997 resultados para freshwater ecosystem


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The ERSEM model is one of the most established ecosystem models for the lower trophic levels of the marine food-web in the scientific literature. Since its original development in the early nineties it has evolved significantly from a coastal ecosystem model for the North-Sea to a generic tool for ecosystem simulations from shelf seas to the global ocean. The current model release contains all essential elements for the pelagic and benthic part of the marine ecosystem, including the microbial food-web, the carbonate system and calcification. Its distribution is accompanied by a testing framework enabling the analysis of individual parts of the model. Here we provide a detailed mathematical description of all ERSEM components along with case-studies of mesocosm type simulations, water column implementations and a brief example of a full-scale application for the North-West European shelf. Validation against in situ data demonstrates the capability of the model to represent the marine ecosystem in contrasting environments.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The EU Marine Strategy Framework Directive (MSFD) sets out a plan of action relating to marine environmental policy and in particular to achieving ‘good environmental status’ (GES) in European marine waters by 2020. Article 8.1 (c) of the Directive calls for ‘an economic and social analysis of the use of those waters and of the cost of degradation of the marine environment’. The MSFD is ‘informed’ by the Ecosystem Approach to management, with GES interpreted in terms of ecosystem functioning and services provision. Implementation of the Ecosystem Approach is expected to be by adaptive management policy and practice. The initial socio-economic assessment was made by maritime EU Member States between 2011 and 2012, with future updates to be made on a regular basis. For the majority of Member States, this assessment has led to an exercise combining an analysis of maritime activities both at national and coastal zone scales, and an analysis of the non-market value of marine waters. In this paper we examine the approaches taken in more detail, outline the main challenges facing the Member States in assessing the economic value of achieving GES as outlined in the Directive and make recommendations for the theoretically sound and practically useful completion of the required follow-up economic assessments specified in the MSFD.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A mixed-method approach was used to assess and value the ecosystem services derived from the Dogger Bank, an extensive shallow sandbank in the southern North Sea. Three parallel studies were undertaken that 1) identified and quantified, where possible, how indicators for ecosystem service provision may change according to two future scenarios, 2) assessed members of the public's willingness-to-pay for improvements to a small number of ecosystem services as a consequence of a hypothetical management plan, and 3) facilitated a process of deliberation that allowed members of the public to explore the uses of the Dogger Bank and the conflicts and dilemmas involved in its management. Each of these studies was designed to answer different and specific research questions and therefore contributes different insights about the ecosystem services delivered by the Dogger Bank. This paper explores what can be gained by bringing these findings together post hoc and the extent to which the different methods are complementary. Findings suggest that mixed-method research brings more understanding than can be gained from the individual approaches alone. Nevertheless, the choice of methods used and how these methods are implemented strongly affects the results obtained.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ecosystem services provided by the marine environment are fundamental to human health and well-being. Despite this, many marine systems are being degraded to an extent that may reduce their capacity to provide these ecosystem services. The ecosystem approach is a strategy for the integrated management of land, water and living resources that promotes conservation and sustainable use in an equitable way (UN Convention on Biological Diversity, 2000). Its application to marine management and spatial planning has been proposed as a means of maintaining the economic and social value of the oceans, not only in the present but for generations to come. Characterising the susceptibility of services (and combinations of services) to particular human activities based on knowledge of impacts on biodiversity and ecosystem functioning (as described in preceding chapters) is a challenge for future management of the oceans. In this chapter, we highlight the existing, but limited knowledge of how ecosystem services may be impacted by different human activities. We discuss how impacts on one service can impact multiple services and explore how the impacts on services can vary both spatially and temporally and according to context. We focus particularly on the effects on ecosystem services of activities whose impacts on biodiversity and ecosystem functioning have already been considered in previous chapters. Some of these activities are associated with poor management of ecosystem benefits, for example, from provisioning services (aquaculture and fisheries), or with excessive input of wastes, fertilisers and contaminants into the system overburdening the waste treatment and assimilation services. Other impacts are associated with the construction of structures or use of space designed to generate benefits from environmental services such as the presence of water as a carrier for shipping, or sources of wind, wave and tidal power. We discuss the trade-offs that are made, consciously or otherwise, between different ecosystem services, which arise from human activities to optimise or manage specific ecosystem services.