Repository of the Department of Marine Studies at the University of Split
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Genetic diversity and the origin of invasive populations of ctenophore Mnemiopsis leidyi
No full textRasprostranjenost rebraša Mnemiopsis leidyi je do 1980-tih godina bila ograničena na područje atlantske obale Sjeverne i Južne Amerike, nakon čega se vrsta proširila balastnim vodama u Crno more, a zatim postupno i u Azovsko more, Kaspijsko jezero, Sredozemno more te Sjeverno i Baltičko more. U radu su opisani podrijetlo i dinamika invazije M. leidyi te biološko-ekološke značajke ove vrste. Mnemiopsis leidyi nastanjuje priobalne vode umjerenih mora gdje postiže najveću biomasu i dominira planktonskim zajednicama u toplom dijelu godine s izraženim sezonskim promjenama. Genetske studije pokazuju da je do invazije u euroazijske vode došlo iz dva područja: populacija iz Crnog mora potječe iz Meksičkog zaljeva dok su Sjeverno i Baltičko more kolonizirani jedinkama iz Nove Engleske. Zahvaljujući prekooceanskom prijevozu, predviđa se nastavak širenja Mnemiopsisa a kakav će utjecaj imati na novi ekosustav ovisi o različitim abiotičkim čimbenicima, lokalnim strujama te prisustvu ili odsustvu prirodnih predatora.Distribution of a ctenophore Mnemiopsis leidyi was until 1980s limited to the Atlantic coast of North and South America, after which the species spread by ballast waters into the Black Sea, then progressively to Azov Sea, Caspian Sea, Mediterranean Sea, North and Baltic Sea. In this thesis, the origin and dynamics of M. leidyi invasion and the biological – ecological features of this species are described. Mnemiopsis leidyi inhabits coastal temperate waters where it achieves the highest biomass and dominates the planctonic communities during the warm season with notable seasonal changes. Genetic studies demonstrated that the invasion of Euroasian waters had two origins: the Black Sea population originated from the Gulf of Mexico, while the North and Baltic Sea were colonized by individuals from New England. Due to continuing transport by transoceanic shipping it is anticipated that M. leidyi will continue to expand. The impact the species elicits on the invaded ecosystem depends on various abiotic factors, local curents and the presence or absence of natural predators
Lipids of cold sea cartilaginous fishes
No full textRazredu hrskavičnjača pripadaju morski psi, raže i cjeloglavke. U ovom radu se osvrćemo na morske pse, i to na tri dubokomorske vrste: portugalski kostelj (Centroscymnus coelolepis), listoljuskavi morski pas (Centrophorus squamosus) i crni morski pas (Centroscyllium fabricii). Usporedit ćemo lipidni sastav u njihovom organizmu i razmotriti prilagodbu lipidnih komponenti, ponajprije masnih kiselina, s obzirom na stanište i život u hladnijim područjima.The animal class Chondrichthyes comprises sharks, rays, and chimeras. In this thesis, we will focus on three species of deepsea sharks: Portuguese dogfish (Centroscymnus coelolepis), leafscale gulper shark (Centrophorus squamosus), and black dogfish (Centroscyllium fabricii). We will compare the lipid composition in their body and consider adjustments in lipid components, mainly fatty acids, related to their habitat and life in colder areas
The neurotoxic effects of domoic acid
