Trend analysis of indicators: a comparison of recent changes in the status of marine ecosystems around the world
|Author(s)||Blanchard Julia L.8, Coll Marta1, 9, Trenkel Verena2, Vergnon Remi3, Yemane Dawit4, Jouffre Didier5, Link Jason S.6, Shin Yunne-Jai7|
|Affiliation(s)||1 : CSIC, ICM, Inst Marine Sci, Barcelona 08002, Spain.
2 : IFREMER, F-44311 Nantes 03, France.
3 : Univ Sheffield, Dept Anim & Plant Sci, Western Bank, Sheffield S10 2TN, S Yorkshire, England.
4 : Dept Environm Affairs & Tourism, ZA-8012 Cape Town, South Africa.
5 : Univ Montpellier 2, IRD, Lab ECOLAG, UMR 5119, F-34095 Montpellier 5, France.
6 : Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Woods Hole, MA 02543 USA.
7 : Inst Rech Dev, UMR EME 212, F-34203 Sete, France.
8 : Ctr Environm Fisheries & Aquaculture Sci, Lowestoft Lab, Lowestoft NR33 0HT, Suffolk, England.
9 : Dalhousie Univ, Dept Biol, Halifax, NS B3H 4J1, Canada.
|Source||Ices Journal of Marine Science : Journal du Conseil (1054-3139) (Oxford Univ Press), 2010-05 , Vol. 67 , N. 4 , P. 732-744|
|WOS© Times Cited||67|
|Note||European Network of Excellence EUR-OCEANS (FP6, contract 511106) et EU IMAGE (FP6 contract 044227)|
|Keyword(s)||community, ecological indicators, ecosystem-based fisheries management, ecosystem effects of fishing, natural resource management|
|Abstract||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.|