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Ovim istraživanjem su praćene promjene dielektričnih svojstava i pH vrijednosti kao pokazatelji svježine trlje skladištene u prikladnim i neprikladnim temperaturnim uvjetima u odnosu na promjene organoleptičkih svojstava. Elektrovodljivost je mnogo brže opadala s vremenom skladištenja u neprikladnim uvjetima, blizu donje razine prihvatljivosti, dok je u prikladnim uvjetima skladištenja riba zadržala visoku kvalitetu. Razina pH se u prikladnim uvjetima nije mijenjala za razliku od neprikladnog skladištenja gdje je varirala kroz dane. Promjene organoleptičkih svojstva pratile su promjene dielektričkih svojstava i pH vrijednosti koje su se pokazali validnim metodama u praćenju promjene svježine skladištene ribe.

The objective of this research was to isolate and identify lactic acid bacteria living in the digestive tract of the queen scallop Aequipecten opercularis and further test it as a probiotic culture on the growth of the bivalve during one month in captivity. Classic microbiological techniques (API and MALDI TOF) were used and four different strains of Lactiplantibacillus and one Lactococcus were identified and further analyzed, namely: Lactiplantibacillus plantarum I, Lactiplantibacillus plantarum 1, Lactiplantibacillus plantarum 2, Lactococcus lactis, and Lactiplantibacillus brevis. The isolated cultures were further tested for the highest antimicrobial activity towards the most common marine pathogens and survival at different temperatures and pH levels. The strain Lactiplantibacillus plantarum I had the best results, with the highest antimicrobial activity (77–85% pathogen growth inhibition) and the best safety standards showing no antibiotic resistance, and no ability to synthesize biogenic amine and degrade red blood cells. Considering all the abovementioned characteristics, the strain Lpb. plantarum I was further tested on the growth and health status of the bivalve Aequipecten opercularis during a month of cultivation in captivity. The results showed that the incorporation of Lpb. plantarum I led to a decrease in the quantity of test microorganisms in the bivalve and an increase in both the growth rate weight and growth rate length of the queen scallop A. opercularis. Furthermore, the scallops fed with the algae culture + Lpb. plantarum I gained significantly higher meat yield (33.15 ± 2.63%) compared with the control scallops fed only with the algae culture (29.66 ± 2.87%). To conclude, the results from this research indicate that including Lpb. plantarum I as a dietary supplement could enhance growth performance and serve as a feasible approach to reduce pathogen levels while cultivating A. opercularis in captivity.

Discharging untreated ballast waters supports the spread of invasive species. One of the most successful ballast-water mediated biological invasions was a transatlantic transport of the ctenophore Mnemiopsis leidyi to many Eurasian seas, where it has significantly impacted local ecosystems. To prevent its spread to new areas, we studied the survival of different M. leidyi life stages exposed to several eradication techniques. We looked closely into the technical applicability of an onboard thermal treatment by calculating its duration and the required energy to perform it. The duration was considered as a sum of the time to heat ballast tanks by using the engine's waste heat for two types of ships and M. leidyi's eradication. The calculated duration of the proposed treatment allowed us to estimate a minimum travel length undertaken by a specific type of ship to eliminate M. leidyi successfully. The travel length determines the appropriate technique and minimal requirements to eliminate M. leidyi successfully and, thus, can serve as a guideline for a management plan. In conclusion, the proposed onboard treatment would be efficient on smaller ships and minimum distances of 200-300 km depending on the season but not on the short routes where other treatment techniques, e.g. exposure to ultrasonic cavitation or microwave radiation, should be considered.

