What is a Trophic Cascade?

Damped trophic cascades driven by fishing in model marine ecosystems.

The largest perturbation on upper trophic levels of many marine ecosystems stems from fishing. The reaction of the ecosystem goes beyond the trophic levels directly targeted by the fishery. This reaction has been described either as a change in slope of the overall size spectrum or as a trophic cascade triggered by the removal of top predators. Here we use a novel size- and trait-based model to...

When is a trophic cascade a trophic cascade?

The body size dependence of trophic cascades.

Trophic cascades are indirect positive effects of predators on resources via control of intermediate consumers. Larger-bodied predators appear to induce stronger trophic cascades (a greater rebound of resource density toward carrying capacity), but how this happens is unknown because we lack a clear depiction of how the strength of trophic cascades is determined. Using consumer resource models,...

Critical assessment and ramifications of a purported marine trophic cascade

When identifying potential trophic cascades, it is important to clearly establish the trophic linkages between predators and prey with respect to temporal abundance, demographics, distribution, and diet. In the northwest Atlantic Ocean, the depletion of large coastal sharks was thought to trigger a trophic cascade whereby predation release resulted in increased cownose ray abundance, which then...

Piscivore addition causes a trophic cascade within and across ecosystem boundaries

Th e addition of predators can play a key role in structuring ecological communities through both consumptive and nonconsumptive eff ects. Stocking of piscivorous fi sh in lakes and similar experimental introductions have provided fundamental evidence in support of trophic cascade theory. Yet, the impact of piscivore addition on cross ecosystem subsidies and meso-predator resource use has not b...