89 research outputs found

    MiljĂžmessig vurdering av utslipp av natriumklorat til Frierfjorden fra Hydro Polymers AS, Bamle

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    Årsliste 2005Det er gjort en undersĂžkelse og vurderinger av utslippet av klorat fra Hydro Polymers fabrikk pĂ„ Rafnes. AvlĂžpsvannet slippes ut i 20-25 m dyp og innlagres oftest i ca. 12-22 m dyp. Beregninger av innlagringsdyp, fortynning og av kloratkonsentrasjon er sammenholdt med grenseverdier for akutte skader og langtidseffekter pĂ„ marin flora og fauna. Resultatene tilsier at utslippet av natriumklorat ikke vil medfĂžre skader pĂ„ dyreplankton, bunndyr og fisk i sjĂžvannslaget der avlĂžpsvannet til vanlig innlagres og spres. UndersĂžkelsen av blĂžtbunnsfauna viste ikke tegn til skader pĂ„ faunaen i omrĂ„det. Det er en reell mulighet for lokale negative effekter pĂ„ planteplanktonalger, men risikoen for skader pĂ„ fjordens produksjonssystem ansees som ubetydelig.Hydro Polymers A

    Factors influencing organic carbon recycling and burial in Skagerrak sediments

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    Different factors influencing recycling and burial rates of organic carbon (OC) were investigated in the continental margin sediments of the Skagerrak (NE North Sea). Two different areas, one in the southern and one in the northeastern part of the Skagerrak were visited shortly after a spring bloom (March 1999) and in late summer (August 2000). Results suggested that: (1) Organic carbon oxidation rates (Cox) (2.2–18 mmol C m-2d-11) were generally larger than the O2 uptake rates (1.9 –25 mmol m-2d-1). Both rates were measured in situ using a benthic lander. A mean apparent respiration ratio (Cox:O2corr) of 1.3±0.5 was found, indicating some long-term burial of reduced inorganic substances in these sediments. Measured O2 fluxes increased linearly with increasing Cox rates during the late summer cruise but not on the early spring cruise, indicating a temporal uncoupling of anaerobic mineralization and reoxidation of reduced substances. (2) Dissolved organic carbon (DOC) fluxes (0.2–1.0 mmol C m-2d-1) constituted 3–10% of the Cox rates and were positively correlated with the latter, implying that net DOC production rates were proportional to the overall sediment OC remineralization rates. (3) Chlorophyll a (Chl-a) concentrations in the sediment were significantly higher in early spring compared to late summer. The measured Cox rates, but not O2 fluxes, showed a strong positive correlation with the Chl-a inventories in the top 3 cm of the sediment. (4) Although no relationship was found between the benthic fluxes and the macrofaunal biomass in the chambers, total in situ measured dissolved inorganic carbon (CT) fluxes were 1–5.4 times higher than diffusive mediated CT fluxes, indicating that macrofauna have a significant impact on benthic exchange rates of OC remineralization products in Skagerrak sediments. (5) OC burial fluxes were generally higher in northeastern Skagerrak than in the southern part. The same pattern was observed for burial efficiencies, with annual means of ~62% and ~43% for the two areas respectively. (6) On a basin-wide scale, there was a significant positive linear correlation between the burial efficiencies and sediment accumulation rates. (7) The calculated particulate organic carbon (POC) deposition, from benthic flux and burial measurements, was only 24 –78% of the sediment trap measured POC deposition, indicating a strong near-bottom lateral transport and resuspension of POC. (8) A larger fraction of the laterally advected material of lower quality seemed to settle in the northeastern Skagerrak rather than in the southern Skagerrak. (9) Skagerrak sediments, especially in the northeastern part, act as an efficient net sink for organic carbon, even in a global continental margin context

    Aquaculture Perspective of Multi-Use Sites in the Open Ocean: The Untapped Potential for Marine Resources in the Anthropocene