No full textDomoična kiselina je neurotoksin, glavni predstavnik ASP toksina (engl. Amnesic Shellfish Poisoing; amnezijsko trovanje školjkašima). Može se bioakumulirati u morskim organizmima kao što su školjkaši i ribe koji se hrane fitoplanktonom, glavnim izvorom toksičnih spojeva u moru. Simptomi trovanja školjkašima, koji u sebi sadrže domoičnu kiselinu, kod čovjeka su gubitak pamćenja, dezorijentiranost, glavobolja, abdominalni grčevi, povraćanje te koma. Nažalost, smrt je također mogući ishod trovanja i to samo nekoliko dana nakon konzumacije intoksiciranih školjkaša. Toksični fitoplanktonski organizmi svojim masovnim razmnožavanjem povećano troše kisik i na taj način uzrokuju cvjetanje algi, često nazvano i cvjetanje mora, koje može biti uzrok masovnom trovanju mekušaca, riba, ptica i ostalih organizama koji su na bilo koji način povezani uz more.Domoic acid is a neurotoxin, the main representative of the ASP group of toxic compounds (Amnesic Shellfish Poisoning). It can be bioaccumulated in marine organisms such as bivalves and fishes, which feed on phytoplankton, the main source of toxic compounds in the sea. Symptoms of poisoning with shellfish that contain domoic acid in humans include memory loss, disorientation, headache, abdominal cramps, vomiting and finally coma. Unfortunately, death is also a possible outcome of poisoning, just a few days following ingestion of intoxicated shellfish. Toxic phytoplankton organisms, with a high mass reproduction efficiency, increasingly consume oxygen and cause algae blooms, which may cause mass poisoning of molluscs, fishes, birds and other organisms, which are in any way associated with the sea
Microorganisms in bioremediation
No full textBioremedijacija je proces u kojem se mikroorganizmi koriste za sanaciju okoliša i uklanjanje toksičnih spojeva iz ekosustava. Zahvaljujući tome što mikroorganizmi mogu živjeti na zagaĎenom području i vrlo su prilagodljivi na teške životne uvjete koriste se u procesu bioremedijacije. Evolucijski su razvili mnoge enzime kojima razgraĎuju i razne umjetno stvorene spojeve i tako osiguravaju sebi energiju za život i rast. Razvojem tehnologije i mnogih tehnika saniranja okoliša možemo kvalitetno upotrijebiti navedene karakteristike organizama u sanaciji okoliša bez prouzrokovanja daljnje štete na okoliš. Kako bi proces bio što brži i efikasniji potrebno je poznavati prirodu i karakteristike mikroorganizama, kemijske strukture zagaĎivala te karakteristike zagaĎenog tla, podzemnih voda i mora. Na optimizaciju bioremedijacije utječu abiotički i biotički čimbenici kao što su nutrijenti, temperatura, dotok kisika i kompeticija meĎu mikroorganizmima.Bioremediation is a process that uses microorganisms to degrade toxic compounds in the polluted environment. Microorganisms are able to survive in the most hostile environments and they can adapt quickly to the local environmental conditions. Over the years, During the evolution, microbes developed many enzymes that can break down various artificially created compounds, and thus provide themselves with the energy needed for life and growth. With the development of environmental technology and technological progress in general, we can use certain characteristics of microorganisms in bioremediation without harming the environment. To make the process fast and efficient, it is necessary to know the nature and characteristics of microorganisms, the chemical structure of contaminants, and the characteristics of the contaminated area. Bioremediation is usually regulated by abiotic and biotic factors such as nutrients, temperature, oxygen supply, and competition between microorganisms
The effect of the mixture of enzymes as nutritional supplements for the gilthead seabream Sparus aurata L.
