Repository of the Department of Marine Studies at the University of Split
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Structure and composition of ichthyoplankton from wider area of Jabuka pit
No full textJadransko more je poluzatvoreni bazen u Sredozemnom moru. Zbog konstantnog ribolovnog pritiska riblji stokovi brojnih gospodarski značajnih vrsta su trenutno u stanju prelova. Stoga se proučavanje ranih razvojnih stadija riba nameće kao jedan od načina boljeg razumijevanja dinamike populacija u cilju zaštite istih. Za potrebe ovog rada prikupljeni su uzorci ihtioplanktona s 33 postaje na širem području Jabučke kotline u ljetnom razdoblju 2019. i 2020. godine. U ihtioplanktonskim uzorcima je sveukupno izolirano 20 različitih ribljih vrsta razvrstanih u 12 porodica. Stopa bioraznolikosti bila je blago veća u prvoj godini istraživanja, a abiotički parametri obje godine su odgovarali očekivanima za područje Jabučke kotline. U prikupljenim ihtioplanktonskim uzorcima dominirao je inćun Engraulis encrasicolus (67,82 %) tijekom obje godine istraživanja. Od ostalih komercijalno značajnih vrsta nađeni su oslić Merluccius merluccius, trlja blatarica Mullus barbatus, trup Auxis rochei, luc Euthynnus alletteratus, lokarda Scomber colias i šnjur Trachurus trachurus. Nisu pronađene nove i do sada nezabilježene vrste na istraživanom području. Prikupljene i izolirane vrste bile su očekivane u uzorcima jer se razdoblje istraživanja preklapa s razdobljem mrijesta svih izoliranih vrsta. Ovo istraživanje doprinosi razumijevanju ekoloških odnosa morskih organizama u otvorenom srednjem Jadranu.The Adriatic Sea is a semi-enclosed basin in the Mediterranean. Due to constant fishing pressure, fish stocks of numerous economically important species are currently in the state of overfishing. Therefore, the study of fish early growth stages is imposed as one of the ways to better understand the dynamics of populations in order to protect them. For the purposes of this work, ichthyoplankton samples were collected from 33 stations in the wider area of the Jabuka Pit in the summer period of 2019 and 2020. A total of 20 different fish species classified into 12 families were isolated in the samples. The rate of biodiversity was slightly higher in the first year of the study, and the abiotic parameters of both years corresponded to those expected for the Jabuka Pit. The anchovy Engraulis encrasicolus dominated the collected ichthyoplankton samples (67.82 %) during both years of the study. Among the other commercially important species, hake Merluccius merluccius, red mullet Mullus barbatus, bullet tuna Auxis rochei, little tunny Euthynnus alletteratus, Atlantic chub mackerel Scomber colias and Atlantic horse mackerel Trachurus trachurus were found. No new and previously unrecorded species were found in the research area. Collected and isolated species were expected since the research period coincides with the spawning period of all found species. This research contributes to the understanding of the ecological relationships of marine organisms in the open central Adriatic Sea
Spatio-temporal variations in the concentration of microbiological indicators of bathing water quality at three beaches in Kaštela bay
No full textOnečišćenje mora ima štetne učinke na zdravlje ljudi, ekosustav i okoliš. Indikatorski mikroorganizmi poput bakterija Escherichia coli i crijevnih enterokoka služe kao "upozoravajuće svijetlo" koje ukazuje na onečišćenje fekalnog podrijetla te mogući rizik za zdravlje kupača. U ovom istraživanju određivana je kakvoća morske vode za kupanje na trima plažama u Kaštelanskom zaljevu: Gojača, Kamp i Torac. Mjerenja su provedena 3 puta dnevno (ujutro, prijepodne i poslijepodne) tijekom 7 dana u sezoni kupanja 2022. godine. Rezultati su pokazali prostorne i vremenske varijacije indikatora fekalnog onečišćenja. Osim problema uzrokovanog stanjem kanalizacijskog sustava na ovom području, razine indikatorskih mikroorganizama na identificiranim izvorima fekalnog onečišćenja u blizini ovih plaža ukazuju na značajno opterećenje fekalnim materijalom. Zbog raznih fizikalnih utjecaja poput Sunčevog zračenja, crijevni enterokoki su se pokazali kao bolji indikator kvalitete mora neovisno o vremenu uzorkovanja, dok je E. coli bila bolji pokazatelj tijekom istraživanja rano ujutro. Kada se