Rebuilding Global Fisheries

Science, Journal Year: 2009, Volume and Issue: 325(5940), P. 578 - 585

Published: July 30, 2009

Fighting for Fisheries In the debate concerning future of world's fisheries, some have forecasted complete collapse but others challenged this view. The protagonists in now joined forces to present a thorough quantitative review current trends world fisheries. Worm et al. (p. 578 ) evaluate evidence global rebuilding marine capture fisheries and their supporting ecosystems. Contrasting regions that been managed with those not, reveals trajectories decline recovery from individual stocks species, communities, large management solutions most successful ecosystems, include both large- small-scale around world.

Language: Английский

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Cascading Effects of the Loss of Apex Predatory Sharks from a Coastal Ocean

Science, Journal Year: 2007, Volume and Issue: 315(5820), P. 1846 - 1850

Published: March 30, 2007

Impacts of chronic overfishing are evident in population depletions worldwide, yet indirect ecosystem effects induced by predator removal from oceanic food webs remain unpredictable. As abundances all 11 great sharks that consume other elasmobranchs (rays, skates, and small sharks) fell over the past 35 years, 12 14 these prey species increased coastal northwest Atlantic ecosystems. Effects this community restructuring have cascaded downward cownose ray, whose enhanced predation on its bay scallop was sufficient to terminate a century-long fishery. Analogous top-down may be predictable consequence eliminating entire functional groups predators.

Language: Английский

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Global phytoplankton decline over the past century

Nature, Journal Year: 2010, Volume and Issue: 466(7306), P. 591 - 596

Published: July 1, 2010

Language: Английский

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Predicting ecological consequences of marine top predator declines

Trends in Ecology & Evolution, Journal Year: 2008, Volume and Issue: 23(4), P. 202 - 210

Published: March 6, 2008

Language: Английский

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Global fish production and climate change

Proceedings of the National Academy of Sciences, Journal Year: 2007, Volume and Issue: 104(50), P. 19709 - 19714

Published: Dec. 7, 2007

Current global fisheries production of ≈160 million tons is rising as a result increases in aquaculture production. A number climate-related threats to both capture and are identified, but we have low confidence predictions future because uncertainty over aquatic net primary the transfer this through food chain human consumption. Recent changes distribution productivity fish species can be ascribed with high regional climate variability, such El Niño–Southern Oscillation. Future may increase some high-latitude regions warming decreased ice cover, dynamics low-latitude governed by different processes, decline reduced vertical mixing water column and, hence, recycling nutrients. There strong interactions between effects fishing reduces age, size, geographic diversity populations biodiversity marine ecosystems, making more sensitive additional stresses change. Inland additionally threatened precipitation management. The frequency intensity extreme events likely major impact on inland systems. Reducing mortality majority fisheries, which currently fully exploited or overexploited, principal feasible means reducing impacts

Language: Английский

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Cascading top‐down effects of changing oceanic predator abundances

Journal of Animal Ecology, Journal Year: 2009, Volume and Issue: 78(4), P. 699 - 714

Published: March 9, 2009

Summary Top‐down control can be an important determinant of ecosystem structure and function, but in oceanic ecosystems, where cascading effects predator depletions, recoveries, invasions could significant, such had rarely been demonstrated until recently. Here we synthesize the evidence for top‐down that has emerged over last decade, focusing on large, high trophic‐level predators inhabiting continental shelves, seas, open ocean. In these controlled manipulations are largely infeasible, ‘pseudo‐experimental’ analyses predator–prey interactions treat independent populations as ‘replicates’, temporal or spatial contrasts climate ‘treatments’, increasingly employed to help disentangle from environmental variation noise. Substantial reductions marine mammals, sharks, piscivorous fishes have led mesopredator invertebrate increases. Conversely, abundant suppressed prey abundances. Predation also inhibited recovery depleted species, sometimes through role reversals. Trophic cascades initiated by linking neritic food webs, seem inconsistent pelagic realm with often attenuating at plankton. is not uniformly strong ocean, appears contingent intensity nature perturbations Predator diversity may dampen except nonselective fisheries deplete entire functional groups. other cases, simultaneous exploitation inhibit responses. Explicit consideration anthropogenic modifications foodwebs should inform predictions about trophic control. Synthesis applications . Oceanic socio‐economic, conservation, management implications mesopredators invertebrates assume dominance, overexploited impaired. Continued research aimed integrating across levels needed understand forecast changing abundances, relative strength bottom‐up control, intensifying stressors change.

