NeveN Cukrov - Ruder Boskovic Institute (original) (raw)

Papers by NeveN Cukrov

Anchialine and submarine caves

U radu je dan pregled nastanka, distribucije te ekoloskih znacajki anhijalinih i morem preplavlje... more U radu je dan pregled nastanka, distribucije te ekoloskih znacajki anhijalinih i morem preplavljenih speleoloskih objekata, kao i kratka povijest njihova istraživanja.

Science of The Total Environment, Jun 1, 2020

Understanding the potential bioavailability of trace metals (TM) in marine systems is of prime im... more Understanding the potential bioavailability of trace metals (TM) in marine systems is of prime importance to implement adapted regulations and efficiently protect our coastal and estuarine waters. In this study Diffusive Gradients in Thin films (DGT) technique with two different pore size was used to evaluate the potentially bioavailable fractions (DGT-labile) of Cd, Co, Cu, Ni, Pb and Zn at various depths of a highly stratified estuary (the Krka River estuary, Croatia) both in winter and summer. DGT-labile concentrations were compared to (1) total dissolved concentrations, (2) concentrations of labile species measured by anodic stripping voltammetry (ASV-labile) for Cu and (3) concentrations derived by chemical speciation modelling. High correlation between dissolved and DGT-labile concentrations were found for all metals, except for Zn where contamination problems prevented reliable conclusions. Percentages of DGT-labile fractions over total dissolved concentrations were (AVG±SD): 92±3%, 64±2%, 23±5%, 61±3% and 57±6% for Cd, Pb, Cu, Ni and Co, respectively. No significant difference was found between trace metal concentrations measured with an open pore and restricted pore devices, implying the predominance of kinetically labile metal complexes smaller than 1 nm. For Cu, ASV-labile and DGT labile concentrations were highly correlated (0.97) with ASV-labile concentration being around 35% lower than that of the DGT-labile. Modelling of chemical speciation reliably predicted dynamic (free, inorganic and part of organic complexes) concentration of Cd, whereas dynamic concentrations of Cu and Pb were underestimated by 32% and 65%, respectively. In view of the relative simplicity of DGT devices, they are well suited for the monitoring effort of coastal waters, informing on potentially bioavailable concentrations of TM and thereby, helping to achieve good environmental status of coastal waters, as stipulated within the EU Water Framework Directive.

A preliminary study of the cultivable microbiota on the plastic litter collected by commercial fishing trawlers in the south-eastern Adriatic Sea, with emphasis on Vibrio isolates and their antibiotic resistance

Marine Pollution Bulletin

Oxidative stress biomarkers in fish as biological responses to marine pollution and microplastics

International scientific conference “Marine ecosystems: research and innovations” : Book of abstracts (27-29 October, 2021, Odessa, Ukraine) / Minicheva G.G., Snigirova A.A. (eds.) Odessa-Istanbul, 2021. – 88 pp., 2021

Upotreba podvodne video kamere za procjenu učestalosti pojavljivanja gospodarski važnih vrsta riba na postaji Martinska kraj Šibenika

Iako se radi o preliminarnom rezultatu, mjerenju na temelju samo jednog uzorkovanja, provedeno is... more Iako se radi o preliminarnom rezultatu, mjerenju na temelju samo jednog uzorkovanja, provedeno istraživanje je znacajno jer je otvorilo jednu novu stranicu u istraživanju i razumijevanju tragova ekotoksicnih metala u prirodi na svjetskoj razini.

Geologija estuarija rijeke Krke

Coastal monitoring networks of cabled video-observatories and stand-alone cameras

University of Montenegro, Apr 7, 2019

International Conference Adriatic Biodiversity Protection (AdriBioPro2019), 7-10 April 2019, Koto... more International Conference Adriatic Biodiversity Protection (AdriBioPro2019), 7-10 April 2019, Kotor, Montenegro.-- 2 pagesThe Mediterranean Sea displays high species diversity and represents a key area for study of the impacts of natural and anthropogenic changes on biodiversity and its consequences on ecosystem. Habitat destruction, over-fishing, contaminants, eutrophication, introduction of alien species, and climate changes are causing increasingly evident changes in community structure and biodiversity of this warm and miniaturized ocean. Yet, Mediterranean fish biodiversity is undergoing rapid changes due to the rise of water temperature and the increasing success of thermophile biota. In this context, the analysis of continuous long-term and multiparametric data offers a new and promising opportunity to ecologists to understand those processes which regulate marine biodiversity and may also contribute to define possible strategies of conservation and ecosystem-based management. Coastal-cabled video observatories such as the Observatory of the Sea (OBSEA; www.obsea.es) off Vilanova i la Gertrù (Spain) have been indicated as innovative and challenging technological tools for monitoring fish assemblages in marine systems. In addition, these devices can be successfully employed to monitor and help to understand the responses of fish species to both, environmental drivers and human stressors, as also invoked by the EU Marine Strategy Framework Directive. These multiparametric intelligent platforms represent one of the key elements for Blue Growth development policies. Cabled, fixed and permanent observatories are being worldwide-distributed within growing geographic networks. They provide long-term monitoring of several characteristics (oceanographic, biological etc.) of the seabed and water column at various depths, in a synchronous and highly integrated fashion. Here, we describe how are the video monitoring actions introduced and applied at the OBSEA within the framework of RESBIO Spanish National Project and the resulting experience transferred to a cabled video station in Šibenik , Croati

