Repository of the Department of Marine Studies at the University of Split
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Catch composition of purse seine oližnica in fishing zone A
No full textU ovom radu analiziran je sastav ulova plivarice oližnice veličine oka 10 mm i 14 mm u ribolovnoj zoni A. Uzorci su prikupljeni tijekom deset ribolovnih dana u periodu od siječnja do ožujka 2018. godine. Prosječni maseni udio olige i gavuna Atherina sp. u ulovima plivarice oližnice veličine oka 10 mm iznosio je 76,6%, a plivarice oližnice veličine oka od 14 mm 98,23%. To pokazuje da se za vrijeme trajanja uzorkovanja plivarica oližnica koristila namjenski. Prosječni brojčani udio Atherina sp. se neznatno razlikovao od masenog udjela i iznosio je u mreži veličine oka 10 mm 83,4%, dok je u mreži veličine oka od 14 mm iznosio 96,9%. Prosječna duljina olige i gavuna (Atherina sp.) u ulovu plivarice oližnice veličine oka 10 mm iznosila je 6,52 ± 2,12 cm dok je u ulovu plivarice oližnice veličine oka 14 mm prosječna duljina iznosila 10,5 ± 2,42 cm.This thesis analyses the catch composition of purse seine „oližnica“, made of 10 and 14 mm mesh size in the fishing zone A. The sampling was performed during ten fishing days in period from January to March 2018. Atherina sp. was dominant in catches. In purse seine made of 10 mm mesh size, it represented 76.6% of the total catch, while in the purse seine made of 14 mm mesh size it represents 98.23% of the total catch. In terms of numbers, Atherina sp. was also predominant in the catches. In purse seine made of 10 mm mesh size, it represented 83.4% of the total catch, while in the purse seine made of 14 mm mesh size it represented 96.9% of the total catch. The average length of Atherina sp. in the catches of purse seine made of 10 mm mesh size was 6.52 ± 2.12 cm, while in the catches of purse seine made of 14 mm mesh size, average length was 10.5 ± 2.42 cm
Metabolic activity of the bivalves Noah's ark, Arca noae Linnaeus, 1758 and bearded horse Mussel, Modiolus barbatus (Linnaeus, 1758)
Get PDFMetabolizam je skup kemijskih reakcija u organizmu koje omogućuju izgradnju i razgradnju tvari, dobivanje energije i rast i njegovo poznavanje daje vrijedne informacije o istraženim vrstama. Temeljni cilj ovog rada je istražiti fiziološki odgovor kunjke Arca noae i bijele dagnje Modiolus barbatus na različite vrijednosti saliniteta, količine hrane i veličinu jedinka. Istraživana je potrošnja kisika, izlučivanje amonijaka, atomski odnos kisika i dušika (O:N) i stopa pročišćavanja. Iako su ove vrste često istraživane, vrlo je malo podataka objavljeno o njihovim fiziološkim odgovorima na stres. Istraživanje je provedeno u Malostonskom zaljevu u razdoblju od travnja 2014. do lipnja 2016. godine. Zabilježena je statistički značajna razlika u potrošnji kisika kunjke u odnosu na različite vrijednosti saliniteta i na različite veličine jedinka. U potrošnji kisika bijele dagnje opažena je statistički značajna razlika u odnosu na vrijeme hranjenja i na različite veličine jedinka. Statistički značajna razlika u izlučivanju amonijaka kod kunjke zabilježena je u odnosu na različite vrijednosti saliniteta, promjenu količine hrane, vrijeme hranjenja i veličine jedinki. Kod bijele dagnje različite vrijednosti saliniteta ne utječu značajno na izlučivanje amonijaka, a statistički značajna razlika javlja se u odnosu na vrijeme izlaganja salinitetu, promjenu količine hrane i vrijeme hranjenja. Različite veličine pokusnih jedinka, promjena količine hrane i vrijeme hranjenja statistički značajno utječu na O:N odnos kunjke i bijele dagnje. Razlike u stopi pročišćavanja kod obje vrste zabilježene su u odnosu na salinitet, vrijeme hranjenja i veličinu jedinka. Vrijeme izlaganja različitom salinitetu ima veći utjecaj kod kunjke. Rezultati pokazuju fiziološki odgovor školjkaša na promijenjene uvjete u kojima bijela dagnja nešto bolje reagira na stres. Sezonska istraživanja bi mogla detaljnije opisati dugotrajniji odnos između ovih vrsta i okoliša.Metabolism is a set of chemical reactions in an organism that provide energy and enable growth and knowledge about its