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Piet G. J.; Quirijns F. J.; Robinson L.; Greenstreet S. P. R. 《ICES Journal of Marine Science》2007,64(1):110-121
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Neutral aldoses as source indicators for marine snow 总被引：2，自引：0，他引：2
Annelie Skoog Alice Alldredge Uta Passow John Dunne James Murray 《Marine Chemistry》2008,108(3-4):195-206
The chemical characteristics of aggregating material in the marine environment are largely unknown. We investigated neutral aldose (NA) abundance and composition in aggregation of marine snow and other organic matter (OM) size fractions in the field. Four sample sets were fractionated using membrane filtration and ultrafiltration into the following size fractions: particulate material, high-molecular-weight (HMW) material, and low-molecular-weight (LMW) material. We also collected three sample sets of marine-snow aggregates. Each sample set contained small, medium, and large aggregate size fractions and each size fraction consisted of 25–50 aggregates. For 7 marine-snow samples and for each water-sample size fraction, we determined monomeric and polymeric NA concentration, NA yield (amount of NA-C normalized to organic carbon), and composition; total organic carbon (TOC) concentration; transparent exopolymer particles (TEP) concentration, and TEP propensity (TEP concentration after inducing TEP formation in filtered samples). This is the first study to include compound-specific NA determinations on these four marine OM size fractions.The mass balances of organic carbon and NA indicated that there were no serious contamination or loss problems. Concentrations, yields, and NA mol fractions in water samples were similar to results from other studies. Glucose and galactose had the highest relative abundance in all size fractions. The NA yield increased with increasing molecular weight or particle size for all fractions except marine snow. The NA yield increased in the order: LMW< marine snow< HMW< particles. Marine snow had a higher average NA yield than the LMW fraction, but lower than particle and HMW-fractions. This indicates that OM in marine snow could have been diagenetically derived from particulate and HMW-fractions, that is, marine snow may include material from the particulate and the colloidal phase.TEP concentration or TEP propensity was positively correlated with concentrations of all individual NAs as well as the sum NA concentrations, indicating that TEP contains neutral sugars in addition to the acidic polysaccharides stained in the determination of TEP concentrations.Despite the relatively low NA yield in marine snow, marine snow was enriched in NA when compared with seawater, with enrichment factors of 34–225 (average 125). By combining data from this study with data from other studies, we estimate that < 10% of carbohydrates in marine snow comprise NAs.There was no clear correlation between marine-snow aggregate size and NA yield, that is, there appears to be no general age difference between small and large marine-snow aggregates. NA composition was similar among different marine-snow size fracions collected during the same day, indicating that aggregation/disaggregation reactions resulted in homogenizing NA composition in marine-snow aggregates of all sizes. The NA composition of marine snow was different from that of other OM size fractions, indicating either that bacterial degradation has modified the composition of marine snow to a larger extent than other OM size fractions or that marine snow is formed through the aggregation of selected subcomponents of OM. 相似文献
3.
《Ocean & Coastal Management》2003,46(3-4):235-259
Ecologists have proposed hundreds of quantitative indicators of the status of ecosystems for evaluation of and reporting on the status of marine ecosystems. The talk applies a common approach to classifying indicators, summarises the main properties of each class of indicator, and provides some illustrations.Indicators of ecosystem status have roles in both communication and decision support. For both roles, strengths and weaknesses of indicators are usually only partially known. Few have been tested systematically for sensitivity and robustness across a range of contexts… However, to determine best practices for selecting indicators for specific uses, one must have a fairly complete understanding of the information content of the various indicators. The paper explores some alternative approaches to documenting the information content of various indicators of ecosystem status.As the Precautionary Approach becomes broadly used as the basis for management decision-making, the role of indicators of ecosystem status becomes central. The PA is made operational in decision-making through use of indicators and reference points. This means that it is necessary to identify values of an ecosystem indicator associated with harm to the environment that is serious or difficult to reverse. Methods for identifying and justifying reference points for ecosystem indicators are being developed and tested, but the task is turning out to be complex. Alternative strategies for identifying reference points are reviewed.When choices must be made from a suite of candidate indicators, it is desirable make the selection on objective grounds. This requires explicit a priori criteria, on which there is not yet scientific consensus. Recent developments in this area are reviewed, and again a way forward proposed. 相似文献