Geochemical mobility of 137Cs in marine environments based on laboratory and field studies

Chemical Geology, Dec 1, 2022

Estuarine Coastal and Shelf Science, Mar 1, 2019

As an important component of the hydrological and biogeochemical cycle, porewater discharge repre... more As an important component of the hydrological and biogeochemical cycle, porewater discharge represents a significant pathway for releasing chemical solutes into coastal zones, particularly in highly permeable aquifers. In this study, a 222 Rn advection-diffusion model was used to estimate the porewater discharge in a coastal aquifer (Shengsi Island, East China Sea) during November 2015. Porewater discharge was estimated to range from 7.4 to 25.8 (mean: 12.9 ± 5.8) cm d −1. Furthermore, the estimated porewater-derived nutrient fluxes (dissolved inorganic nitrogen (DIN), phosphorus (DIP) and silicon (DSi)) (mol m −2 d −1) were (1.7 ± 1.4) × 10 −2 , (2.1 ± 1.1) × 10 −4 and (1.5 ± 1.3) × 10 −2 , respectively. The Si/N ratio of coastal seawater at Shengsi Island was ∼0.83, which is close to that of porewater along the coastal aquifers of Shengsi Island (∼0.92) but higher than that of the Yangtze River Estuary (∼0.68). Thus, porewater-derived Si flux with a higher Si/N ratio may mitigate the outbreak of non-siliceous algae (i.e., Prorocentrum dentatum) in adjacent waters of Shengsi Island. By comparing the SGD-derived nutrient fluxes worldwide, this study suggests that Si flux with a higher Si/N ratio through porewater discharge (or SGD) may strongly influence the Si budget and cycling because such porewater/SGD-derived Si can compensate for the dwindling Si flux from riverine sources due to human activity (i.e., dam construction, reservoirs). Our results are expected to increase our understanding of not only biogenic elements of cycling processes but also eco-environment processes such as the occurrences of harmful algal blooms alone river-influenced coasts.

Geochimica et Cosmochimica Acta, 2020

Anchialine caves are common in Mediterranean karstic shorelines and elsewhere, delivering point-s... more Anchialine caves are common in Mediterranean karstic shorelines and elsewhere, delivering point-source fresh groundwater and nutrients to the coastal ocean. Here, we first quantified submarine groundwater discharge (SGD) in a typical karstic system (Zaton Bay, Croatia) receiving groundwater from anchialine caves using a radon (222 Rn) mass balance model. We then combine our new observations with the literature to provide a Mediterranean-scale estimate of karstic fresh SGD nutrient fluxes. We found that SGD and related nutrient fluxes in the upper brackish layer were much higher than those in the underlying layer in Zaton Bay. In the upper brackish layer, both SGD (m d À1) and associated nutrient fluxes (mmol m À2 d À1) in the wet season (SGD: 0.29-0.40; DIN: 52; DIP: 0.27) were significantly higher than those in the dry season (SGD: 0.15; DIN: 22; DIP: 0.08). Red tides were observed in the wet season but not in the dry season. Nutrient budgets imply that SGD accounted for >98% of the total dissolved inorganic nitrogen (DIN) and phosphorous (DIP) sources into Zaton Bay. These large SGD nutrient fluxes with high N/P ratios (190-320) likely trigger and sustain red tide outbreaks. Combining our results with 30 previous studies in the region revealed that point-source DIN and DIP fluxes via karstic fresh SGD may account for 8-31% and 1-4%, respectively, of riverine inputs in the Mediterranean Sea. Overall, we demonstrate the importance of karstic SGD as a source of new nutrients with high N/P ratios to the Mediterranean Sea and emphasize how SGD lagging precipitation can drive red tide outbreaks.

Mineralogical and geochemical assessment of marine peloids used for therapeutic purposes from Lokrunja Bay nearby the Pag salt pans (Eastern Adriatic)