function provides valuable information on the species researched. The aim of this paper was to investigate the physiological response of Noah's ark, Arca noae and bearded horse mussel, Modiolus barbatus to different salinity values, the amount of food and the size of the individual. The oxygen consumption, ammonia excretion, atomic oxygen and nitrogen ratio (O: N) and clearance rate were investigated. Although these species are often explored, very little information has been published about their physiological responses to stress. The study was conducted in the Mali Ston Bay in the period from April 2014 to June 2016. There was a statistically significant difference in the consumption of oxygen of Noah' Ark shell due to different salinity values of seawater and considering the different sizes of test organisms. In the oxygen consumption of bearded horse mussel, a statistically significant difference was observed with respect to feeding time and to different sizes of individuals. There was a statistically significant difference in the excretion of the ammonia of Noah' Ark shell due to the different values of seawater salinity, given the different amount of food, time of feeding and the different size of the individual. In bearded horse mussel different values of seawater salinity do not significantly affect the excretion of ammonia, a statistically significant difference occurs with respect to exposure time to salinity, different amount of food and feeding time. Different sizes of experimental animals, change of food quantity and feeding time statistically significantly affect the O:N ratio of bearded horse mussel and Noah' Ark shell. Differences in the clearance rate in both species were recorded in terms of salinity, feeding time and the size of the individual. Exposure time to different salinity has a greater impact on the Noah' Ark shell. The results show the physiological response of bivalve molluscs to changed conditions where the bearded horse mussels respond better to stress. Seasonal research could provide a more detailed description of the longer-lasting relationship between these species and the environment
Biological and breeding characteristics of tuna
No full textCilj ovog rada je predstaviti tune, kao vrste morskih riba porodice Scombridae. Tune su najrazvijenije meĎu skušovkama, a od četrnaest vrsta tuna, plavoperajne tune (atlantska, pacifička i juţna), ţutoperajna tuna, tunj prugavac, tunj dugokrilac i velikooka tuna se često navode kao komercijalno najznačajnije vrste. Tijela svih riba iz ove porodice su robustna, izduţena i aerodinamična. Preferiraju ţivot blizu površine tropskih, suptropskih i umjerenih oceana i mora. Vaţni okolišni parametri za ove ribe su količina otopljenog kisika, površinska temperatura mora i salinitet. Tune su izvrsni plivači i moraju neprestano plivati da bi preţivjele i zadovoljile potrebe za kisikom. Kreću se u potrazi za hranom ili zbog razmnoţavanja, a migracije su im sezonske. Tune su jedine koštunjače sposobne regulirati svoju tjelesnu temperaturu. Atlantska plavoperajna tuna je jedna od najcjenjenijih vrsta u akvakulturi. Uzgoj plavoperajne tune na Mediteranu točnije je nazvati tovom. 2016. godine je prvi put zatvoren ţivotni ciklus ove vrste u zatočeništvu.The aim of this thesis is to present tunas, a group of marine fishes, members of the family Scombridae. The tunas are the most highly evolved of the scombrids and among the 14 species of tuna, bluefin tunas (Atlantic, Pacific and southern bluefin tuna), yellowfin tuna, skipjack, albacore and bigeye, are often referred as principal market tuna species. The bodies of all the fishes in this family are robust, elongate and streamlined. They prefer life near the surface of tropical, subtropical and temperate oceans and seas. Important environmental parameters for these fishes are the quantity of dissolved oxygen, the sea surface temperature and the salinity. Tunas are excellent swimmers and they must swim constantly to stay alive and to satisfy oxygen requirements. They move to search for food or for the purpose of reproduction, migrations are seasonal movements. Among all bony fish, the tunas are unique in ability to regulate their body temperatures. Atlantic bluefin tuna is one of the high value aquaculture species. Atlantic bluefin tuna farming in the Mediterranean is more relevant to call „fattening“. In 2016, the life cycle of this species in captivity, was closed for the first time
