Coupling between subtidal prey and consumers along a mesoscale upwelling gradient in the Galápagos Islands

Research in the Galápagos Islands reveals that upwelling intensity significantly influences prey production and predator-prey dynamics at mesoscale levels. The study found that strong upwelling sites (SUP) exhibited higher barnacle recruitment and growth, driven by vertical flow speeds and larval concentrations, compared to weak upwelling sites (WUP). This bottom-up effect was coupled with top-down control, as whelk densities correlated strongly with barnacle cover and recruitment. Predation experiments further demonstrated that 33–100% of barnacles were consumed by whelks and fish, with higher consumption rates at SUP sites. The study also linked upwelling duration to seafloor topography, suggesting that steep slopes and deep water enhance upwelling from internal waves and the Equatorial Undercurrent (EUC). These findings highlight the critical role of oceanographic processes in structuring marine communities over broad spatial scales.

Witman, J. D., Brandt, M., & Smith, F. (2010). Coupling between subtidal prey and consumers along a mesoscale upwelling gradient in the Galápagos Islands. Ecological Monographs, 80(1), 153–177. Portico. https://doi.org/10.1890/08-1922.1