Repository of the Department of Marine Studies at the University of Split
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The role of marine protected areas in regulating fisheries
No full textU ovom radu je objašnjeno što je zaštićeno morsko područje, kakvi stupnjevi zaštite postoje te što svaki stupanj zaštite podrazumijeva. Navedena je ukupna površina mora i oceana koja se trenutno nalazi pod određenim stupnjem zaštite i različite globalne inicijative koje zagovaraju povećanje broja zaštićenih područja u svijetu. Objašnjen je efekt prelijevanja organizama iz zaštićenih morskih područja u okolna područja i utjecaj koji prelijevanje ima na ulov lokalnih ribara. Navedena je usporedba dinamičnog i statičkog modela zatvaranja određenog morskog područja te njihov utjecaj na ulov neciljanih vrsta. Osim pozitivnih primjera koji zagovaraju zaštitu što veće površine svjetskih mora i oceana, u radu su navedeni i primjeri koji pokazuju da prisustvo zaštićenih morskih područja ne mora nužno imati veliki pozitivni utjecaja na biomasu određenih vrsta. Navedena je i zabrinutost određenih autora vezana za migriranje ribolovnog napora iz zaštićenih morskih područja u nezaštićena i utjecaj navedenog migriranja na iskorištavane organizme.This thesis explains what marine protected area is, different levels of protection that exist and what each level of protection implies. A total fraction of the ocean surface that is currently protected is given together with a description of different global initiatives that advocate the expansion of marine protected areas. A description of the spillover effect, where organisms from marine protected areas are migrating to neighbouring areas and the effect of the spillover on the local fishery is explained. A description of dynamic and static models of closures and their effect on the bycatch reduction is given. This thesis is not only listing positive effects that marine protection areas have on the fisheries resources. It also emphasizes that not all fish species benefit from marine protection areas and describes situation where displacement of the fishing effort from marine protected areas to unprotected areas can also be detrimental to some species
The effect of sampling frequency and spatial and temporal variation in the density of fecal indicator bacteria on the assessment of coastal bathing water quality
No full textThe time and location of sampling as well as the number of samples per season can influence a reliable assessment of bathing water quality. In this study, we investigated the spatio-temporal variation of fecal indicator bacteria (FIB) density and the effects of FIB variability and sampling frequency on the assessment of a single sample and the annual and final assessment of coastal bathing water quality. Increasing the number of samples from 10 to 20 per bathing season had a significant impact on bathing water quality assessment at sites where water quality fluctuations had previously been observed, resulting in a change in water quality to a lower category in 36 % of annual and 54 % of final assessments, suggesting that the minimum number of samples per season should be increased at such sites. Increasing the number of samples at sites assessed as excellent over a longer period had no impact on water quality assessment.
Spatial and temporal variations in FIB density were significant at a considerable number of sites both in the single sample assessment and in the annual and final assessment. Bathing water quality was spatially unrepresentative at a quarter of the sites analyzed and temporally unrepresentative at a fifth, as there was at least one additional point with a lower bathing water quality than the official sampling point or the bathing water quality was lower in the afternoon than in the morning.
