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Framework for understanding marine ecosystem health

Tett, P; Gowen, RJ; Painting, SJ; Elliott, M; Forster, R; Mills, DK; Bresnan, E; Capuzzo, E; Fernandes, TF; Foden, J; Geider, RJ; Gilpin, LC; Huxham, M; McQuatters-Gollop, AL; Malcolm, SJ; Saux-Picart, S; Platt, T; Racault, MF; Sathyendranath, S; van der Molen, J; Wilkinson, M


P Tett

RJ Gowen

SJ Painting

M Elliott

R Forster

DK Mills

E Bresnan

E Capuzzo

TF Fernandes

J Foden

RJ Geider

AL McQuatters-Gollop

SJ Malcolm

S Saux-Picart

T Platt

MF Racault

S Sathyendranath

J van der Molen

M Wilkinson


Although the terms ‘health’ and ‘healthy’ are often applied to marine ecosystems and communicate information about holistic condition (e.g. as required by the Ecosystem Approach), their meaning is unclear. Ecosystems have been understood in various ways, from non-interacting populations of species to complex integrated systems. Health has been seen as a metaphor, an indicator that aggregates over system components, or a non-localized emergent system property. After a review, we define good ecosystem health as: ‘the condition of a system that is self-maintaining, vigorous, resilient to externally imposed pressures, and able to sustain services to humans. It contains healthy organisms and populations, and adequate functional diversity and functional response diversity. All expected trophic levels are present and well interconnected, and there is good spatial connectivity amongst subsystems.’ We equate this condition with good ecological or environmental status, e.g. as referred to by recent EU Directives. Resilience is central to health, but difficult to measure directly. Ecosystems under anthropogenic pressure are at risk of losing resilience, and thus of suffering regime shifts and loss of services. For monitoring whole ecosystems, we propose an approach based on ‘trajectories in ecosystem state space’, illustrated with time-series from the northwestern North Sea. Change is visualized as Euclidian distance from an arbitrary reference state. Variability about a trend in distance is used as a proxy for inverse resilience. We identify the need for institutional support for long time-series to underpin this approach, and for research to establish state space co-ordinates for systems in good health.


Tett, P., Gowen, R., Painting, S., Elliott, M., Forster, R., Mills, D., …Wilkinson, M. (2013). Framework for understanding marine ecosystem health. Marine Ecology Progress Series, 494, 1-27.

Journal Article Type Article
Acceptance Date Nov 1, 2013
Online Publication Date Dec 4, 2013
Publication Date Dec 4, 2013
Deposit Date Oct 11, 2017
Journal Marine Ecology Progress Series
Print ISSN 0171-8630
Electronic ISSN 1616-1599
Publisher Inter Research
Peer Reviewed Peer Reviewed
Volume 494
Pages 1-27
Keywords Ecosystem approach, Functional and response biodiversity, Resilience, State space, Regime shift, EU Marine strategy, framework directive
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