Ekološka studija o razmnožavanju endolitskih babica na pješčenjaku tršćanskog zaljeva

The present research aimed at evaluating the importance of endolithic holes for the spawning of blennies and at studying the selection and utilization of holes by blennies in the Gulf of Trieste. The study was conducted using the all-occurrence sampling method, a non-destructive visual census method, aided by SCUBA. Resident, egg-guarding males of Lipophrys dalmatinus, Lipophrys canevae, Aidablennius sphynx, Parablennius incognitus, Parablennius zvonimiri and Parablennius rouxi were caught. Speciesspecific differences in the utilization of holes were found for species that nest in endolithic holes. Smaller species (e.g. Lipophrys dalmatinus and Lipophrys canevae) choose holes that are little larger than their heads and approximately as long as their body, which prevent small males from being dislodged by bigger ones. Bigger species that are probably less exposed to interspecific competition for holes, choose mostly holes with an entrance diameter twice as big as their head diameter and much longer than their body. Species living in shallow waters (e.g. Aidablennius sphynx) prefer hole positions exposed to daylight, while species living in deeper waters were mostly found in the shade of boulders and rocks.Cilj ovog rada je istaknuti značaj endolitskih rupa za razmnožavanje endolitskih babica i proučavanje načina odabira i uporabe istih u tršćanskom zaljevu. U radu su primjenjene metode neselektivnog uzorkovanja i vizualna metoda potpomognuta SCUBA promatranjem. Uzorkovani su primjerci mužjaka koji su čuvali polegnuta jaja od grabežljivaca. Zamjećena je različita uporaba rupa ovisno o vrsti koja se razmnožava u endolitskim rupama. Manji primjerci odabiru rupe koje su nešto veće od njihove glave i približno njihove duljine tijela što spriječava mogučnost da manji mužjaci budu istjerani iz rupe od strane većih primjeraka mužjaka. Veći primjerci koji su manje izloženi međusobnom natjecanju za rupu, pretežito biraju rupe sa ulazom čiji je dijametar otvora dvostruko veći od dijametra njihovih glava i veći je od duljine njihovih tijela. Primjerci koji žive u plitkim vodama imaju sklonosti prema rupama izloženim sunčevoj svjetlosti, dok su primjerci iz dubljeg mora pronađeni u sjenovitim mjestima ispod velikih morskih stijena

Najprikladnije vrijeme i dubina za uzorkovanje livada morske cvjetnice Cymodocea nodosa (Ucria) Ascherson, u plitkom obalnom području. Iskustva iz sjevernog Jadrana

The Lesser Neptune grass, Cymodocea nodosa, is the most common seagrass species in shallow sheltered to semi-exposed sites along the Mediterranean soft bottom. The MediSkew index was recently developed as an improvement of the CymSkew index, in order to assess the status of C. nodosa meadows correctly in view of the implementation of three European Directives. The index takes into account the length of the photosynthetic part of C. nodosa leaves, which increases from the less degraded meadow to the most degraded meadow. To adequately assess temporal and spatial trends in the status of C. nodosa meadows, including estimates of the effects of natural disturbances within marine protected areas, the MediSkew index was applied to new samples collected at 3 m and at 6 m of depth, during two months (in July and in September). The analyses are discussed in view of monitoring and conservation of C. nodosa meadows. According to the results of this study, the monitoring programme in the northern Adriatic Sea should be conducted in July, with the collection of samples at 3 m of depth. The presented sampling and assessing methodology proved to be time- and cost-effective for the evaluation of the status of C. nodosa meadows and of human-induced pressures.Čvorasta morska resa, Cymodocea nodosa, najučestalija je vrsta morske cvjetnice u plitkim zaklonjenim i poluzaklonjenim uvalama duž mediteranskog mekog dna. MediSkew indeks je nedavno razvijen kao poboljšanje indeksa CymSkew u cilju ispravne procjene stanja livada vrste C. nodosa u skladu s provedbom triju europskih direktiva. Indeks u obzir uzima duljinu foto sintetskog dijela lišća C. nodosa, koji se povećava od manje do najviše degradirane livade. Kako bi se na odgovarajući način procijenili vremenski i prostorni trendovi stanja livada vrste C. nodosa, uključujući procjene učinaka prirodnih poremećaja unutar zaštićenih morskih područja, MediSkew indeks primijenjen je na nove uzorke prikupljene na 3m dubine i na 6m dubine, tijekom srpnja i rujna. Analize su rađene s obzirom na praćenje i očuvanje livada vrsteC. nodosa. Prema rezultatima ovog istraživanja, program praćenja u sjevernom Jadranu trebao bi biti proveden u srpnju, a uzorci bi se prikupljali na 3m dubine. Prikazana metodologija uzorkovanja i procjenjivanja pokazala se vremenski i troškovno učinkovita za procjenu stanja livada vrste C. nodosa i ljudskog utjecaja na njih

