Jellyfication of marine ecosystems as a likely consequence of overfishing small pelagic fishes: Lessons from the Benguela
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Date
2013
Journal Title
Journal ISSN
Volume Title
Publisher
University of Miami, Rosenstiel School of Marine and Atmospheric Science
Abstract
Changes in two contrasting ecosystems of the Benguela upwelling region,
one dominated at mid-trophic level by jellyfishes (Namibia, northern Benguela
ecosystem, where small pelagic fish abundance has been severely depleted) and
one still dominated by small pelagic fishes (South Africa, southern Benguela)
were compared in an effort to determine ecosystem trajectories under different
exploitation regimes. The role of small pelagic fishes (clupeoids) was highlighted in
the context of their importance in maintaining interactions in marine ecosystems.
In particular, we examined trophic cascades and possible irreversible changes
that promote the proliferation of jellyfishes in marine systems. We found that
the presence of large populations of small pelagic fishes has a fundamental role
in preserving beneficial trophic interactions in these marine ecosystems. The
implications of trophic cascades, such as those observed in the northern Benguela,
for ecosystem-based management were apparent. In addition, this comparison
provides contrasting case studies to inform the development of management
scenarios that avoid ecosystem shifts that affect predators and reduce the value of
fisheries production.
Description
Keywords
Marine ecosystems, Benguela, Pelagic fish, Ecosystem shifts, Fisheries
Citation
Roux, J.P. (2013). Jellyfication of marine ecosystems as a likely consequence of overfishing small pelagic fishes: Lessons from the Benguela. Bulletin of Marine Science, 89(1): 249-284