The temporal variation of the main parameters in this pelagic system is analysed. Temperature, salinity, water transparency, nutrients, dissolved oxygen, chlorophyll a and zooplanktonic biomass data were sampled monthly at three points in the bay, from May 1988 to May 1992. Results showed remarkable global stability despite the normal irregularity of some annual and interannual evolution parameters typical of a low depth inshore area open to the Western Mediterranean Sea's offshore oligotrophic conditions as well as to some terrestrial and anthropogenic influences.