Preoblikovani ključ za brzo određivanje jadranskih babica

The identification key covers 20 species of Blennioidea presently known in the Adriatic Sea, and one additional species known to occur in freshwaters. The standard format of a dichotomous bracket key was used. The key was developed in order to make the process of identification of Adriatic blennioids clear, simple and non-destructive, thus providing a small number of easily verifiable characters instead of proposing overlapping or highly variable characters. The key is also aimed at in-the-lab-training of SCUBA observers, since many biases may influence the accuracy and precision of blennioid identification when using non-destructive visual census techniques.Ključ za određivanje obuhvaća 20 vrsta babica koje su do sada poznate u Jadranskom moru te jednu slatkovodnu vrstu. Za ključ je uzet standardni oblik dihotomskog ključa sa zagradama. Ovaj ključ bi trebao omogućiti da proces određivanje babica u Jadranu bude jasan, jednostavan i nedestruktivan, te stoga sadrži mali kluč lako prepoznatljivih značajki u ključu umjesto preklapajućih ili značajki koje znatno kolebaju. Ključ je namijenjen i za one istraživaće koje koriste SCU BA metode, s obzirom na mnoge neobjektivnosti koje mogu utjecati na ispravnost i preciznost određivanja babica pri uporabi nedestruktivnih vizualnih tehnika

Makrozoobentos mekanih dna južnog dijelg tršćanskog zaljeva: faunistička, biocenozna i ekološka istraživanja

A faunistic, biocoenotic and ecological survey of soft-bottom macrozoobenthic communities was carried out for the southern part of the Gulf of Trieste on the basis of samplings in 2005 and 2006. At 28 sampled stations a total of 14595 specimens belonging to 306 animal taxa were identified. The most abundant species were Capitella capitata, Lumbrineris gracilis, heteromastus filiformis, Corbula gibba and Tellina distorta. The highest relative species abundance in all water bodies was close to 15%. The dominant species confirmed that the environment of the Gulf of Trieste is unstable. This environmental instability could also explain the rather high values of AMBI. The MDS analysis and other applied indices indicated that there were no statistically significant differences between water bodies. The values for Shannon-Wiener diversity index (H’) and Pielou’s index (J’) were among the highest ever recorded for the soft-bottom assemblages of the Gulf of Trieste. The analysis of benthic biocoenoses revealed that the sampling area is a boundary between infra- and circalittoral belts, which could explain the very high species richness.Obavljen je faunistički, biocenozni i ekološki pregled zajednica makrozoobentosa mekih dna južnog dijela tršćanskog zaljeva na temelju uzorkovanja u 2005. i 2006. godini. Uzorci su prikupljani na 28 postaja, a ukupno je sakupljeno 14 595 primjeraka organizama odnosno određeno je 306 životinjskih svojti. Najbrojnije vrste su Capitella capitata, Lumbrineris gracilis, Heteromastus filiformis, Corbula gibba i Tellina distorta. Najveća relativna brojnost vrsta u svim vodenim tijelima iznosila je blizu 15%. Dominantna vrsta je potvrdila da je okruženje u tršćanskom zaljevu nestabilno. Ova nestabilnost okoliša također može objasniti prilično visoke AMBI vrijednosti. MDS analize i druge primjene indeksa ukazuju da nema statistički značajne razlike između vodenih tijela. Vrijednosti za Shannon-Wiener indeks raznolikosti (H‘) i Pielou indeks (J’) bile su prema sastavu među najvišim ikada zabilježenim za mekana dna u tršćanskom zaljevu. Analiza bentoske biocenoze je otkrila da je područje uzimanja uzoraka granica između infra-i cirkalitoralnog pojasa, što bi moglo objasniti izuzetno bogatstvo vrsta

Stjenovita zajednica mediolitoralnog makrozoobentosa u Tršćanskom zaljevu (sjeverni Jadran) duž hidromorfološkog gradijenta

