Macroalgal biomass data (Preburn, Postburn, and Ash-Free Dry Weight) collected in the nearshore shallow subtidal during six field experiments conducted at Cerro Mundo Bay in the Galapagos Islands between July 2021 and May 2022

Increased standing macroalgal biomass in upwelling zones is generally assumed to be the result of higher nutrient flux due to upwelled waters. However, other factors can strongly impact macroalgal communities. For example, herbivory and temperature, via their effects on primary producers and the metabolic demands of consumers, can also influence macroalgal biomass and productivity, respectively. Although there are a fair number of studies looking at the interactive effects of herbivores and nutrients in both tropical and temperate regions, there is a lack of studies looking at these effects in tropical or subtropical upwelling regions. The purpose of this study was to measure the effects that herbivores, temperature, and nutrient availability have on standing macroalgal biomass. We manipulated nutrient availability and herbivory in six field experiments during contrasting productivity and thermal regimes (cool-upwelling and warm, non-upwelling season) on a subtidal nearshore rocky reef.

Here, we present the macroalgal biomass raw data (Preburn, Postburn, and Ash-Free Dry Weight) collected in the nearshore shallow subtidal during the six field experiments.