SHORT-TERM CHANGES IN SETTLEMENT OF MICRO-AND MACROFOUUNG ORGANISMS• rn BRACKISH WATERS Department of Biology, Uru:remty of R!lffllk, Fedew Republic of Gmnmy Colonization of test panels by micro• and macrofouling organisms was studied at two selected sites in the Wamow estuary. The stations differed substantially in terms of their physical and chemical parameters. Station .1 was 1itu11ted in the W amemiinde marina and can be considered typical of the outer port area. The site selected for Station 2 was a flosting shipyard dock about 10 km upstream. The water there had lower salinity and higher nutrient loads than 11t Station 1. The short, 14-day•long periods of exposure were intended primarily to yield information concerning the rate and variability of colonization. In addition, long-term exposure panels were deployed for the entire period of the experiment at both stations. Species diverisity was lower in both the micro• and macro• fouling communities at Station 2. Settlement of diatoms and ciliates proceeded throughout the whole season, its intensity being higher in spring at both stations. Domination of ciliates was more pronounced at Station 2 than at Station 1, diatoms being more abundant at Station 1. The macrofouling community at Station l was dominated by Balanw improvisus, Laomedea loyeni, Electra crustulenta, Mytilus edulis, and Fabncia sabella, while the community at Station 2 was dominate. d by B11la11us impro,isus, Cordylophora caspia, and Nais elinguis.