Promjene u ihtiofauni okarakterizirane su kao najznačajniji ekološki utjecaj globalnog zagrijavanja te dugoročno mogu uzrokovati kaskadne učinke u hranidbenim mrežama i posljedično dovesti do promjena u opskrbi morskim proizvodima što može negativno utjecati na gospodarski ribolov i tržište. Prodorom predatorskih termofilnih vrsta riba na sjeverni Jadran, odnosno u staništa gdje donedavno nisu bile prisutne, proširuje se spektar trofičke eksploatacije plijena. Iako je Medulinski zaljev, zbog raznolikosti staništa i produktivnosti, važno ribolovno područje na sjevernom Jadranu, oskudni literaturni podaciju ukazuju da je ribolov na tom području slabo istražen, naročito termofilne vrste koje se sve češće ondje izlovljavaju. Cilj ovog rada je ispitati sastav ulova termofilnih vrsta riba kao i ukupnog ulova ribe, utvrditi prostorno-vremensku distribuciju termofilnih vrsta, njihovu brojčanu i masenu zastupljenost u ulovu, istražiti njihove hranidbene navike te morfometrijske, merističke i biološko-ekološke značajke. Za potrebe prikupljanja uzoraka korišteni su uobičajeni ribolovni alati u gospodarskom ribolovu na moru (jednostruke mreže stajaćice i obalna potegača) tijekom trogodišnjeg perioda (od 2017. do 2019. godine). Istraživanjem je na tri postaje sakupljeno sedam termofilnih vrsta riba; gof (Seriola dumerili), strijelka skakuša (Pomatomus saltatrix), škaram (Sphyraena sphyraena), strijela bijelica (Lichia amia), strijela modrulja (Trachinotus ovatus), lampuga (Coryphaena hippurus) i plavi trkač (Caranx crysos) te 45 ostalih vrsta riba. Nakon brojanja i vaganja svake termofilne jedinke, sakupljeni su morfometrički i metrički podaci, izdvojeni su i izvagani jetra i gonade te je analiziran sastav probavila kako bi se odredio intenzitet prehrane, plijen i preklapanje u ishrani termofilnih vrsta. Za statističku obradu podataka korišteni su paketi PAST i CANOCO. Istraživanjem je utvrđeno da se termofilne vrste riba u Medulinskom zaljevu pojavljuju sezonski gdje se zadržavanju nekoliko mjeseci, najčešće od rujna do studenog iskorištavajući raspoložive energetske resurse na tom području. To je vidljivo po povećanju srednjih mjesečnih vrijednosti Fultonova indeksa kondicije (kod vrsta S. dumerili i S. sphyraena) i hepatosomatskog indeksa kod vrsta S. dumerili i L. amia. Hranidbeni indeksi ukazuju na preferenciju ishrane ribljim plijenom, a za razliku od ostalih termofilnih vrsta, u prehrani S. dumerili utvrđen je, uz pelagični i bentopelagični, još i demerzalni plijen. Analiza sastava prehrane termofilnih vrsta riba u Medulinskom zaljevu upućuje da među njima trenutno ne dolazi do preklapanja prehrambenih navika čime se dade zaključiti da je svaka termofilna vrsta zauzela svoju ekološku nišu. Rezultati ovog istraživanja doprinose boljem poznavanju promjena u ribljim morskim zajednicama i utjecaju klimatskih promjena na ribolov u Medulinskom zaljevu. The expansion of the range of thermophilic fish species towards the northern parts of the Mediterranean Sea and their impact on new habitats is a direct consequence of climate change. Changes in ichthyofauna are characterized as the most significant ecological impact of global warming. In the long run they may cause cascading effects in food webs, which can consequently lead to changes in the supply of seafood and negatively affect commercial fishing and the overall market. The ingression of predatory thermophilic fish species in habitats where they were not present until recently (such as in the northern Adriatic), expands the spectrum of their trophic exploitation. Although, due to its diversity of habitats and productivity, the Bay of Medulin is an important fishing area in the northern Adriatic, scarce literature data suggests that fishing in this area is poorly researched, especially thermophilic species that are more common in the last decades. The aim of this research is to examine the composition of catches of thermophilic fish species as well as the total fish catch, to determine the spatial and temporal distribution of thermophilic species, their numerical and mass representation in the catch, to investigate their feeding habits, and morphometric, meristic, and biological-ecological characteristics. Regular commercial fishing tools were used (gillnets and coastal purse seine) to collect thermophilic species during a three-year survey (from 2017 to 2019). In the research, seven thermophilic fish species at three stations have been collected: Greater Amberjack (Seriola dumerili), Bluefish (Pomatomus saltatrix), the Mediterranean Barracuda (Sphyraena sphyraena), the Leerfish (Lichia amia), the Pompano (Trachinotus ovatus), Dolphinfish (Coryphaena hippurus) and the Blue Runner (Caranx crysos). After counting and weighing each individual thermophilic species, morphometric and metric data was collected. Afterwards, liver and gonads were isolated and weighed. Gastrointestinal content was analyzed to determine feeding intensity, prey, and dietary overlap of thermophilic species. Assessment of the fish diet was based on the frequency of occurrence (F%), numerical frequency (N%), and mass frequency (W%) of the different diet components. The analysis of changes in feeding habits was performed using the fulness index (FI%) and vacuity coefficient (VI%). The index of absolute (IAIα) and relative importance IRI was calculated for each prey category to calculate the diet overlap. PAST and CANOCO packages were used for statistical data processing. The research has revealed that thermophilic fish species in the Bay of Medulin appear seasonally and remain in the area for several months, mostly from September to November, foraging on available energy resources. This is evident by the increase in mean monthly values of the Foulton condition index (for S. dumerili and S. sphyraena) and the hepatosomatic index for S. dumerili and L. amia. Feeding analysis suggests that important food items of L. amia were garfish, Belone belone (Linnaeus, 1760), and different species of Atherina, a pelagic prey consumed at the Kazela sampling station. At the Školjić and Dražice sampling stations, S. dumerili consumed benthopelagic organisms such as cephalopods, Mysidaceae crustaceans, common pandora, Pagellus erythrinus (Linnaeus, 1758), and demersal species represented by Mullus species. In the diet of S. sphyraena, the most important prey was represented by pelagic genus Trachurus from the Carangidae family. A number of gill rakers for S. dumerili, and mouth height and width for S. dumerili and L. amia, represent an important meristic trait in prey selectivity. Feeding indices indicate the preference of feeding on fish prey. In the diet of S. dumerili, in contrast to other thermophilic species, besides pelagic and bentopelagic pray, demersal species were also found. The analysis of the composition of the diet of thermophilic fish species indicates that there is currently no overlap of feeding habits between them, which leads to the conclusion that each species has found its ecological niche. The results of this research contribute to a better understanding of the changes in marine fish communities in the northern Adriatic and the impact of climate change on fishing.