When revising the current recreational water quality regulations, the impact of sampling frequency of and of spatio-temporal variation of FIB density on the relevance of bathing water quality assessment at sites subjected to pollution needs to be seriously considered
The technological process of salting fish in the past and today
No full textSoljenje je jedan od najstarijih procesa konzerviranja hrane, posebice ribe. Proces se temelji na biokemijskim promjenama koje se odvijaju zbog djelovanja soli na tkivo sirovine. Zbog visoke koncentracije soli i dehidracije tkiva tijekom soljenja stvaraju se nepovoljni uvjeti za razvoj mikroorganizama. Na području Jadrana najčešće se sole srdela (Sardina pilichardus) i inćun (Engraulis encrasicolus). Soljenje se dijeli na mokro, suho i kombinirano soljenje. Mokro soljenje ili salamurenje je konzerviranje proizvoda potapanjem u zasićenu otopinu soli tijekom kojeg sol brzo prodire u tkivo ribe. Suho soljenje provodi se na način da se riba soli direktno sa suhom solju u posudama i ostavlja da zrije. Ovom tehnikom sol znatno sporije prodire u tkivo nego tijekom mokrog soljenja. Kombinirano soljenje spaja dobre strane i suhog i mokrog soljenja i njime se postižu najbolji rezultati. Industrijsko soljenje obuhvaća oba procesa. Vrijeme zrenja ribe ovisi o temperaturi, vrsti i udjelu masti u mesu ribe. Završetkom zrenja sirovina se dorađuje i nastaje finalni proizvod.Salting has been known to mankind since ancient times as a method of preserving food, especially fish. The process is based on the osmotic effect of salt on the raw tissue, i.e. the cells, creating unfavorable conditions for the vast majority of harmful microorganisms. Salting can be divided into wet, dry and combined salting. In wet salting or curing, the product is preserved by immersing it in a saturated salt solution, whereby the salt quickly penetrates the fish tissue. In dry salting, the salt is applied directly to the fish in containers so that the salt can penetrate the tissue. With this method, the salt is absorbed much more slowly than with curing. Combined salting combines the advantages of wet and dry salting to achieve the best results. The most commonly salted species in the Adriatic region are Sardina pilichardus and Engraulis encrasicolus. Industrial salting involves similar processes to traditional salting, but with the help of mechanization. The maturing time of fish depends on the temperature, species and fat content. Once the maturing process is complete, the material is further processed to create the final product
Distribution and biological characteristics of genus Pagellus in northern and central Adriatic sea
No full textAnalizirane su tri vrste roda Pagellus koje obitavaju u Jadranu (P. erythrinus, P. bogaraveo, P. acarne) korištenjem podataka dobivenih tijekom ekspedicija provedenih na području sjevernog i srednjeg Jadrana u sklopu programa MEDITS u razdoblju od 1996. do 2024. godine. Raspon dubina vrste P. erythrinus kretala se od 21 do 198 m, P. bogaraveo od 24 do 397 m te P. acarne od 24 do 318 m. Vrsta P. erythrinus i P. acarne imaju najveće prosječne indekse brojnosti u stratumu 10–50 m, a P. bogaraveo u stratumu 50–100 m. Raspon ukupnih dužina tijela za sve godine MEDITS istraživanja za P. erythrinus kretao se od 25 do 450 mm, za P. bogaraveo od 65 do 290 mm te za P. acarne od 65 do 250 mm. Analizom dužine i mase proizlazi da P. erythrinus (b=2,6367), P. bogaraveo (b=2,6784) i P. acarne (b=2,8659) imaju negativno alometrijski rast. Omjer spolova (F/F+M*100) za P. erytrhinus iznosi 68,77 % što ukazuje na dominaciju ženki u uzorku, za P. bogaraveo omjer spolova je 9,09 % te za vrstu P. acarne 27,26 %, odnosno kod ove dvije vrste prevladavaju mužjaci u uzorku. Određivanjem udjela pojedinih stupnjeva zrelosti gonada, utvrđeno je da je najviše jedinki oba spola vrste P. erythrinus u stadiju spolnog sazrijevanja (ženke 46,36 %, mužjaci 79,65 %). Za vrstu P. bogaraveo utvrđena je dominacija nezrelih jedinki oba spola (ženke 37,14 % i mužjaci 81,14 %) dok P. acarne ima najviše jedinki oba spola u stadiju sazrijevanja (ženke 71,51 % i mužjaci 58,61 %).Three species of the genus Pagellus living in the Adriatic (P. erythrinus, P. bogaraveo, P. acarne) were analyzed using data obtained during expeditions carried out in the area of the northern and central Adriatic as a part of the MEDITS programme in the period from 1996 to 2024. The depth range of P. erythrinus ranged from 21 to 198 m, P. bogaraveo from 24 to 397 m, and P. acarne from 24 to 318 m. The species P. erythrinus and P. acarne have the highest average abundance indices in the 10-50 m stratum, and P. bogaraveo in the 50-100 m stratum. The range of total body lengths for all years of the MEDITS surveys for P. erythrinus ranged from 25 to 450 mm, for P. bogaraveo from 65 to 290 mm, and for P. acarne from 65 to 250 mm. Analysis of length and mass shows that P. erythrinus (b=2,6367), P. bogaraveo (b=2,6784) and P. acarne (b=2,8659) have negative allometric growth. The sex ratio (F/F+M*100) for P. erytrhinus is 68.77 %, which indicates the dominance of females in the sample, for P. bogaraveo 9.09 % and for the species P. acarne 27.26 %, meaning that for these two species males predominate in the sample. By determining the share of individual stages of gonad maturity, it was determined that most individuals of both sexes of the species P. erythrinus are in the stage of sexual maturation (females 46.36 %, males 79.65 %). For the species P. bogaraveo, the dominance of immature individuals of both sexes was determined (females 37.14 % and males 81.14 %), while P. acarne has the most individuals of both sexes in the maturation stage (females 71.51 % and males 58.61 %)