Despite the increasing urban and industrial development in coastal areas our knowledge on direct consequences of coastal modifications on benthic communities is still limited. The aim of the present study was to assess the response of rocky macrozoobenthos mediolittoral communities to human-induced hydromorphological pressures. Sampling was carried out by SCUBA diving and snorkeling in June 2008. Ten sites were selected along a gradient of hydromorphological alterations in the southern part of the Gulf of Trieste. Variables used to describe the stressor gradient were: water retention (from normal hydrology in unprotected coast to closed areas with only one opening), substrate composition, texture and rugosity. Despite natural differences between upper and lower mediolittoral subbelts, the present work showed that human-induced alterations of the coastal zone impact biological assemblages. There was a marked difference in biodiversity among sites with pristine conditions and stressed zones, mainly due to evenness of species distribution. Structural complexity of the substrate resulted to be the main factor influencing benthic diversity in the upper mediolittoral subbelt, while in the lower subbelt also the human-induced water retention seemed to play a key role. Anyhow, this response was complex, and the major human-induced alterations considered had different level of pressure within the two subbelts. The current study has a good potential to contribute to existing coastal assessment methods, since the impact of hydromorphological pressures on mediolittoral communities was almost neglected in the past. However, further work is needed to fully explain the impact of main human-induced threats on benthic communitiesUnatoč rastućem urbanom i industrijskom razvoju u obalnim područjima samo nekolicina istraživača je fokusirana na direktne posljedice obalnih modifikacija na bentičke zajednice. Cilj ovog istraživanja je procijeniti odgovore stjenovitih zajednica mediolitoralnog makrozoobentosa na hidromorfološke pritiske. Uzorkovanje je provedeno ronjenjem sa bocama i ronjenjem na dah u lipnju 2008. godine. Izabrano je deset postaja duž hidromorfološkog gradijenta u južnom dijelu Tršćanskog zaljeva. Upotrebljavane varijable za razvoj gradijenta stresora bile su: zadržavanje vode, sastav supstrata, tekstura i naboranost. Unatoč prirodnim razlikama između gornjih i donjih mediolitoralnih podpojaseva, sadašnji rad je pokazao da promjene krajolika povezane sa ljudskim djelovanjem u obalnoj zoni utječu na biološke cjeline. Postoji značajna razlika u bioraznolikosti između postaja s odličnim ekološkim stanjem i ostalih postaja, uglavnom zbog ravnomjerne rasprostranjenosti vrsta. Strukturna složenost supstrata rezultatirala je time da je bila glavni čimbenik koji utječe na raznolikost bentosa u gornjem mediolitoralnom podpojasu, dok je izgleda u donjem podpojasu ili podregiji također cirkulacija vode odigrala ključnu ulogu (CCA analiza). Odgovor bentičke zajednice bio je kompleksan i vjerojatno su također biotički čimbenici (pokrivenost algama, kompeticija) bili uključeni. Ovo istraživanje ima dobar potencijal da doprinese postojećim metodama procjene obale, iako se treba provesti daljnje istraživanje na području utjecaja kojeg imaju hidromorfološke promjene na obalne bentičke zajednice

Neuobičajeno cvjetanje tetrasporofita nezavičajnih crvenih algi Asparagopsis armata na sjevernom Jadranu

The tetrasporophyte of the non-indigenous red alga Asparagopsis armata (the Falkenbergia stage) is considered to be established in Slovenian coastal waters. However, until 2016, it was found only in low coverage and in few localities with hard substrata. The paper reports a recent bloom of these tetrasporophytes in the mediolittoral belt of the Bay of Piran, where thalli of this red alga overgrew the articularted coralline alga Corallina officinalis. The sites affected by this large expansion of tetrasporophytes of A. armata should be regularly monitored in the future, in order to point out which environmental factors are responsible for such phenomenon, and to formulate proper conclusions on the status of this non-indigenous alga in the coastal area concerned.Tetrasporofite ne-autohtone crvene alge Asparagopsis armata (Falkenbergia faza) smatra se prisutnom u slovenskim obalnim vodama. Međutim, do 2016. godine, ustanovljena je isključivo mala pokrivenost i to na nekoliko lokaliteta s tvrdom podlogom (sediment). U ovom radu se navodi nedavni procvat tetrasoprofita u mezolitoralnom pojasu Piranskog zaljeva gdje je crvena alga A. armata nadjačala koraljnu algu Corallina officinalis. U budućnosti će se redovito nadzirati mjesta na koja utječe ova velika ekspanzija tetrasporofita, kako bi se istaknulo koji su ekološki čimbenici odgovorni za takav fenomen, te da bi se mogli formulirati odgovarajući zaključci o statusu ove ne-autohtone alge u tim obalnim područjima

