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  • 1
    Electronic Resource
    Electronic Resource
    Marine pollution and coral reefs (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Global change biology 2 (1996), S. 0 
    Details
    ISSN: 1365-2486
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: Coral reefs are exposed to many anthropogenic stresses increasing in impact and range, both on local and regional scales. The main ones discussed here are nutrient enrichment, sewage disposal, sedimentation, oil-related pollution, metals and thermal pollution. The stress comprising the main topic of this article, eutrophication, is examined from the point of view of its physiological and ecological mechanisms of action, on a number of levels. Nutrient enrichment can introduce an imbalance in the exchange of nutrients between the zooxanthellae and the host coral, it reduces light penetration to the reef due to nutrient- stimulated phytoplankton growth, and, most harmful of all, may bring about proliferation of seaweeds. The latter rapidly outgrow, smother and eventually replace, the slow-growing coral reef, adapted to cope with the low nutrient concentrations typical in tropical seas.Eutrophication seldom takes place by itself. Sewage disposal invariably results in nutrient enrichment, but it also enriches the water with organic matter which stimulates proliferation of oxygen-consuming microbes. These may kill corals and other reef organisms, either directly by anoxia, or by related hydrogen sulfide production. Increased sediment deposition is in many cases associated with other human activities leading to eutrophication, such as deforestation and topsoil erosion.Realistically achievable goals to ensure conservation, and in some instances, rehabilitation of coral reefs are listed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2486.1996.tb00064.x
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  • 2
    Electronic Resource
    Electronic Resource
    The role of phytoplankton in determining the underwater light climate in Lake Constance (1995)
    Springer
    Hydrobiologia 316 (1995), S. 161-172 
    Details
    ISSN: 1573-5117
    Keywords: spectral water transparency ; underwater light field ; Lake Constance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract At all seasons, the underwater light field of meso-eutrophic large (480 km2) deep (mean: 100 m) Lake Constance was studied in conjunction with the assessments of vertical distributions of phytoplankton chlorophyll concentrations. Vertical profiles of scalar, downwelling and upwelling fluxes of photosynthetically available radiation, as well as fluxes of spectral irradiance between 400 and 700 nm wavelength were measured. The overall transparency of the water for PAR is highly dependent on chlorophyll concentration. However, the spectral composition of underwater light is narrowing with water depth regardless of phytoplankton biomass. Green light is transmitted best, even at extremely low chlorophyll concentrations. This is explained by the selective absorption of blue light by dissolved organic substances and red light by the water molecules. Nevertheless, significant correlations were found between vertical attenuation coefficients of downwelling spectral irradiance and chlorophyll concentrations at all wavelengths. The slopes of the regression lines were used as estimates of chlorophyll-specific spectral vertical light attenuation coefficients (K c(λ)). The proportions of total upwelling relative to total downwelling irradiance (reflectance) increased with water depth, even when phytoplankton were homogeneously distributed over the water column. Under such conditions, reflectance of monochromatic light remained constant. Lower reflectance of PAR in shallow water is explained by smaller bandwidths of upwelling relative to downwelling light near the water surface. In deeper water, by contrast, the spectra of both upwelling and downwelling irradiance are narrowed to the most penetrating components in the green spectral range. Reflectance of PAR was significantly correlated with chlorophyll concentration and varied from ∼ 1% and ∼1-% at low and high phytoplankton biomass, respectively. Over the spectrum, reflectance exhibited a maximum in the green range. Moreover, in deeper layers, a red maximum was observed which is attributed to natural fluorescence by phytoplankton chlorophyll.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00017434
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  • 3
    Electronic Resource
    Electronic Resource
    The underwater light field in the Bellingshausen and Amundsen Seas (Antarctica) (1997)
    Springer
    Hydrobiologia 344 (1997), S. 41-56 
    Details
    ISSN: 1573-5117
