Data for: Bed-scale impact and recovery of a commercially important intertidal seaweed

As the value of ecosystem-based management (EBM) approaches is increasingly recognized in marine ecosystems, it is critical that the impacts of resource harvest are assessed at various spatial scales. This is particularly true for habitat-forming resources, such as wild seaweeds, that act as foundation species by physically structuring ecosystems. The impacts of spatially heterogeneous harvest may change with scale and have different management implications based on the ecosystem process or organism under consideration. Ascophyllum nodosum (hereafter rockweed) is a canopy-forming fucoid seaweed endemic to rocky coastlines in the North Atlantic Ocean that has been harvested for centuries. We conducted a Before-After Control-Impact study of commercial rockweed harvest at 38 sites across the coast of Maine (USA) from 2018 to 2020 in an effort to understand impact and one-year recovery of two rockweed bed structural characteristics, height and biomass, at a scale similar to a single harvest..., All data were collected in the field between 2018 and 2020 in Maine (USA).
All datasets were cleaned and organized in program R., Datasets are .csv files and can be opened in any text editor. Code for analyses can be opened in program R., # Data for \"Bed-scale impact and recovery of a commercially important intertidal seaweed\"

# Johnston et al. 2023

# Journal of Experimental Marine Biology and Ecology

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This dataset contains five files that focus on field-collected data and data analyses of a research study assessing the impacts of rockweed (*Ascophyllum nodosum*) harvest on rockweed height and biomass.

## Description of the Data and file structure

baci.csv - Raw field collected data for Before-After Control-Impact study. Contains date and location information, and values of several rockweed characteristics collected throughout the study. The file also includes mean values at different hierarchical spatial scales.

baci_metadata.csv - metadata for baci.csv. Explains the data collected in each column.

baci_delta.csv - site-level averages that summarizes the data in baci.csv. Includes absolute and percent changes in three rockweed characteristics (holdfast count, height, biomass) over several time period intervals...