sagleda godišnja ocjena, plaža Gojača imala je nezadovoljavajuću ocjenu, dok su plaže Kamp i Torac imale izvrsne ocjene, ali rezultati uzakuju na povremena kratkotrajna onečišćenja. To znači da su potrebni dodatni napori kako bi se locirali i uklonili izvori fekalnog onečišćenja na ovom području te donijele ispravne mjere za zaštitu zdravlja ljudi i očuvanje okoliša.Pollution of coastal marine environment has harmful effects on human health and the ecosystem. Indicator microorganisms such as Escherichia coli and intestinal enterococci serve as "warning signals" of potential marine pollution, especially of fecal origin and a possible risk bathers’ health. In this study, the quality of seawater for bathing was determined at three beaches in Kaštela Bay: Gojača, Kamp and Torac. Measurements were performed 3 times a day (morning, before noon, and afternoon) on 7 days during the bathing season in 2022. The results showed spatial and temporal variations. In addition to the problems with the sewage system in the area, the levels of indicator microorganisms at the identified sources of fecal pollution near these beaches indicate a significant load of fecal material. Due to various physical influences such as solar radiation, intestinal enterococci proved to be a better indicator of seawater quality for samples collected during the day, while E. coli samples were the most reliable indicator for early morning measurements. In the annual assessment, Gojača obtained unsatisfactory results, while Kamp and Torac obtained excellent ratings, but some measurements indicated short-term pollution. This means that additional efforts are needed to locate and eliminate sources of fecal pollution in the area and to implement appropriate measures to protect human health and preserve the environment
The influence of time of exposure to the marine environment on the change in the ratio of Escherichia coli bacteria and intestinal enterococci in the sea for swimming
No full textU ovom je radu istraživan je utjecaja vremena izloženosti morskom okolišu na promjenu omjera broja bakterija Escherichia coli i crijevnih enterokoka u moru za kupanje. Terenska istraživanja provedena su na plaži Gojača u Kaštel Sućurcu tijekom sezone kupanja 2022., dok su in situ eksperimenti provedeni u neposrednoj blizini Instituta za oceanografiju i ribarstvo. Rezultati terenskih istraživanja pokazali su da je omjer broja bakterija E. coli i crijevnih enterokoka manji na točki udaljenijoj od izvora onečišćenja, što je rezultat značajnijeg smanjenja broja E. coli nego crijevnih enterokoka tijekom izloženosti okolišnim čimbenicima na putu od izvora onečišćenja do kontrolne točke. Rezultati in situ eksperimenata pokazali su smanjenje omjera s vremenom izloženosti indikatorskih mikroorganizama utjecaju okolišnih čimbenika, što je također rezultat bržeg ugibanja E. coli u odnosu na crijevne enterokoke. Brže ugibanje obaju indikatorskih bakterija u površinskom sloju u odnosu na dublji sloj mora ukazuje na važnost Sunčevog zračenja za reduciranje indikatorskih bakterija u morskoj vodi.In this thesis, the influence of the exposure time in the marine environment on the change in the ratio of the number of Escherichia coli and intestinal enterococci in bathing seawater was investigated. The field research was conducted on Gojača beach in Kaštel Sućurac during the 2022 bathing season, while the in situ experiments took place in the immediate vicinity of the Institute of Oceanography and Fisheries. The results of the field investigations showed that the ratio of the number of Escherichia coli and intestinal enterococci is lower at a point further away from the pollution source, which is because the number of E. coli decreases more than that of intestinal enterococci during exposure to environmental factors on the way from the pollution source to the control point. The results of the in situ experiments showed a decrease in the ratio with the time the indicator microorganisms were exposed to the influence of environmental factors, which is also the result of a faster reduction of E. coli compared to the intestinal enterococci. The faster reduction of both indicator bacteria in the surface layer compared to the deeper layer of seawater indicates the importance of solar radiation for the reduction of indicator bacteria in seawater.
