| 1. |
- Andersen, J. H., et al.
(författare)
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Approaches for integrated assessment of ecological and eutrophication status of surface waters in Nordic Countries
- 2016
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 45:6, s. 681-691
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Tidskriftsartikel (refereegranskat)abstract
- We review approaches and tools currently used in Nordic countries (Denmark, Finland, Norway and Sweden) for integrated assessment of 'ecological status' sensu the EU Water Framework Directive as well as assessment of 'eutrophication status' in coastal and marine waters. Integration principles for combining indicators within biological quality elements (BQEs) and combining BQEs into a final-integrated assessment are discussed. Specific focus has been put on combining different types of information into indices, since several methods are currently employed. As a consequence of the variety of methods used, comparisons across both BQEs and water categories (river, lakes and coastal waters) can be difficult. Based on our analyses, we conclude that some principles and methods for integration can be critical and that a harmonised approach should be developed. Further, we conclude that the integration principles applied within BQEs are critical and in need of harmonisation if we want a better understanding of potential transition in ecological status between surface water types, e.g. when riverine water enters a downstream lake or coastal water body.
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| 2. |
- Gilbert, F., et al.
(författare)
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Sediment reworking by the burrowing polychaete Hediste diversicolor modulated by environmental and biological factors across the temperate North Atlantic. A tribute to Gaston Desrosiers
- 2021
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Ingår i: Journal of Experimental Marine Biology and Ecology. - : Elsevier BV. - 0022-0981. ; 541
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Tidskriftsartikel (refereegranskat)abstract
- Particle mixing and irrigation of the seabed by benthic fauna (bioturbation) have major impacts on ecosystem functions such as remineralization of organic matter and sediment-water exchange. As a tribute to Prof. Gaston Desrosiers by the Nereis Park association, eighteen laboratories carried out a collaborative experiment to acquire a global snapshot of particle reworking by the polychaete Hediste diversicolor at 16 sites surrounding the Northern Atlantic. Organisms and soft sediments were collected during May - July at different geographical locations and, using a common laboratory protocol, particulate fluorescent tracers (`luminophores') were used to quantify particle transport over a 10-day period. Particle mixing was quantified using the maximum penetration depth of tracers (MPD), particle diffusive coefficients (D-b), and non-local transport coefficients (r). Non-local coefficients (reflecting centimeter scale transport steps) ranged from 0.4 to 15 yr(-1), and were not correlated across sites with any measured biological (biomass, biovolume) or environmental parameters (temperature, grain size, organic matter). Maximum penetration depths (MPD) averaged similar to 10.7 cm (6.5-14.5 cm), and were similar to the global average bioturbation depth inferred from short-lived radiochemical tracers. MPD was also not correlated with measures of size (individual biomass), but increased with grain size and decreased with temperature. Bio-diffusion (D-b) correlated inversely with individual biomass (size) and directly with temperature over the environmental range (Q(10) similar to 1.7; 5-21 degrees C). The transport data were comparable in magnitude to rates reported for localized H. diversicolor populations of similar size, and confirmed some but not all correlations between sediment reworking and biological and environmental variables found in previous studies. The results imply that measures of particle reworking activities of a species from a single location can be generally extrapolated to different populations at similar conditions.
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| 3. |
- Glover, A. G., et al.
(författare)
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A live video observatory reveals temporal processes at a shelf-depth whale-fall
- 2010
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Ingår i: Cahiers De Biologie Marine. - 0007-9723. ; 51:4, s. 375-381
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Tidskriftsartikel (refereegranskat)abstract
- There have been very few studies of temporal processes at chemosynthetic ecosystems, even at relatively more accessible shallow water sites. Here we report the development and deployment of a simple cabled video observatory at 30 m water depth in Gullmarsfjorden, Sweden. The camera provides a live video feed to the internet of faunal activity in the experiments, which to date have included 5 separate whale-fall deployments. Our data suggest that the time to decomposition of small cetacean carcasses at shelf-depth settings is considerably slower than at deep-sea sites. We have also provided a new methodology for the deployment of low-cost live video observatories at up to 30 m water depth, which can be used both for research and outreach activities.