AIR - SEA INTERACITON IN THE NORTHERN, MIDDLE AND SOUTH ADRIATIC SEA
No full textOvaj rad donosi prikaz izmjena energija tj. tokova topline na granici atmosfere i mora za odabranu točku na području srednjeg Jadrana. Obrađeni podaci preuzeti su iz specifičnih globalnih spektralnih modela. Obradom podataka dobiveni su odgovori na pitanja u vezi funkcioniranja termohaline cirkulacije, ventilacije pridnenih slojeva te procesa grijanja i hlađenja površinskih slojeva mora. Svi navedeni procesi su uvelike značajni za ekosustav Jadrana. Računati su klizni srednjaci i anomalije te su radi lakše analize prikazani na linijskim grafovima. Analizom su utvrđene sezonske, godišnje, a zatim i dekadne, fluktuacije tokova topline uvjetovane položajem Sunca prema promatranoj točki te globalnim klimatskim promjenama.This paper gives an overview of the energy changes, i.e. the heat flux between atmosphere and the sea for selected point on area of the Middle Adriatic. Analyzed data are taken from specific global spectral models. The processing of the data provided answers to the questions regarding the functioning of thermohaline circulation, ventilation of the bottom layers and the process of heating and cooling of the sea surface. All these processes are of great importance for the Adriatic ecosystem. The averages and anomalies data are calculated, analyzed and visualized on line graphics. The analysis determined the seasonal, annual and decadal, fluctuations of the heat flux
IS TBX AGAR A SUITABLE MEDIUM FOR MONITORING ESCHERICHIA COLI IN BATHING WATER USING THE MEMBRANE FILTRATION METHOD?
No full textBudući da se TBX agar uspješno koristi za određivanje i brojenje vrste Escherichia coli u mikrobiologiji hrane pomoću tehnike brojanja kolonija, sa ili bez uporabe membranskih filtera, ideja je bila ispitati je li ga moguće koristiti za određivanje i brojenje navedene vrste u uzorcima mora za kupanje. U ovom radu prikazani su rezultati primjene metode membranske filtracije za brojanje E. coli u uzorcima mora za kupanje koristeći TBX agar. Za testnu metodu su korišteni različiti mediji: TBX agar, jednoslojni MMGA i TBX agar te dvoslojni MMGA/TBX agar. Za određivanje temeljnih značajki TBX agara, različiti volumeni prirodnih uzoraka su filtrirani i inkubirani na odabranom mediju i različitim uvjetima inkubacije. Rezultati pokazuju da pre-inkubacija u blažim uvjetima (36±2°C) i na neselektivnom mediju (MMGA) značajno povećava oporavak bakterijskih stanica, što rezultira većim brojem E. coli. Inkubacija pri 44±0.5°C na dvoslojnom MMGA/TBX agaru sa 6-satnom preinkubacijom pri 36±2°C te naizmjenična inkubacija, 4-satna preinkubacija na MMGA pri 36±2°C praćena 20-satnom inkubacijom na TBX pri 44± 0.5°C, rezultirali su prihvatljivim relativnim oporavkom E. coli. Postignute kategoričke značajke su prihvatljive pa bi se oba postupka mogla koristiti za određivanje i brojenje E. coli u uzorcima mora za kupanje.Since TBX agar has been successfully used for E. coli detection and enumeration in food microbiology by colony counting technique, with or without using membrane filters, the idea was to examine whether it could be used to detect and enumerate E. coli in bathing seawater samples. This paper presents the results of the membrane filtration method for counting E. coli in seawater samples using TBX agar. Different media were used for test method: TBX agar, single-layered MMGA and TBX agar, and double-layered MMGA/TBX agar. To determine the basic performance characteristics of TBX agar, different volumes of natural samples were filtered and incubated on the selected medium under different incubation conditions. The results suggested that pre-incubation in mild conditions (36±2°C) on non-selective medium (MMGA) significantly increases the recovery of bacterial cells, resulting in higher number of E. coli. Incubation at 44±0.5°C on double-layered MMGA/TBX with 6-hour pre-incubation at 36± 2°C and alternate incubation, 4-hour pre-incubation on MMGA at 36±2°C followed by 20-hour incubation on TBX at 44±0.5°C, resulted in acceptable relative recovery of E. coli. The achieved performance characteristics are acceptable and both procedures could be used for E. coli detection and enumeration in bathing seawater samples
