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The structure and composition of Mediterranean biodiversity has changed significantly. So far, in Montenegrin coastal waters, nine new non-native species have been recorded: Tylosurus acus imperialis, Caranx crysos, Siganus luridus, Fistularia commersonii, Stephanolepis diaspros, Sphoeroides pachygaster, Lagocephalus sceleratus, Callinectes sapidus and Farfantepanaeus aztecus. Allochthonous species are starting to compete for food and space and leading to habitat degradation, socio-economic impacts and can hybridise with the native species. Natural factors and human activities have enabled the arrival of non-native species into the Adriatic Sea. Four of the species are Lessepsian immigrants, which arrived via the Suez Canal, but five others were introduced from the Atlantic Ocean, through the Strait of Gibraltar. Analysis using the Marine Fish Invasiveness Screening Kit (MFISK), Aquatic Invasiveness Screening Kit (AS-ISK) and Receiver operating characteristic (ROC) showed a calibration threshold of 22.5 for MFISK, a BRA (Basic Risk Assessment) score of 34 and a CCA (Climate Change Assessment) score of 46. A measure of the accuracy of the calibration analysis is the area under the ROC curve (AUC). Two species were characterised as non-invasive: Tylosurus acus imperialis and Caranx crysos, but five others were characterised as invasive and covered by the categories from moderate to high-risk., Struktura i sastav bioraznolikosti Sredozemlja značajno su se promijenili. Do sada je u crnogor- skom primorju zabilježeno devet novih ne-nativnih vrsta: Tylosurus acus imperialis, Caranx crysos, Siganus luridus, Fistularia commersonii, Stephanolepis diaspros, Sphoeroides pachygaster, Lagocephalus sceleratus, Callinectes sapidus i Farfantepanaeus aztecus. Alohtone vrste počinju se natjecati za hranu i prostor i dovode do degradacije staništa, socio-ekonomskih učinaka i mogu hibridizirati s autohtonim vrstama. Prirodni čimbenici i ljudske aktivnosti omogućili su dolazak ne- nativnih vrsta u Jadransko more. Četiri vrste su lesepsijski imigranti, koji su stigli preko Sueskog kanala, ali pet drugih uneseno je iz Atlantskog oceana, kroz Gibraltarski tjesnac. Analiza korištenjem programa MFISK (Marine Fish Invasiveness Screening Kit), AS-ISK (Aquatic Invasiveness Screen- ing Kit) i ROC (Receiver operating characteristic) pokazala je prag kalibracije od 22,5 za MFISK, BRA (Basic Risk Assessment)) rezultat od 34 i CCA (Climate Change Assessment) ocjenu od 46. Mjera točnosti kalibracijske analize je površina ispod ROC krivulje (AUC). Dvije vrste okarakter- izirane su kao neinvazivne: Tylosurus acus imperialis i Caranx crysos, no pet drugih okarakter- izirano je kao invazivno i obuhvaćeno kategorijama od umjerenog do visokog rizika.

Biological aspects (length frequency distribution, length-weight ratio, sex ratio, allometric growth, Fulton's condition factor) of Upogebia pusilla were studied in Tivat Saline (Tivatska solila), Boka Kotorska Bay in 2019. A total of 1,415 individuals were collected. The total length of all studied individuals ranged from 27 to 55 mm (8 and 20 mm CL), while the total weights ranged from 0.29 to 2.56 g (the total length of males ranged from 27 to 51 mm, non-ovoid and ovoid females ranged from 27 to 51 mm and 30 to 55 mm, respectively; the weights ranged from 0.29 to 2.52 g, 0.34 to 2.52 g and 0.47 to 2.56 g for males, non-ovoid and ovoid females, respectively). The overall female:male ratio was 1.2:1. Egg-shaped females were recorded from April (74.3%) to June (23.8%), with a peak in May (91.4% of all females). Males dominated in July (66.4%). The relationship between CL and W was negatively allometric in both males and females and in all sampled individuals. Fulton?s condition factor was higher only in females during the breeding season, while there were no significant differences between males and females during the rest of the year. Since this species is mainly used as live bait for commercial and sports fishermen, the results of this study would be useful for the sustainable management of this species.

