UCL logo

UCL Discovery

UCL home » Library Services » Electronic resources » UCL Discovery

Community management indicators can conflate divergent phenomena: two challenges and a decomposition-based solution

Adams, GL; Jennings, S; Reuman, DC; (2017) Community management indicators can conflate divergent phenomena: two challenges and a decomposition-based solution. Journal of Applied Ecology , 54 (3) pp. 883-893. 10.1111/1365-2664.12787. Green open access

[img]
Preview
Text (Published article)
Adams_et_al-2017-Journal_of_Applied_Ecology.pdf - ["content_typename_Published version" not defined]

Download (1MB) | Preview
[img]
Preview
Text (Supplementary information)
Adams_Community_management_indicators_Suppl.pdf

Download (2MB) | Preview

Abstract

SUMMARY: 1.Community indicators are used to assess the state of ecological communities and to guide management. They are usually calculated from monitoring data, often collected annually. Since any given community indicator provides a univariate summary of complex multivariate phenomena, different changes in the community may lead to the same response in the indicator. Sampling variation can also mask ecologically important trends. 2.This study addresses these challenges for community indicators, with a focus on the large fish indicator (LFI), internationally used to report status of marine fish communities. The LFI expresses ‘large’ fish biomass as a proportion of total fish biomass and is calculated from species–size–abundance data collected on trawl surveys. We develop new methods to decompose the contributions of species, sampling locations and season to trends over time in the LFI, and highlight consequences for assessment and management. 3.Our results showed that both species and locations made divergent contributions to overall trends in the LFI indicator, with contributions differing by several orders of magnitude and in sign. Only small proportions of species and locations drove overall LFI trends, and their contributions changed with season (spring and autumn surveys). To assess significance of component trends, a resampling method was developed. Our method can be generalized and applied to many other community indicators based on survey data. 4.Synthesis and applications. Our new method for decomposing community indicators and generating confidence intervals makes it possible to extract much more information on what drives a ‘headline’ indicator, providing a solution to challenges arising from multiple possible interpretations of changes in the indicator and from sampling variation. Analysis of the effects of indicator components on headline indicator values is recommended, because the results allow assessors and managers to identify and interpret how divergent factors (e.g. species, sampling locations and seasons) contribute to the headline indicator value.

Type: Article
Title: Community management indicators can conflate divergent phenomena: two challenges and a decomposition-based solution
Open access status: An open access version is available from UCL Discovery
DOI: 10.1111/1365-2664.12787
Publisher version: http://dx.doi.org/10.1111/1365-2664.12787
Language: English
Additional information: Copyright © 2016 The Authors. Journal of Applied Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society. This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Keywords: community indicators; ecosystem approach to management; fish community; fisheries management; large fish indicator; North Sea; resampling method; size-based indicators; trawl surveys
UCL classification: UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences
URI: http://discovery.ucl.ac.uk/id/eprint/1563692
Downloads since deposit
90Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item