    Keywords: underwater light field ; spectral water transparency ; UV-A ; chlorophyll absorption ; natural fluorescence ; Antarctica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The underwater light field in the Bellingshausen andAdmundsen Seas was characterised using data collectedduring the R/V Polarstern cruise ANT XI/3, from12.1.94 to 27.3.94. The euphotic zone varied from 24to 100 m depth. Spectral diffuse vertical attenuationcoefficients (K d (λ))were determined for 12narrow wavebands as well as for photosyntheticallyavailable radiation (PAR, 400–700 nm): K d (490)ranged from 0.03 to 0.26 m™1; K d (550) from0.04 to 0.17 m™1; K d (683) from 0.04 to0.17 m™1; and K d (PAR) varied from 0.02 to0.25 m™1. K d (λ) for wavelengths centred at412 nm, 443 nm, 465 nm, 490 nm, 510 nm, 520 nm and550 nm were significantly correlated with chlorophyllconcentration (ranging from 0.1 to 6 mg m™3). Thevertical attenuation coefficients for 340 nm and380 nm ranged from 0.10 to 0.69 m™1 and from 0.05to 0.34 m™1, respectively, and were also highlycorrelated with chlorophyll concentrations. These K d values indicate that the 1% penetration depthmay reach maxima of 46 m and 92 m for 340 nm and380 nm, respectively. The spectral radiancereflectances (Rr(λ)) for 443 nm, 510 nm and 550 nmwere less than 0.01 sr™1. Rr(λ) for 665 nm and683 nm increased with depth up to 0.2 sr™1 because ofchlorophyll fluorescence. Using a model that predicts downwardirradiances by taking into account the attenuation bywater and absorption by chlorophyll, we show thatchlorophyll fluorescence has a significant influenceon the red downward irradiance (E d (633, 665, 683))in deeper layers. The ability of the phytoplanktonpopulation to influence the light environment byautofluorescence and absorption processes depends onthe light conditions and on the photoacclimation ofthe cells, represented by the in vivo crosssection absorption coefficient of chlorophyll (a*). Theobtained mean chlorophyll-specific light attenuationcoefficients of phytoplankton in situ (k d ) are higherthan the in vivo absorption coefficient of chlorophyll,more than to be excepted from the scattering. a*(λ), m2 mg chl™1, decreased due topackaging effect with increasing chlorophyllconcentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1002993925441
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  • 4
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    Upgrading Marine Ecosystem Restoration Using Ecological–Social Concepts (2016)
    In:  EPIC3BioScience, 66(2), pp. 156-163
    Details
    Publication Date: 2016-02-23
    Description: Conservation and environmental management are principal countermeasures to the degradation of marine ecosystems and their services.However, in many cases, current practices are insufficient to reverse ecosystem declines. We suggest that restoration ecology, the science underlying the concepts and tools needed to restore ecosystems, must be recognized as an integral element for marine conservation and environmental management. Marine restoration ecology is a young scientific discipline, often with gaps between its application and the supporting science. Bridging these gaps is essential to using restoration as an effective management tool and reversing the decline of marine ecosystems and their services. Ecological restoration should address objectives that include improved ecosystem services, and it therefore should encompass social–ecological elements rather than focusing solely on ecological parameters. We recommend using existing management frameworks to identify clear restoration targets, to apply quantitative tools for assessment, and to make the re-establishment of ecosystem services a criterion for success.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
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  • 5
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    The ocean sampling day consortium (2015)
    BioMed Central
    Details
    Publication Date: 2022-10-18
    Description: © The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in GigaScience 4 (2015): 27, doi:10.1186/s13742-015-0066-5.
    Description: Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits.
    Description: This work was supported by the Micro B3 project, which is funded from the European Union’s Seventh Framework Programme (FP7; Joint Call OCEAN.2011‐2: Marine microbial diversity – new insights into marine ecosystems functioning and its biotechnological potential) under the grant agreement no 287589.
    Keywords: Ocean sampling day ; OSD ; Biodiversity ; Genomics ; Health index ; Bacteria ; Microorganism ; Metagenomics ; Marine ; Micro B3 ; Standards
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
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