Fishes account for more than half of all living vertebrates on Earth and their diversity is very high, in terms of their morphology, biology and habitats they inhabit. There are almost 28,000 of valid living species of fishes (including the superclass Agnatha), but despite their high number and diversity, fishes are among the most endangered groups of marine organisms. Pressures on fishes are numerous: habitat degradation, marine pollution, alien species, climate changes, fisheries, etc. and in most cases those pressures act simultaneously and in combination with each other. By combining and cross-referring different sources of relevant literature and legal documents, a list of rare and endangered fish species of the Adriatic is prepared. According to IUCN Red list 17 species are listed as Critically Endangered, while three species are considered Regionally Extinct: cartilaginous species smoothback angelshark Squatina oculata, and two bony species, sturgeon Acipenser sturio and meagre Argyrosomus regius. Numerous anthropogenic negative impacts raise a need for protection measures for marine ecosystems and marine fish species. Various protection measures have been established across the Mediterranean and Adriatic Seas, most of them related to fisheries, aiming to protect marine fishes and their stocks.

The fisheries represent one of the oldest occupations of the coastal population of Montenegrin Sea and the Skadar Lake. Even though fishery in Montenegro is still relatively undeveloped compared to other Adriatic countries, without industrial fishing, this activity has great importance for the local population in terms of tradition, culture, and history. This paper provides an overview of the state of fishery in Montenegro in recent times, main fishing gears and types of the fishery, fishing fleet size and characteristics, the importance of the fishing sector, etc. Additionally, the history and tradition of the fishery in Montenegro, both in the Skadar Lake and the Adriatic coast, is described. Main limitations and threats to Montenegrin fishery, as well as possibilities of its further development, are also presented in this paper.

An annotated species of crustacean Decapoda list is provided for the Montenegrin territorial waters according to the available scientific literature, official reports, and from data collected from the MEDITS trawl surveys performed on continental shelf and continental slope in summer months from 2008 to 2018. Species are collected mainly by bottom trawl net but also with other various sampling methods such as trammel nets, gillnets, crustacean traps as well as scuba diving techniques. A total of 95 species belonging to 37 families is reported. Data on distribution and findings in Montenegrin territorial waters, Adriatic distribution, literature, and potential commercial interest for fishery are presented for the most significant species.

The Center for Adriatic Biodiversity Conservation “Aquarium Boka” is established in 2020 as organizational unit of the Institute of Marine Biology, Kotor, Montenegro with two subunits: marine aquarium and rescue center. The aquarium is designed as first Montenegrin public aquarium and conservation advocacy center. Its mission is to be a catalyst for global sustainability through promoting and practicing effective conservation on behalf of the Adriatic Sea’s wildlife. Exhibit philosophy of the Aquarium Boka is developed to be mission-driven, message-driven, and visitor-driven and follows “community concept” type of display with 16 theme tanks grouped in four sections: Entrance section – exhibiting the World Sea and Mediterranean Sea life, Central section – exhibiting the Adriatic Sea biodiversity, Special section – exhibiting the Boka Kotorska Bay sea life, and Exit section – exhibiting tropical seas life. A flagship species was considered as an important support for conservation activities, promoting public awareness and raising funds for conservation. John Dory (Zeus faber) is selected as flagship species of the Aquarium Boka. The services of the Aquarium Boka are grouped into three clusters: research, education, and conservation. The Aquarium Boka is designed and set to move people to act on behalf of the marine species we seek to protect. The Rescue center is designed with four main roles: (1) Animal welfare: short-term shelter, care and rehabilitation center with the goal of finding a more suitable placement of threatened species for longer term stay elsewhere; (2) Law enforcement: receiving confiscated animals, providing expert testimony, helping the police, customs, and wildlife authorities pursue the prosecution of traffickers and animal abusers; (3) Raising awareness; and (4) Nature conservation and biodiversity.