No full textTestiran je enzimski dodatak ENZYMMIX - F u ribljoj hrani s ciljem procjene učinkovitosti i iskoristivosti hranjivih sastavnica s obzirom na različite koncentracije enzima (0,5%, 1%, 5%, 10%) u odnosu na kontrolnu skupinu (bez enzima). Pritom su analizirani parametri rasta, biokemijski te masnokiselinski sastav mišićnog tkiva mlađi komarče (Sparus aurata). Jedinke prosječne mase 11,96 ± 4,89 g (±SD) i dužine 9,47±1,15 cm (N=600) bile su raspoređene unutar pet pokusnih skupina, s tim da je svaka tretmanska skupina sagledavana kroz tri replikacije. Korišteni su četvrtasti bazeni zaobljenih uglova, volumena 70 litara svaki, s protočnim optokom prethodno filtriranog ambijentalnog mora. Pokus je tajao 60 dana. Statistički značajne razlike u dužini riba utvrđene su između pokusne skupine s 10% enzima u hrani i ostalih pokusnih skupina. Skupina s 0,5% enzima u hrani imala je najveći maseni prirast i posljedično najbolji indeks kondicije u odnosu na ostale tretmanske skupine te najslabiji rast u dužini. Vrijednost b>3 dužinsko-masenog odnosa kod pokusne skupine s 0,5% enzima u hrani upućuje na pozitivan alometrijski rast ribe. Nije zabilježen povećan prirast mase i specifične stope rasta tretmanskih skupina u odnosu na kontrolnu skupinu. Veći udio prehrambeno korisnih masnih kiselina (palmitinska, oleinska, linolna, EPA, DPA i DHA) uočen je kod svih pokusnih skupina riba hranjenih smjesom komercijalne hrane obogaćene enzimskim dodatkom. Probabljivost fosfora iz riblje hrane je najbolja kod pokusne skupine s 10% enzima u hrani.ENZYMMIX - F enzyme supplementation in fish food was tested to evaluate the efficacy and usefulness of nutrient components with respect to different enzyme concentrations (0,5%, 1%, 5%, 10%) compared to control group (without enzyme). The growth parameters, the biochemical and the fatty acid composition of the muscle tissue of the gilthead seabream (Sparus aurata) were analyzed. Units of average mass of 11,96 ±4,83 g (±SD) and length of 9,47 ± 1,15 cm (N=600) were distributed within five experimental groups, so that each treatment group was screened through three replications. Square pools with rounded corners, a volume of 70 liters each, have been used and with a flow of optically pre-filtered abient water. The test lasted for 60 days. Statistically significant differences in the length of fish were found between the 10% enzyme experiment in food and other experimental groups. A group of 0,5% enzymes in food had the highest mass gain, and consequently the best Fulton's conditions factor in comparison to other treatment groups, and the lowest growth in length. The b>3 length-to-weight ratio in the 0,5% of the food enzymes in the food indicates a positive alometric growth of fish. Increase in weight gain and a higher specific growth rate of test specimens has not been recorded in treatment group compared to the control group. A higher proportion of dietary fatty acids (palmitic, oleic, linoleic, EPA, DPA and DHA) was observed in all experimental groups of fish fed by commercially food enriched enzyme supplement. Apparent digestibility coefficients of phosphorus from fish food is highest in the experimental group with 10% enzyme in food
Food additives in marine products
No full textPrehrambeni aditivi ili dodaci koriste se u proizvodnji hrane kako bi se proizvodima produljio rok trajanja ili poboljšala određena svojstva. Dodaci hrani mogu biti prirodni ili umjetni (sintetizirani). U proizvodima morskog ribarstva dodaci se najčešće koriste za sprječavanje oksidacije lipida koja uvelike utječe na kakvoću tih proizvoda te za kočenje rasta mikroorganizama. Današnji prehrambeni trendovi promiču korištenje prirodnih aditiva u proizvodima, jer umjetni u većim količinama mogu izazvati štetan učinak za ljudsko zdravlje. Od prirodnih aditiva u ribarstvu se najčešće koriste biljke i biljni ekstrakti koji ne samo da svojom aromom doprinose okusu proizvoda već imaju antioksidativni i antimikrobni učinak u proizvodu. Kako bi se osigurala pravilna uporaba aditiva u hrani i spriječile alergijske reakcije kod ljudi, aditivi su kategorizirani i označeni E brojevima te je njihova primjena regulirana kroz zakonske akte. Iz istoga je razloga jako važno da je proizvod dobro i jasno deklariran zbog sigurnosti i zdravlja potrošača.Nutritive supplements are often used in food production in order to prolong shelf life of the product or to enhance some particular product properties. These supplements can be classified in two categories: natural and artificial. Fishing industry usually uses supplements to slow down growth of microorganisms, as well as to prevent oxidation of lipids, which can have a great impact on the quality of the product. Current trends in nutrition are promoting usage of natural supplements, since artificial ones may have a negative impact on human health. The most common natural additives used in fishing industry are various herbs and herbal extracts, which improve the product's aroma and have anti-oxidant and antimicrobial effect. In order to ensure proper usage of supplements in dietary products and to prevent allergic reactions, all supplements must be categorised and marked by a special E number. Furthermore, usage of these supplements is strictly regulated by laws. Hence, it is very important that each product has a valid and accurate product declaration to avoid any negative impact on the end consumers