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Marine legislation is becoming more complex and marine ecosystem-based management is specified in national and regional legislative frameworks. Shelf-seas community and ecosystem models (hereafter termed ecosystem models) are central to the delivery of ecosystem-based management, but there is limited uptake and use of model products by decision makers in Europe and the UK in comparison with other countries. In this study, the challenges to the uptake and use of ecosystem models in support of marine environmental management are assessed using the UK capability as an example. The UK has a broad capability in marine ecosystem modelling, with at least 14 different models that support management, but few examples exist of ecosystem modelling that underpin policy or management decisions. To improve understanding of policy and management issues that can be addressed using ecosystem models, a workshop was convened that brought together advisors, assessors, biologists, social scientists, economists, modellers, statisticians, policy makers, and funders. Some policy requirements were identified that can be addressed without further model development including: attribution of environmental change to underlying drivers, integration of models and observations to develop more efficient monitoring programmes, assessment of indicator performance for different management goals, and the costs and benefit of legislation. Multi-model ensembles are being developed in cases where many models exist, but model structures are very diverse making a standardised approach of combining outputs a significant challenge, and there is a need for new methodologies for describing, analysing, and visualising uncertainties. A stronger link to social and economic systems is needed to increase the range of policy-related questions that can be addressed. It is also important to improve communication between policy and modelling communities so that there is a shared understanding of the strengths and limitations of ecosystem models.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper we present the first decadal reanalysis simulation of the biogeochemistry of the North West European shelf, along with a full evaluation of its skill and value. An error-characterized satellite product for chlorophyll was assimilated into a physical-biogeochemical model of the North East Atlantic, applying a localized Ensemble Kalman filter. The results showed that the reanalysis improved the model predictions of assimilated chlorophyll in 60% of the study region. Model validation metrics showed that the reanalysis had skill in matching a large dataset of in situ observations for ten ecosystem variables. Spearman rank correlations were significant and higher than 0.7 for physical-chemical variables (temperature, salinity, oxygen), ∼0.6 for chlorophyll and nutrients (phosphate, nitrate, silicate), and significant, though lower in value, for partial pressure of dissolved carbon dioxide (∼0.4). The reanalysis captured the magnitude of pH and ammonia observations, but not their variability. The value of the reanalysis for assessing environmental status and variability has been exemplified in two case studies. The first shows that between 340,000-380,000 km2 of shelf bottom waters were oxygen deficient potentially threatening bottom fishes and benthos. The second application confirmed that the shelf is a net sink of atmospheric carbon dioxide, but the total amount of uptake varies between 36-46 Tg C yr−1 at a 90% confidence level. These results indicate that the reanalysis output dataset can inform the management of the North West European shelf ecosystem, in relation to eutrophication, fishery, and variability of the carbon cycle.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ecosystem services assessments are increasingly being used to inform marine policy and planning. These assessments involve significant time, effort, and expertise. It is important at the outset to determine which of many ecosystem services should be quantified and which measures of ecological output, economic impact, or value should be assessed. Furthermore, the literature shows that in practice such assessments are unevenly applied and rarely used effectively in decision-making processes. We develop a structured decision-making approach, called a triage, to assess what types of ecosystem services should be assessed to improve the uptake and usefulness of such information in marine planning. Two case studies, in France and the United Kingdom, provide examples of the application of the triage approach.