Cilj ovog istraživanja bio je utvrditi sezonske promjene kondicije i spolnu zastupljenost plavog raka (Callinectes sapidus, Rathbun 1896.), alohtone invazivne vrste, koja je sve učestalija u lovinama ribara na području estuarija Neretve i Neretvanskog kanala. Uzorci su u suradnji s ribarima prikupljani iz lovina jednostrukih i trostrukih mreža stajaćica tijekom sva četiri godišnja doba u 2021. godini. Ukupni broj jedinki i spolna zastupljenost varirali su u ovisnosti o sezoni. Tijekom istraživanog razdoblja zastupljeniji su bili mužjaci (63%), a najveći broj jedinki utvrđen je u toplijem dijelu godine. Promjene indeksa kondicije i nalaz spolno zrelih ženki upućuju na uspostavu stabilne populacije. S obzirom da se radi o potencijalno tržišno značajnoj vrsti predlažu se mjere poticanja njezine komercijalizacije.

Ovim istraživanjem su praćene promjene dielektričnih svojstava i pH vrijednosti kao pokazatelji svježine arbuna skladištenog na ledu u razdoblju od 7 dana. Elektrovodljivost je opadala s vremenom skaldištenja, dok se vrijednost pH nakon početnog pada nije značajno mijenjala do kraja istraživanja. Dobiveni rezultati ukazuju da je tijekom razdoblja istraživanja arbun zadržao zadovoljavajuću kvalitetu mesa.

Seasonal changes in environmental parameters affect the metabolic activities and physiology of bivalves. The aim of this study was to determine the impact of environmental parameters on the queen scallop Aequipecten opercularis (Linnaeus, 1758). Scallops were sampled in October 2020 at the Kamenjak Peninsula area, Northern Adriatic. Their culture was maintained for a period of one year in tanks with flowing seawater exchange. To assess the seasonal impact of temperature, pH, and oxygen levels on growth and physiological status, queen scallops were sampled from the tanks four times a year and morphometric parameters, somatic indices and condition index were measured. Seasones had the greatest impact on the scallop's soft body weight, followed by the bivalve total weight, and finally on the morphometric characteristics. The highest condition index was recorded in autumn (94.04%) and the lowest in summer (46.67%). Somatic indices varied during the seasons ; the muscle index was lowest in summer (3.81%) and the highest in winter (5.96%) while the gonadosomatic index is lowest in autumn (18.01%) and highest in spring (34.06%). The wet soft body weight and the condition index are dependent on the seawater temperature and pH, while morphometric parameters were less influenced by environmental factors.

Special ornithological reserve Palud – Palù is a saltmarsh wetland of antropogenic origin located on the west coast of Istria near the sea, about 8 km southeast of Rovinj. This important part of protected areas in Istria covers about 18 ha and is one of the few remaining coastal wetlands on the eastern Adriatic coast. This natural depression has turned into a wetland due to the rainwater inflow from the surrounding area and springs in the northern part. It is connected to the sea by the Austro-Hungarian army in 1906 by digging a 200-m canal in order to prevent the development of mosquito larvae that were carriers of malaria by increasing the salinity of the water. As result the wetland has become more brackish, and over time increasingly saline to its current hypersaline state (> 45 ppt). Wetland is a very valuable habitat primarily for wading birds as a nesting, resting and feeding area during migrations. The analysis of the available data shows no systematic and comprehensive research of ichthyofaunistic values. During the project "CREW – Coordinated Wetland Management in Italy – Croatia Cross Border Region" (Project ID: 10044942) a preliminary inventory of fish fauna was made. Sampling of fish was performed during July and August 2021. In the study of the composition, biomass and structure of fish communities, experimental fishing was performed using small coastal seine nets, hand nets and fish traps. The presence of 6 species has been recorded ; 3 from the family Mugilidae – Mugil cephalus, Chelon saliens and Chelon auratus, as well as Sparus aurata, Gambusia sp. and Anguilla anguilla. Gambusia was the most numerous with 67% in the total number of catches, followed by Ch. saliens (18.77%), M. cephalus (9.83%), Ch. auratus (4.34%), while A. anguilla and S. aurata were presented with 0.12%. Juvenile stages predominated in the fish communities of mullets indicating wetland as important feeding and nursery habitat. Record of A. anguilla is rare finding of this species in such saline habitat conditions on the eastern Adriatic coast. Although there are few species, the wetland ichthyofauna is of dynamic composition since the mullet populations show periodic day – night migrations to the sea, while gambusia is a permanent resident. In a broader ecological sense, although the composition of fish communities in the wetland is not natural, it is of special importance for the ichthyophage bird fauna and as such is necessary to maintain their nesting and migrating populations.