This study focuses on the historical data from the “HVAR” Expedition, i.e. the M/V “HVAR” cruise researches into fisheries biology in the open Adriatic, carried out in 1948–1949. These results are still of great importance for the Adriatic, even today, 71 years after the conclusion of the expedition, as they provide a unique insight into the state of fishery resources before the mass exploitation of the second half of the twentieth century. The most represented species in the catches by weight were M. merluccius, R. clavata, S. canicula, A. sphyraena and Z. faber. The significant presence of chondrichthyan species is noted, as is the absence of deep-water pink shrimp, P. longirostris, which is the dominant species in bottom trawl fisheries today. A comparison between “HVAR”, two other historical surveys (“BIOS” 1961, and “GORICA”, 1973) and MEDITS survey of 2018, shows a decrease in chondrichthian species and Catch per Unit of Effort (CPUE; kg/h), with a recent increase in P. longirostris abundance.

This study includes a review of recently published records, as well as new field records of sea turtles along the Montenegrin coast, up until 2020. There are 77 records of three different sea turtle species in Montenegrin waters in total. Most of them were sightings of the loggerhead turtle (59 records). There were two cases of sightings of the green turtle, while two incidences of the leatherback turtle were also recorded. For 14 individuals there was no information about species, but most probably all of them were loggerhead turtles. Collisions with boats, as well as fishing nets were found to be major threat to sea turtles in Montenegrin waters. Five turtles were found in different fishing net, alive and unhurt, while two individuals were found dead because of fishing activities. Four turtles died because of collisions with boats, while three were hurt in collisions with boats, but survived. One turtle was killed by spearing with a speargun by a local man in Stoliv.

The annual alteration of gonad morphology in anchovy, Engraulis encrasicolus (Linnaeus,1758), caught in the period from July 2006 to June 2007 using beach seines in the region of Boka Kotorska Bay (Montenegro, southern Adriatic) was studied. Samples were taken each month. Total length of individuals ranged from 6.6 to 12.2 cm, while weight ranged from 1.58 to 11.27 g, Their ovaries were extracted and weighed, and a piece of female gonad tissue was sampled for histological analysis. The length–weight relationship of all anchovy specimens was described by the equation: \(W = 0.0032\) \(L_T^3.2537; (r^2 = 0.9528)\). The lowest GSI values were found in November and remained at low levels until April, which corresponded to the gonad rest stage. The GSI increased gradually during April and May, which coincides with the begining of spawning period. Although primary oocytes (stage I) were present during all months, their percentage increased from October and was the highest during the winter months (November-March 100%). Mature cells, stage IV, were present during April – October period, with highest value in May when they comprised 12.3% of total oocyte number. An increase in the percentage of oocytes in the yolk vesicle (II) and yolk (III) stages occurred in April, remaining almost unchanged until October. Smallest average oocyte size was noticed in period November – February with an average of 59.69 μm, while greatest size was recorded in April 2007, 185.84 μm.

This paper presents the first record of the Lessepsian migrant fish Lagocephalus sceleratus (silver-cheeked toadfish) on the Italian side of the south Adriatic Sea. In addition, four specimens of Sphoeroides pachygaster (blunthead puffer) were analysed. Meristic and morphometric data of the silver-cheeked toadfish and blunthead puffer are in accordance with data from the Mediterranean. The specimen of silver-cheeked toadfish was a female with gonad in resting stage and the specimens of blunthead puffer were adults (male and female) with gonads in maturing, mature/spawner and post-spawning stage. The stomach contents of the specimen of silver-cheeked toadfish were composed by Mollusca Opistobranchia and Crustacea Brachyura. Stomach contents analysis of S. pachygaster confirmed that Mollusca are the preferred prey for this species. However, the presence of Crustacea (shrimps, crabs) and fish in the stomachs indicates that the blunthead puffer has a broad and variable diet in the south Adriatic Sea. The present study suggests the presence of an established population of blunthead puffer on the continental shelf of the southeast Adriatic Sea.

