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Priobalni morski sedimenti predstavljaju završno spremište za razna zagađivala koja mogu znatno utjecati na bentoske zajednice. Kroz resuspenziju ili biološku ugradnju, zagađivala se mogu vratiti u vodeni stupac ili ući u hranidbeni lanac te predstaviti rizik za ljudsko zdravlje. Analizom kvalitativnog i kvantitativnog sastava bentoskih organizama i bakterija kao indikatora izmjerena je razina fekalnog onečišćenja i njen utjecaj na morsko dno u blizini glavnog ispusta grada Rovinja. Izmjerene koncentracije fekalnih koliforma i streptokoka pokazale su da je morsko dno na udaljenosti do 150m jako zagađeno i da onečišćenje na većim udaljenostima opada. Utvrđeno je da se zagađenje najviše širi u sjeverozapadnom smjeru zbog morskih struja i morfologije dna. Trend kretanja onečišćenja sličan je u svim smjerovima osim u sjeveroistočnom gdje zbog smanjenja dubine dolazi do akumulacije fekalnog materijala na 50m od ispusta i opadanja širenja na većoj udaljenosti. Brojnost, raznolikost i distribucija mnogočetinaša, meiofaune, školjkaša i foraminifera pokazale su da je utjecaj ispusta značajan. Blizu ispusta i u smjeru širenja zagađenja prevladavaju oportunističke vrste. Udaljavanjem od izvora zagađenja povećava se raznolikost vrsta. U sjeveroistočnom pravcu na udaljenostima većim od 50m uočena je velika raznolikost svih navedenih organizama, što ukazuje na povoljne uvjete za njihov rast. Prirodni čimbenici kao što su tip sedimenta i organska tvar također su utjecali na distribuciju bentoskih zajednica. Postaje koje su imale veći udio krupnijeg sedimenta s manjim udjelom sitnozrnatih čestica silta i gline odlikovale su se raznolikošću organizama. Preliminarni rezultati ukazuju da na sastav i strukturu bentoskih organizama utječu prirodni i antropogeni čimbenici.

Priobalni morski sedimenti predstavljaju završno spremište za razna zagađivala koja mogu znatno utjecati na bentoske zajednice. Kroz resuspenziju ili biološku ugradnju, zagađivala se mogu vratiti u vodeni stupac ili ući u hranidbeni lanac te predstaviti rizik za ljudsko zdravlje. Analizom kvalitativnog i kvantitativnog sastava bentoskih organizama i bakterija kao indikatora izmjerena je razina fekalnog onečišćenja i njen utjecaj na morsko dno u blizini glavnog ispusta grada Rovinja. Preliminarni podaci ukazuju da je morsko dno u blizini ispusta jako onečišćeno te da opada s udaljenošću od ispusta. Utvrđeno je da se onečišćenje najviše širi u sjeverozapadnom smjeru zbog morskih struja i morfologije dna, dok na 50 m u smjeru sjeveroistoka zbog smanjenja dubine dolazi do zamjetne akumulacije i zadržavanja fekalnog materijala. Brojnost, raznolikost i distribucija mnogočetinaša, meiofaune, školjkaša i foraminifera također su pokazale da je utjecaj ispusta značajan. Blizu ispusta i u smjeru širenja onečišćenja prevladavaju oportunističke vrste. Udaljavanjem od izvora onečišćenja povećava se raznolikost vrsta. U sjeveroistočnom pravcu na udaljenostima većim od 50 m uočena je velika raznolikost svih navedenih organizama, što ukazuje na povoljne uvjete za njihov rast. Prirodni čimbenici kao što su tip sedimenta i organska tvar također su utjecali na distribuciju bentoskih zajednica. Postaje koje su imale veći udio krupnijeg sedimenta s manjim udjelom sitnozrnatih čestica silta i gline odlikovale su se raznolikošću organizama. Dosadašnji rezultati pokazuju da na sastav i strukturu bentoskih organizama utječu prirodni i antropogeni čimbenici. Očekujemo da će preostale analize upotpuniti i potvrditi navedene rezultate.

