7 research outputs found

    Domoic acid in phytoplankton net samples and shellfish from the Krka River estuary in the Central Adriatic Sea

    Get PDF
    This paper deals with the precise identification of species of Pseudo-nitzschia, focusing on those which are a potential source of domoic acid, from the Krka River estuary of the Central Adriatic Sea. Domoic acid was measured in phytoplankton net samples and shellfish collected in the winter and early spring of 2011 and 2012. Domoic acid was only detected in early March 2011, both in plankton net samples and shellfish extracts, during a Pseudo-nitzschia species bloom. The measured concentrations of particulate domoic acid (DA) in filtered concentrated seawater varied from 3.1˗6.2 ng DA ml-1. In shellfish sample DA concentration was 0.2 μg g-1. Species belonging to the Pseudo-nitzschia delicatissima complex were more common than those from the Pseudo-nitzschia seriata complex. Morphological analyses by electron microscopy revealed the presence of three potentially toxic species: P. calliantha, P. pseudodelicatissima and P. pungens, and one non-toxic species: P. subfraudulenta. However, P. calliantha and P. pseudodelicatissima dominated during the March 2011 bloom. This study presents the first evaluation of particulate domoic acid along the Eastern Adriatic Sea and the first record of the presence of P. calliantha, P. pseudodelicatissima, P. pungens and P. subfraudulenta in the Krka River estuary

    Re-discovery of a "living fossil" coccolithophore from the coastal waters of Japan and Croatia

    Get PDF
    The extant coccolithophore Tergestiella adriatica Kamptner, which had not been reported since its original description in 1940, was recently re-discovered in coastal-nearshore waters at Tomari, Tottori (Japan) and offshore Rovinj (Croatia). Morphological analysis shows that extant Tergestiella and the Mesozoic genus Cyclagelosphaera (Watznaueriaceae), thought to have been extinct since the early Eocene (~. 54. Ma), are virtually identical. Molecular phylogenetic study supports the inference that T. adriatica is a direct descendent of Cyclagelosphaera. It is therefore a remarkable example of a living fossil. Our documentation of patchy coastal distribution in living T. adriatica and records of rare occurrences of fossil Cyclagelosphaera in Oligocene-Miocene shallow water sediments. , from the New Jersey shelf, suggest that Tergestiella/. Cyclagelosphaera was restricted to nearshore environments during much of the Cenozoic. This restricted ecology explains the lack of fossil Tergestiella/. Cyclagelosphaera recorded in open ocean sediments deposited during the last 54. myr.Floristic study of coccolithophores in the coastal and offshore waters of Tomari over a six-year period, show that T. adriatica occurs synchronously with the unusual neritic species, Braarudosphaera bigelowii, in mid-June. The environmental factors that induce the co-occurrence of these two taxa are uncertain, and T. adriatica did not co-occur with B. bigelowii at any other sites

    European policies and legislation targeting ocean acidification in european waters - Current state

    Get PDF
    Ocean acidification (OA) is a global problem with profoundly negative environmental, social and economic consequences. From a governance perspective, there is a need to ensure a coordinated effort to directly address it. This study reviews 90 legislative documents from 17 countries from the European Economic Area (EEA) and the UK that primarily border the sea. The primary finding from this study is that the European national policies and legislation addressing OA is at best uncoordinated. Although OA is acknowledged at the higher levels of governance, its status as an environmental challenge is greatly diluted at the European Union Member State level. As a notable exception within the EEA, Norway seems to have a proactive approach towards legislative frameworks and research aimed towards further understanding OA. On the other hand, there was a complete lack of, or inadequate reporting in the Marine Strategy Framework Directive by the majority of the EU Member States, with the exception of Italy and the Netherlands. We argue that the problems associated with OA and the solutions needed to address it are unique and cannot be bundled together with traditional climate change responses and measures. Therefore, European OA-related policy and legislation must reflect this and tailor their actions to mitigate OA to safeguard marine ecosystems and societies. A stronger and more coordinated approach is needed to build environmental, economic and social resilience of the observed and anticipated changes to the coastal marine systems

    Toxin-Producing Ostreopsis cf. ovata are Likely to Bloom Undetectedalong Coastal Areas

    No full text
    Mass appearances of the toxic dinoflagellate genus Ostreopsis are known to cause dangerous respiratory symptoms in humans exposed to aerosols. The outbreaks can appear in shallow marine waters of temperate regions around the globe. We followed a massive bloom event on a public beach on the northern Adriatic coast near Rovinj, Croatia. We identified the responsible species and the produced toxins as well as the dynamics of the event with respect to environmental conditions. Ostreopsis cf. ovata appeared in masses from September through October 2010 on a public beach near Rovinj, Croatia but stayed undetected by public health organizations. Respiratory symptoms were observed whenever humans were exposed to substrate samples containing large numbers of Ostreopsis cells. During the mass abundance of O. cf. ovata also exposure to the aerosols on the beach evoked respiratory symptoms in humans. Our measurements showed high cell abundances and high toxin contents with a stable relative contribution of putative Palytoxin and Ovatoxins a-e. Artificial beach structures proved to dramatically reduce settling of the observed Ostreopsis biofilm. Blooms like those reported herein have a high potential to happen undetected with a high potential of affecting the health of coastal human populations. Increased monitoring efforts are therefore required to understand the ecology and toxicology of those bloom events and reduce their negative impact on coastal populations

    Global SEM coccolithophore abundance compilation

    No full text
    Coccolithophores are globally important marine calcifying phytoplankton. They contribute to the organic carbon pump through the primary production and the ballast of organic matter, and to the carbonate pump through the production of calcium carbonate. Here we compiled all available scanning electron microscopy (SEM) coccolithophore abundance observations. Taxa were standardized following NannoTax3 to a species level where possible. Subspecies (e.a. C. leptoporus subsp. leptoporus and C. leptoporus subsp. quadriperforatus) were grouped as single species. The database contains 2556 abundance observations from 35 different publications. The data span the period of 1993-2017, with observations from all ocean basins and all seasons, and at depths ranging from the surface to 5000 m. We limited our compilation to SEM observations (or observations which further identified samples with SEM) because SEM provides greater detail of coccolithophore diversity than more commonly used polarized light microscopy. Although this limits the number of observations, this allows for a more in-depth analysis of coccolithophore ecology, such as the ecological significance of the coccolithophore life cycle
    corecore