The Istrian peninsula hosts more than a thousand karstic ponds and a few swamps. Those water bodies are generally artificial or partially modified by humans who relied on them throughout history, mainly for agricultural and livestock activities. Ponds and swamps in the past also represented a problem for human health by favouring mosquito reproduction and malaria diffusion. Thus were massively treated at the beginning of the 20th century with insecticides or artificially connected to the Sea. Nowadays, ponds are often abandoned and prone to regression due to vegetation growth and lack of maintenance. Moreover, they often collect agricultural and urban water runoffs, accumulating microbial and chemical contaminants. Superficial water bodies around the Mediterranean are fundamental for the survival of the surrounding land flora and fauna. In addition, they function as hotspots of aquatic biodiversity that offer the only refuge to various endemic species and are paramount for migratory birds providing an ecosystem network key for preserving the south European biodiversity. This research aimed to examine the habitat characteristics using probe (for temperature, salinity, pH, oxygen saturation) and secchi disk (for depth and water transparency), the microbiological and sanitary conditions and the traces of inorganic contaminants (nutrients such as NH3, NO2-, NO3-, PO43-, SiO4) in the waters of five ponds and a brackish swamp in the southwestern part of the Istrian peninsula. With this investigation, we provided the first data on the status of those fragile and precious environments, which will be the basis to implement their future conservation and sustainable management programs.

Ulov ribe mrežom poponicom istraživan je od svibnja do rujna 2018. godine u Medulinskom zaljevu. Analizirani su ukupna brojčana zastupljenost svake pojedinačne vrste u ukupnom ulovu, maseni udio svake gospodarski važne vrste u ukupnom ulovu ribe te njihov prosječni mjesečni maseni udio. Zabilježeno je 27 vrsta riba, od čega 19 gospodarski važnih. Najveću brojčanu zastupljenost među gospodarski važnim vrstama imala je vrsta škarpun, Scorpaena porcus (27, 3 %), a od gospodarski nevažnih lumbrak, Symphodus tinca (13.64 %). Prosječna mjesečna masena zastupljenost pojedinačnih vrsta ovisila je o sezoni uzorkovanja. S obzirom na utvrđene mjesečne razlike kao i za potpunu inventarizaciju vrsta potrebno je provesti dopunska istraživanja tijekom cijele godine.

U radu su istraživane razlike u trajanju proizvodnog ciklusa, brzini rasta, konverziji hrane i preživljavanju lubina i orade s obzirom na vrijeme nasađivanja mlađi u plutajuće kaveze. Mlađ lubina nasađena u travnju 2017. godine dostigla je prosječnu masu od 250±3, 76 g početkom kolovoza slijedeće godine, dok je mlađ iste veličine nasađena u kolovozu dostigla tek 117±0, 83 g do kolovoza slijedeće godine. Mlađ orade nasađena u travnju 2017. dostigla je prosječnu masu od 296±11, 58 početkom kolovoza slijedeće godine, dok je mlađ iste veličine nasađena u srpnju dostigla 211±0, 94 g početkom kolovoza slijedeće godine. Kod obje istraživane vrste su utvrđene statistički značajne razlike u rastu s obzirom na vrijeme nasađivanja.

The Mediterranean Sea displays high species diversity and represents a key area for study of the impacts of natural and anthropogenic changes on biodiversity and its consequences on ecosystem. Habitat destruction, over-fishing, contaminants, eutrophication, introduction of alien species, and climate changes are causing increasingly evident changes in community structure and biodiversity of this warm and miniaturized ocean. Yet, Mediterranean fish biodiversity is undergoing rapid changes due to the rise of water temperature and the increasing success of thermophile biota. In this context, the analysis of continuous long-term and multiparametric data offers a new and promising opportunity to ecologists to understand those processes which regulate marine biodiversity and may also contribute to define possible strategies of conservation and ecosystem-based management. Coastal-cabled video observatories such as the Observatory of the Sea (OBSEA ; www.obsea.es) off Vilanova i la Gertrù (Spain) have been indicated as innovative andchallenging technological tools for monitoring fish assemblages in marine systems. In addition, these devices can be successfully employed to monitor and help to understand the responses of fish species to both, environmental drivers and human stressors, as also invoked by the EU Marine Strategy Framework Directive. These multiparametric intelligent platforms represent one of the key elements for Blue Growth development policies. Cabled, fixed and permanent observatories are being worldwide-distributed within growing geographic networks. They provide long-term monitoring of several characteristics (oceanographic, biological etc.) of the seabed and water column at various depths, in a synchronous and highly integrated fashion. Here, we describe how are the video monitoring actions introduced and applied at the OBSEA within the framework of RESBIO Spanish National Project and the resulting experience transferred to a cabled video station in Šibenik, Croatia.

Procjena učestalosti pojavljivanja gospodarski važnih vrsta riba u estuariju rijeke Krke, uvala Martinska nasuprot Šibenika provedena je od siječnja do travnja 2018. godine podvodnom video kamerom s kabelskim napajanjem. Na osnovu analize videozapisa utvrđeni su: postotak zastupljenosti gospodarski značajnih vrsta u odnosu na ostale prisutne vrste riba, ukupan broj gospodarski važnih vrsta riba i učestalost pojavljivanja njihovih jedinki po mjesecima. Utvrđeno je ukupno 36 vrsta, od čega su 23 gospodarski značajne (63, 9 %). Analize bogatstva ihtiofaune pokazale su varijacije tijekom četiri mjeseca. U cilju dobivanja detaljnih podataka o učestalosti pojavljivanja svake pojedinačne vrste i stanju njihovih populacija, bilo bi potrebno provoditi ovakav nelovni monitoring kroz duži vremenski period.

