Samples for phytoplankton investigations were collected in annual period (September 2003 - August 2004) in the Kotor and Risan Bay. Mean-values percentage contribution of the group diatoms (Bacillariophyceae) through the annnual period were from 79.70% to 86.50%. Species Skeletonema costatum, Pseudo-mitzschia delicatissima, Leptocylindrus minimus and Chaetoceros affinis, were the main edificators of diatom population. Densities of these species were from 10**5 to 10**6 cells/cubic dm. These values are characteristic of eutrophic and extreme eutrophic area. It is needed one permanent monitoring to protect this part of Boka Kotorska Bay negative consequences.

In Boka Kotorska Bay there are two recorded species of Copepoda from family Temoridae: Temora stylifera and Temora longicomis. This paper presents the data on horizontal distribution and abundance of these species during 2007. Temora stylifera has a wide horizontal distribution in coastal and open waters of Adriatic sea, while Temora longicomis is a typical representative of estuary-neritic waters of northern Adriatic, Kvarner area and the Italian coats at the west. Their abundance was particularly high in spring and summer.

Lake ecosystems determined by trophic conditions, accurately defined Ecological status of protected area. Trophic condition of water of Lake Skadar and two rivers, the inflow Moraca and the outflow Bojana was described via plankton data considering abundance of phytoplankton, seasonal dynamics of organotrophs, cyanobacteria, total coliforms, plankton biodegrading potential and nitrogen fixing bacterioplankton. The trophic potential for phytoplankton growth has been detected in late autumn throughout September-November 2004, contrary to early summer June-July 2005, and adverse growth of bacterioplankton in May, June and September 2005, respectively. The results of quantitative analysis of coliforms showed good relation of Lake Skadar and Ada Bojana, contrary to similarities between Moraca River and Ada Bojana estimates in accordance with the Pantle-Buck index. Nevertheless, investigation pointed out Lake Skadar beta-mesosaprobic level and moderate self-purification rate. In evaluating trophic conditions the good ecological potential of protected area has been proposed.

The length - weight relationship of juvenile anchovy, Engraulis encrasicolus at Bokakotorska Bay (Adriatic sea, Montenegro) was analyzed. The better knowledge of juvenile growth needs more attention for the entire Adriatic, especial for the Montenegrin coast were this investigation made for the first time. The results obtained from this investigation were compared with the data obtained from the period 1989-1991 from the area of Novigrad Sea of the the eastern Adriatic coast (5).

The red algae Womersleyella setacea is Indo-Pacific species but introduced to Mediterranean Sea were is now relatively widely distributed. During research of benthic communities in Ponta Veslo locality (Lusnica peninsula, Montenegrian coast, Adriatic sea) in summer 2007 dense assemblages on rocky substratum and on sea grass Posidonia oceanica (L.) Del. rhizomes were discovered. The impact on biocenosis structure is discussed.

In this paper some results of investigations of physical, chemical and biological parameters were presented from the parts of Montenegrin coastal sea exposed to the impact of the open waters of the Southern Adriatic sea. As Herceg Novi area is simultaneously the part of the Boka Kotorska Bay (which goes deeply to mainland), eutrophication is more visiable there. Biological parameters were the most visiable indicators of eutrophication during these investigations.

In the beginning of 2008, on the Montenegrin coast is confirmed finding of new species, what was unknown until now in this part of Adriatic sea. The Sphoeroides cutaneus is tropical species with habitat in warm sea around Japan, China and Indonesia. Probably is one of the Lessepsian migrant. It tooks around 130 years for a fish to come through Suez Canal and Red Sea to Mediterranean, then through Otrant Strait into Adriatic sea. It is possible, also that this apparition has something with the global climate change and temperature rise in saltwater in Mediterranean as well as in Adriatic.

During the first five months of 2007 at one station in front of the entrace the Bay of Boka Kotorska, it was collected mesozooplankton using Nansen net, mesh netting of 200 microns. Analyses included determination of biomass and qualitative composition. Data are given on the number of specimens per cubic meter as well as on the volume organisms. Qualitative composition showed domination Copepoda of zooplankton groups.