Sediment oxygen demand (SOD), silicate and ammonia fluxes, benthic macro- and meiofauna and phytopigments were measured during two cruises in March 1992 and August 1993 in the northwestern Adriatic Sea. Nine, mostly shallow (< 50 m) stations, on a transect stretching from the Po mouth southwards, were visited. Two major issues were addressed: (1) To what extent does the river Po affect the benthic communities along this transect ? and (2) Is there any indication of an eutrophic situation as described in earlier studies ? The spatial patterns of SOD (range +/- 100 to 1450 mu mol O-2 . m(-2). h(-1)) and benthic fauna do not provide evidence for a simple latitudinal decrease in organic enrichment from the Po to the south. However, northern stations generally had the highest SOD, faunal densities and biomass. Water column characteristics (temperature, salinity, phytopigments) in August 1993 indicate a rough partition of the transect into two groups of stations, of which the northern cluster experiences the direct influence of Po water. This is in conformity with the vision of existing deviations of the general anticyclonic flow regime in the northern Adriatic in summer, whereby Po water is directed offshore instead of southwards. Compared to the southern North Sea, the present SOD and benthic fauna figures are moderate and do not indicate any alarming situation in terms of enrichment.