Oysters, including the Pacific oyster Magallana gigas, are popular aquaculture species and are therefore moved and introduced worldwide. The Pacific oyster is native to the northwest Pacific Ocean and is the most agressive invader of all oyster species. It was first introduced to Europe (France) in the 1960s for aquaculture. Its first record in the Croatian region of the Adriatic Sea was in 1972 in Istria (Lim Bay), where it was intentionally introduced to determine its potential as an aquaculture species and from where it is presumed to have spread to form wild colonies. So far, wild Pacific oyster colonies are restricted to the northern part of the Adriatic Sea along the Istrian Peninsula, where only a few colonies have been recorded (Budava Bay, Lim Bay). In June 2017, two colonies of oysters were found in a bay near Medulin, Istria. Some individuals had an unusual morphology and could not be identified to species from their shells, but were suspected to be Pacific oysters. A small piece of mantle edge tissue was excised from each specimen, preserved in 96% ethanol and stored at 4°C for molecular analysis. After total genomic DNA isolation, the species- specific mitochondrial gene cytochrome c oxidase I gene (COI) was analysed for each sample. Results showed that colonies were mixed, including both Pacific oysters and native European flat oyster Ostrea edulis, Linnaeus 1758. All specimens identified as Pacific oysters had valves with an unusual toothed shape. In the intertidal zone the Pacific oysters were located above the native oysters. These findings are additional proof that invasive Pacific oysters are spreading across the northern Adriatic region and that they should be monitored as a potential threat to native European flat oysters, because they are competing for food with them and are also feeding on native oyster larvae.

Legally prescribed ecological data monitoring has not been established at most of marine Natura 2000 areas in Croatia, and therefore legislation of ecosystems management and protection is not completely fulfilled. For the first time, to the best of our knowledge, a coastal time-lapse imaging survey has been carried out targeting the Šibenik coastal fish community (off Krka River, 5 m depth). Temperature and salinity data were collected concomitantly, both parameters being relevant to fish presence and abundance. One image per hour was collected during daytime continuously from January to March 2018, such collection is still being continued today. A total of 7 311 time-lapse images were analyzed for species classification and 288 Fish Forum Book of abstracts animal counting (epibenthic invertebrates included). Forty-one taxa were detected with fish prevalence, 70.73 percent of all recorded species. The rest being echinoderms (12.25 percent), cephalopods (7.3 percent), crustaceans (2.43 percent), anthozoans (2.43 percent), reptilians (2.43 percent) and birds (2.43 percent). Relevant observations were made of flagship species such as bluefin tuna, Thunnus thynnus (Linnaeus, 1758) and loggerhead sea turtle, Caretta caretta (Linnaeus, 1758). The latter was observed in both hibernation and swimming modes. Species richness, calculation of biodiversity, and degree of coverage of benthic invertebrates were also obtained as proof of concept of the validity of such coastal monitoring actions for large and growing EU infrastructural assets such as the Expandable Seafloor Observatory (OBSEA) and the European Multidisciplinary Seafloor and water column Observatory (EMSO) testing sites. Our data support the need for permanent video-based technical development of the European Strategy Forum on Research Infrastructures (ESFRI) to increment its social projection.

Posljednjih godina su u Jadranu utvrđene nove vrste riba u različitim razvojnim stadijima. Radi se pretežno o termofilnim vrstama, koje preferiraju toplija mora. Nadalje, vrste uobičajene za južni dio Jadrana pomiču se sjevernije te su sve prisutnije u ribarskim lovinama tih područja. Stručnjaci objašnjavaju kako se zbog povećane brojnosti novih vrsta, Jadran nalazi pod utjecajem procesa „tropikalizacije“. Porast temperature i promjene u kemijskom sastavu mora pomažu uspostavljanju njihovih populacija. Određene vrste utvrđene su jednom ili nekoliko puta te još uvijek nije izvjesno jesu li stalni stanovnici ili samo povremeni gosti Jadrana. Putevi unosa brojnih vrsta još su uvijek nepoznati. Mnogi od njih su „lesepsijski migranti“, vrste koje su migrirale iz Crvenog mora kroz Sueski kanal. Osim ovim putem, neke su vrste unesene balastnim vodama, pomorskim transportom, bijegom ili uvođenjem novih vrsta u marikulturu. Kao putevi širenja spominju se i morske struje, koje s Otranta, uz nakupine smeća, najvjerojatnije donose i različite razvojne stadije novih vrsta. Za determinaciju novopridošlih vrsta te utvrđivanje njihovoga zemljopisnog podrijetla, uz klasične metode se sve češće rabe i molekularne. U ovom su radu prikazane nove vrste riba u Jadranu, promjena prostorne distribucije već prisutnih, mogući učinci na morski ekosustav te potencijalna mogućnost gospodarskoga iskorištavanja pojedinih vrsta.

Prisutnost i distribucija termofilnih vrsta riba istraživani su metodom vizualnog cenzusa na sedam postaja u Medulinskom zaljevu u od lipnja do listopada 2017. godine. Utvrđena je prisutnost gofa Seriola dumerili (Risso, 1810), lice modrulje Trachinotus ovatus (Linnaeus, 1758), škarama Sphyraena sphyraena (Linnaeus, 1758), lice bilizme Lichia amia (Linnaeus, 1758) i strijelka Pomatomus saltatrix (Linnaeus, 1766). U ukupnom uzorku najzastapljeniji su bili gof i škaram. Najveći ukupni broj jedinki utvrđen je u uvali Polje, dok je najveći broj termofilnih vrsta zabilježen u uvali Lokva. Rezultati ukazuju na potencijalne buduće promjene u sastavu ihtiofaune Medulinskog zaljeva te je, s obzirom da se radi o području od značaja za izlov gospodarski važnih vrsta riba, potrebno provesti detaljnija istraživanja.

