Introduction of allochthonous species may have noticeable affects on populations communities of native species, ecosystem, but also could result in socio-economic consequences. Therefore, creating and applying risk assessment protocols of aquatic invasive species is a main step in supression of biological invasions. SBC index is used for estimation of biological contamination.

Aquatic biotopes are, due to their features, among the most disposed ecosystems to bioinvasion. Serbia waters are not an exception, with and increasing colonization by allochthnous organisms observed there during the last few decades. Non-indigenous aquatic species were found among plants, vertebrates and invertebrates. The aim of this work is to present the current status of aquatic ecosystems in Serbia in regard to biological invansions and to point up to the problem of introduction, presence and influence of aquatic non-indigenous species.

Based on all available data a review of introduced non-indigenous species is reported for the area of Montenegrian coastal sea (South-East Adriatic Sea). All together 11 species were recorded, three algae and eight animals. Monitoring of invasive species has been done partially only for Caulerpa racemose var. cylindracea, while for other species distribution and impact on autochthonous environment is unknown.

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.