assessment of fouling communities.