Istarski poluotok je zahvaljujući svojem reljefu i klimatskim uvjetima od davnina obilježen močvarnim područjima kao i stalnim i privremenim lokvama koje predstavljaju žarišta bioraznolikosti. Sediment močvara i lokvi predstavlja jedan od temeljnih staništa koji bilježi dugoročne uvijete i promjene u takvim sustavima. Stoga, proučavanje mikrobne zajednice u sedimentima, koja je najbrojnija komponenta bentosa lokvi, može doprinijeti boljoj interpretaciji ukupnog ekološkog stanja spomenutih vodenih tijela a uz kvantifikaciju fekalnih bakterija moguće je prepoznati i kvantificirati razinu određenih potencijalnih antropogenih pritisaka za ekosustave i predlaganje daljnjih mjera za zaštitu ovih područja. Istraživanje je provedeno kroz zimu i ljeto na šest različitih lokacija jugozapadne Istre. Brojnost heterotrofnih prokariota u sedimetima određena je pomoću epifluorescentntnog mikroskopa dok je sanitarna kvaliteta sedimenta odrađena metodom najvjerojatnijeg broja. Na temelju prikupljenih podataka može se zaključiti da je ekološko stanje analiziranih sedimenata umjerene kvalitete, pogotovo kod vodenih tijela u neposrednoj blizini ljudskih naselja. Dakle, potrebno je poduzeti odgovarajuće mjere kako bi se spriječio dodatni unos hranjivih soli, organske tvari ili zagađivala s prometnica, kako bi se stabilnost spomenutih vodenih tijela mogla dugoročno očuvati. Thanks to its landscape and climatic conditions, the Istrian peninsula has long been characterized by wetlands as well as permanent and temporary ponds that represent hotspots of biodiversity. The sediment of swamps and ponds represents one of the fundamental habitats which records long-term conditions and changes in such systems. Therefore, the study of the microbial community in sediments, which is the most numerous component of the benthos of ponds, can contribute to a better interpretation of the overall ecological state of the aforementioned water bodies, and with the quantification of fecal bacteria, it is possible to recognize and quantify the level of certain potential anthropogenic pressures on the ecosystems and propose further measures for the protection of these areas. The research was conducted during winter and summer at six different locations in southwestern Istria. The number of heterotrophic prokaryotes in the sediments was determined using an epifluorescence microscope, while the sanitary quality of the sediment was determined using the most probable number method. Based on the collected data, it can be concluded that the ecological condition of the analyzed sediments is of moderate quality, especially in water bodies in the immediate vicinity of human settlements. Thus, it is necessary to take appropriate measures to prevent the additional intake of nutrient salts, organic matter or pollutants from roads, so that the stability of the mentioned water bodies can be preserved in the long term.

Unatoč maloj veličini, lokve imaju izniman značaj za biološku raznolikost. Naime, pružaju utočište endemskim vrstama flore i faune, a posebice su značajne za ptice selice. Medulinska lokva je permanentna stajaćica koja se nalazi u jugozapadnom dijelu općine Medulin na Istarskom poluotoku. Okružena je umjereno urbaniziranim naseljem te se nalazi pod umjerenim antropogenim utjecajem. Cilj ovog istraživanja bila je procjena ekološkog stanja i sanitarnih uvjeta Medulinske lokve kako bi se ona sačuvala te kako bi se u potpunosti iskoristila njena višestruka namjena u vidu rekreacije. Tijekom istraživanja provedeno je geodetsko mjerenje, analiza hidrografskih parametara i makrofaune lokve te su prikupljeni uzorci za analizu mikrobne zajednice, sanitarne kvalitete vode i sedimenta. Geodetskim mjerenjem dobivena je dubina lokve koja je do sada bila nepoznata, a ekosustav lokve je karakteriziran visokom primarnom proizvodnjom i visokom saturacijom kisikom. Mikrobiološki parametri izmjereni u površinskoj vodi Medulinske lokve ukazuju na povišenu brojnost mikroorganizama, dok je analizom indikatora sanitarne kakvoće vode Medulinske lokve utvrđen umjereni stupanj kontaminacije, što vodu kvalificira kao dobru ili izvrsnu. Analizom makrofaune utvrđena je visoka bioraznolikost, a posljednjih je godina uočena i obnova populacije vretenaca što ukazuje na kvalitetan i bogat ekosustav Medulinske lokve. Ovo istraživanje može poslužiti kao podloga za daljnja istraživanja. Despite their small size, ponds are extremely important for biodiversity. They provide a refuge to endemic species of flora and fauna and are especially important for migratory birds. Medulin pond is located in the southwestern part of the municipality of Medulin on the Istrian peninsula. The pond is surrounded by a moderately urbanized settlement and is under a moderate anthropogenic influence. The aim of this research was to assess the ecological and sanitary conditions of the Medulin pond in order to preserve it and to make full use of its multiple purposes in forms of recreation. For research purposes, the geodetic measurement, analysis of hydrographic parameters and macrofauna of the pond were carried out. Samples were collected for the analysis of the microbial community, sanitary quality of water and sediment. The depth of the pond, which was unknown until now, was obtained by geodetic measurement. The pond ecosystem is characterized by high primary productivity and high oxygen saturation. Microbiological parameters measured in the surface water of the Medulin pond indicate an increased number of microorganisms, while the analysis of sanitary quality indicators displayed a moderate contamination, which qualifies the water as good or excellent. Analysis of the macrofauna revealed a high level of biodiversity, and in recent years a reintroduction of the dragonfly population has been observed, which indicates a high-quality and rich ecosystem. This research can serve as a basis for further research.

