Global meta-analysis of how marine upwelling affects herbivory

Aim: Nutrient subsidies support high primary productivity, increasing herbivore abundance and influencing their top-down control of producers. Wind-driven upwelling events deliver cold nutrient-rich water to coastlines, supporting highly productive marine environments. Results from studies comparing ecological processes across upwelling regimes are mixed: some reveal weaker herbivory in upwelling regions, while others report a positive relationship between upwelling and herbivory. In this synthesis we examine the influence of upwelling on top-down control of producers across the globe.

Location: Global; marine ecosystems.

Time period: 1978-2017.

Major taxa studied: Marine herbivores and algae.

Methods: We used data from herbivory studies focusing specifically on the influence of upwelling activity (upwelling studies), and a broader collection of herbivore exclusion studies dating back four decades. For the upwelling studies we compared herbivore effects between experiments r...