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Freshly excreted droppings from Canada geese (n=80), black swans (n=80), ducks (n=80) and gulls (n=80) were collected from sites around New Zealand. The droppings were enumerated for Escherichia coli, enterococci and Salmonella spp., and for the presence/absence of Cryptosporidium spp. Overall prevalence of E. coli and enterococci in samples was 95% and 94%, respectively. Cryptosporidium spp. was detected in 2% of the samples, whereas no Salmonella spp. were detected in the survey. Preliminary estimates of daily microbial outputs suggest that ducks will produce the highest loadings of E. coli and enterococci per bird, whereas Canada geese will produce the highest loadings of Campylobacter spp. per bird. This study provides the first set of indicator and pathogen counts for one of the largest sources of diffuse faecal contamination of natural waters in New Zealand. 相似文献
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Translating ecosystem indicators into decision criteria 总被引：3，自引：1，他引：3
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Monitoring pelagic ecosystems using plankton indicators 总被引：2，自引：0，他引：2
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A method is presented to study the carbohydrate composition of marine objects involved into sedimento- and diagenesis (plankton,
particulate matter, benthos, and bottom sediments). The analysis of the carbohydrates is based upon the consecutive separation
of their fractions with different solvents (water, alkali, and acid). The ratio of the carbohydrate fractions allows one to
evaluate the lability of the carbohydrate complex. It is also usable as an indicator of the biogeochemical processes in the
ocean, as well of the genesis and the degree of conversion of organic matter in the bottom sediments and nodules. The similarity
in the monosaccharide composition is shown for dissolved organic matter and aqueous and alkaline fractions of seston and particulate
matter. 相似文献
10.
《Ocean & Coastal Management》2003,46(3-4):299-312
The need to better understand the linkages and interdependencies of socio-economic and coastal environmental dynamics has taken on a more deliberate role in the development and assessment of Integrated Coastal Management world-wide. The analysis and establishment of indicator-driven programs to assess change in coastal and watershed systems have increasingly moved to stress socio-economic forcings and impacts. This article serves to review the need for and provide an assessment of important frameworks designed to foster such integration. It argues that the evolution of the Driver–Pressure–State–Impact–Response (DPSIR) framework, now in broad use, provides an essential contribution. 相似文献
11.
Quantitative ecosystem indicators for fisheries management 总被引：1，自引：2，他引：1
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Recent benthonic foraminifera respond to even minor changes in environmental conditions. On the basis of statistical analyses of both foraminiferal population and bottom sediments, a new morphological terminology for the Lagoon of Venice is presented.The various geomorphic units are here differentiated on the basis of the relative occurrence of subpopulations that respond to local physicochemical and biological parameters. This reduces the need to evaluate the tolerance limits of each individual species, necessary to identify environments in terms of species or groups of species. 相似文献
14.
ABSTRACT National assessments have highlighted that urban streams have some of the poorest water quality in New Zealand, yet there has been no analysis focussing on these streams. In this study we defined urban streams as >15% catchment urban land cover and used monitoring data to assess several indicators of water quality including dissolved metals, nutrients, bacteria and the macroinvertebrate community index. We investigated associations between the indicators and urban land cover, imperviousness and geographic location. Water quality was highly variable, within and between monitored sites; and invariably poor when compared to water quality criteria. Dissolved zinc was positively related to the proportion of urban land cover and imperviousness in the upstream catchment. There were significant differences in ammoniacal-N, nitrate-N, turbidity, MCI, dissolved zinc and E. coli between geographic locations. The analysis indicates that if urban development continues in its current form, increases in urban land cover around New Zealand can be expected to result in further declines in water quality and a reduced likelihood that water quality objectives will be achieved at impacted locations. 相似文献
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This paper analyzes demographic data (the time series of the number of births and deaths for over 50 years in the 20th and
21st centuries). The properties of the time series are revealed, and some of them are explained. A comparison of data for
men and women has resulted in the revelation that seasonal changes for women are more strongly evident than for men. The possible
causes for the differences between the time series of the number of deceased men and women are discussed. 相似文献
17.
Trophodynamic indicators for an ecosystem approach to fisheries 总被引：8，自引：3，他引：8
Cury P.M.; Shannon L.J.; Roux J-P.; Daskalov G.M.; Jarre A.; Moloney C.L.; Pauly D. 《ICES Journal of Marine Science》2005,62(3):430-442
18.