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Sea as reservoirs of antibiotic resistance genes
No full textKroz desetljeća, uporaba antibiotika kontinuirano raste, kako u sektoru zdravstva tako i u
drugim sektorima, uključujući poljoprivredu. Antibiotici su lijekovi koji se koriste za
prevenciju bakterijskih infekcija. Postoji raznolikost mehanizama kojima određeni antibiotik
djeluje na bakterijske stanice, kao i različiti načini na koje bakterije mogu razviti otpornost na
ove lijekove. Rezistencija na antibiotike predstavlja globalni izazov, a prisutnost bakterija i
gena povezanih s ovom rezistencijom ima poseban utjecaj na vodene ekosustave, posebno na
mora i oceane. Osim u morima i oceanima, velike količine gena rezistencije na antibiotike
možemo pronaći u postrojenjima za pročišćavanje otpadnih voda. Također, geni rezistencije na
antibiotike mogu se nalaziti na fragmentima plastike koji pluta po morima i oceanima, a njihova
prisutnost sve više raste svakim danom. Istraživanja i opisivanje rezistencije na pojedine
antibiotike koncentriraju se na otpornost prema najčešće korištenim antibioticima kao što su
tetraciklini, ampicilin, streptomicin i slični. Rezultati tih istraživanja pomažu razumjeti
učestalost rezistentnih bakterija i gena te stupanj njihove otpornosti na antibiotike koji se široko
koriste. Ovaj problem ima globalni utjecaj na javno zdravlje i ekosustave, te je ključno nastaviti
istraživanja kako bismo razvili strategije za suzbijanje širenja rezistencije na antibiotike u
vodenim okolinama i šire.For decades, the use and variety of antibiotics have been steadily increasing, both within the
healthcare sector and in other sectors such as agriculture. Antibiotics are drugs used to prevent
bacterial infections. Antibiotics can affect bacterial cells through various mechanisms, and
bacteria can develop resistance to specific antibiotics. Antibiotic resistance is a global problem.
The prevalence of antibiotic-resistant bacteria and genes is particularly concerning for aquatic
ecosystems, especially in seas and oceans. Not only in seas and oceans but also in wastewater
treatment plants, significant amounts of antibiotic resistance genes have been discovered. These
genes are often found on fragments of plastic that freely float in the seas and oceans, and their
numbers are increasing daily. Research on resistance to specific antibiotics focuses on
commonly used ones, such as Tetracycline, Ampicillin, and Streptomycin. The results reveal
the frequency of resistant bacteria and genes, as well as the degree of resistance to these
antibiotics
Concentration of heavy metals in shellfish in the Adriatic Sea
No full textSvrha istraživanja bila je prikupiti sve dostupne podatke o koncentraciji teških metala (Cd, Pb, Hg, As) u mediteranskoj dagnji Mytilus galloprovincialis te analizirati uzorke s tri različite lokacije uključivši sjeverni, srednji i južni Jadran u razmaku od četiri godine: Malostonski zaljev, Šibenski kanal i Limski zaljev u 2018. i 2022. godini. Također, provedena usporedba s postojećim podacima o koncentraciji teških metala u Jadranu. S obzirom na toksičnost i kancerogenost većine teških metala, njihova koncentracija u školjkašima predstavlja zdravstveni rizik. Uzorci M. galloprovincialis su prikupljeni i analizirani, a koncentracija teških metala je određena tehnikama atomske apsorpcijske spektrometrije generacije hidrida i atomske apsorpcijske spektrometrije uz primjenu grafitne peći. Analiza koncentracije teških metala otkrila je prostorne i vremenske varijacije. U Limskom zaljevu, koncentracije olova, žive i arsena bile su više u 2022. godini u usporedbi s 2018. godinom, dok se razina kadmija smanjila. Slični trendovi su zabilježeni i u Šibenskom kanalu, s povećanjem koncentracija olova i arsena, ali smanjenjem razine kadmija i žive u 2022. godini. U Malostonskom zaljevu su se koncentracije