Trend analysis of indicators: a comparison of recent changes in the status of marine ecosystems around the world

Blanchard, J. L., Coll, M., Trenkel, V. M., Vergnon, R., Yemane, D., Jouffre, D., Link, J. S., and Shin, Y-J. 2010. Trend analysis of indicators: a comparison of recent changes in the status of marine ecosystems around the world. – ICES Journal of Marine Science, 67: 000– 000. Time-series of ecological and exploitation indicators collected from 19 ecosystems were analysed to investigate whether there have been temporal trends in the status of fish communities. Using linear and non-linear statistical methods, trends are reported for six indicators (mean length of fish in the community, mean lifespan, proportion of predatory fish, total biomass of surveyed species, mean trophic level of landings, and inverse fishing pressure), and the redundancy of these indicators across ecosystems is evaluated. The expected direction of change for an ecosystem that is increasingly impacted by fishing is a decline in all indicators. A mixture of negative and positive directions of change is recorded, both within and among all ecosystems considered. No consistent patterns in the redundancy of the ecological indicators across ecosystems emerged from the analyses, confirming that each indicator provided complementary information on ecosystem status. The different trends in indicators may reflect differing historical exploitation patterns, management, and environmental regimes in these systems. Commitment to monitoring programmes and development of system-specific baseline, target, and threshold reference levels are required. Improved understanding of the responsiveness and performance of ecological indicators to management actions are needed to address adequately whether ecosystems are recovering from, or being further impacted by, fishing, and whether management targets are being met. The relative effects of multiple environmental and ecological processes as well as multiple human-induced stressors that characterize exploited ecosystems also need to be quantified.

[1]  Y. Shin,et al.  Relating marine ecosystem indicators to fishing and environmental drivers: an elucidation of contrasting responses , 2010 .

[2]  Y. Shin,et al.  Using indicators for evaluating, comparing, and communicating the ecological status of exploited marine ecosystems. 2. Setting the scene. , 2010 .

[3]  M. Coll,et al.  Comparing trophic flows and fishing impacts of a NW Mediterranean ecosystem with coastal upwelling systems by means of standardized models and indicators , 2006 .

[4]  V. Trenkel,et al.  Performance of indicators derived from abundance estimates for detecting the impact of fishing on a fish community , 2003 .

[5]  N. Stenseth,et al.  Spatio–temporal dynamics of the grey–sided vole in Hokkaido: identifying coupling using state-based Markov–chain modelling , 2003, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[6]  Bernard Cazelles,et al.  Symbolic dynamics for identifying similarity between rhythms of ecological time series , 2004 .

[7]  S. Wood.  Generalized Additive Models: An Introduction with R , 2006 .

[8]  Gerjan J. Piet,et al.  Long-term trends in the trophic structure of the North Sea fish community: evidence from stable-isotope analysis, size-spectra and community metrics , 2002 .

[9]  S. Neira,et al.  Long-term changes in the mean trophic level of central Chile fishery landings , 2005 .

[10]  Elizabeth A. Fulton,et al.  Estimating EAF indicators from scientific trawl surveys: theoretical and practical concerns , 2010 .

[11]  S. Neira,et al.  Comparing the Benguela and Humboldt marine upwelling ecosystems with indicators derived from inter-calibrated models , 2005 .

[12]  J. Blanchard,et al.  Power of monitoring surveys to detect abundance trends in depleted populations: the effects of density-dependent habitat use, patchiness, and climate change , 2008 .

[13]  Simon Jennings,et al.  Indicators to support an ecosystem approach to fisheries , 2005 .

[14]  Richard Law,et al.  Fishing, selection, and phenotypic evolution , 2000 .

[15]  M. Coll,et al.  Food-web dynamics in the South Catalan Sea ecosystem (NW Mediterranean) for 1978-2003 , 2008 .

[16]  V. Trenkel,et al.  Intersection–union tests for characterising recent changes in smoothed indicator time series , 2009 .

[17]  G. Casella,et al.  Statistical Inference , 2003, Encyclopedia of Social Network Analysis and Mining.

[18]  K. R. Clarke,et al.  Change in marine communities : an approach to statistical analysis and interpretation , 2001 .

[19]  Laurence T. Kell,et al.  Do climate and fishing influence size-based indicators of Celtic Sea fish community structure? , 2005 .

[20]  Y. Shin,et al.  The good(ish), the bad, and the ugly: a tripartite classification of ecosystem trends , 2010 .

[21]  S. Baird.  Report on the Condition of the Sea Fisheries of the South Coast of New England in 1871 and 1872 , 2017, Nature.

[22]  M. Coll,et al.  Exploring the dynamics of ecological indicators using food web models fitted to time series of abundance and catch data , 2009 .

[23]  Jae S. Choi,et al.  Transition to an alternate state in a continental shelf ecosystem , 2004 .

[24]  Simon Jennings,et al.  Structural change in an exploited fish community: a consequence of differential fishing effects on species with contrasting life histories , 1999 .

[25]  Y. Shin,et al.  Ranking the ecological relative status of exploited marine ecosystems , 2010 .

[26]  John G. Pope,et al.  Changes in the North Sea fish community: evidence of indirect effects of fishing? , 2003 .

[27]  Carrie V. Kappel,et al.  A Global Map of Human Impact on Marine Ecosystems , 2008, Science.

[28]  J. Reynolds,et al.  Climate Change and Distribution Shifts in Marine Fishes , 2005, Science.

[29]  Simon Jennings,et al.  Testing candidate indicators to support ecosystem-based management: the power of monitoring surveys to detect temporal trends in fish community metrics , 2004 .

[30]  Keith Sainsbury,et al.  Impact of fishing on size composition and diversity of demersal fish communities , 2000 .

[31]  J. Pinnegar,et al.  Different surveys provide similar pictures of trends in a marine fish community but not of individual fish populations , 2004 .

[32]  J. Link.  Translating ecosystem indicators into decision criteria , 2005 .

[33]  Johanna J. Heymans,et al.  Can simple be useful and reliable? Using ecological indicators to represent and compare the states of marine ecosystems , 2010 .

[34]  Y. Shin,et al.  Comparing data-based indicators across upwelling and comparable systems for communicating ecosystem states and trends , 2010 .

[35]  George L. Hunt,et al.  Comparison of the biophysical and trophic characteristics of the Bering and Barents Seas , 2005 .