《Ocean & Coastal Management》2003,46(3-4):347-361
The fundamental purpose of all integrated coastal management (ICM) initiatives is to maintain, restore or improve specified qualities of coastal ecosystems and their associated human societies. A defining feature of ICM is that it addresses needs for both development and conservation in geographically specific places—be they a single community, an estuary or the coast of an entire nation. The times required to achieve these fundamental goals at significant spatial scales far exceed those of the usual 4–6-year project, the dominant ICM modality in developing nations. This paper offers two simple, but elastic frameworks for assessing progress over the extended time periods involved. The first is the four Orders of Outcomes that group together the sequences of institutional, behavioral and social/environmental changes that can lead to more sustainable forms of coastal development. The second framework is a version of the more familiar ICM policy cycle. These conceptually simple frameworks are making it possible to unbundle and organize into consistent formats the usually implicit assumptions that underpin project and program designs and then group activities and outcomes along a critical path that leads—or is presumed to lead—to the desired outcomes. Each step in the ICM policy cycle and each Order of Outcomes suggest the indicators by which progress and learning can be assessed. The application of these frameworks to a diversity of ICM initiatives is proving useful in assessing progress across portfolios of ICM initiatives, extracting good practices and teasing out how different governance contexts effect the forces that shape the evolution of ICM initiatives. 相似文献
19.
《Ocean & Coastal Management》2003,46(3-4):277-297
Different signals of distress from the North Sea ecosystems started a discussion on the protection of the ecosystem at the third North Sea Ministers Conference in 1990. This was followed by a number of workshops on ecological indicators under the auspices of the North Sea Task Force and the Oslo and Paris Commissions (OSPAR). In 1997 the member countries around the North Sea agreed to develop and apply an ecosystem's approach in the management programs for both the North Sea fisheries and the marine environment. Following this agreement the identification of the ecological qualities objectives for the North Sea ecosystem started. Further work in this direction has lead to the setting up of various national projects geared towards creating a better understanding of the North Sea ecosystem.In the Netherlands, two departments (Water management and Nature and fisheries management) from the Ministry of Transport, Public works and Water Management (V&W) and the Ministry of Agriculture, Nature and Fisheries Management (LNV) agreed to integrate their policies for the management of the Netherlands section of the North Sea. The results from these projects (started in 1996) should enable the policy makers and managers to formulate policies that could lead to the creation of a balance between the effects of human activities and the preservation of the natural qualities of the North Sea ecosystem.One of the projects is strictly designed to develop ecological indicators for the Dutch part of the North Sea. These indicators are based on various monitoring data and related in one way or another with human activities. In this way it is possible to evaluate the effects of human impacts on the ecosystem. Long-term changes in the ecological performance of the ecosystem can be elucidated by the use of the ecological indicators. Thereby making it possible for the policy makers and the managers of the NCP to evaluate the effects of their policies and management recommendations on the quality of the ecosystem.This paper describes the process and the steps taken by the authorities in the countries around the North Sea to develop a set of ecological indicators for the management of the North Sea ecosystem. Focus will be made on the efforts made in the Netherlands to develop indicators that did provide the basis for the development of Water and Nature conservation policies and new management strategies for maintaining the sustainable use of the Dutch section of the North Sea. 相似文献
20.
《Marine Policy》2015
International policy frameworks such as the Common Fisheries Policy and the European Marine Strategy Framework Directive define high-level strategic goals for marine ecosystems. Strategic goals are addressed via general and operational management objectives. To add credibility and legitimacy to the development of objectives, for this study stakeholders explored intermediate level ecological, economic and social management objectives for Northeast Atlantic pelagic ecosystems. Stakeholder workshops were undertaken with participants being free to identify objectives based on their own insights and needs. Overall 26 objectives were proposed, with 58% agreement in proposed objectives between two workshops. Based on published evidence for pressure-state links, examples of operational objectives and suitable indicators for each of the 26 objectives were then selected. It is argued that given the strong species-specific links of pelagic species with the environment and the large geographic scale of their life cycles, which contrast to demersal systems, pelagic indicators are needed at the level of species (or stocks) independent of legislative region. Pelagic community indicators may be set at regional scale in some cases. In the evidence-based approach used in this study, the selection of species or region specific operational objectives and indicators was based on demonstrated pressure-state links. Hence observed changes in indicators can reliably inform on appropriate management measures. 相似文献