Macroalgal biomass data collected in the nearshore shallow subtidal during eight field experiments conducted at Cerro Mundo Bay in the Galapagos Islands between Sept 2021 and Apr 2023

Abstract

Increased standing macroalgal biomass in upwelling zones is generally assumed to result from higher nutrient flux associated with upwelled waters. However, other factors can also strongly impact macroalgal communities. For example, herbivory and temperature—through their effects on primary producers and the metabolic demands of consumers—can influence macroalgal biomass and productivity, respectively. Although there are numerous studies examining the interactive effects of herbivores and nutrients in both temperate regions, few have addressed these dynamics in tropical or subtropical upwelling systems.

The purpose of this study was to assess the effects of herbivores, temperature, and nutrient availability on standing macroalgal biomass and total algal cover. Total algal cover is presented in the related dataset. We manipulated nutrient availability and herbivory in eight field experiments conducted under contrasting productivity and thermal regimes (cool upwelling vs. warm, non-upwelling seasons) on a subtidal nearshore rocky reef.

Here, we present the raw macroalgal biomass data (dry weight in grams) collected from the shallow subtidal zone during September 2021 to April 2023 field experiments.

For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/894169