Comparison of catch composition of beach seineswith mesh size of 24 and 12 mm
Get PDFU ovom radu analiziran je ulov obalne potegače migavice u srednjem Jadranu, odnosno u ribolovnoj zoni F. Uzorci su prikupljeni tokom 20 potega mreţama veličine oka u vreći 12 mm i 24 mm. Ukupno je analizirano 5222 primjerka, ukupne mase 109,4 kilograma. U ukupnom ulovu zabiljeţena je 31 vrsta, od čega 28 vrsta riba i 3 vrste glavonoţaca. Po brojčanoj zastupljenosti u ulovu mreţom migavicom veličine oka 12 mm dominantna je gira oblica (Spicara smaris) s 57,1%, a na drugom mjestu je knez (Coris julis) s 14,1% ukupnog ulova. Što se tiče masenog udjela, na prvom mjestu je gira oblica s 37,1%, a na drugom mjestu je bukva (Boops boops) s 17,9% ukupnog ulova. Po brojčanoj zastupljenosti u ulovu migavicom veličine oka 24 mm najbrojnija je bukva s 41,4%, a na drugom mjestu je srdela (Sardina pilchardus) s 20,9%. Što se tiče masenog udjela na prvom mjestu je bukva s 35,6%, a na drugom mjestu je srdela s 18,9% ukupnog ulova. MeĎu najzastupljenijim vrstama, najveći udio spolno nezrelih jedinki u ulovu migavice veličine oka 12 mm zabiljeţen je za giru oblicu, kneza i trlju blataricu, dok je u ulovu migavice veličine oka 24 mm, najveći udio spolno nezrelih jedinki zabiljeţen za bukvu i giru oblicu.This thesis analysed the catch of beach seine migavica in the middle Adriatic Sea, in the fishing zone F. The samples were collected during 20 tows in total with mesh size in the codend being either 12 mm or 24 mm. A total of 5222 specimens were collected, with total weight of 109.4 kilograms. There were 31 species in the catch, of which 28 species of fish and 3 species of cephalopods. Regarding the number of specimens caught with a mesh size of 12 mm, the most represented species in the catch was picarel (Spicara smaris) with 57.1%, followed by mediterranean rainbow wrasse (Coris julis) with 14.1% of the total catch. Regarding the weight, S.smaris is ranked first with 37.1% and bogue (Boops boops) second with 17.9% of the total catch. Regarding the number of specimens caught with a mesh size of 24 mm, the most represented species in the catch was B.boops with 41.4%, followed by european pilchard (Sardina pilchardus) with 20.9% of the total catch. Regarding the weight, B.boops is ranked first with 35.6%, while S. pilchardus is second with 18.9%. For the most abundant species in the catches of beach seine "migavica", the highest proportion of sexually immature specimens caught with mesh size 12 belonged to S.smaris, C.julis and red mullet (M. Barbatus). For the mesh size 24 the highest proportion of sexually immature specimens in the catch belonged to B.boops and S.smaris
Analysis of the seasurface temperature measurement at the "Glava gata" station
No full textU ovom radu analizirana je vremenska promjenjivost površinske temperature mora koja se mjerila na postaji Instituta za oceanografiju i ribarstvo u Splitu u razdoblju od 2000 do 2013. godine. Podatci su obrađeni statističkim metodama: srednja vrijednost, standardna devijacija, anomalije, klizni srednjaci, a skupljani su tijekom 14 godina. Pomoću grafova prikazani su tjedni, mjesečni i godišnji srednjaci mjerenja. Dobiveni su odgovori na pitanja u vezi klime na području Splita, koliki su se ekstremi javljali, te koji su problemi u mjerenjima.This paper presents the time-varying seasurface temperature measured at the station in front of the Institute of Oceanography and Fisheries in Split during 2000-2013 period. Temperature data, collected over 14 years, were processed by statistical methods: mean value, standard deviation, anomalies, sliding averages. Weekly, monthly, and yearly variations of temperature have been graphically represented. Answers to questions on climate variability in the Split area were obtained, as well as answers to questions on extremes, and problems in measurements