Cilj ovog istraživanja bio je utvrditi glavne morfometrijske i merističke karakteristike populacije S. porcus u Medulinskom zaljevu, uključujući analizu dužinsko – masenih odnosa, njihovu korelaciju s dobi, omjerom spolova, kondicionim stanjem i gonadosomatskim i hepatosomatskim indeksom te njihova usporedba s drugim istraženim populacijama. Uzorkovanje je obavljeno od ožujka 2020. do veljače 2021. godine dva puta mjesečno, osim u siječnju kada je izvršeno jednom. Ulov za dvije korištene mreže poponice veličine oka 32 i 40 mm, analiziran je te prikazan na mjesečnoj bazi i ukupno. Prikupljeno je 163 uzoraka.Svaka jedinka je vagana, su uzete morfometrijske i merističke mjere, određena je starost, dužinsko – maseni odnosi, von Bertalanffyjeva funkcija masenog i dužinskog rasta, Fultonov faktor kondicije te gonadosomatski i hepatosomatski indeks. Ulov mrežama poponicama bio je veći u ljetnim mjesecima. Utvrđena je dominantnost ženki naspram mužjaka s omjerom 17.1:1 (χ2=128.99, p

Livade morskih cvjetnica su važni ekosustavi za mnoge druge vrste. U današnje vrijeme prijete im razni čimbenici poput invazivnih vrsta i antropogenog utjecaja. U svrhu izrade ovog rada praćene su tri lokacije na području zapadne Istre u 2020. godini, a to su: uvala Ribnjak, uvala Funtana i uvala Veštar. Na ovim lokacijama su ukupno pronađene četiri livade morskih cvjetnica. Flora na livadama se sastojala od vrsta Cymodocea nodosa i Zostera noltii, a uz cvjetnice su pronađene i određene alge. U uvali Funtana na livadi cvjetnice Cymodocea nodosa uočena je velika kolićina alge Caulerpa cylindracea koja se smatra invazivnom vrstom u Jadranskom moru. Ova se alga smatra invazivnom vrstom jer nije autohtona za naše područje te je otkriveno da je u kompeticijoi za prostor, svjetlost i nutrijente sa našim autohtonim vrstama te da ih polako potiskuje. Upravo ovo se događa sa livadom Cvjetnice Cymodocea nodosa u uvali Funtana koja je radi invazivne alge Caulerpa cylindracea prorijeđena. Osim invazivne vrste, prijetnju predstavljaju i antropogeni čimbenici poput izgradnje i nasipavanja obale, turizma, otpadnih voda itd. Seagrass meadows are important ecosystems for many other species. Nowadays, they are threatened by various factors such as invasive species and anthropogenic impact. For the purpose of preparing this paper, three locations in the area of ​​western Istria in 2020 were monitored, namely: Ribnjak Bay, Funtana Bay and Veštar Bay. A total of four seagrass meadows were found at these locations. The flora in the meadows consisted of the species Cymodocea nodosa and Zostera noltii, and certain algae were found along with the seagrass plants. In the bay of Funtana on the meadow of seagrass Cymodocea nodosa, a large amount of algae Caulerpa cylindracea was observed, which is considered an invasive species in the Adriatic Sea. This algae is considered an invasive species because it is not indigenous to our area and has been found to compete for the space, light and nutrients with our indigenous species and is slowly suppressing them. This is exactly what is happening with the Cymodocea nodosa meadow in Funtana Bay, which has been thinned due to the invasive algae Caulerpa cylindracea. In addition to the invasive species, anthropogenic factors such as coastal construction and embankment, tourism, wastewater, etc. are also a threat.