Data set used in ANN-SOM approach has been obtained from 48 sediment samples taken from the River Cetina estuary (eastern coast of the Adriatic Sea). The sediment cores (up to 12 cm long) were collected at two stations (P1 and P2) in front of the Cetina River mouth over the period of one year (four sampling campaigns: May, August, November 2003 and April 2004). As ANN work with numerical data sets only, a quantitative analysis of benthic foraminifera was performed on the fraction >63 µm. All the parameters have been scaled down using normalization methods which ensured that they all have the same impact on the ANN. As opposed to standard data analysis and low dimensional statistical observations ANN are able to comprehend today’s modern environments with numerous characteristics (sediment type, organic matter, etc.) in a more complex manner by correlating all the parameters of the data set. This was the core idea for this experimental approach. The data set was used to prepare two record sets (two tables) that could be used for cluster forming analysis. Five tests were performed to determine the clusters in two record sets using Self Organizing Maps (SOMs). In the first test a relative abundance of foraminifera per sample was used (the first record set) which pointed out dominant species of foraminifera. Three clusters were formed. The first and the biggest cluster gathered foraminiferas that occurred rarely on both stations. The second cluster contained foraminiferas with moderate occurrence (Bulimina aculeata, Cribroelphidium decipiens, Cibicides sp., Rosalina bradyi, Ammonia inflata and Miliolinella subrotunda). In the third cluster dominant species were found. The third cluster contained sub-clusters which separated dominant species on station P1 (Elphidium punctatum, Quinqueloculina sp., Q. seminula, Q. bosciana, Globorotalia sp., Globigerina sp. and Ammonia tepida) and dominant species on station P2 (Pseudoparrella exigua, Haynesina depressula and Ammonia tepida). Relative abundance of species, granulometric parameters, organic matter, carbonates, foraminiferal density and relative number of planktonic species were used (the second record set) in the remaining 4 tests which were done by excluding certain parameters from the analysis under suspicion that they had greater influence in cluster forming than the other parameters. The second test was done using the whole second record set but it was suspected that the foraminiferal density and the number of planktonic species were too concrete for the analysis. The third test included the second record set with all the parameters except foraminiferal density and relative number of planktonic species. Generally, the SOM map was divided among the two stations probably because of the parameters that were characteristic for each station (organic matter, carbonates, etc.). Although station P2 was deeper than the station P1, no data regarding depth were included in this analysis. The most distinctive cluster formed in this test contained data from the first three measurements on the station P1. Sub-cluster structure was also noticeable in this cluster between different sediment layers and measuring seasons on that station. Further analysis of this cluster showed that it could be described with lower values of silt, organic matter, clay, sorting, skewness and curtosis, and higher values of gravel, sand, carbonates and mean size. It is interesting how the cluster was clearly formed under influence of all these parameters. The last two tests were done additionally only for better understanding of the cluster forming by analyzing separately the relative abundance of species and granulometric parameters. The test results showed that, indeed, clusters and sub-clusters were formed in a way so that they could be described by common parameter values. Different graphical visualizations of the clusters were able to show how each parameter in the record sets participated in forming certain clusters. These tools could be better utilized if bigger data sets were available where the full potential of this approach would come to the fore.