Pregled puževa golaća u Bokokotorskom zaljevu, Crna Gora

Heterobranch molluscs fauna in Montenegro has been poorly investigated so far. The aim of the present paper is to improve the knowledge about species diversity of these marine organisms in the Boka Kotorska Bay, a specific fjord-like entity in the southern Adriatic Sea. New records of seven heterobranch species were obtained by field surveys in 2017, while three new records were provided by analysing underwater photographs from previous periods. The resulted checklist summarizes the knowledge of the diversity of heterobranchs in the Boka Kotorska Bay from the oldest record in 1967 to the present day and consists of a total of 62 heterobranch species.Fauna puževa golaća (Heterobranchia) u Crnoj Gori je do sada slabo istražena. Cilj ovog rada je bio unaprijediti saznanja o ovim morskim organizmima u zalivu Boka Kotorska, specifičnom, nalik fjordu zalivu južnog Jadrana. Novi nalazi za sedam vrsta heterobranchia su pronađeni tijekom naših terenskih istraživanja u 2017. godini, dok su podaci za tri nova nalaza dobijeni analizom podvodnih fotografija iz prethodnih razdoblja. Ažurirana lista sumira saznanja o raznolikosti puževa golaća u Bokokotorskom zalijevu od najs-tarijeg zapisa iz 1967.g. do danas, a obuhvaća ukupno 62 vrste

Too Hot to Handle: Effects ofWater Temperature on the Early Life Stages of Gongolaria barbata (Fucales)

Gongolaria barbata plays a crucial role as a habitat-forming Fucales species in the Mediterranean Sea, thriving in shallow, sheltered coastal regions, where it exhibits optimal growth in a temperature range of 10 to 25 ◦C. In the northern Adriatic Sea, a semi-enclosed part of the Mediterranean, there has been a remarkable increase in seawater temperatures in recent decades, often exceeding 28 ◦C in summer. These high temperatures pose a significant threat to the vulnerable early life stages of G. barbata. This study delves into the effects of four temperatures (15, 18, 24, and 28 ◦C) on the growth of G. barbata over its first 16 days, closely monitoring mortality, deformities, and overall survival. Our experiments reveal that higher temperatures can result in deformities and increased mortality of germlings. Notably, a temperature of 28 ◦C resulted in the death of all germlings within the first week, whereas those exposed to 24 ◦C survived until the second week, albeit with significant deformities prior to death. In contrast, germlings cultivated at 15 and 18 ◦C exhibited normal development with minimal deformities. These results highlight the susceptibility of the early life stages of G. barbata to temperature-induced stress and provide valuable insights into the potential consequences of rising seawater temperatures in the Mediterranean

Keep It Simple: Improving the Ex Situ Culture of Cystoseira s.l. to Restore Macroalgal Forests

Brown algae from genus Cystoseira s.l. form dense underwater forests that represent the most productive areas in the Mediterranean Sea. Due to the combined effects of global and local stressors such as climate change, urbanization, and herbivore outbreaks, there has been a severe decline in brown algal forests in the Mediterranean Sea. Natural recovery of depleted sites is unlikely due to the low dispersal capacity of these species, and efficient techniques to restore such habitats are needed. In this context, the aims of our study were (1) to improve and simplify the current ex situ laboratory protocol for the cultivation of Gongolaria barbata by testing the feasibility of some cost-effective and time-efficient techniques on two donor sites of G. barbata and (2) to evaluate the survival and growth of young thalli during the laboratory phase and during the most critical five months after out-planting. Specifically, the following ex situ cultivation methods were tested: (A) cultivation on clay tiles in mesocosms with culture water prepared by three different procedures (a) filtered seawater with a 0.22 m filter membrane, (b) filtered seawater with a 0.7 m filter membrane (GF), and (c) UV-sterilized water, and (B) cultivation on clay tiles in open laboratory systems. After two weeks, all thalli were fixed to plastic lantern net baskets suspended at a depth of 2 m in the coastal sea (hybrid method), and the algal success was monitored in relation to the different donor sites and cultivation protocol. The satisfactory results of this study indicate that UV-sterilized water is suitable for the cultivation of G. barbata in mesocosm, which significantly reduces the cost of the laboratory phase. This opens the possibility of numerous and frequent algal cultures during the reproductive period of the species. Additionally, if the young thalli remain in the lantern net baskets for an extended period of several months, they can grow significantly in the marine environment without being exposed to pressure from herbivorous fish