Teleconnection of hemispheric meteorological indices and climate of the Adriatic Sea
Get PDFU ovoj disertaciji predstavljeni su rezultati istraživanja utjecaja daljinskih meteoroloških indeksa na klimu Jadrana. Obrađeni su dugogodišnji (> 50 godina) podatci oborine i temperature zraka mjereni na odabranim postajama na Jadranu, te daljinski meteorološki indeksi koji su preuzeti iz NCAR/NCEP baze podataka. Podaci su obrađeni odabranim statističkim metodama: metode za određivanje anomalija, prosjeka, kliznih srednjaka, standardne devijacije, te korelacije. Najveći utjecaj na Jadran je Sjeverno-atlantska oscilacija ili NAO, zatim Istočno-atlantska ili EA, Istočnoatlantska-zapadnoruska struktura ili EA-WR, Skandinavska struktura ili SCA i kao globalno važna struktura El Ninõ. Rezultati su prikazani grafovima i tablicama za svaku strukturu i njihove indekse posebno.In this dissertation, a study has been presented of how teleconnection hemispheric meteorological indexes indices affect the Adriatic climate. Long-term precipitation data and air temperature measured at selected stations in the Adriatic, and teleconnection meteorological indexes that are downloaded from the NCAR / NCEP database have been processed. Data were processed using selected statistical methods: methods for determining anomalies, averages, sliding averages, standard deviations, and correlations. The largest impact on the Adriatic is North Atlantic oscillation or NAO, followed by East Atlantic or EA, followed by East Atlantic / Western Russian structure or EA / WR, Scandinavian structure or SCA, and as a globally important structure El Ninõ. The results are presented graphs and tables for each structure and their indices in particular
Influence of soak time on catch performance of commercial Norway lobster creels in fishing zone G
No full textOvim radom je ispitana efikasnost ulova vrša za lov škampa koje su u moru provele jedan i dva dana. Istraživanje je provedeno u periodu od 26. svibnja 2016. godine do 5. srpnja 2016. godine na području ribolovne zone G (Brački i Hvarski kanal). Analiziran je ulov 2400 vrša. Ukupno je ulovljeno 2153 jedinki raspodijeljenih na 25 različitih vrsta. Škamp (Nephrops norvegicus), ugotica (Trisopterus minutus), vabić (Squilla mantis), gira oštrulja (Spicara flexuosa) i rakovica loptašica (Liocarcinus depurator) su vrste koje su sačinjavale 98% ukupnog ulova. Rezultati su pokazali da vrijeme urona nema statistički značajnog utjecaja na efikasnost ulova škampa, ugotice, vabića i rakovice loptašice. Ulov gire oštrulje u vršama koje su u moru provele dva dana statistički je značajno manji u odnosu na vrše koje su u moru provele jedan dan.This graduate thesis investigates the influence of one and two-day soak time on the catch performance of commercial Norway lobster creels. The study was conducted from May 26th 2016 through July 5th 2016, in the fishing zone G (Brač and Hvar Channel). A catch of 2400 creels was analysed. In total, 2153 individuals belonging to 25 different species were captured. Nephrops norvegicus, Trisopterus minutus, Squilla mantis, Spicara flexuosa and Liocarcinus depurator accounted for 98% of the total catch. The results showed that the increase in soak time from one to two days did not significantly increase the catch of Nephrops norvegicus, Trisopterus minutus, Squilla mantis and Liocarcinus depurator. The catch of Spicara flexuosa was significantly reduced in creels that were soaked for two days
Biologically active substances from marine invertebrates
No full textMorski beskralježnjaci su skupina unutar životinjskog carstva koja ima široku
rasprostranjenost i raznolikost. Kod nekih skupina morskih bekralježnjaka kao što su spužve,
žarnjaci, mekušci, mahovnjaci i mješčićnice pronalazimo veliki broj sekundarnih metabolita
koje ovi organizmi koriste u svrhu obrane od predatora, komunikacije ili kao prednost pri
kompeticiji. S početkom 20. stoljeća otkriveno je kako ovi sekundarni metaboliti posjeduju
različita farmakološka obilježja, a brojna istraživanja su dokazala kako bi se ovi kemijski
spojevi mogli koristiti u medicinske svrhe. Najbitnija obilježja ovih spojeva su njihova
antitumorska, antibakterijska, antimikrobna te antivirusna aktivnost. Određeni metaboliti
posjeduju svojstva koja djeluju na različite stanične mehanizme, a mogu se koristiti u
liječenju bolesti živčanog sustava, ili mogu imati primjenu u molekularnoj biologiji kao sonde
za opisivanje i istraživanje različitih staničnih procesa.Marine invertebrates are a group within the animal kingdom which are widely dispersed and
diverse. In some groups of marine invertebrates such as sponges, cnidarians, molluscs,
bryozoans and ascidians we find a large number of secondary metabolites which are used by
this organisms for protection from predators, communcation or as a competitive advantage.