This paper presents the results of growth rate and condition index analysis of Mytilus galloprovincialis in integrated system and monoculture. The aim of this study was to show if there are differences in growth and condition index of mussels between integrated multi-trophic aquaculture (IMTA) and monoculture farming. The growth rate and condition index were monitored during a 13-month study at three different sites: 1) close to fish cages (NBL), 2) 100 m removed from fish cages (NUD), 3) at a monoculture mussel farm (SVN) around 8 km far away from cages. The most intense growth of mussels was recorded in spring, and the least intense in summer. After 13 months, monitored individuals at all three locations achieved commercial size. The growth rate was very similar at all sites. The condition index showed spatial and temporal differences. Condition index values on site NUD were mostly higher compared to SVN and NBL, which were very similar, exept for the period from October to December when CI was similar on NBL and NUD site and higher in comparation with SVN. CI values on NBL an NUD site during cold period indicate on fact that mussels probably feed on the nutrients from fish farm origins.The highest mortality rate was recorded at the NBL site, probably due to the effects of fouling organisms., Cilj ovog istraživanja bio je pokazati postojanja mogućih razlika u rastu i kondicijskom indeksu dagnji (Mytilus galloprovincialis) u integralnom multi-trofičkom uzgoju i uzgoju u monokulturi. Rast i kondicijski indeks praćeni su tijekom razdoblja od 13 mjeseci na tri postaje: 1) u blizini uzgajališta ribe (NBL), 2) 100 m od uzgajališta ribe (NUD), 3) u monokulturi (SVN) na uzgajalištu koje je oko 8 km udaljeno od kaveza sa ribom. Najintenzivniji rast zabilježen je tijekom proljetnog razdoblja, a najmanje intenzivan tijekom ljetnog. Nakon 13 mjeseci, praćene jedinke su na sve tri pozicije dostigle komercijalnu dužinu. Stopa rasta je bila slična na sve tri pozicije, dok je kondicijski indeks pokazao prostorne i vremenske razlike. Vrijednosti kondicionog indeksa na postaji NUD bile su više od vrijendosti na postajama SVN i NBL, koje su međusobno bile prilično slične, osim u razdoblju od listopada do prosinca kada su vrijednosti kondicijskog indeksa bile slične na postajama NBL i NUD, a veće u usporedbi sa vrijednostima na postaji SVN poziciji. Vrijednosti kondicionog indeksa na postajama NBL i NUD tijekom hladnog perioda godine ukazuju na to da se dagnje vjerovatno hrane nutrijentima porijeklom sa uzgajališta riba. Visoki mortalitet zabilježen je na postaji NBL, najvjerojatnije zbog obraštajnih organizama.

The present study provides updated information on the occurrence, abundance and biomass distribution patterns and length frequencies of Merluccius merluccius in the Mediterranean Sea, by analysing a time series of data from the Mediterranean International Trawl Surveys (MEDITS) from 1994 to 2015. The highest values of abundance and biomass were observed in the Sardinian Seas. The use of a generalized additive model, in which standardized biomass indices (kg km–2) were analysed as a function of environmental variables, explained how ecological factors could affect the spatio-temporal distribution of European hake biomass in the basin. High biomass levels predicted by the model were observed especially at 200 m depth and between 14°C and 18°C, highlighting the preference of the species for colder waters. A strong reduction of biomass was observed since the year 2009, probably due to the strengthening of the seasonal thermocline that had greatly reduced the availability of food. The general decrease in biomass of several stocks of anchovy and sardine, preys of European hake, might be indirectly connected to the decreasing biomass detected in the present study. The length analysis shows median values lower than 200 mm total length of most of the investigated areas.

The Boka Kotorska Bay, as a unique geographical area, with specific ecological conditions, was always inhabited by cetaceans. There is very little recorded data on their presence in the bay. This article presents an overview of cetacean species inhabiting the southern Adriatic Sea, with a particular focus on bottlenose dolphin and fin whale, species whose presence has been documented in the Boka Kotorska Bay. A detailed review on the presence of one of the most famous dolphins in the bay, the dolphin Joca, who was a favourite with swimmers and bathers and was awarded a special protection status by the local government of the city of Kotor has been carried out. A history of unfortunate events – accidental and intentional dolphin deaths in the last 20 years – is provided, as recorded by the society for protection of animals ‘Fifi’ from Kotor. This society of volunteers was involved in the protection of the Boka Kotorska Bay environment since its founding in 1997, and the protection of marine mammals was among its activities. An overview of the first survey of marine mammal populations in the Boka Kotorska Bay area within the frame of the EU IPA NETCET project is also provided. The results of the survey represent the first scientifically collected data on cetaceans in the area. Preservation of these species in the area of the bay requires constant involvement, education of the local population and children on the importance of preservation of cetaceans and careful development of all forms of tourism, including the nautical tourism, which is one of the gravest threats to marine mammals in the Boka Kotorska Bay area.