Coastal marine sediment quality is being affected nowadays by a combination of human activities, ... more Coastal marine sediment quality is being affected nowadays by a combination of human activities, such as coastal pollution and nutrient enrichment from urban and agricultural runoff, solid-waste leachate, mining spoils and atmospheric deposition. Improper management of urban and industrial waste may greatly affect the quality of coastal marine sediments and all littoral habitats types. Despite regulatory and practical advances in source reduction, disposal of wastes continue to be source of contaminants to the coastal environment. Coastal zone development, first of all urbanization and tourism, altered flow regimes because of coast protection works or modification of water flow. Contaminants are mostly associated with fine-grained materials and/or are characteristic of specific sources or input periods. Four sites were chosen within the salt pan lagoons and canal from Lokrunja Bay nearby the Pag salt pans (Eastern Adriatic) in order to reflect the possible anthropogenic influence on the peloids quality. For each sampling location, a sediment column of up to 15 cm was cut into 5-cm-slices and the mineralogical, chemical and morphological composition of three typical samples was determined. It was found that calcite and quartz are predominant mineral phases, while the concentrations of trace metals, which indicate the anthropogenic influence, are lower than the threshold effect concentrations proposed by generally accepted marine sediments quality standards (Table 1). Accordingly, peloids can be proposed as suitable for therapeutic purposes. However, notable variations in trace metals concentrations among the sampling sites indicate anthropogenic contamination on specific sampling site within the lagoon.

Arhiv Za Higijenu Rada I Toksikologiju, Sep 1, 2006

Mercury is one of the most toxic and hazardous pollutant which occurs in the environment in diffe... more Mercury is one of the most toxic and hazardous pollutant which occurs in the environment in different chemical forms, of which methylmercury is the most dangerous. Recently it was recognised that long-term anthropogenic inputs of mercury into environment resulted in the global mercury pollution and it was concluded that action should be taken to quantify the pollution sources and reduce human-generated releases of mercury. This paper presents new data on mercury levels in aquatic sediments from about 15 Croatian rivers, lakes and estuaries. It also brings data on mercury concentrations in soils from eight different regions of Croatia. Distribution of mercury species is discussed in more details for the Sava River, the Krka estuary and the Kaštela Bay on the eastern Adriatic coast. Results show that sediments and soils from Croatia are generally not contaminated by mercury, except for some rivers and coastal locations under direct anthropogenic influence.

Microbial Ecology, Apr 26, 2021

Anchialine ecosystems in the eastern Adriatic Sea are diverse both morphologically and biological... more Anchialine ecosystems in the eastern Adriatic Sea are diverse both morphologically and biologically. In this study, for the first time, we explored the microeukaryotic and prokaryotic community of anchialine caves in the Mediterranean region using high-throughput sequencing. Four anchialine caves located on nearby islands with a well-pronounced salinity gradient were sampled at the surface freshwater area, halocline area, and seawater area. Sequencing revealed a surprisingly wide diversity of the microeukaryotic and prokaryotic community with the relative abundance of major phyla differing within the salinity gradient and between the caves. Interestingly, microeukaryotic and prokaryotic communities clustered into four groups based on location, pointing out that sampled anchialine caves have different microbial community patterns and high microbial endemism. Our results indicate that even with the halocline acting as a selecting barrier, the salinity is not the only community structuring factor. Despite the short geographical distance, the isolation of anchialine caves facilitated high microbial community adaptation and endemism. Our study suggests that anchialine caves represent reservoirs of new biodiversity, maintaining unique and complex microbial diversity influenced by biotic interactions and abiotic environmental conditions.

Metal pollution and bacterial diversity in the surface sediments in the north Adriatic Sea

Raspodjela metala i metaloida u sedimentu i vodi ušća rijeke Krke

Metal dynamics in the sediments of the Krka River estuary

Th e KNOX11RR cruise of Nov. 2007 was a 19-day, multi-national joint geochemical sampling and geo... more Th e KNOX11RR cruise of Nov. 2007 was a 19-day, multi-national joint geochemical sampling and geophysical surveying cruise to the Central Indian Ridge (CIR), between 16°70’S and 20°16’S, and the adjacent Gasitao Ridge, Th ree Magi Ridges, and Rodrigues Ridge (Fig. 1; Dyment et al., 1999). Th is region presents an opportunity to study the oblique interaction between a spreading ridge (CIR) and a hotspot (presently located at Réunion Island, ~1100 km to the west of the ridge).

Frontiers in Marine Science, 2022

Deep-sea ecosystems are reservoirs of biodiversity that are largely unexplored, but their explora... more Deep-sea ecosystems are reservoirs of biodiversity that are largely unexplored, but their exploration and biodiscovery are becoming a reality thanks to biotechnological advances (e.g., omics technologies) and their integration in an expanding network of marine infrastructures for the exploration of the seas, such as cabled observatories. While still in its infancy, the application of environmental DNA (eDNA) metabarcoding approaches is revolutionizing marine biodiversity monitoring capability. Indeed, the analysis of eDNA in conjunction with the collection of multidisciplinary optoacoustic and environmental data, can provide a more comprehensive monitoring of deep-sea biodiversity. Here, we describe the potential for acquiring eDNA as a core component for the expanding ecological monitoring capabilities through cabled observatories and their docked Internet Operated Vehicles (IOVs), such as crawlers. Furthermore, we provide a critical overview of four areas of development: (i) Integ...

Pleistocene tufa deposits at Roški Slap in Krka National Park, Croatia – geochronology and evolution

4th Scientific meeting «Quaternary geology in Croatia and Slovenia», Abstracts, Excursion guidebook, 2015