svih teških metala smanjile u 2022. godini u usporedbi s 2018. godinom., pri čemu nisu zabilježene koncentracije koje premašuju zakonom propisane vrijednosti. Zaključno, M. galloprovincialis s ispitanih lokacija u Jadranu ne predstavljaju opasnost za zdravlje potrošača u pogledu koncentracije teških metala, ali potrebno je kontinuirano praćenje i daljnje istraživanje kako bi se osigurala sigurnost i kvaliteta ovih školjkaša u prehrambenom lancu.The purpose of the research was to collect all available data on the concentration of heavy metals (Cd, Pb, Hg, As) in the Mediterranean mussel Mytilus galloprovincialis and to analyze samples from three different locations, including the northern, middle and southern Adriatic, over a period of four years: Mali Ston Bay, Šibenik channel and Lim Bay in 2018 and 2022. Also, a systematic review and comparison with existing data on the concentration of heaviest metals in the Adriatic was conducted. Considering the toxicity and carcinogenicity of the heaviest metals, their concentration in shellfish represents a health risk. Mytilus galloprovincialis samples were collected and analyzed, and the concentration of heavy metals was determined using hydride generation atomic absorption spectrometry and graphite furnace atomic absorption spectrometry techniques. Analysis of heavy metal concentration revealed spatial and temporal variations. In Lim Bay, lead, mercury and arsenic concentrations were higher in 2022 compared to 2018, while cadmium levels decreased. Similar trends were recorded in the Šibenik Canal, with increased lead and arsenic concentrations but decreased cadmium and mercury levels in 2022. In Mali Ston Bay, the concentrations of all heavy metals decreased in 2022 compared to 2018, while no concentrations exceeding the legally prescribed values were recorded. In conclusion, M. galloprovincialis from the examined locations in the Adriatic Sea do not pose a danger to the health of consumers in terms of the concentration of heavy metals, anyhow continuous monitoring and further research is needed to ensure the safety and quality of shellfish in the food chain
Determination of biocidal activity of active compounds from selected herbs on L3 larvae of Anisakis spp
No full textU ovom diplomskom radu su predstavljeni rezultati određivanja biocidnog djelovanja aktivnih spojeva (eukaliptola, alil disulfida (80%), dialil sulfida, kurkumina, rutina i galne kiseline) odabranog začinskog bilja na L3 ličinke oblića Anisakis pegreffii. Oblići Anisakis spp. nastanjuju organe probavnog trakta morskih organizama (riba i glavonožaca) te se prenose trofički do morskih sisavca, kao krajnih domaćina. Ljudi također mogu postati slučajni domaćini konzumacijom nedovoljno termički obrađene ribe i glavonožaca zaraženih larvalnim stadijima. Zoonoza koja se može dobiti na ovaj način se naziva anisakijaza i njena važnost se sve više prepoznata s epidemiološkog stajališta. Aktivni spojevi začinskog bilja mogu povećati sigurnosnu ispravnost hrane, ili se koristiti u medicinske svrhe. Kurkumin, eukaliptol, alil disulfid i dialil sulfid pokazali su larvicidno djelovanje na L3 ličinke A. pegreffi pri 37° tijekom 24 sata dok rutin i galna kiselina nisu. Procijenjena koncentracija koja uzrokuje smrtnost 50% ličinki (LC(50)) u ovim uvjetima je procjenjena na 0.61 mM za dialil sulfid, 0.31 mM za alil disulfid, 0.52 MM za kurkumin i 1.23 mM za eukaliptol (1,8-cineol).In this graduate thesis the results of determining the biocidal effect of active compounds (eucalyptol, allyl disulfide (80%), diallyl sulfide, curcumin, rutin and gallic acid) of selected herbs on L3 larvae of Anisakis pegreffii are presented. Anisakis spp. inhabit the digestive tract of marine organisms (fish and cephalopods) and are transmitted trophically to marine mammals, as final hosts. Humans can also become accidental hosts by