Otolith morphology and morphometrics of the sardine, Sardina pilchardus (Walbum, 1792) in the eastern Adriatic
No full textTijekom ovog istraživanja analizirana su morfološka i morfometrijska obilježja otolita jedinki srdele koje potječu s područja istočnog Jadrana. Uzorak je činilo ukupno 258 jedinki, od čega je 119 jedinki ženskog spola, 118 jedinki muškog spola, dok kod 21 jedinke spol nije određen. Dužinski raspon tijela ulovljenih jedinki srdele je iznosio od 10,6 do 14,9 cm, s prosječnom dužinom od 12,79 ± 0,68 cm. Masa tijela je bila u rasponu od 10,3 do 32,4 g, s prosječnom vrijednosti od 19,23 ± 3,59 g. Dužinsko–maseni odnos srdele, Sardina pilchardus imao je pozitivnu alometriju, što pokazuje da riba raste brže maseno nego dužinski. Na temelju izmjerenih vrijednosti standardne dužine tijela i mase tijela za srdelu, S. pilchardus je izračunat indeks kondicije 0,559. Otoliti srdele su eliptičnog oblika, s nazubljenim trbušnim rubom. U radu se istraživala veza između morfometrije otolita i standardne dužine i mase tijela jedinki srdele, S. pilchardus. Pri tome je najbolja veza zabilježena između dužine otolita i mase tijela ribe, te možemo zaključiti da se kod primjeraka jedinki srdele, S. pilchardus standardna dužina i masa tijela jedinki mogu najbolje procijeniti iz dužine otolita.During this research, morphological and morphomentric characteristics of sardine otoliths from the eastern Adriatic were analyzed. The sample consisted of a total of 258 individuals, of which 119 individuals were females, 118 were males, while the gender of 21 individual was not determined. The body length range of sardines was from 10.6 to 14.9 cm, with an average length of 12.79 ± 0.68 cm. Body mass ranged from 10.3 to 32.4 g, with an average value of 19.23 ± 3.59 g. The length-mass relationship of Sardina pilchardus had a positive allometry, which shows that the fish grows faster in mass than in lenght. Based on the measured values of standard body length and body mass for sardine, S. pilchardus, a fitness index was 0.559. Sardine otoliths are elliptical in shape, with a jagged ventral edge. The work investigated the relationship between otolith morphometry and the total length and body mass of sardine individuals, S. pilchardus. The best correlation was recorded between the length of the otolith and the weight of the fish, and it can be concluded that the standard body length and weight of the sardine, S. pilchardus, can best be estimated from the length of the otolith
Biomineralization of bivalve shells
No full textBiomineralizacija je rasprostranjen i raznolik proces, a odnosi se na skup procesa kojima organizmi otopljene ione iz okoliša pretvaraju u čvrste minerale. Više od 60 minerala sudjeluje u procesu mineralizacije, a sudjeluju gotovo svi eukarioti. U ovom radu detaljnije su obrađeni školjkaši koji su temeljito istraženi zbog njihove komercijalne upotrebe. Uočeno je da linije rasta ljušture uglavnom proizlaze iz periodičnih odnosno sezonskih, dnevnih ili plimnih procesa, iako se mogu pojaviti nasumične anomalije rasta koje mogu biti izazvane stresnim događajima. Uzorak rasta na ljušturi je vidljiv i prvenstveno odražava promjene okolišnih čimbenika, i zbog toga se školjkaši smatraju biološkim arhivarima, školjkaši se zbog toga smatraju biološkim arhivarima. Iako dolazi do sinkronizacija s varijablama okoliša, točno podrijetlo povećanja rasta ljušture se još uvijek raspravlja u literaturi. Informacije o biosferi ili kemijskom sastavu oceana možemo dobiti zahvaljujući ljušturama školjkaša koje služe kao arhive okolišnih promjena. Neke od metoda za istraživanje ljušture školjkaša kao bioloških arhiva su: LA-ICP-MS metoda, Mg/Ca termometrija, onečišćenje olovom odnosno koncentracija Pb u prirastu ljušture i promatranje promjena u bazi karbonata u ljušturama školjkaša.Biomineralization is a widespread and diverse process, and it refers to a set of processes by which organisms convert dissolved ions from the environment into solid minerals. More than 60 minerals participate in the mineralization process, and almost all eukaryotes participate. This paper deals in more detail with bivalves that have been extensively researched due to their use for commercial purposes. It has been observed that the growth growth lines of the valves result mainly from periodic or seasonal, daily or tidal processes, although random growth anomalies can also occur which can be triggered by stressful events. Therefore, the growth pattern on the valve of the individual is visible and primarily reflects changes in its environment. For this reason bivalves are rearded as biological archives. Information about the biosphere or the chemical composition of the ocean can be obtained thanks to the valve of bivalves, which serve as archives of the environment surrounding the individual. Although it is not yet known how organisms form minerals, we do know how they control their formation. Some of the methods for researching bivalve shells as biological archives are LA-CP-MS method, Mg/Ca thermometry, lead pollution or Pb concentration in the shell growth and observation of changes in the carbonate base in bivalve valves
Levels of gymnodimines and spirolides in the central and southern Adriatic Sea in 2016., 2017. and 2022.
