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The oceans at the time of the Cenomanian–Turonian transition were abruptly perturbed by a period of bottom-water anoxia. This led to the brief but widespread deposition of black organic-rich shales, such as the Livello Bonarelli in the Umbria–Marche Basin (Italy). Despite intensive studies, the origin and exact timing of this event are still debated. In this study, we assess leading hypotheses about the inception of oceanic anoxia in the Late Cretaceous greenhouse world by providing a 6 Myr long astronomically tuned timescale across the Cenomanian–Turonian boundary. We procure insights into the relationship between orbital forcing and the Late Cretaceous carbon cycle by deciphering the imprint of astronomical cycles on lithologic, physical properties, and stable isotope records, obtained from the Bottaccione, Contessa and Furlo sections in the Umbria–Marche Basin. The deposition of black shales and cherts, as well as the onset of oceanic anoxia, is related to maxima in the 405 kyr cycle of eccentricity-modulated precession. Correlation to radioisotopic ages from the Western Interior (USA) provides unprecedented age control for the studied Italian successions. The most likely tuned age for the base of the Livello Bonarelli is 94.17 ± 0.15 Ma (tuning 1); however, a 405 kyr older age cannot be excluded (tuning 2) due to uncertainties in stratigraphic correlation, radioisotopic dating, and orbital configuration. Our cyclostratigraphic framework suggests that the exact timing of major carbon cycle perturbations during the Cretaceous may be linked to increased variability in seasonality (i.e. a 405 kyr eccentricity maximum) after the prolonged avoidance of seasonal extremes (i.e. a 2.4 Myr eccentricity minimum). Volcanism is probably the ultimate driver of oceanic anoxia, but orbital periodicities determine the exact timing of carbon cycle perturbations in the Late Cretaceous. This unites two leading hypotheses about the inception of oceanic anoxia in the Late Cretaceous greenhouse world.

Development of human activities in the Klaipe˙ da strait generates a wide spectrum of underwater noise. In the fall of 2013, at the liquid natural gas terminal construction site in the shallow Curonian Lagoon area, an assessment of possible negative impacts on migrating salmon fish caused by pile driving noise was made. It is well known that impact hammer pile driving generates pulses with extremely high underwater noise levels. The obtained results proved that the pile hammering into the lagoon bottom generated pulses with a sound exposure level of 218 dB re 1 lPa2 s @1 m thus posing a risk to the migrating fish.

Based on the idea that contribution of volunteers might play a fundamental role in monitoring and protecting the environment, CNR-ISTI designed and developed a mobile application in order to allow people to timely report oil spills. By downloading the FREE app "ARGO Sentinel" volunteers are helping to monitor the health of our seas and the scientific research by demonstrating that the use of this new technology could be really important to combat pollution. Moreover this experiment suggests that this kind of technology can be applied in many other fields. Whoever at sea sights pollution by oil or hydrocarbons is now able to immediately report the event to the Laboratory of Signals and Images SI-LAB (si.isti.cnr.it) of the Institute of Science and Information Technologies of the Italian National Research Council (CNR-ISTI) in Pisa, allowing the realization of a detailed map of the health of our seas. This information is recorded in the Marine Information System (MIS) produced by CNR, able to collect geotagged data relating to critical and health issues of the sea from various sources (satellites, optical sensors, electronic noses, autonomous underwater vehicles systems) and integrate and generate predictive models to assist the authorities in the management of emergencies at sea. The application, distributed in Italian, English and Greek languages, for smartphones equipped of GPS is an easy to use tool designed for anyone, that for any reason, sail the seas. It allows you to send reports of suspected spills to the CNR specifying the precise point, severity and a description of the spill.

Tonic displacements of the fish lateral line cupula were observed during stimulation of the organ with amplitude-modulated water motion. The modulation frequency was fixed at 2.4 Hz and the carrier frequency was varied from 25 to 500 Hz. The time wave-forms of the cupular displacement.at carrier frequencies below 280 Hz and above 470 Hz were essentially amplitude-modulated waves. Between 350 Hz and 410 Hz the magnitude at the modulation frequency increased sharply and the predominant shape of the displacement waveform changed to that of the modulating frequency. The mechanism for ''traction of the modulation component may play a key role in the decoding of sensory information.