consuming undercooked fish and squid infected with larval stages. The fish-borne zoonosis, also known as anisakiasis, is increasingly recognized worldwide from epidemiological point of view. Active compounds of herbs can increase the safety of food, and have potential application in medicinal purposes. Curcumin, eucalyptol, allyl disulfide and dyallyl sulfide showed a larvicidal effect on L3 larvae of A. pegreffi at 37° during 24 hours, while cedrol and rutin did not. The estimated concentration causing 50% larval mortality (LC(50)) under these conditions was estimated at 0.61 mM for diallyl sulfide, 0.31 mM for allyl disulfide, 0.52 mM for curcumin, and 1.23 mM for eucalyptol (1,8-cineole)
Morphological characteristics of gastric mill in norway lobster, Nephrops norvegicus (Linnaeus, 1758) in the Adriatic sea
No full textŠkamp, Nephrops norvegicus, osim krutog egzoskeleta posjeduje i kruti endoskelet odnosno želučani aparat koji je srastao s opnom želuca, a sastoji se od mezokardijalnog, zigokardijalnog i pterokardijalnog zuba. te njegova su Predmet ovog istraživanja su morfološka obilježja mezokardijalnog zuba Škamp nastanjuje kanale sjevernog i srednjeg Jadrana te otvoreni Jadran, a izlovljava se upotrebom dvaju ribolovnih alata, koćom i vršom. Cilj ovog rada je bio utvrditi moguće razlike dužinskih parametara mezokardijalnog zuba među jedinkama uzorkovanim na osam lokacija u Jadranu. Kod svih uzorkovanih jedinki je utvrđena pozitivna korelacija između širine i dužine mezokardijalnog zuba, širine i dužine glavopršnjaka, kao i rasta glavopršnjaka i rasta mezokardijalnog zuba, osim kod uzoraka iz Moščeničke Drage gdje rast mezokardijalnog zuba nije uvjetovana rastom glavopršnjaka škampa. Usporedbom dužinskih parametara utvrđena je razlika između mužjaka i ženki škampa, jedinki koje nastanjuju različita područja u Jadranu, kao i jedinki ulovljenih različitim ribolovnim alatom. Prosječna dužina želučanog zuba jedinki iz kanalskog područja iznosila je za mužjake 2,83±0,29 mm, a za ženke 2,79±0,35 mm, te za mužjake i ženke iz otvorenog Jadrana 2,38±0,36 mm i 2,24±0,41 mm. Rezultati ovog rada mogu poslužiti budućim istraživanjima morfoloških karakteristika škampa i za bolje razumijevanje utjecaja okolišnih čimbenika i ribolovnih alata na rast i razvoj krutih struktura kod škampa u Jadranu.Norway lobster, Nephrops norvegicus, has a hard exoskeleton, and also an endoskeleton, i.e. a gastric mill, which is fused with the stomach membrane and consists of three structures: mesocardial, zygocardial and pterocardiac teeth. The mesocardial tooth and its morphometric characteristics are the subject of this research. Norway lobster is inhabiting channel areas of the Northern and Central Adriatic, and the open Adriatic Sea, where it is exploited by bottom trawl nets and creels. The aim of this study was to explore the differences of mesocardial tooth length and width, carapace length and width between the sexes and between samples from different fishing grounds in the Adriatic Sea. A positive correlation was found for all sampled individuals between mesocardial tooth width and length, carapace width and length, mesocardial tooth length and carapace length and mesocardial tooth width and carapace width, except for the samples from Moščenička Draga where the growth of the mesocardial tooth of the shrimp is not conditioned by the growth of the carapace length. The difference in length parameters was found between males and females, between samples from different fishing grounds and also between samples fished with different fishing gears, except in samples from Moščenička Draga. The average length of the mesocardial tooth for males inhabiting the channel area was 2.83±0.29 mm, for females 2.79±0.35 mm, and for males and females inhabiting the open sea 2.38±0.36 mm and 2.24±0.41 mm, respectively. The results of this thesis can be the basis for further research of morphological characteristics of Norway lobster, and can lead to a better understanding of the influence of ecological factors and fishing gears on the growth and development of the Norway lobster endoskeleton