No full textRad prikazuje rezultate istraživanja toksina gimnodimina i spirolida u školjkašima srednjeg i južnog Jadrana s devet postaja tijekom 2016., 2017. i 2022. godine. Istraživanje se provodilo zbog praćenja masenih udjela gimnodimina i spirolida, prirodnih toksina, koji spadaju pod cikličke imine. Sakupljeni su primjerci dagnji, Mytilus galloprovincialis iz uzgajališta i brbavica, Venus verrucosa iz prirodnih populacija. Određivanje gimnodimina i spirolida obavljeno je u Laboratoriju za plankton i toksičnost školjkaša primjenom LC-MS/MS metode, a kvantifikacija primjenom MassHunter programa. Cilj diplomskog rada je prikazati vremensku i prostornu raspodjelu masenih udjela gimnodimina i spirolida u uzorkovanim školjkašima. Do danas nije utvrđen negativan utjecaj gimnodimina i spirolida na ljudsko zdravlje, međutim ustanovljeno je njihovo toksično djelovanje na eksperimentalne životinje, što je razlog za preporuke njihovog praćenja i uključivanja u monitoring aktivnosti.This thesis presents the results of the investigation of gymnodimine and spirolide toxins in shellfish from the central and southern Adriatic Sea from nine stations in 2016, 2017 and 2022. The study was conducted to monitor the mass fractions of gymnodimine and spirolide, natural toxins belonging to cyclic imines. Mytilus galloprovincialis is collected from farms and Venus verrucosa from natural populations. The determination of gymnodimine and spirolide was carried out in the Plankton and Shellfish Toxicity using the LC-MS/MS method and the quantification was performed with the MassHunter program. The aim of the work is to show the temporal and spatial distribution of the mass fractions of gymnodimines and spirolides in the sampled mussels. To date, no negative effects of gymnodimines and spirolides on human health have been identified, but their toxic effect on laboratory animals has been demonstrated, which is the reason for recommendations to monitor them and to start surveillance measures
Spatial temporal changes in the sea level of the Mediteranean Sea
No full textU ovom radu analizirane su prostorno-vremenske promjene razine Sredozemnog mora koristeći podatke iz baze Copernicus Marine Service za razdoblje 1988. do 2020. godine. Korišteni su podaci o visini mora, amonijaku, nitratima, fosfatima i klorofilu. BIOS sustav Jonskog mora značajno utječe na dinamiku morskih struja i biogeokemijska svojstva mora. Primjena Neural Gas algoritma omogućila je prepoznavanje obrazaca promjena. Rezultati pokazuju najveće promjene u Levantinskom moru, s najvišim razinama mora ljeti i najnižim zimi. Više razine mora povezane su sa smanjenjem koncentracija amonijaka i nitrata, dok su veće koncentracije fosfata i nitrata zabilježene pri nižim razinama mora u Jadranu.In this study, the spatio-temporal changes in sea level in the Mediterranean Sea are analyzed using data from the Copernicus Marine Service from 1988 to 2020. Data on sea level, ammonia, nitrates, phosphates and chlorophyll were used.The BiOS system in the Ionian Sea significantly influences sea currents and biogeochemical properties. By applying the Neural Gas algorithm, patterns of change were identified. The results show the largest changes in the Levantine Sea, with the highest sea levels in summer and the lowest in winter. Higher sea levels are associated lower ammonia and nitrate concentrations, while higher phosphate and nitrate concentrations were recorded at lower sea levels in the Adriatic Sea
Ozone hole