Bioactive components of Adriatic algae
No full textAlge su široka skupina uglavnom vodenih fotosintetskih organizama koje se s obzirom na dimenziju talusa dijele na mikroalge i makroalge. Široko su rasprostranjene u morskim ekosustavima a njihova biomasa predstavlja vrijednu sirovinu. Od 17-og stoljeća alge se koriste kao hrana u Aziji, a sve više i u drugim zemljama gdje se smeđe (Odjeljak: Ochrophyta), crvene (Odjeljak: Rhodophyta) i zelene (Odjeljak: Chlorophyta) alge mogu naći u obliku ekstrakata koji se koriste u farmaceutskoj, kozmetičkoj i prehrambenoj industriji. Također, bogate su različitim organskim molekulama koje imaju povoljan utjecaj na zdravlje te mogućnost korištenja u obliku suplemenata. Alge i ekstrakti algi sve se više koriste u različitim industrijama zbog visokog sadržaja bioaktivnih tvari, lake genetske manipulacije i mogućnosti uzgoja u različitim uvjetima. U radu su opisani karakteristični spojevi istaknutih smeđih, zelenih i crvenih alga u Jadranu te njihova svojstva i primjena.Algae are a broad group of mostly water based photosynthetic organisms which considering the size of the thallus exist as macro algae and micro algae. They are widespread in marine ecosystems and their biomass is a valuable raw material. From the 17th century they have been traditionally used as food in Asia and now more and more in other countries, where mostly brown (Division: Ochrophyta), red (Division: Rhodophyta) and green (Division: Chlorophyta) algae can be found in form of extracts which are used in pharmaceutical, cosmetic and food industry. They are rich in various organic molecules that have beneficial effects on human health and are suitable for usage as supplements. Algae and their extracts are increasingly used in many industries due to their high content of bioactive substances, easiness of genetic manipulation and possibility of cultivation in various conditions. This paper describes characteristic compounds of the highlighted brown, green and red algae in the Adriatic Sea, their properties and application
Particulate phosphorus in water column of the middle Adriatic sea
No full textPartikularni fosfor (PP) istraživan je u vodenom stupcu srednjeg Jadrana na 34 postaje, od toga na 7 postaja u priobalju i 4 postaje u otvorenom moru (vertikalna raspodjela), na 4 postaje na uzgajalištima školjkaša i riba (vertikalna raspodjela) i na 19 postaja u estuarijima Krke, Cetine i Jadra (površinski sloj). U svim uzorcima morske vode određene su i koncentracije otopljenog anorganskog (DIP) i ukupnog fosfora (TP).
Na postajama priobalja i otvorenog mora mjereni su hidrografski parametri, koncentracije hranjivih soli dušika i silicija i koncentracije klorofila a. U uzorcima morske vode iz područja srednjeg Jadrana provedena su dva laboratorijska eksperimenta u kojima su koncentracije partikularnog i ukupnog fosfora mjerene tijekom razdoblja od 9 dana.
Koncentracije PP-a u području priobalja i otvorenog mora srednjeg Jadrana bile su u rasponu od 0,007 μmol dm-3 (otvoreno more blizu otoka Palagruže) do 0,589 μmol dm-3 (Šibenski zaljev). U priobalnom području više koncentracije PP-a zabilježene su u površinskom sloju tijekom proljeća, jeseni i zime, a tijekom ljeta u pridnenom sloju. U području otvorenog mora koncentracije PP-a bile su prostorno i vremenski ujednačene. Koncentracije PP-a u području priobalja bile su više od koncentracija otopljenog anorganskog fosfora, a u području otvorenog mora niže. Statističkom analizom rezultata sezonskih istraživanja hranjivih soli, temperature, saliniteta i koncentracija klorofila a određene su značajne pozitivne korelacije PP-a s klorofilom a te hranjivim solima dušika i silicija i negativna korelacija sa salinitetom.
Na uzgajalištima školjkaša najniže koncentracije PP-a izmjerene su na dubini pergolara. U području uzgajališta riba najviše koncentracije PP-a zabilježene su u sloju vodenog stupca gdje se ribe uzgajaju.