This paper presents data on initial scientific research activities conducted in order to explore the possibilities for bivalve farming in the conditions of the Boka Kotorska Bay; the data on experimental project related to technology transfer and protection of farming sites against predators, as well as the methods for defining the mariculture sites and principles that sustainable bivalve and fish farming should be based on. Mariculture development in Montenegro began after the completion of initial explorations on the possibilities of farming edible bivalves on the area of the Boka Kotorska Bay, which were conducted in the 1960s. After this period, the first commercial farming of mussels (Mytilus galloprovincialis) began, while the first commercial farming of oysters (Ostrea edulis) began in 2009 in the Bay of Kotor. Today, there are around 20 active shell farms as well as two fish farms using the multitrophic aquaculture system. Bivalve farming is done using the traditional method of floating parks system (long-lines), while fish farming is done in floating cages.

An annotated species of crustacean Decapoda list is provided for the area of Boka Kotorska Bay, based on the available literature. Review of the relevant literature showed that the number of the species known in this area is 62. Two of these species are recognized as Atlanto-tropical immigrants. All species were collected using trawl, dredge, grab bottom sampler, gillnets, as well as scuba-diving techniques. Description of each species gives the valid scientific name and vernacular, common names, literature, distribution and findings in Boka Kotorska Bay, Adriatic distribution, and some remarks as well as their potential commercial interest for fishery. Most of these species have a wide distribution range, including the whole Mediterranean Sea.

SUMMARY This paper presents the results of physical and chemical changes that occur during the process of hot smoking of rainbow trout (Oncorhynchusmykiss), including differences occurring when using fresh or frozen/thawed fish as raw material for the same process. Fresh fish were gutted and subjected to temperature 'shocking' (-35°C for 3.5 h) before salting in a 2% NaCl solution for 12 h. The fish were subsequently smoked at 75-80 °C for 2 h. All material for analysis, 92 fishes, was provided by the private company "AHILEAS", Podgorica (Montenegro), and analysis were made following processing steps used in this company in the process of hot smoking. Water content, water holding capacity, pH and yield were determined before processing, after salting, and after smoking. The possible effect of using frozen/thawed fish as raw material was studied by freezing (-17°C, 30 days) a group of the fresh gutted fish. After slow thawing, the fish were processed similar to the fresh raw material. Results of the performed analysis indicate that freezing of fish has no influence on the quality and yield of final, smoked product. The research was performed as a part of the SEAMED project, financed by the Norwegian ministry of foreign affairs through HERD (High Education and Research for Development) programme for West Balkans.

The otolith morphology, biometry and otolith size and fish length relationship of three demersal fish species: red mullet Mullus barbatus, common pandora Pagellus erythrinus and hake Merluccius merluccius were examined. Based on otoliths relative sizes P. erythrinus and M. merluccius have Large otoliths, while M. barbatus has Small sagittal otoliths. The relationships between otolith variables and fish somatic growth were described by a linear function. All relationships were statistically highly significant (p, Ispitana je morfologija otolita, biometrija i odnos veličine otolita i duljine tri pridnene vrste riba: trlja Mullus barbatus, arbun Pagellus erythrinus i oslić Merluccius merluccius. Na temelju relativnih veličina otolita P. erythrinus i M. merluccius imaju velike otolite, dok M. barbatus ima male sagitalne otolite. Odnosi između varijabli otolita i somatskog rasta riba opisani su linearnom funkcijom. Svi odnosi bili su statistički visoko značajni (p