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| Blanchard, Julia L.; Coll, Marta; Trenkel, Verena; Vergnon, Remi; Yemane, Dawit; Jouffre, Didier; Link, Jason S.; Shin, Yunne-jai. |
| 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... |
| Tipo: Text |
Palavras-chave: Community; Ecological indicators; Ecosystem-based fisheries management; Ecosystem effects of fishing; Natural resource management. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11373/8166.pdf |
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| Blanchard, Julia L.; Jennings, Simon; Law, Richard; Castle, Matthew D.; Mccloghrie, Paul; Rochet, Marie-joelle; Benoit, Eric. |
| Widely observed macro-ecological patterns in log abundance vs. log body mass of organisms can be explained by simple scaling theory based on food (energy) availability across a spectrum of body sizes. The theory predicts that when food availability falls with body size (as in most aquatic food webs where larger predators eat smaller prey), the scaling between log N vs. log m is steeper than when organisms of different sizes compete for a shared unstructured resource (e.g. autotrophs, herbivores and detritivores; hereafter dubbed 'detritivores'). In real communities, the mix of feeding characteristics gives rise to complex food webs. Such complexities make empirical tests of scaling predictions prone to error if: (i) the data are not disaggregated in... |
| Tipo: Text |
Palavras-chave: Size spectrum; North Sea; Macroecology; Ecosystem effects of fishing; Community ecology; Benthic pelagic coupling; Allometric scaling. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7318.pdf |
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