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The EU Marine Strategy Framework Directive (MSFD) sets out a plan of action relating to marine environmental policy and in particular to achieving ‘good environmental status’ (GES) in European marine waters by 2020. Article 8.1 (c) of the Directive calls for ‘an economic and social analysis of the use of those waters and of the cost of degradation of the marine environment’. The MSFD is ‘informed’ by the Ecosystem Approach to management, with GES interpreted in terms of ecosystem functioning and services provision. Implementation of the Ecosystem Approach is expected to be by adaptive management policy and practice. The initial socio-economic assessment was made by maritime EU Member States between 2011 and 2012, with future updates to be made on a regular basis. For the majority of Member States, this assessment has led to an exercise combining an analysis of maritime activities both at national and coastal zone scales, and an analysis of the non-market value of marine waters. In this paper we examine the approaches taken in more detail, outline the main challenges facing the Member States in assessing the economic value of achieving GES as outlined in the Directive and make recommendations for the theoretically sound and practically useful completion of the required follow-up economic assessments specified in the MSFD.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The European Regional Seas Ecosystem Model (ERSEM) is one of the most established ecosystem models for the lower trophic levels of the marine food web in the scientific literature. Since its original development in the early nineties it has evolved significantly from a coastal ecosystem model for the North Sea to a generic tool for ecosystem simulations from shelf seas to the global ocean. The current model release contains all essential elements for the pelagic and benthic parts of the marine ecosystem, including the microbial food web, the carbonate system, and calcification. Its distribution is accompanied by a testing framework enabling the analysis of individual parts of the model. Here we provide a detailed mathematical description of all ERSEM components along with case studies of mesocosm-type simulations, water column implementations, and a brief example of a full-scale application for the north-western European shelf. Validation against in situ data demonstrates the capability of the model to represent the marine ecosystem in contrasting environments.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Executive Summary The programme of work was commissioned in September 1998 to supply information to underpin the UK’s commitments to protection and conservation of the ecosystems and biodiversity of the marine environment under the 1992 OSPAR Convention on the Protection of the Marine Environment of the North East Atlantic. The programme also provided support for the implementation of the Biodiversity Convention and the EU Habitats Directive. The MarLIN programme initiated a new approach to assessing sensitivity and recoverability characteristics of seabed species and biotopes based on structures (such as the seabed biotopes classification) and criteria (such as for assessing rarity and defining ‘sensitivity’) developed since 1997. It also developed tools to disseminate the information on the Internet. The species researched were those that were listed in conventions and directives, included in Biodiversity Action Plans, or were nationally rare or scarce. In addition, species were researched if they maintained community composition or structure and/or provided a distinctive habitat or were special to or especially abundant in a particular situation or biotope At its conclusion in August 2001, the work carried out under the contract with DETR/DEFRA had: · Developed protocols, criteria and structures for identifying ‘sensitivity’ and ‘recoverability’, which were tested by a programme management group. · Developed a database to hold research data on biology and sensitivity of species and biotopes. · Defined the link between human activities and the environmental factors likely to be affected by those activities. · Developed a user-friendly Web site to access information from the database, on the sensitivity and recoverability characteristics of over 100 species and basic information on over 200 species. Additionally, the project team have: · Brought together and facilitated discussion between current developers and users of electronic resources for environmental management, protection and education in the conference ‘Using Marine Biological Information in the Electronic Age’ (19-21 July 1999). · Contributed to the development of Ecological Quality Objectives for the North Sea (Scheveningen, 11- 3 September 1999 and subsequent papers). · Provided detailed information on species as a supplement to the National Biodiversity Network Gateway demonstration www.searchnbn.net. · Developed a peer-reviewed approach to electronic publication of updateable information. · Promoted the contract results and the MarLIN approach to the support of marine environmental management and protection at European research fora and, through the web site, internationally. The information available through the Web site is now being used by consultants and Government agencies. The DEFRA contract has been of critical importance in establishing the Marine Life Information Network (MarLIN) programme and has encouraged support from other organisations. Other related work in the MarLIN programme is on-going, especially to identify sensitivity of biotopes to support management of SACs (contract from English Nature in collaboration with Scottish Natural Heritage), to access data sources (in collaboration with the National Biodiversity Network) and to establish volunteer recording schemes for marine life. The results of the programme are best viewed on the Web site (www.marlin.ac.uk). Three reports have been produced during the project. A final report detailing the work undertaken, a brochure ‘Identifying the sensitivity of seabed ecosystems’ and a CD-ROM describing the programme and demonstrating the Web site have been delivered as final products in addition to the Web site.