The work is concerned with the study of groundwater quality in respect of hydrocarbons content, carried out on several sites on the territory of the Oil Refinery Novi Sad (Serbia, Serbia&Montenegro). In the course of four year that elapsed since the time spillage of crude and oil derivatives and deposition of burning products on the Refinery soil (April-June 1999) the processes of passive in situ bioremediation have been taking place on the contaminated area. By comparing the results for three contamination zones in a circle of 270 m from the site at which the spillage occurred, a certain increase in content of mineral oil was observed in deeper water-bearing layers at a distance of 200 and 270 m from the spillage site. A content of BTEX components the "movement" of the pollution was observed from the close zone 1 via the farther zone 2 to the farthest zone 3, which indicates that the intensity of bioremediation and all physico-chemical processes in general, taking place on the pollution site, is not sufficient to prevent pollution spreading. The assumption that the zone in question in probably a limiting zone is based on the results of the fourth sampling campaign, in which BTEX components were not detected on any of the locations of the zones 2 and 3.

Water quality analyses were performed on littoral water samples, collected on Lake Ohrid in 2002 (January, February, June, July, August and September). Several microbiological parameters were compared. The number of Escherichia coli, the number of organotrophic bacteria and the phosphatase activity index were measured. Samples were collected along the shore of Lake Ohrid, i.e. at the village of Pestani, at Hotel Metropol, in Ohrid Bay and at the lake inflow of River Velgoska. The results of the study show that the different parameters are not compatible in terms of water quality characterization. The differences found are discussed below.

During the parasitological investigations on the gills of 3 cyprinid species from Lake Dojran (the Former Yugoslav Republic of Macedonia), are found 4 monogenean species: in Rutilus rutilus dojranensis are found Dactylogyrus similis and Dactylogyrus suecicus, in Scardinius erythrophthalmus dojranensis is found Dactylogyrus difformis, and in Alburnus alburnus macedonicus is found Ligophorus sp. Prevalence in Rutilus alburnus dojranensis is 40.46%, in Scardinius erythrophthalmus dojranensis is 55.56%, and in Alburnus alburnus macedonicus is the lowest and amounts 2.02%. All monogenean species represents the first record for parasitic fauna of fish species in the Former Yugoslav Republic of Macedonia. Finding of Ligophorus sp. in the fishes of the family Cyprinidae is new to science generally.

The process of removal of natural organic matter from groundwater by adsorption on powdered activated carbon, coagulation and flocculation was investigated. It was found that the combination of these processes yielded a decrease of KMnO4 values, which allowed the reduction of the coagulant concentration, needed to achieve the necessary quality of drinking water, up to 50%. Also, it was established that the sequence of adding powdered activated carbon and coagulant is one of the essential factors determining the efficiency of NOM removal from water, and which is primarily conditioned by the nature of the organic matter present in the investigated water.

This report presents investigation performed as a part of a wider study desined to examine the level of pollution effects on fish in Ohrid lake (The Former Yugoslav Republic of Macedonia). Faunal investigation of the fish Barbus meridionalis petenyi Heck. were carried out at the five localities in Ohrid lake. Microscope analysis of histological preparation of barbel hepatic tissue displayed a dominant presence of granulomatous inflammation on a level of hepatocelular parenchyme and cholangiofibrosis on a level of hepatic bile duck. The analysis did not exhibit any correlation between the granulomatous inflammation and the manifestation of the cholangiofibrous alterations.

Importance of sediments quantity and quality problems addressing to land reclamation canal network in Vojvodina (Serbia, Serbia&Montenegro) are pointed out in this paper. Necessity for sediments monitoring and criteria definition for environmental discharge are drown. Special attention is paid to agricultural land as recipient of these sediments.

In scope of complex physical-chemical and biological examination of water quality of the Bocac lake, the river Vrbas and tributaries Ugar and Crna Rijeka, examinations of phytoplankton and zooplankton were performed during 2002 (March-November). In qualitative structure of phytoplankton 7 division were registered, with 93 taxa from 49 genera in total. In warmer period extreme domination have fire algae (Pyrrophyta). In zooplankton structure (Rotatoria, Cladocera, Copepoda) 78 taxa were registered from 36 genera, with distinct domination of Rotatoria group. According to saprobiological analysis species of olligo- and beta-mesosaprobic character are prevailing.