Starting in 20th century, it was discovered that these secondary metabolites have various
pharmacological properties and many studies have proved that these chemical compounds
could be used in medical purposes. Most important properties are antitumor, antibacterial,
antimicrobial and antiviral effects. Some compounds though have properties that have effect
on various cellular mechanisms, and can be used in treatment of nervous diseases or have
their application in molecular biology as probes, describing and exploring various cellular
processes
Intrusions of the saltwater into the river estuaries
No full textTema ovog rada su prodori morske vode u riječna korita. Prikazana su istraživanja na tri hrvatske rijeke Neretvi, Jadru i Rječini. Primjeri zaslanjivanja korita rijeke Neretve prikazani su pomoću numeričkog modela stratificiranog strujanja. Pri analizi zaslanjivanja ušća rijeke Jadro, primijenjen je identičan model kao i u slučaju Neretve, a u proučavanju procesa zaslanjivanja ušća Rječine korištena je regresijska analiza. U uvodnom dijelu rada opisan je utjecaj rijeka na more, podjela estuarija i zaslanjivanje riječnih ušća općenito. Utvrđeno je da u području donje Neretve postoje dva prirodna pravca prodora slane morske vode: prvi, kroz korito rijeke Neretve, te drugi kroz duboke podzemne slojeve. Prikazan je i opisan model stratificiranog strujanja te je primijenjen za proračun zaslanjivanja rijeke Neretve. Kvalitetan uvid u procese zaslanjivanja ušća rijeke Jadro dobiven je primjenom numeričkog modela za različita hidrološka stanja. Istraživanja Krvavice i sur. (2013) pokazala su da je u ušću Rječine prisutno stratificirano strujanje slatke riječne vode iznad klina slane morske vode. Izradili su nekoliko regresijskih modela koji opisuju funkcionalnu vezu protoka Rječine s duljinom slanog klina i dubinom razdjelnice slojeva.Subject of this work is intrusion of the saltwater into the river estuaries. Investigations conducted on three rivers: Neretva, Jadro and Rječina, are shown. The examples of salinization of Neretva riverbed are shown using the numerical model of the current flow. The same model applied for Neretva estuary, was also used for Jadro River, whereas salinization of the Rječina is described using regression analysis. Introduction describes influence of rivers on the sea, types of river estuaries and salinization of river mouths in general. Two natural pathways of salt water in the lower parts of Neretva River are discovered: the first one, through the Neretva riverbed, and the second one through deep underground layers. Model of the current flow and its application for the Neretva intrusions is described. Application of the same numerical model for different hydrological conditions, resulted in high-quality insight of salinization in Jadro River. Investigations conducted by Krvavica et al. (2012) reveal flow of fresh water above wedge of salt sea water in the lower part of Rječina River. Several regression analyses were made to describe functional connection between the Rječina flow rate and the salt wedge length