Na istarskom se poluotoku nalazi više od tisuću kraških lokvi i nekoliko močvara. Zajedno s četiri male rijeke i akumulacijskim bazenom, one čine jedine površinske slatke vode u regiji. Ta malena vodna tijela općenito su umjetna ili djelomično modificirana od strane ljudi koji su se na njih oslanjali kroz povijest, uglavnom za poljoprivredne i stočarske djelatnosti. Lokve i močvare u prošlosti su također predstavljale problem za ljudsko zdravlje pogodujući razmnožavanju komaraca i difuziji malarije te su stoga početkom 20. stoljeća masovno tretirane insekticidima ili umjetno povezane s morem. U današnje vrijeme lokve su često napuštene i sklone degradaciji zbog neodržavanja i rasta vegetacije. Štoviše, u njima se često nakupljaju poljoprivredne i urbane vode, a s time i mikrobiološka i kemijska onečišćenja. Površinska vodna tijela na području Sredozemlja ključna su za opstanak okolne kopnene flore i faune. Uz to, djeluju kao žarišta vodene biološke raznolikosti koja pružaju jedino utočište raznim endemskim vrstama i veoma su bitna za ptice selice koje imaju ključnu ulogu u umrežavanju ekosustava te se tako doprinosi očuvanju biološke raznolikosti južne Europe. Cilj ovoga istraživanja bio je ispitati karakteristike staništa, mikrobiološke i sanitarne uvjete te tragove anorganskih zagađivala u vodama pet lokvi i jedne bočate močvare na jugozapadnom dijelu istarskog poluotoka. Ovim su se istraživanjem pružili prvi podaci o statusu tih osjetljivih i dragocjenih okoliša, koji će biti temelj za provedbu njihovih budućih programa očuvanja i održivog upravljanja. There are more than a thousand karst ponds and several wetlands on the Istrian peninsula. Together with four small rivers and a reservoir, they form the only surface freshwater in the region. These small water bodies are generally artificial or partially modified by people who have relied on them throughout history, mainly for agricultural and livestock activities. Puddles and wetlands have also been a problem for human health in the past, favoring mosquito breeding and malaria diffusion, and were therefore massively treated with insecticides or artificially linked to the sea in the early 20th century. Nowadays, ponds are often abandoned and prone to degradation due to lack of maintenance and vegetation growth. Moreover, they often accumulate agricultural and urban water, and with it microbiological and chemical contaminants. Surface water bodies in the Mediterranean area are crucial for the survival of the surrounding terrestrial flora and fauna. In addition, they act as foci of aquatic biodiversity that provide the only refuge for various endemic species and are very important for migratory birds that play a key role in ecosystem networking and thus contribute to the conservation of southern European biodiversity. The aim of this study was to examine habitat characteristics, microbiological and sanitary conditions and traces of inorganic pollutants in the waters of five ponds and one brackish wetland in the southwestern part of the Istrian peninsula. This research provided the first data on the status of these sensitive and valuable environments, which will be the basis for the implementation of their future conservation and sustainable management programs.

Onečišćenje mora i oceana izravnim i neizravnim ljudskim djelovanjem ima pogubne posljedice za morske ekosustave koje se vide kao promjene u ponašanju morskih organizama, smanjenje populacija i izumiranje biljnih i životinjskih vrsta, povećanje temperature i kiselosti mora i oceana, cvjetanje algi. Ugrožavanje morskih ekosustava uzrokuju klimatske promjene, unošenje otpada u more (najviše plastike), eutrofikacija, antropogene buke, te svjetlosna zagađenja. Svrha ovog rada je podizanje ekološke svijesti o ulogama mora i oceana, o važnosti njihove zaštite, te informiranje o ljudskom utjecaju i aktivnostima na koje se treba djelovati. Rad je napravljen u suradnji s Fakultetom prirodnih znanosti u Puli.

Cilj ovog istraživanja bio je utvrditi promjene sastava ulova mreže poponice u Medulinskom zaljevu prilikom tranzicije iz hladnog u topli dio godine, odnosno u razdoblju ožujak – srpanj 2020. Mreže poponice srednjeg oka mahe 32 i 40 su polagane dva puta mjesečno u večernjim satima te izvlačene tijekom sljedećeg jutra. Analiza ulova obavljana je za svaku vrstu mreže posebno, a sastav lovine je potom kategoriziran po skupinama: ribe, beskralješnjaci, oštećene ribe, oštećeni beskralješnjaci, morske cvijetnice, alge i anorganski materijal. Ribe i beskralješnjaci su dodatno bili podijeljeni s obzirom na komercijalni značaj. Rezultati su pokazali trend smanjivanja udjela komercijalno značajnih vrsta kroz period uzorkovanja. Brojčano najzastupljenija skupina skupina su bili beskralješnjaci, a maseno ribe. Od riba je maseno najzastupljenija bio škrpun, Scorpaena porcus, a od beskralješnjaka sipa, Sepia officinalis. U mreži oka 32 mm je bilo značajno više oštećenih jedinki kao i neciljane floru i faunu te bismo mogli zaključiti da ima značajno veći negativni učinak na okoliš u usporedbi s mrežom većeg oka. The aim of this paper was to determen the change in composition of trammel nets in the Medulin bay during the transition from the cold to the warm part of the year, from March – July 2020. The trammel nets, with an eyes width of 32 and 40 mm respectively, were layed in the evening hours twice a month and pulled during the next morning. An analysis was conducted for each eyes width separately, and the catch was categorised into the following groups: fish, invertebrates, damaged fish, damaged invertebrates, seagrass, alge and anorganic material. The fish and invertebrate were additionaly grouped into two groups depending on existing economic value. The results showed a trend of decreesing amounts of economicaly valuable species during the sampling period. Invertebrates were numericaly the most abundant, while fish dominated in respect to biomass. The highest biomass caught belonged to the species Scorpaena porcus, for fish, and Sepia officinalis, for invertebrates. The tremmel net with an eye width of 32 mm had recorded a significantly larger amount of damaged individuals as well as untargeted flora and fauna and leads to the conclusion of a much larger negative impact on the suroundings in comparison to the trammel net with the larger eyes width.