Language: Английский

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The Rise of the Mesopredator

BioScience, Journal Year: 2009, Volume and Issue: 59(9), P. 779 - 791

Published: Oct. 1, 2009

Apex predators have experienced catastrophic declines throughout the world as a result of human persecution and habitat loss. These collapses in top predator populations are commonly associated with dramatic increases abundance smaller predators. Known “mesopredator release,” this trophic interaction has been recorded across range communities ecosystems. Mesopredator outbreaks often lead to declining prey populations, sometimes destabilizing driving local extinctions. We present an overview mesopredator release illustrate how its underlying concepts can be used improve management increasingly fragmented world. also examine shifts North American carnivore ranges during past 200 years show that 60% expanded, whereas all apex contracted. The need understand best predict manage is urgent—mesopredator causing high ecological, economic, an...

Language: Английский

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Resolving the effect of climate change on fish populations

ICES Journal of Marine Science, Journal Year: 2009, Volume and Issue: 66(7), P. 1570 - 1583

Published: April 2, 2009

Abstract Rijnsdorp, A. D., Peck, M. A., Engelhard, G. H., Möllmann, C., and Pinnegar, J. K. 2009. Resolving the effect of climate change on fish populations. – ICES Journal Marine Science, 66: 1570–1583. This paper develops a framework for study populations based first principles physiology, ecology, available observations. Environmental variables oceanographic features that are relevant to likely be affected by reviewed. Working hypotheses derived from differences in expected response different species groups. A review published data Northeast Atlantic representing biogeographic affinities, habitats, body size lends support hypothesis global warming results shift abundance distribution (in patterns occurrence with latitude depth) species. Pelagic exhibit clear changes seasonal migration related climate-induced zooplankton productivity. Lusitanian have increased recent decades (sprat, anchovy, horse mackerel), especially at northern limit their areas, while Boreal decreased southern range (cod plaice), but (cod). Although underlying mechanisms remain uncertain, evidence suggests climate-related recruitment success key process, stemming either higher production or survival pelagic egg larval stage, owing quality/quantity nursery habitats.

Language: Английский

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Documented and Potential Biological Impacts of Recreational Fishing: Insights for Management and Conservation

Reviews in Fisheries Science, Journal Year: 2006, Volume and Issue: 14(4), P. 305 - 367

Published: Nov. 13, 2006

While the impacts of high exploitation on fish populations and aquatic ecosystems are well-documented for commercial fishing, particularly in marine environment, potential biological angling received less attention. This paper discusses patterns within a framework basic ecological evolutionary literature examines by focusing study results associated with rates pronounced selective exploitation. The range from occurring directly exploited species (truncation natural age size structure, depensatory mechanisms, loss genetic variability, changes), to those that occur ecosystem (changes trophic cascades, trait-mediated effects). As third category, related activity per se distinguished (habitat modifications, wildlife disturbance, nutrient inputs, fishing gear). Although main threats often localized outside recreational fisheries, there is growing evidence activities can lead decline affect various ways provided degree mortality intensive. In conclusion, management implications sustainable fisheries areas future research outlined. Keywords: anglingbiodiversitycatch-and-releaseecological impactsexploitationevolutionary changesfish communitygenetic diversitylittoral habitatrecreational fishingwildlife Acknowledgments authors grateful colleagues development project "Principles Sustainable Inland Fisheries Management" at Leibniz-Institute Freshwater Ecology helpful discussions, numerous scientists around world material presented this article, two anonymous reviewers their comments improve manuscript. was part financially supported Bundesamt für Naturschutz (BfN), Germany (F&E-Vorhaben Naturschutzfachliche Konkretisierung einer "guten fachlichen Praxis" der Binnenfischerei). Notes ***severe threat communities due low reversibility, sophisticated approaches required. **medium severe effects *effects primarily local importance, reversible easier manage.

Language: Английский

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Ecological extinction and evolution in the brave new ocean

Proceedings of the National Academy of Sciences, Journal Year: 2008, Volume and Issue: 105(supplement_1), P. 11458 - 11465

Published: Aug. 12, 2008

The great mass extinctions of the fossil record were a major creative force that provided entirely new kinds opportunities for subsequent explosive evolution and diversification surviving clades. Today, synergistic effects human impacts are laying groundwork comparably Anthropocene extinction in oceans with unknown ecological evolutionary consequences. Synergistic habitat destruction, overfishing, introduced species, warming, acidification, toxins, massive runoff nutrients transforming once complex ecosystems like coral reefs kelp forests into monotonous level bottoms, clear productive coastal seas anoxic dead zones, food webs topped by big animals simplified, microbially dominated boom bust cycles toxic dinoflagellate blooms, jellyfish, disease. Rates change increasingly fast nonlinear sudden phase shifts to novel alternative community states. We can only guess at organisms will benefit from this mayhem is radically altering selective seascape far beyond consequences fishing or warming alone. prospects especially bleak plants compared metabolically flexible microbes algae. Halting ultimately reversing these trends require rapid fundamental changes fisheries, agricultural practice, emissions greenhouse gases on global scale.

Language: Английский

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