No full textU ovom završnome radu predstavljen je pojam ozonske rupe, što on znači, koliki su njegovi gabariti i kako se kroz povijest mijenjao. Cilj ovoga rada je ukazati da loša briga o okolini i veliko zagađenje mogu dovesti do velikih posljedica za naš planet. Zbog ljudske aktivnosti došlo je do deplecije ozona i u njemu su se stvorile „rupe“. Globalno prepoznavanje ovoga problema dovelo je do Montrealskog sporazuma koji je znatno poboljšao sadašnje stanje ozonskih rupa. Na samom kraju rada je predstavljeno sadašnje stanje ozona kao i predviđanje za budućnost ozonskih rupa.In this final assigniment, the term of ozone hole, the meaning of it, it′s sizes and how does it changes throughout history is being presented. The end goal of this work is showing that poor care for the environment and heavy pollution can lead to major consequences for our planet. Ozone depletion has occurred due to human activity and so called „holes“ have formed in it. Global recognition of this problem led to the Montreal Agreement, which significantly improved the current state of ozone holes. At the very end of this assigniment, the present state of ozone hole will be presented, as well as a prediction for it′s future
Morphological and ecological characteristics of bluefish, Pomatomus saltatrix (Linnaeus, 1766) from the northern Adriatic
No full textStrijelka, Pomatomus saltatrix (Linnaeus, 1766) je termofilna, pelagička i migratorna vrsta koja
posljednjih godina postaje sve prisutnija i na području sjevernog Jadrana. Analizirano je 112 jedinki,
prikupljenih od ribara s područja Istre i Kvarnera u razdoblju od travnja 2022. do travnja 2023. godine.
Statistički značajne razlike (p<0,05) utvrđene su između spolova za sljedeće morfometrijskih omjere:
duljina baze druge dorzalne peraje (D2)/ukupna duljina (TL), duljina baze analne peraje (LA)/ukupna
duljina (TL), preanalna duljina (PA)/ukupna duljina (TL), maksimalna tjelesna širina (BW)/ukupna
duljina (TL) i visina njuške (SH)/duljina glave (CL). Metodom vezane mreže nije pronađena statistički
značajna razlika između spolova. Perajna formula strijelke u sjevernom Jadranu je D: VII+25, P: 15, V:
VI, A: 26. Iako su utvrđene sezonske razlike, u ukupnom uzorku zabilježen je negativan alometrijski
rast za mužjake (b = 2,83), ~enke (b =2,79) i sve jedinke zajedno (b = 2,81). Prosječne vrijednosti
Fultonovog faktora kondicije (CF) za mužjake, ženke i sve jedinke zajedno su iznosile 0,84±0,07,
0,80±0,07 odnosno 0,82 ± 0,07 g/cm3. Najstarija jedinka u ovom istraživanju imala je 8 godina, a
parametri von Bertallanfyjeve krivulje dužinskog rasta strijelki u ovom radu su: L> = 105,3194 cm, K
= 0,1664 godina-1, t0 = -1,6421 godina. Intenzitet ishrane strijelke najvibi je u toplijem periodu godine,
a najznačajniji plijen bila je srdela (Sardina pilchardus). Prema vrijednostima gonadosomatskog
indeksa (GSI) u ovom istraživanju, mrijest strijelke u sjevernom Jadranu odvija se ljeti. Zabilježena je
značajna razlika u vrijednostima hepatosomatskog indeksa (HSI) između mužjaka i ženki tijekom
mrijesta.The bluefish, Pomatomus saltatrix (Linnaeus, 1766) is a thermophilic, pelagic and migratory species that has become more present in the area of the northern Adriatic in recent years. A total of 112 individuals, collected from fishermen in the area of Istria and Kvarner in the period from April 2022 to April 2023, were analyzed. Statistically significant differences (p = 105.3194 cm, K = 0.1664 year- 1, t0 = -1.6421 years. The feeding intensity of the bluefish is highest in the warmer period of the year, and the most important prey was the sardine (Sardina pilchardus). According to the gonadosomatic index (GSI) values in this study, spawning of the bluefish in the northern Adriatic takes place in summer. There wasa a significant difference in HSI values between males and females during spawning