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.

This global level ecological study aimed to investigate the correlation between environmental factors and the COVID-19 indices. This survey is an ecological study, so all studied variables are aggregate variables. To collect the variables in the study, a data set was provided, which includes the information of each country based on the cumulative deaths, case fatality rate, recovery rate, and the number of performed COVID-19 tests. Scatter plots of environmental factors for the studied countries were drawn based on cumulative incidence rate of cases, cumulative incidence rate of death, tests, recovery rate, and case fatality rate of COVID-19. Furthermore, Spearman correlation coefficient was also used to verify the correlation between environmental factors and indicators related to COVID-19. The results of this ecological study showed that among all countries surveyed, Montenegro (60,310.56 per million) and Luxembourg (54,807.89 per million) had the highest cumulative incidence rates of COVID-19 cases, when Tanzania (8.42 per million) and Vietnam (13.78 per million) had the lowest cumulative incidence rates of COVID-19. In addition, in this study, it was shown that the cumulative incidence rate of cases, the cumulative incidence rate of deaths, and performed COVID-19 tests had significant direct correlations with the access to drinking water and the access to sanitation services (p < 0.001). The findings of the present study showed an inverse correlation between the mortality rate due to unhealthy water consumption, poor health status, and a positive correlation between access to drinking water and health services with the cumulative incidence and mortality rates of COVID-19. The differences between our findings and many other studies could be due to the ecological nature of the study. Nevertheless, our findings will help health policymakers to develop timely strategies to reduce the mortality and incidence rate of COVID-19.

Surface sediments collected from twelve stations in the Boka Kotorska Bay were analyzed for the level and distribution of twenty-six elements and ten oxides, grain sizes, organic matter, and carbonate content. Potentially toxic elements (Al, Fe, Mn, Cr, Zn, Ni, Cu, Pb, As, Co, U) were determined to assess the contamination status and potential environmental risk according to the single-element indices (enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (CF)), and combined index (pollution load index (PLI)). The single-element indices EF and CF revealed that the surface marine sediment was moderately polluted with Pb, Cu, and Cr, while Igeo indicated moderate pollution with Ni > Cr > Zn > Cu > As and moderate to heavy pollution with Pb, as a result of the anthropogenic factors. The method of the combined effect of toxic elements, PLI, showed the highest pollution rate at the shipyard location in the Bay of Tivat. Pearson’s correlation coefficient (r), principal component analysis (PCA), and cluster analysis (CA) were applied to highlight similarities and differences in the distribution of the investigated elements in the Bay, confirming the claim obtained by the pollution indices. The sediment contamination with most heavy metals, such as Cr, Zn, Ni, Cu, Pb, and As, has been identified in the Tivat Bay area.

The Balkan Peninsula has rich biodiversity with a large number of endemic species; therefore, a part of its territory has been recognized as a World Biodiversity Hotspot. Despite nature conservation efforts and development of nature conservation networks in countries of the region, anthropogenic influence on natural and semi natural ecosystems is increasing. Moreover, new types of disturbance and pollution arise, and one of the more recent being artificial light at night (ALAN) which has serious consequences on reproduction, navigation, foraging, habitat selection, communication, trophic and social interactions of the biota. We have estimated the level of ecological light pollution in the strict protected areas of the Republic of Serbia, the Republic of Bulgaria, and Montenegro using available Google Earth Pro tools, and the New World Atlas of Artificial Sky Brightness (2016) in the form of a kmz layer. The research has covered 13 National Parks, 11 Nature Parks and 55 Reserves. Our results showed widespread incursion of ALAN within strict protected areas in the studied region that has also been noted for some other countries and regions too. However, the level of light pollution is lower here, than in the most part of Continental Europe, and there are a few areas in each country where the night sky above National and Natural Parks is almost dark. These territories have a special value for nature conservation; therefore, it is important to save the dark night sky there.

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.