Koncentracije PP-a u površinskom sloju duž estuarija rijeka Krke, Cetina i Jadra upućuju na nekonzervativno ponašanje PP-a u odnosu na salinitet. U Cetini i Jadru zabilježeno je pozitivno odstupanje od teoretske raspodjele PP-a duž čitavog estuarija, dok je u Krki u gornjem dijelu estuarija zabilježeno pozitivno odstupanje, a u donjem dijelu negativno odstupanje.Particulate phosphorus (PP) was investigated in the water column of the central Adriatic at 34 stations, of which 7 stations were located in coastal and 4 in the open sea area (vertical distribution), 4 stations at shellfish and fish farms (vertical distribution) and at 19 stations in the estuaries of Krka, Cetina and Jadro rivers (surface layer). At all stations concentrations of dissolved inorganic (DIP) and total phosphorus (TP) were also determined.
Hydrographic parameters, concentrations of nitrogen and silicon nutrient salts and chlorophyll a were also recorded at 11 coastal and open sea stations. In seawater samples from the area of central Adriatic, two laboratory experiments were conducted in which concentrations of particulate and total phosphorus were measured over period of 9 days.
PP concentrations in the coastal and open sea areas were in range from 0,007 μmol dm-3 (open sea near Palagruža Island) to 0,589 μmol dm-3 (Šibenik Bay). In the coastal area higher PP concentrations were recorded in the surface layer during spring, autumn and winter and in the bottom layer during summer.. PP concentrations in the coastal area were higher than the concentration of dissolved inorganic phosphorus, while lower in the open sea area. Statistical analysis of the results determined significant positive correlation of PP with chlorophyll a and nutrient salts of nitrogen and silicon and negative correlation with salinity.
On the shellfish farms, the lowest PP concentrations were measured at the depth of the breeding shellfish. In the fish farm area, the highest concentration of PP was recorded in the layer of water column where organisms are grown.
Concentrations of PP in the surface layer along estuaries of Krka, Cetina and Jadro indicate the non-conservative behavior of PP in relation to salinity. In Cetina and Jadro there was a positive deviation from the theoretical distribution of PP along the entire estuary. In the upper part of the Krka estuary there was a positive deviation and in the lower part negative deviation was recorded. Dissolved inorganic phosphorus was the most common form of phosphorus in the samples of the surface layer in all investigated estuaries
Selectivity of eel pots
Get PDFZa potrebe ovog rada uzorkovane su 94 jedinke jegulje (Anguilla anguilla). Svakog dana, mali uzorak živih jegulja je ubačen u testnu vršu, veličine oka 19,97 mm, koja je postavljena u posudu od 500 l ispunjenu morskom vodom. Nakon 24h, posuda bi se ispraznila, a jeguljama koje su pobjegle kroz oka testne vrše i jeguljama zadržanim unutar vrše izmjerena je ukupna duljina. Na temelju ovih podataka određeni su selektivna krivulja i selekcijski parametri L50 i SR testne vrše za lov jegulje. Mjerenjem opsega najvećeg presjeka jegulja uz pomoć morfometra, te provođenjem testa propadanja, kreiran je prediktivni model kojim je uspješno reproducirana selektivna krivulja testne vrše, te je ustanovljeno da kut otvora mrežnog oka na vrši ne igra nikakvu ulogu u selektivnosti, budući da ga jegulja snagom svog tijela može u potpunosti deformirati tijekom izlaska iz vrše.For the purpose of this thesis, 94 individuals of eel (Anguilla anguilla) were sampled. The eels were previously caught with commercial fyke nets. Each day, a small sample of live eels were transferred inside the test pot, made of 19.97 mm diamond mesh netting. The test pot was placed in a 500 l holding tank filled with seawater. After 24h, holding tank was emptied, eels escaped through the pot meshes and those retained inside the pot were collected and length measured to the nearest mm. Data collected was used to estimate eel pot selectivity. A logit curve was fitted to the experimental data, allowing the estimation of size selection parameters L50 and SR. Using the morphometer, we measured two cross sections with maximum circumference. The eels were then tested for their ability to pass through the range of mesh sizes from 14 mm to 40 mm, with mesh opening angles ranging from 15° to 90°. All this data was used to create predictive size selection model for eel pots. The prediction obtained using the model successfully recreated experimental size selection curve obtained for the test pot