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Research article2018Peer reviewed

A quantitative framework for selecting and validating food web indicators

Otto, Saskia A.; Kadin, Martina; Casini, Michele; Torres, Maria A.; Blenckner, Thorsten

Abstract

Finding suitable state indicators is challenging and cumbersome in stochastic and complex ecological systems. Typically, a great focus is given to criteria such as data availability, scientific basis, or measurability. Features associated with the indicator's performance such as sensitivity or robustness are often neglected due to the lack of quantitative validation tools. In this paper, we present a simple but flexible framework for selecting and validating the performance of food web indicators. In specific, we suggest a 7-step process in which indicator performances at a regional scale are quantified and visualized allowing for the selection of complementary indicator suites. We demonstrate its application by comparing the performance of pelagic food web indicators for three basins of the Baltic Sea and by assessing the food web status based on selected indicator suites. Our analysis sheds light on spatial differences in indicator performances with respect to direct and indirect pressures, the role of non-linearity and non-additivity in pressure responses, as well as relationships between indicators caused by species interactions. Moreover, our results suggest that the present food web states in the Bornholm and Gotland basins of the Baltic Sea deviate distinctly from an earlier reference period. We advocate the use of our quantitative framework as decision-support tool for selecting suites of complementary indicators under given management schemes such as the EU Marine Strategy Framework Directive.

Keywords

Indicator-testing framework; Performance criteria; Marine strategy framework directive (MSFD); Generalized additive modelling (GAM); State space approach; Marine food web indicators; Baltic sea; Zooplankton; Pelagic fish

Published in

Ecological Indicators
2018, Volume: 84, pages: 619-631 Publisher: ELSEVIER SCIENCE BV

      SLU Authors

    • Sustainable Development Goals

      SDG14 Life below water

      UKÄ Subject classification

      Ecology
      Oceanography, Hydrology, Water Resources

      Publication identifier

      DOI: https://doi.org/10.1016/j.ecolind.2017.05.045

      Permanent link to this page (URI)

      https://res.slu.se/id/publ/94532