Trophic cascade induced by molluscivore predator alters pore‐water biogeochemistry via competitive release of prey

• DOI: 10.1890/11-1282.1
• Publication Date: 2011-11-10T20:05:57Z
• Authors: Jan A. van Gils; Matthijs van der ...; Erik J. Jansen; Laura L. Govers; Jimmy de Fouw; Theunis Piersma
• Keywords: Trophic cascade; Biogeochemistry

Effects of predation may cascade down the food web. By alleviating interspecific competition among prey, predators promote biodiversity, but precise mechanisms how alter have remained elusive. Here we report on a predator-exclosure experiment carried out in tropical intertidal ecosystem, providing evidence for three-level trophic induced by molluscivore Red Knots (Calidris canutus) that affects pore water biogeochemistry. In exclosures knots' favorite prey (Dosinia isocardia) became dominant and reduced individual growth rate an alternative (Loripes lucinalis). Dosinia, suspension feeder, consumes suspended particulate organic matter (POM), whereas Loripes is facultative mixotroph, partly living metabolites produced sulfur-oxidizing chemoautotrophic bacteria, also consuming POM. Reduced sulfide concentrations suggest that, without stronger POM forces to rely energy endosymbiotic thus leading enhanced uptake from surrounding water. As toxic most organisms, this competition-induced diet shift detoxify environment, which turn facilitate other species. The inference affect toxicity their environment via multi-level novel, believe it be general phenomenon detritus-based ecosystems.