The latest in the series of information papers issued by the Central Dredging Association (CEDA) is entitled Ecosystem Services and Dredging and Marine Construction.
It has been produced by the CEDA Working Group on Ecosystem Services (WGES) under the remit of the Environment Commission (CEC).
Members of WEGS are scientists and practitioners with a broad range of expertise, representing knowledge institutes, government, manufacturers, ports and contractors.
The concept of ecosystem services (ES) enables a value to be assigned to natural resources that makes it possible to link the environment to human well-being.
This has important implications for the planning and management of dredging and marine construction projects. In short, the ES concept is a tool for decision-making about sustainable development.
The paper explains that there are four basic groups of ecosystem services: provisioning services (food, and water, for example), regulating services (such as flood control and air purification), supporting services (eg navigation) and cultural services (including recreation). Each service is delivered by a set of structures and processes called an ecosystem function. This may be changed in order to deliver a benefit to human well-being, for example by dredging a navigation channel, and, in doing so, creates a pressure.
The ES concept is intended to help project designers create a sustainable balance between pressures and services in ecosystems. The aim is not merely to minimise damage (pressure) but also to look for opportunities to improve the environment. As dredging and marine construction often takes place in and around sensitive, and sometimes degraded, environments, such as coastal waters, rivers, mudflats and sandbanks, the ES concept is of considerable value if used at the earliest stage of project planning.
The paper sets out how individual ecosystem services are affected by dredging. For example, for water quality, dredging may cause a short-term decrease in local water quality and, by altering the morphology of the system, lead to a loss of habitat and species. However, dredging of contaminated sediments decreases the contaminants in the system. Also, if reedbeds are created then water quality will be enhanced.
The paper recommends that a multi-disciplinary project team be set up to assess the ecosystem services, to assign values to those services and pressures, and to design the project. It includes two case studies showing how this has been achieved in practice in the Scheldt estuary and in estuaries in the east of England. Other interesting initiatives include the use of ‘eco-concrete’, which encourages colonisation of marine structures by small organisms, and seabed landscaping after aggregates dredging, which again promotes biodiversity.
This new CEDA information paper shows how, by applying the ecosystem services concept, the dredging and marine construction sector can deliver benefits both for society and for the natural environment.
The CEDA Information Paper Ecosystem Services and Dredging and Marine Construction can be downloaded from the CEDA website www.dredging.org. Select Publications & Resources and click Downloads or just type ‘ecosystem services in the search window.
Press Release, July 12, 2013