Analizirana je foraminiferska zajednica iz površinskog sloja sedimenata dna Jadranskog mora. Cilj istraživanja bio je usporediti sastav zajednica, bioraznolikost i dominaciju s istog tipa sedimenata, ali s različitih dubina i geografski udaljenih postaja. Uzorkovanja su provedena u različitim okolišima obalne zone uzduž istočne obale Jadranskog mora, idući od sjevera prema jugu u razdoblju od 1995. do 2008: Piranski zaljev, uvala Malinska na otoku Krku, uvala Novi Vinodolski, otok Zverinac, ušće rijeke Cetine, otok Vis (6, 5 km od SI obale) te tjesnac Oštro (Bokokotorska vrata). Uzorci su uzeti s dubina od 2 m do 108 m, različitim tehnikama uzorkovanja, ali laboratorijska je obrada slijedila isti protokol: ispiranje na situ promjera 63 mikrona, odvajanje u standardne pod-uzorke od oko 300 jedinki i određivanje vrsta i rodova prema kriterijima LOEBLICH & TAPPAN-ove klasifikacije (1987). Sve interpretacije temelje se na ukupnoj zajednici. Rezultati analize foraminiferske zajednice pokazali su visoku bioraznolikost tipičnu za šelfna mora normalnog saliniteta. Shannon-Wienerov indeks kreće se od 2, 25 u Malinskoj, do 3, 25 na ušću rijeke Cetine ; Fisherov α indeks najmanji je u Malinskoj (8, 9), a najveći u Piranskom zaljevu (16, 8). Na svim postajama tip sedimenta je pijesak, izuzev na otoku Visu i u tjesnacu Oštro, gdje je određen glinoviti pijesak. U zajednicama dominiraju epifaunalni rodovi. U Piranskom zaljevu najbrojnija vrsta je Textularia agglutinans D’ORBIGNY (15% zajednice), a slijede Triloculina affinis D´ORBIGNY, Peneroplis pertusus (FORASKAL), Ammonia beccarii (LINNAEUS) i Cribroelphidium poeyanum (D´ORBIGNY). U uvali Malinska na jedinke vrste P. pertusus otpada čak 48% zajednice, a prema zastupljenosti slijede Elphidium sp. (6, 28%), Siphonaperta aspera (D'ORBIGNY) i Siphonaperta irregularis (D´ORBIGNY), svaka s oko 4%. U uvali Novi Vinodolski jedinke roda Ammonia sačinjavaju oko 55% zajednice, a srednje zastupljene vrste su Miliolinella sp., Elphidium margaritaceum (CUSHMAN) i Elphidium translucens NATLAND. Ispred otoka Zverinca najveći udio u zajednici (6, 4%) ima vrsta Lobatula lobatula (WALKER & JACOB), koju slijede Asterigerinata mamilla (WILLIAMSON), Cibicides boueanus (D´ORBIGNY), Rosalina bradyi (CUSHMAN) i Textularia conica (D´ORBIGNY). Na ušću rijeke Cetine dominantne vrste su Quinqueloculina sp. i Quinqueloculina seminula (LINNAEUS), koje zajedno predstavljaju 35% zajednice, zatim Ammonia tepida (CUSHMAN), Elphidium punctatum TERQUEM i Gyroidinoides sp. Planktonske foraminifere (Globigerina sp., Globorotalia sp.) predstavljaju čak 40% ukupne zajednice. Na postaji u podmorju otoka Visa najbrojnije su jedinke roda Globigerina (21, 4%) i vrste T. agglutinans (10, 5%). U tjesnacu Oštro dominira vrsta Lenticulina cultrata (MONTFORT), sa skoro 11%, a slijede Globigerina bulloides D´ORBIGNY, Globocassidulina subglobosa (BRADY) i Melonis pompiloides (FICHTEL & MOLL). Analizom glavne komponente (PCA) uzorci su grupirani na slijedeći način: Piranski zaljev, uvala Malinska i Novi Vinodolski svrstani su u jednu grupu, Zverinac, Vis i tjesnac Oštro u drugu, dok je ušće rijeke Cetine odvojeno od prethodnih dviju grupa. Sastav zajednica može se protumačiti promjenom dubine mora među grupama i/ili utjecajem riječnog toka: Piranski zaljev, Malinska i Novi Vinodolski karakteriziraju manje dubine mora (od 2 do 33 m), Zverinac, Vis i tjesnac Oštro nalaze se na dubinama od 65 do 108 m, a jedina postaja pod znatnim utjecajem rijeke je ona na ušću Cetine. Na plitkovodnim postajama izrazita je dominacija pojedinih vrsta (P. pertusus i Ammonia sp.), dok sedimenti s dubljevodnih postaja sadrže veće udjele planktonskih foraminifera (što je posljedica utjecaja otvorenog mora). U tjesnacu Oštro, zbog povećanja udjela glinovite komponente u sedimentu, zajednice sadrže više infaunalnih vrsta. Ušće rijeke Cetine specifična je postaja, brojne su jedinke roda Quinqueloculina, a u sedimentima se nalaze i pretaložene eocenske planktonske foraminifere. Iz sastava zajednica, dominacije vrsta, omjera epifaune i infaune, brojnosti oportunista i specijalista te udjela foraminifera prema tipovima stijenki, proizlazi da tip sedimenta dna ne igra važnu ulogu u distribuciji foraminifera, već faktori poput dubine (količine svjetla i količina hrane), ali i rivalski odnosi među vrstama foraminifera.

Benthic foraminifera are a major component of marine communities. They have ability to tolerate a broad range of environmental conditions. Dominant species have been determined ; diversity indices and foraminiferal density were calculated in surface sediments from two karstic river mouths located at east coast of the Adriatic Sea: the Cetina Estuary (CE, outer estuary, depth 30 m) and the Neretva Delta (ND, prodelta, depth 32 m). Both assemblages are dominated by Bulimina, Haynesina, Ammonia and Elphidium genera. However, these genera comprise only 37 % at CE and 70.8 % at ND of total foraminiferal assemblages. At station CE, Fisher α index reaches value of 30.83 and foraminiferal density is 860 specimens per 1 g of dry sediment. On the other hand, at station ND, α index is very low (2.72) and foraminiferal density is 36.8 specimens per 1 g of dry sediment, also. We presume that the difference between foraminiferal assemblages is result of higher river influence at Neretva Delta area.