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    This volume addresses the potential for combining large-scale marine aquaculture of macroalgae, molluscs, crustaceans, and finfish, with offshore structures, primarily those associated with energy production, such as wind turbines and oil-drilling platforms. The volume offers a comprehensive overview and includes chapters on policy, science, engineering, and economic aspects to make this concept a reality. The compilation of chapters authored by internationally recognized researchers across the globe addresses the theoretical and practical aspects of multi-use, and presents case studies of research, development, and demonstration-scale installations in the US and EU

    Comparing trawl and creel fishing for Norway lobster (Nephrops norvegicus): biological and economic considerations

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    This study compares the fishing activity and landings of the trawl and creel fisheries for Norway lobster (Nephrops norvegicus (L.)) off the Portuguese coast, and evaluates the financial viability of two vessels typical of each fleet. Crustacean trawlers are part of an industrial fleet that, besides Nephrops, targets deep water shrimps. Creels are used by a multi-gear, multi-target artisanal fleet, fishing only in areas unavailable to trawlers and, when catching Nephrops, set specifically to target this species. Trawlers have in recent years contributed with 85% of the landings in weight, but only 74% in value (2005-2009 average). Despite smaller landings, the Nephrops creel fishery provides individuals of larger size and in better condition, thereby obtaining higher unit prices. Economic viability was also higher for the creel vessel, with trawling being only viable if major costs (such as labor and fuel) are covered by the revenue from other target species (e. g., the rose shrimp). At present, Nephrops populations on the South and SW coast are subject to intense fishing and to a recovery plan. The possibility of reallocation of some of the fishing effort directed at Nephrops from trawlers to creels is discussed in terms of the conservation of the resource and economic return.Foundation for Science and Technology, Portugal: Project "Nephrops survival when escaping from trawls nets and by-catch escaping devices" [PDCT/MAR/59366/2004]; Foundation for Science and Technology, Portugal: Project "Environmental impact of fixing gears in the southwest coast of Portugal. Combine fisheries and marine ecosystem conservation" [POCTI/CTA/49248/2002]info:eu-repo/semantics/publishedVersio

    Benthic ecology of semi-natural coastal lagoons, in the Ria Formosa (Southern Portugal), Exposed to different water renewal regimes

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    Several studies in semi-natural coastal lagoons in the Ria Formosa lagoonal system have been carried out. These man-made water reservoirs behave as small lagoons with one opening to the tidal channels, which may be intermittent. Because of their size, these reservoirs are ideal sites for ecological studies. Water quality and macrobenthic fauna were analysed in five water reservoirs. All reservoirs received the same incoming water through a tidal channel, but they differed in water renewal regime. Multidimensional Scaling (MDS) and Discriminant Analysis were used to evaluate the similarity among sites, stations and sampling occasions. Different levels of taxonomic resolution (family, large taxonomic groups and phylum level) were also evaluated. The separation of sites and stations became unclear using high taxonomic levels. Results from the multivariate analyses suggest a slight differentiation of the stations according to sampling occasion but a clear differentiation of the several water reservoirs. Some of the lagoons studied with low water renewal rates showed strong environmental variations. They were characterised by low diversity indexes and abundance of small-sized organisms. Other lagoons, with high water renewal rates, showed low environmental variation and well diversified and structured benthic communities. The main environmental factor that seems to affect the benthic communities was the variation in salinity between neap and spring tides, which is related with the water renewal regime. Coastal lagoons offer a protected shallow habitat, which can be highly productive. Well structured communities, controlled by k-strategists, can develop and settle in leaky lagoons, that is, lagoons with wide entrance channels and tidal currents which guarantee a good water renewal. In these lagoons, biomass can accumulate in large organisms. In contrast, lagoons with a single narrow entrance, that may be closed for long periods, are characterised by persistent physical stress and are dominated by communities of small-sized r-strategists

