Data from: Drivers of kelp forest refugia during successive disturbance events
Data files
May 15, 2025 version files 163.12 MB
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northCoast_refugia_2017.tif
27.18 MB
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northCoast_refugia_2018.tif
27.18 MB
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northCoast_refugia_2019.tif
27.17 MB
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northCoast_refugia_2020.tif
27.20 MB
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northCoast_refugia_2021.tif
27.19 MB
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northCoast_refugia_2022.tif
27.19 MB
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README.md
1.57 KB
Abstract
Cooler areas with localized upwelling acted as climate refugia during the increased ocean temperatures from the 2014-2016 marine heatwave, supporting nutrient-rich environments and mitigating heat stress for kelp forests. However, these temperature refugia often did not spatially overlap with areas providing protection from grazing pressure, leaving kelp forests vulnerable to future warming even within temperature refugia if grazing pressure remains high.
Dataset DOI: 10.5061/dryad.6m905qgbm
Description of the data and file structure
This dataset contains annual kelp canopy extent maps for northern California from 2017 to 2022. The maps cover the coastline between 40.031311°N and 38.430004°N, and all files are provided as GeoTIFFs at 3 m spatial resolution, with binary values indicating kelp presence (1) or absence (0). The annual kelp canopy maps from 2014 to 2016 used in this paper are already publicly available and can be found via the California Department of Fish and Wildlife.
2017–2022 (PlanetScope-Based Maps)
- Source: Derived from PlanetScope satellite imagery
- Methods:
- For each year, a minimum of five cloud-free images from September and five cloud-free images from October were classified using a Naive Bayes model to detect kelp
- Images were composited using a majority filter, where pixels labeled as kelp in ≥50% of input images were assigned kelp in the final map
- For methodological details, see: Cavanaugh et al. (2023), "CubeSats show persistence of bull kelp refugia amidst a regional collapse in California"
- File names:
- northCoast_refugia_2017.tif
- northCoast_refugia_2018.tif
- northCoast_refugia_2019.tif
- northCoast_refugia_2020.tif
- northCoast_refugia_2021.tif
- northCoast_refugia_2022.tif
Code/software
Files are GeoTiff format and can be loaded using any compatible coding or GIS platform (i.e., R, Matlab, QGIS, ArcGIS Pro, etc.).