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| 4. |
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| 5. |
- Lindqvist, Stina, 1981, et al.
(författare)
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Biogeochemistry in highly reduced mussel farm sediments during macrofaunal recolonization by Amphiura filiformis and Nephtys sp.
- 2009
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Ingår i: Marine environmental research. - : Elsevier BV. - 0141-1136. ; 67:3, s. 136-45
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Tidskriftsartikel (refereegranskat)abstract
- Mussel farming is considered a viable means for reducing coastal eutrophication. This study assessed the importance of bioturbation by recolonizing fauna for benthic solute fluxes and porewater distributions in manipulated mussel farm sediments. Three consecutive time-series flux incubations were performed during an experimental period of three weeks in sieved farm sediment treated with the brittle star Amphiura filiformis and the polychaete Nephtys sp. The functional behavior of Nephtys sp. and interactions between Nephtys sp. and the spontaneously colonizing spionid Malacoceros fuliginosus determined the biogeochemical response in the Nephtys sp. treatment. For example, the oxic zone was restricted and benthic nitrate and silicate fluxes were reduced compared to the brittle star treatment. A. filiformis seemed to enhance the bioadvective solute transport, although an increased supply of oxygen was due to the highly reducing conditions of the sediment mainly seen as secondary effects related to porewater distributions and benthic nutrient fluxes.
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| 6. |
- Mermillod-Blondin, F., et al.
(författare)
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Influence of bioturbation by three benthic infaunal species on microbial communities and biogeochemical processes in marine sediment
- 2004
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Ingår i: Aquatic Microbial Ecology. - : Inter-Research Science Center. - 0948-3055 .- 1616-1564. ; 36:3, s. 271-284
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Tidskriftsartikel (refereegranskat)abstract
- Benthic invertebrates play a key role in the physical, chemical, and biological properties of the marine water-sediment interface. The influences of invertebrates on biogeochemical processes have mainly been attributed to their sediment reworking and bioirrigation activities. The aim of this study was to compare the influences of bioturbation activities by 3 dominant species of shallow water habitats (Cerastoderma. edule, Corophium volutator, and Nereis diversicolor) on microbial communities and biogeochemical processes in sediment cores. C. edule acted as a biodiffuser, mixing surface particles in the top 2 cm of the sediment. Despite this mixing activity, this species had little effect on O-2 consumption, water exchange between the water column and the sediment, microbial characteristics, and release of nutrients from the sediment, In contrast, C. Volutator and N. diversicolor produced burrows in the sediment that allowed transport of surface particles into biogenic structures. These 2 species doubled the solute exchange between the water column and the sediment, Such modifications of sediment structure and solute transport increased the O-2 consumption and the release of nutrients from the sediment. Both C. volutator and N. diversicolor stimulated the microbial communities as indicated by higher percentages of active bacteria. Reduction of the numbers of sulphate reducing bacteria was observed when the 3 invertebrates were present and could be attributed to the penetration of O-2 due to animal activities. N. diversicolor had a greater influence than C. volutator on pore water chemistry, ammonium release, and active bacteria. As N. diversicolor burrowed deeper in the sediment than C. volutator, it irrigated a greater volume of sediment. The modes of sediment reworking and structure building, irrigation behaviour, and burrowing depths were factors sufficient to assign the 3 species into different functional groups.
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| 7. |
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| 8. |
- Ramirez-Llodra, E., et al.