Two different species of sea urchin, Paracentrotus lividis and Spaerechinus granularis, were collected by scuba divers from the shallow rocky shore in the northern Adriatic Sea, Croatia. Primary spines and the small area of the skeleton under the spines were analyzed by X-ray diffraction. Magnesium calcite was found to be the dominant component and quartz and magnesite were present in small amounts in all samples. However, for an individual organism, a shift of diffraction lines toward higher Bragg angles was noticed, that shift being bigger for the skeletons than for the spines. That is consistent with a contraction in lattice parameters ascribed to a varying fraction of magnesium being included in the crystal structure. The comparison between the two species showed that the skeletons appeared to have the same composition, on the contrary, the needles showed different composition. That analysis opens interesting questions as to why the primary skeleton under the spines of different species is the same yet the needles are different, and what is the biological control mechanism for that contrast.

This work is a continuation of the previous work reported at the 16th Croatian-Slovenian Crystallographic Meeting. Transmission electron microscopy (TEM), SAED and HRTEM were used in order to find and locate starting biominerals in the early embryos of the sea hare species Aplysia punctata. The former results obtained by scanning electron microscopy (ESEM) with energy dispersive X-ray analysis (EDS) showed morphological changes during development of numerous (about 40 in each capsule) embryos incorporated in a jelly-like egg-string immediately after deposition on the substratum ( in a form of a spaghetti-like tissue ) until hatch of the veliger larvae. Diffraction patterns of A. punctata embryos confirmed that the very first aragonite mineral appeared 12 days after egg-strings deposition. Fully formed aragonite crystals were recorded in more developed embryos even before hatching, which occurred 23 days after deposition. The same series of powdered samples of egg-strings and embryos were also used for TEM, SAED and HRTEM investigation. A special attention was paid to the sample of 9 days old embryos that appeared amorphous for XRD. During observation of the amorphous area by TEM, the appearance/precipitation of first grains of a nanocrystalline phase was marked showing a strong reflection in SAED. This precipitation of the first nucleated phase was induced by the electron beam in the amorphous area. Three separate regions were analyzed in order to give confidence of distribution of crystallographic phases. At higher magnification (area of 100x100 nm2), after disappearance of the amorphous area, layers of monocrystalline dolomite in [010] orientation were seen by SAED. In all regions nanocrystalline diffraction rings of calcite or aragonite were observed. It could be presumed that in A. punctata biomineralization process starts by formation of the dolomite crystals which serve as centers of crystallization for further aragonite deposition in the larval shell.

The Adriatic Sea is a long semi-enclosed basin of the Mediterranean whose northern end (North Adriatic) terminates in a relatively flat shelf with a mean depth of 50 m. This shallow shelf area, covering an area of about 29, 000 km2, starts to the north of an imaginary sea line from Pula (Croatia) in the east to Rimini (Italy) in the west. This area is bounded by the Apennines to the west, the Italian Alps to the north, and the Slovenian Alps, Croatian Čičarija and Učka mountains to the east. The geographic position, specific sea bottom topology, semi-enclosed circulation with reduced exchange with Mediterranean waters in the warm period of the year, large seasonal inflow of fresh water from the river Po (Italy) and intensive anthropogenic activity along the entire coast characterize this area resulting in ecological changes that are oftentimes unexpected and sometimes harmful on living marine organisms. In the present study numerous natural environmental events as well as anthropogenic influences on the North Adriatic ecosystem during the past 25 years are described.

Biomineralization is a complex combination of biochemical and physiological processes, depending on endogenous activity of an organism and the exogenous environmental influence. In all marine organisms biomineralization starts in early stages of development and continues throughout the entire life. These processes take place in different tissues, shells and skeletons, and are manifested in calcification, decalcification and in polymorph transformation of calcium carbonate in particular shell or skeleton layers. The calcareous skeletons of the marine organisms act as concentrators of dissolved minor polluting elements in seawater, permitting easier analysis and more reliable measurements than those carried out directly on the water or on soft tissues. The minor elements, including heavy metals and organic molecules, are incorporated in the calcareous structure through isomorphism. For this reason, the shells and skeletons are stable and can be used as bioindicators of different forms of contamination in the sea. This ecological study correlates extreme natural events or harmful environmental factors (lack of oxygen, toxic algal blooms, heavy metals, organic pollutants, antifouling paints) with disease, deformation, mutagenicity or genotoxicity in marine organisms. Furthermore, in this present research the interaction between changed environmental factors, pollutants and biomineralization, calcification processes and mineral composition of marine organisms have been described.