Fish communities are characterized by a high degree of variability in space and in time, which mostly results from the influence of physical processes. Identifying the main variables governing changes in fish communities, as well as quantifying their influence, are basic in an attempt to assess anthropogenetic impacts. In south-eastern France, the Durance River is a Mediterranean, highly regulated river. The water resource is used to fulfill various human needs, including hydropower generation, drinkable water supply, or irrigation for agriculture. The hydroelectric scheme of the Durance River, decided in 1955, now numbers 19 electricity generation plants all along the river course. Human influences are therefore huge on the ecosystem, and include multiple and combined stressors. Here, we focused on the relationships between changes in fish assemblage structure and flow variables that depend on the hydropower plants functioning. Fish were sampled by electrofishing at 6 sites along the medium and lower Durance River. Sampling spanned the years 2005-2011, and was performed annually at the end of summer or early autumn. Multivariate analyses were performed to analyze the spatial-temporal pattern of fish assemblage variation across the 6 sites for 7 years, and to test whether inter-annual changes in seasonal flow characteristics could explain part of the taxonomic structure of fish assemblages. Analyses revealed a strong spatial structure along the 6 sites, with 31.5 % of total inertia being due to the site effect. Assemblages through time were alternatively dominated by subsets of species, whose relative dominance significantly depended on the flood magnitude. Toxonomic responses were relevant with expectations based on our biological and ecological knowledge of these species. Such a multiple site and year approach helped understanding the consequences of flow regulation on biological assemblages in a large river, and allowed flow management guidelines to be suggested.

Sediment trapping within reservoirs is a worldwide phenomenon which impairs the ecological functioning of upstream and downstream ecosystems. It also reduces reservoir water storage volume, which lessens the services dams provide such as hydropower production or flood control and questions their sustainability. Hydraulic flushing is a widely used operation to recover the reservoir volume, but ecological impacts are massive. Recently, environmental awareness led dam operators to modify their management practices: ‘Controlled Sediment Flushing Operations’ (CSFOs) include environmental objectives in their implementation and are designed to be less harmful for aquatic ecosystems by controlling the flow and Suspended Sediment Concentration (SSC) downstream. However, CSFOs are not yet widespread, their ecological impacts are poorly documented, and comparisons with ‘classical’ flushing operations are unreported. Here, we analysed impacts on fish of the first CSFO of the Verbois reservoir in 2016, both upstream and downstream of the dam, and compared these with those from the empty flushing of 2012 using the same methodology (Grimardias et al., 2017). Time-series of hydroacoustics surveys enabled us to estimate the fish abundance in the reservoir, while radiotelemetry measured movements and apparent survival below the dam for four representative species. The 2016 CSFO lasted 10 days, and released a mean Suspended Sediment Concentration (SSC) of 3.47 g·L−1 (peak = 11.98 g·L−1). The fish density as assessed by the mean acoustic scattering strength SA in the reservoir did not change significantly pre- and post-CSFO, and SA seasonal estimates of year 2016 did not differ from those of 2015 and 2017. The apparent survival estimated from capture-recapture survey of marked fish (N = 118) decreased significantly during the CSFO for all species and differed across species, while the distances moved downstream increased. By comparison with the 2012 empty flushing, the 2016 CSFO allowed fish to remain in the reservoir, while impacts below the dam were mostly behavioural rather than lethal. Overall, despite significant impacts, the CSFO advantageously replaced ‘classical’ flushing from an ecological viewpoint. Provided that an acceptable balance between economical, ecological and technical aspects is found, CSFO can be considered for many reservoirs while accounting for their biological and physical site-specificity.

This paper discusses the results of the LifeCLEF 2014 multimedia identification challenges with regards to the requirements of real-world ecological surveillance systems. In particular, we study the identification performances of the evaluated systems as a function of the ordinariness or rarity of the species in the dataset. This allows us to assess the ability of the underlying methods to be robust to heavily tailed distributions such as the ones encountered in real-world collections of life observations. Results show that all methods are more or less affected by the long-tail curse but that the best methods making use of classifiers with good discrimi- nation capacities do resist the phenomenon pretty well.

Bioaccumulation of POPs in an aquatic food web and historical trends in POPs recorded in sediment layers were studied in the Brno Lake's environment. Current levels of organochlorines were determined in the chub from the Svratka River and the hygienic quality of fishes from recreational fishing was evaluated as well. Current levels of POPs in terrestrial environment were determined using conifer needles as a suitable biomonitoring tool. Specimens of three raptor species were collected at localities of Central Moravia during 2003-2007 and investigated for the content of PCBs and organochlorine pesticides. POPs were also determined in sediment and fish prey of water raptors from the Záhlice Ponds in order to document the process of bioaccumulation of persistent pollutants in the food chain. The last part of this thesis presents the results of an assessment of two modern extraction techniques for the determination of chlorinated POPs in various matrices. Byla provedena studie bioakumulace POP v potravním řetězci a historických trendů hladin POP v sedimentech Brněnské přehrady. Současné úrovně kontaminantů byly stanoveny v jelci tloušti z řeky Svratky a rovněž byla posouzena hygienická kvalita ryb z rekreačního rybolovu. Současné úrovně POP v terestrickém ekosystému byly posouzeny pomocí analýz jehličí jako přirozeného indikátoru znečištění. Studium jedinců tří druhů dravých ptáků z ČR bylo zaměřeno na zhodnocení kontaminace těchto vrcholných predátorů POP. S pomocí analýz vybraných druhů ryb ze Záhlinických rybníků byl rovněž studován proces bioakumulace. Posouzení parametrů dvou moderních extrakčních technik a jejich využitelnosti pro izolaci POP z různých matric bylo námětem poslední části dizertace. P