Marine bioinvasions require integrating monitoring tools with other complementary strategies. In this study, we collected information about the invasive alien crab Callinectes sapidus in Italy, Croatia and Montenegro, by means of online questionnaires administered to recreational fishers (n = 797). Our records matched the current distribution of the species: C. sapidus resulted far more common in the Adriatic/Ionian than in the Tyrrhenian/Ligurian sector. Most respondents rated the species as ‘occasional’ or ‘rare’. Moreover, the more C. sapidus was considered to be abundant, the more fishers tended to perceive it as a negative disturbance over fisheries and the environment. Our findings suggest that C. sapidus is more common than previously thought in most of the study area, and it could have reached the levels of a true invasions in the south-eastern Adriatic Sea. This experience demonstrates that online questionnaires can be appropriate tools to effectively engage stakeholders in alien species monitoring.

Mytilus galloprovincialis was used as a biomonitoring organism in Boka Kotorska Bay, a coastal transitional ecosystem in south-western Montenegro. Native mussels were collected in June 2008 at four sites thought to be differently impacted. Biological effects were investigated analysing both generic and specific biomarkers at cellular level (metallothionein content, lysosomal membrane stability, lipofuscin and neutral lipid accumulation, lysosomal structural changes). Trace element levels in mussels were quite low, only Cu and Zn exhibiting slight increases in the two sampling sites of Tivat Bay, the first one in front of a small working dockyard and the other in the water area of a former Naval dockyard. Mussels collected from these sites exhibited the highest values in neutral lipid and lysosomal volume density and the lowest neutral red retention times. Metallothionein content was always low, reflecting the minor body burden of the trace elements and suggesting a non-relevant environmental induction.

This study deals with the issue of beach litter pollution in the context of the Descriptor 10 of the Marine Strategy Framework Directive Good Environmental Status of EU waters and Ecological objective 10, Common indicator 22 of IMAP. Analyses of the amount, distribution and categorization of beach litter were conducted on nine beaches during 108 surveys covering the area of 206.620 m² in Albania, Italy and Montenegro. Our findings showed that the level of beach litter pollution on south Adriatic beaches is significantly above the adopted threshold values, with a median item numbers of 327, 258 and 234 per 100 m of beach stretch for Albania, Italy and Montenegro, respectively. It can be concluded that, when it comes to beach litter pollution, GES has not been achieved. Given the defined baseline and threshold values at the EU level, the process of reducing the total amount of marine litter in southern Adriatic Sea will be very challenging and needs urgent and specific actions.

Marine litter is a threat to marine life and an economic burden for coastal communities, but efforts to address the issue are hampered by the lack of data for many countries. We performed the first harmonized assessment of seafloor litter (trawl and visual surveys) in six countries of the Adriatic-Ionian macroregion. Seafloor litter showed an uneven distribution throughout the area, with large differences in litter densities and composition among countries and locations. An emerging problem in the area resulted in short-term & single-use objects that represented the largest fraction of litter. Packaging was the economic sector contributing most to seafloor litter on the continental shelf and upper slope, while in some areas aquaculture (mussel farming) represented a key activity producing marine litter. In coastal areas and bays (e.g. Boka Kotorska bay, Montenegro), seafloor litter was mainly related to construction activities and electronic goods, which are a consequence of fly-tipping/illegal dumping.

The abundance, composition and sources of marine litter were determined on beaches located in the seven countries of the Adriatic-Ionian macroregion, namely Albania, Bosnia and Herzegovina, Croatia, Greece, Italy, Montenegro and Slovenia. A total of 70,581 marine litter items were classified and recorded through one-year long surveys carried out in 31 sites. The average litter density of 0.67 items/m2 found within this study is considered to be relatively high. The beaches investigated differed in terms of human-induced pressures; their majority is classified either as semi-urban or semi-rural, while very few beaches could be characterized as urban or remote/natural. The majority of litter items were made of artificial/anthropogenic polymer materials accounting for 91.1% of all litter. Litter from shoreline sources accounted for 33.4% of all litter collected. The amount of litter from sea-based sources ranged in the different countries from 1.54% to 14.84%, with an average of 6.30% at regional level.

Concentration of lead (Pb), lame (Cr), copper (Cu) and cadmium (Cd) were detrmined in Cystoseira algae collected from the Montenegrin mediolittoroal, during the spring 2007. Samples of three species of Cystoseira algae (C. amentacea, C. barbata and C. compressa) were analyzed in order to have information on bioaccumulation of these elements and possibility to use these algae as biomonitors for heavy metal pollution. The data obtained for heavy metals were similar with other area of Mediterranean Sea, with exception for significantly higher concentration of copper, on Budva location.

A length-weight relationship (LW) for five cephalopod species, of which three decapod (Illex coindetii, Loligo vulgaris, Sepia officianlis) and two octopod species (Eledone cirrhosa, Eledone moschata) is given in this paper. The mean exponent b was found to be significantly lower than 3.

In this work physico-chemical and microbiological indicators of coastal waters of Boka Kotorska Bay were presented. As results these parameters of waters quality for mariculture were estimated, especially for breeding of high quality species: mussels-Mytilus galloprovincialis and oyster-Ostrea edulis. The data of primary production which is important for food chain for these organisms were presented. Investigated locations are suitable for mariculture which was requested from Public Enterprise Coastal zone. Temporary, higher eutrophic level was noticed as result of anthropogenic influence. The data are from one year period (2010- montly and seasonally intervals) by monitoring on 10 locations.

Results of phytoplankton investigations that were performed in May, July, August and October 2010 are presented in this paper. The investigated areas are in Boka Kotorska Bay on four locations: Kotor Bay-IBM, Tivat Bay, Hercegnovi Bay-two positions and one position on the open sea – Mamula. In this area the influence of the open sea and the land are expressed to the phytoplankton community. As a consequence of that quantities of phytoplankton are lower in the outer part and higher in the inner part. Diatoms are the most dominant species, which is very frequent in the eutrophic area.

The concentration of trace metals (Pb, Cd, As and Hg) were measured in sea water and sediments in the coastline of the Montenegro. The obtained results of trace metals in sea water were compared with those found in the sediment. Sampling was performed in the fall of 2005 and spring 2006 at five locations in the Montenegrin coastline, Sveti Stasije, Herceg Novi, Budva, Bar and Rt Djeran which present different levels and sources of human impact. The heavy metals analyses in seawater and sediment of the Montenegrin coastline identified to be contaminated with lead the harbor Bar and Sv. Stasije, with arsenic Rt Djeran, with mercury the harbor Bar and Herceg Novi and with cadmium Herceg Novi.