Different, although related, sea hares (Gastropoda, Opisthobranchia, Anaspidea) occur simultaneously over wide areas within the zone of infralittoral algae in the Mediterranean and Adriatic Seas. Species of Aplysia punctata and A. fasciata are characterised by different lengths of embryonal development and especially by morphological differences and size of adult specimens. Scanning electron microscopy was used to determine the physical characteristics of larval shells of the A. punctata. Concurrently, a comparative study of adult shells' morphology in A. punctata and A. fasciata was performed. The spiral veliger shell of the species A. punctata comprised of several smooth surfaces on the curved part, with small visible knobs, delineated by conspicuous lines. On the ventral part in front of the mouth is an outstanding punctuate area. Within the two analysed species A. punctata and A. fasciata the composition of adult reduced shells differ in the size, form and deposits of carbonate and chlorite crystals.

Bottom sediment characteristics and composition dynamics of foraminiferal assemblages in samples taken in front of the Cetina River mouth indicate that this is stable envoronment with the occasional input of large amount of terrigenous material. In this sedimentary environment relative large number of shallow water benthic foraminiferas was found (236) with prevalence of individuals from Quinqueloculina, Ammonia and Haynesina genera.

One of the characteristics of marine gastropods is a spiral shell in the larval life phase which completely encloses and protects the specimen's soft tissue. As distinguished from the majority of other species the Opisthobranch group, in adult life, have solid shells that are more or less reduced. After veliger metamorphosis the shell may develop into a complete shell (Cephalaspidea), a reduced form of simple shell (Anaspidea) or may completely disappear in adult specimens (Nudibranchia). Herein, the crystal structure and phase composition of larval and adult shells of two sea hare species Aplysia spp. were analysed by X-ray diffraction. Diffraction patterns of A. punctata embryos show that the very first aragonite minerals appear 12 days after egg-strings deposition. Fully formed aragonite crystals were recorded in more developed embryos even before hatching (23 days). Veligers have the first shell made of aragonite and interestingly the operculum is also calcified. Morphologically reduced adult shells consist of two organic layers between which is inserted a calcified layer comprising of aragonite (71 M %) and feldspar (19 M %). The first traces of mineralisation within the related species A. fasciata do not appear until 14 days after egg-strings deposition. The adult shell was found to consist only of aragonite crystals.

Bottom sediment characteristics and composition dynamics of foraminiferal assemblages in samples taken in front of the Cetina River mouth indicate that this is stable envoronment with the occasional input of large amount of terrigenous material. In this sedimentary environment relative large number of shallow water benthic foraminiferas was found (236) with prevalence of individuals from Quinqueloculina, Ammonia and Haynesina genera.

Analizirane su foraminiferske zajednice u sedimentnim jezgrama (2 lokacije, 4 uzorkovanja)radi određivanja sezonskih promjena. Pokazalo se da je sedimentacijski okoliš ispred ušća Cetine dinamičan pretežno stabilan okoliš (određeno je 234 foraminiferskih vrsta)s malom dominacijom vrsta.

U području luke Pula te otoka Veliki Brijun uzeta su četiri uzorka sedimenta radi određivanja zajednica živih (obojanih) i ukupnih foraminifera. Za analizu su korišteni poduzorci koji su sadržavali oko 300 jedinki u frakciji sedimenta > 63 μ m. U području luke Pula (postaje P1 i P2) određen je najviši broj rodova (73) te širok raspon broja jedinki na jedan gram suhog sedimenta (272-2682 ind. g-1). Prevladavaju epifaunalne vrste s dominantnim rodom Quinqueloculina, a udio živih (obojanih) jedinki je do 1%. Postaje na području otoka Veliki Brijun sadrže najniži broj vrsta (42) te uži raspon broja jedinki (319-403 ind. g-1). Epifaunalne vrste prevladavaju na postaji s vanjske strane otoka (B1) s dominantnom vrstom Asterigerinata mamilla. Izdvaja se postaja B2 (Ribnjak) sa visokim udjelom infaune i dominacijom roda Ammonia. Udio živih jedinki kreće se od 4 do 14%. Istraživane postaje pripadaju normalnim marinskim uvjetima, što potvrđuju rezultati indeksa biloške raznolikosti (Fisher i Shannon indeks) kao i trokomponentni dijagram odnosa tipova stijenki foraminifera.