(författare)
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A snap shot of the short-term response of crustaceans to macrophyte detritus in the deep Oslofjord
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- A test deployment of a time-lapse camera lander in the deep Oslofjord (431 m) was used to obtain initial information on the response of benthic fauna to macroalgal debris. Three macroalgal species were used on the lander baited plate: Fucus serratus, Saccharina latissima and Laminaria hyperborea and observed during 41.5 hours. The deep-water shrimp Pandalus borealis were attracted to the macroalgae rapidly (3 min after the lander reached the seafloor), followed by amphipods. Shrimp abundances were significantly higher in areas covered by macroalgae compared to the adjacent seafloor and the number of shrimp visiting the macroalgae increased with time. Amphipods arrived 13 hours later and were observed mainly on decaying L. hyperborea. The abundance of amphipods on L. hyperborea increased rapidly, reaching a peak at 31 h after deployment. These initial observations suggest that debris from kelp forests and other macroalgal beds may play an important role in fuelling deep benthic communities in the outer Oslofjord and, potentially, enhance secondary production of commercial species such as P. borealis.
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| 9. |
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| 10. |
- Rosenberg, Rutger, 1943, et al.
(författare)
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Recovery of marine benthic habitats and fauna in a Swedish fjord following improved oxygen conditions
- 2002
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Ingår i: Marine Ecology-Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 234, s. 43-53
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Tidskriftsartikel (refereegranskat)abstract
- The Gullmarsfjord on the Swedish west coast has a sill at 40 m and a maximum depth of 118 m. The stagnant bottom water is usually renewed with oxygen-rich water each spring. In 1997 this did not occur, and the fauna was eliminated at depths below about 100 m and severely reduced between 80 and 100 m depth. In spring 1998, the whole fjord was re-oxygenated and the succession of the benthic fauna was studied at 5 stations over a 2 yr period. Simultaneously, the benthic habitat quality (BHQ) was assessed by analysing sediment redox conditions and faunal burrow structures in sediment profile images. Succession of the benthic fauna is described as increases in number of species, abundance and biomass. Conspicuous colonisers below 100 m depth were the polychaete Capitella capitata and the heart urchins Echinocardium cordatum and E. flavescens. Return to pre-oxygen stressed conditions was slowest at the deepest stations. By using a multivariate technique (multi-dimensional scaling) we show that the benthic communities at all depths more or less returned to the same faunal composition as during pre-disturbed conditions. The pioneering and mature benthic faunal Successional Stages I and III were predictable but not the intermediate Stage 11, The path of recovery of the benthic community succession did not retrace the path of degradation. The sedimentary habitats and redox conditions were similarly restored over the 2 yr period as analysed by the BHQ index.
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| 11. |
- Solan, M., et al.
(författare)
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In situ quantification of bioturbation using time-lapse fluorescent sediment profile imaging (f-SPI), luminophore tracers and model simulation
- 2004
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Ingår i: Marine Ecology-Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 271, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- In order to link actual biological data on bioturbation to the abstract parameters in bioturbation models, high-resolution data on the frequency and lengths of particle displacements are required. The temporal variation in bioturbation for a subtidal macrofaunal assemblage was studied non-invasively and in situ using an optically modified fluorescence sensitive time-lapse sediment profile imaging camera (f-SPI), fluorescent-dyed sediment particles (luminophores) and mathematical modelling. This combined approach allowed tracer particles to be non-invasively tracked and their displacements monitored at an unprecedented spatial (78 mum) and temporal (every 10 min) resolution for extended periods of time (16 h). The redistribution of luminophores was digitally acquired from sequential images and compared to model predictions, with particle transport modelled as (1) a diffusive process, allowing the biodiffusion coefficient, D-b, to be estimated, and (2) a non-local process, allowing a reworking activity constant, a, to be calculated. Model predictions of luminophore particle transport for the final image of the f-SPI sequence gave: D-b = 1.26 x 10(2) cm(2) yr(-1); a = 5.23 x 10(-2) cm(-1) yr(-1). Discrete values of a fluctuated widely throughout the sequence and allowed discrete bioturbation events to be identified. Time-lapse movie sequences revealed that most of the bioturbation observed during the deployment could be directly attributed to the behaviour of the brachyuran crab Hyas araneus. Our findings demonstrate that f-SPI provides a rapid and non-invasive means to visualise and quantify, in situ, the extent and influence of discrete infaunal bioturbation events on particle mixing. This technique provides detailed information on the spatial and temporal resolution of such bioturbation events, which could significantly improve existing models of bioturbation.
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