Marine Ecosystem Connections: essential indicators of healthy, productive and biologically diverse seas

Abstract

Welcome to this Special Issue of Biogeochemistry, which highlights the key research findings from a fiveyear study entitled ‘‘Marine Ecosystem Connections: essential indicators of healthy, productive and biologically diverse seas’’. The overall aims of the programme were to improve our scientific understanding of the functioning of shelf seas, develop tools for predicting the impact of human activity on ecosystem structure and function, and contribute to the development of indicators for assessments of ecosystem health and environmental status. Key to these studies was the focus on linkages between benthic and pelagic food webs, in response to environmental drivers (Fig. 1), and an underpinning requirement to link the research on biogeochemical cycling to the development of tools and approaches for improved management of marine resources. Around the world, in countries such as Australia, Canada, China, North America and South Africa, recent policy and legislative drivers require integrated, ecosystem-based assessments of the impacts of human activities (see Borja et al. 2008; Elliott 2011). In Europe, for example, the Marine Strategy Framework Directive (MSFD, CEC 2008) aims to achieve Good Environmental Status (GES) in all water bodies by 2020, and requires that ‘‘the structure, functions and processes of the constituent marine ecosystems’’ allow them ‘‘to function fully and to maintain their resilience to human-induced environmental change’’, taking account of ‘‘associated physiographic, geographic, geological and climatic factors’’. A number of coastal and marine regions, including the North Sea, have therefore become the focus of ongoing research on ecosystem structure and function, and the development of indicators for assessing environmental status (see COM 2010). Studies carried out during ‘Marine Ecosystem Connections’ (MEC) are part of this effort. A combined fieldwork and modelling approach was used to quantify carbon and nitrogen fluxes through pelagic and benthic food webs in the temperate North Sea, to predict the impacts of climate change and demersal trawling on these fluxes (van der Molen et al. 2012), and to select and evaluate indicators of ecosystem functioning in terms of their suitability for assessing and managing the impacts of climate change and demersal trawling (Painting et al. 2012). For the pelagic food web, only lower trophic levels (up to zooplankton) were considered, as they have fast turnover rates and are useful as early warning indicators of environmental change. For the benthic food web, the main functional groups of the faunal communities were considered. Coupled physical-biogeochemical models (GOTM-ERSEM-BFM) were developed to improve their suitability for temperate shelf seas (see van der Molen et al. 2012), e.g. through parameterisation to allow growth of diatoms S. J. Painting (&) R. M. Forster Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft, Suffolk NR33 0HT, UK e-mail: suzanne.painting@cefas.co.uk