Sea-cage fish farming influence on wild fish populations
No full textU ovom završnom radu je predstavljen utjecaj kaveznog uzgoja riba na morski okoliš i organizme u blizini uzgojnih instalacija. Opisani su dobri i/ili loši utjecaji na riblje populacije u blizini kaveza. Potencijalni problemi uzgoja na divlje populacije se mogu javiti utjecajem otpadnih tvari nastalih kao nusprodukt uzgoja. Također, moguć je prebjeg riba iz kaveza u vanjsku sredinu što može rezultirati izmjenom genetičkog materijala, ali i potencijalnim prijenosom bolesti među divljim populacijama. Zbog unosa hrane tijekom uzgoja u blizini kaveza prisutnije su divlje populacije organizama, posebno riba što dovodi do pojave predatora koji mogu imati veliki utjecaj na prirodnu ravnotežu u ekosustavu. Ne smije se zanemariti ni utjecaj na morski okoliš, što dodatno, direktno ili indirektno, utječe na divlje populacije riba.This final thesis presents the impact of cage fish farming on the marine environment and organisms in the vicinity of breeding installations, primarily fish populations. It dwells into the issue of cage farming as part of the mariculture and the potential influences on fish populations, good or bad, that may occur during fish farming. Potential problems can occur due to the impact of waste generated as a by-product of cultivation. Furthermore, it is possible for fish to escape from the cages to the outside environment, which can result in the transmission of disease on wild populations, as well as the change of genetic material. Due to the food intake during breeding, wild populations of organisms are present near the cages, especially fish, which leads to the emergence of predators that can have a major impact on the natural balance in a particular ecosystem. Impact on marine environment must not be overlooked, which can additionally, directly or indirectly, affect wild fish populations
Overview of the allochthonous species Asparagopsis taxiformis in the Adriatic
No full textNe-nativne ili alohtone vrste su sve one vrste koje su čovjekovom namjernom ili slučajnom aktivnošću prenesene na područja koja nisu prirodno nastanjivale te nemaju nužno štetan utjecaj na novi okoliš i postojeće populacije. Pojam invazivnih vrsta obuhvaća sve organizme introducirane u određeni okoliš koji masovnom uspostavom vlastitih populacija štetno djeluju na samo stanište i autohtone organizme. Jedna od takvih vrsta jest i Asparagopsis taxiformis, čija je prisutnost u Mediteranu počela uvelike mijenjati sastav bentoskih zajednica. U Jadranu je prisutna na području Dubrovnika, Nacionalnog parka Mljet te Splita. Jedna od osobitosti vrste A. taxiformis očituje se u iznimnom potencijalu iskorištavanja u svrhe redukcije stakleničkih plinova te u svrhu kontrole bolesti u akvakulturi.Non-native or allochthonous species are all species that have been translocated by human activity intentionally or accidentally to the areas that they did not inhabit before and they don’t necessarily have harmful effects on the new environment and existing populations. However, invasive species are all organisms that once introduced to a new environment, produce unwanted effects on biodiversity by their mass reproduction. One such species is Asparagopsis taxiformis, whose presence in the Mediterranean Sea has started making big changes in local benthic populations. Its presence has also been reported in the Adriatic Sea in the coastal areas near Dubrovnik, National Park Mljet and Split. Asparagopsis taxiformis has exceptional potential use in producing antimicrobial agents to prevent aquaculture diseases and reduce greenhouse gasses from life-stock