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Morphology and seasonal distribution of the rare planktonic bloom forming dinoflagellate Prorocentrum arcuatum in Medulin Bay are described in this study. It demonstrates first record of high abundance of this species in the coastal waters of the Adriatic Sea. Samples were collected fortnightly in the period from July 2013 to October 2014 for analysis of phytoplankton community structure and for environmental parameters. Using both light and scanning electron microscopy, a morphometric study of P. arcuatum was performed according to cell shape, size, ornamentation of thecal plates and apical spine. Cells of P. arcuatum are asymmetrical, medium to large. At the anterior side it is broadest at the middle part of the cell and attenuated at the posterior end. This species posses marked torsion of the cells, which is distinctive feature in relation to other Prorocentrum species. The cell surface is covered with shallow depressions and scattered pores. The anterior apical spine is long, sharp and broadest at the base. P. arcuatum was almost continuously occurring in Medulin Bay throughout 15 months of the research period. The cell density of P. arcuatum varied from 80 cells L-1 to 13.200 cells L-1. Regarding vertical distribution, abundances of this species between surface and bottom layer were highly correlated. Variation in length of P arcuatum cells was noticeable having the smallest cells in winter months ; from December till March, while the largest cells occurred in May, June and July. In the period of the highest proliferation of P. arcuatum high temperatures were accompanied by high salinity and therefore both parameters should be accomplished. Also, negative correlation of P. arcuatum with all forms of inorganic nitrogen (NO3-, NO2-, TIN, NTOT) was found.

The classic approach for determining insulating resistance by using commercial testers is not reliable for testing different types of insulation, especially for cables with one conductor and nanoelectronic oxide-based devices (nanotransistors). In this paper an alternative low-voltage method for measuring insulation resistance based on strongly increased current sensitivity is proposed. The proposed method of measuring insulation resistance at low voltages is realized by using a high sensitivity Keithley SMU 2612 unit. The verification of the proposed method is made by measuring insulation resistance of medical Corkscrew Electrode and gate oxide resistance for nano-scaled MOSFET. Finally, results of measuring insulation resistance obtained by commercial testers and proposed method in the verification process are compared.

Solar cell parameters are measured during manufacturing process and they determine quality and properties of solar cells. Standard measurements of typical solar cell parameters (short-circuit current, open-circuit voltage and maximum power point) are performed in laboratory conditions under simulated sunlight (1 kW/m2) and temperature of 25º C and they do not describe solar cell operation under real environmental conditions. To get a better picture of solar cell operation in practical applications, it is necessary to measure its parameters while it is exposed to natural sunlight. In this paper a hardware solution for current-voltage characteristics measurement is presented. This solution is applicable in both cases - whether we measure under laboratory or real environmental conditions. Hardware solution is based on 8-bit microcontroller and circuit which simulates load. The load simulation is performed by MOSFET and operational amplifier. Results obtained by this hardware solution are generally acceptable, though certain disadvantages exist. Disadvantages and possible improvements of this solution are discussed

Using 14 years of environmental data, we investigated distribution of thermohaline properties and phytoplankton biomass in Mali Ston Bay, which is the major shellfish farming area on the eastern Adriatic coast. Sampling was conducted biweekly during summer and monthly during the rest of the year throughout period 1999–2012. Due to strong river inflow and many submarine springs, continuous thermohaline stratification was recorded throughout the entire investigated period. The salinity effect on stratification was more pronounced compared to temperature effect which was mostly expressed in summer. Phytoplankton biomass increased throughout the period 1999–2012, while a negative trend in salinity was observed for the surface layer. Seasonal biomass pattern showed two biomass peaks: the first in late winter/early spring and the second (less pronounced) in the autumn. Regarding phytoplankton size fraction ; such as microplankton and nanoplankton, each component was equally represented in all seasons. Despite continuous enrichment from the Neretva River and underwater springs, lack of significant correlation between phytoplankton biomass and nutrients indicate that nutrients are quickly utilized by phytoplankton and transferred further into food web. Water column was well oxygenized throughout investigated period having high transparency and high diversity of phytoplankton taxa. According to all investigated parameters, and the fact that Mali Ston Bay is naturally productive area, and also aquaculture area, it is hypothesized whether this area could be considered as oligotrophic environment or not.

Lipophilic toxins were analysed in shellfish along eastern Adriatic coast during one-year period. Samples which provided a positive mouse bioassay test (MBA) for lipophilic toxins were analysed by LC-MS/MS. Results of LC-MS/MS analyses revealed okadaates (OAs), yessotoxins (YTXs) and gymnodimine (GYM). YTXs were the most common in all investigated areas, but only OAs were identified in concentration above regulatory limit. Slightly higher toxin content was recorded in shellfish from northern Adriatic Sea in comparison with other investigated areas. Seven potentially toxic phytoplankton species known as OAs producers were recorded: Dinophysis acuminata, Dinophysis acuta, Dinophysis caudata, Dinophysis fortii, Dinophysis sacculus, Dinophysis tripos and Phalacroma rotundatum ; as well as Lingulodinium polyedrum, Gonyaulax spinifera and Protoceratium reticulatum known as causative organisms for YTXs. OAs content in shellfish was associated with presence of D. caudata and D. sacculus in seawater. Species L. polyedrum and G. spinifera were determined concurrently with YTXs in shellfish.

We analyzed and compared Mediterranean mesozooplankton time series spanning 1957–2006 from six coastal stations in the Balearic, Ligurian, Tyrrhenian, North and Middle Adriatic and Aegean Sea. Our analysis focused on fluctuations of major zooplankton taxonomic groups and their relation with environmental and climatic variability. Average seasonal cycles and interannual trends were derived. Stations spanned a large range of trophic status from oligotrophic to moderately eutrophic. Intra-station analyses showed (1) coherent multi-taxa trends off Villefranche sur mer that diverge from the previous results found at species level, (2) in Baleares, covariation of zooplankton and water masses as a consequence of the boundary hydrographic regime in the middle Western Mediterranean, (3) decrease in trophic status and abundance of some taxonomic groups off Naples, and (4) off Athens, an increase of zooplankton abundance and decrease in chlorophyll possibly caused by reduction of anthropogenic nutrient input, increase of microbial components, and more efficient grazing control on phytoplankton. (5) At basin scale, the analysis of temperature revealed significant positive correlations between Villefranche, Trieste and Naples for annual and/or winter average, and synchronous abrupt cooling and warming events centered in 1987 at the same three sites. After correction for multiple comparisons, we found no significant correlations between climate indices and local temperature or zooplankton abundance, nor between stations for zooplankton abundance, therefore we suggest that for these coastal stations local drivers (climatic, anthropogenic) are dominant and that the link between local and larger scale of climate should be investigated further if we are to understand zooplankton fluctuations, Sí

Intensive cage culture system creates waste that may lead to detrimental impact on marine environment. The present study deals with the impact of a seabass cage farm on water quality and structure and composition of benthic communities.