Skip to main content
SLU:s publikationsdatabas (SLUpub)
Forskningsartikel - Refereegranskat, 2009

Trophic cascades promote threshold-like shifts in pelagic marine ecosystems

Casini, Michele; Hjelm, Joakim; Molinero, Juan-Carlos; Lovgren, Johan; Cardinale, Massimiliano; Bartolino, Valerio; Belgrano, Andrea; Kornilovs, Georgs

Sammanfattning

Fisheries can have a large impact on marine ecosystems, because the effects of removing large predatory fish may cascade down the food web. The implications of these cascading processes on system functioning and resilience remain a source of intense scientific debate. By using field data covering a 30-year period, we show for the Baltic Sea that the underlying mechanisms of trophic cascades produced a shift in ecosystem functioning after the collapse of the top predator cod. We identified an ecological threshold, corresponding to a planktivore abundance of approximate to 17 x 10(10) individuals, that separates 2 ecosystem configurations in which zooplankton dynamics are driven by either hydroclimatic forces or predation pressure. Abundances of the planktivore sprat above the threshold decouple zooplankton dynamics from hydrological circumstances. The current strong regulation by sprat of the feeding resources for larval cod may hinder cod recovery and the return of the ecosystem to a prior state. This calls for the inclusion of a food web perspective in management decisions.

Nyckelord

alternative dynamics; ecological thresholds; ecosystem resilience; Baltic Sea; climate versus top-down control

Publicerad i

Proceedings of the National Academy of Sciences
2009, Volym: 106, nummer: 1, sidor: 197-202

              UKÄ forskningsämne

              Ecology

              Publikationens identifierare

              DOI: https://doi.org/10.1073/pnas.0806649105

              Permanent länk till denna sida (URI)

              https://res.slu.se/id/publ/38755