    Diversity and distribution of oribatid mites (Acari:Oribatida) in a lowland rain forest in Peru and in several environments of the Brazilians states of Amazonas, RondĂŽnia, Roraima and ParĂĄ

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    We are summarizing the current state of knowledge of the diversity and distribution of oribatid mites in 26 environments in northern Brazil and of a rain forest in Peru. The published studies were mostly concentrated in Central Amazon. Only one report is a result from an agricultural polyculture. We are providing the first lists of species for savannas and for the Brazilian states of Roraima and ParĂĄ. Up to date, 146 species are definitively identified from a total of 444 taxa with 188 known genera, reinforcing the notion of a rich biodiverse area. The high number of 298 non-described species (morphospecies) clearly shows the inadequacy of the current taxonomic knowledge for the region. Most of the registers are from forest environments. In the soil from primary forests, we registered the highest diversity (54-155 species/morphospecies). Eighty-nine species were unique to primary forests, followed by 34 for savannas, 32 in trees, 10 in "igapĂł", 4 in caatinga, 3 in secondary forests, two in "varzea" and one in polyculture. Twenty genera were the most speciose. The species with the largest home ranges were Rostrozetes foveolatus, Scheloribates sp. A, and Galumna sp. A. Our numbers reflect the lack of taxonomists and show that the taxonomic knowledge must be improved for the region or we will continue to work with taxonomic resolution of Order or Family and a high percentage of morphospecies, which will probably be appropriate to the question being asked in each study, but not for a comparison among environments

    The use of taxonomic relationships among species in applied ecological research: Baseline, steps forward and future challenges

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    Taxonomy is more than a mere exercise of nomenclature and classification of biological diversity: it profiles the identity of species by investigating their biological and ecological traits. Taxonomy is intimately related to ecology which, in turn, cannot be a mere exercise in describing ecological patterns, but instead requires deep knowledge of species’ biological structures, roles, interactions and functions. Thus, the study of taxonomic and phylogenetic relatedness of species is of paramount importance in ecological research, enabling insights into potential evolutionary patterns and processes, allowing a more comprehensive view of biodiversity, and providing opportunities to improve the assessment and monitoring of ecological changes in time and space. The work of K. Robert (‘Bob’) Clarke forged new pathways in this direction, providing new ideas and statistical tools to include and exploit taxonomic relationships in applied marine ecological studies and beyond, also inspiring the next generation of ecologists. In this short review, we synthesise the application and development of these tools and concepts in marine biodiversity research over the last three decades and suggest future pathways in this evolving field

    Utslipp fra Pronova Biocare as, Sandefjord. Vurdering av influensomrÄde, oksygenforbruk og effekter i resipienten

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    Pronova Biocare produserer fiskeolje og fiskeoljekonsentrater og har utslipp av prosessvann pÄ 15 m dyp i indre del av Sandefjordsfjorden. Utslippet inneholder fettstoffer (glyserider, fettsyrer og etylestere), etanol, glyserol, nitrogen og fosfor. Det er gjort beregninger av utslippets spredning og innlagring og vurdering av oksygenforbruk i resipienten. Varierende med sjiktning og strÞmforhold i fjorden vil avlÞpsvannet bli innlagret mellom overflata og ca. 12 m dyp, dypest i sommerhalvÄret. Konservative beregninger basert pÄ kjemisk oksygenforbruk (KOF) viser at utslippet ikke vil gi problematisk lave oksygenkonsentrasjoner i utslippsomrÄdet, noe som heller ikke er observert ved overvÄking av vannkvaliteten i fjorden. Bidraget fra nitrogen i utslippet vil stimulere marin produksjon og medfÞre et visst oksygenforbruk, men er meget lavt i forhold til andre nitrogenkilder som utslipp av kommunal kloakk. AvlÞpsvannet har svÊrt lav pH. Effekter av lav pH kan ikke vurderes da syreinnholdet i utslippet ikke er kjent, men antas Ä ikke vÊre omfattende
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