Over the years we have worked on several projects mapping the cumulative impact of human activities on global oceans. Here you can find the links to these data.
For our most recent work, we used future projections of human stressors to map current and future cumulative impact on marine systems.
*Citation: Benjamin S Halpern, Melanie Frazier, Casey C O’Hara, O Alejandra Vargas-Fonseca, Amanda T Lombard. Cumulative impacts to global marine ecosystems projected to more than double by mid-centurey. Science, 1216-1219.
We evaluated ten anthropogenic pressures for six categories, including climate (water temperature; air heat-index; sea level rise), ocean chemistry (ocean acidification; dissolved oxygen), pollution (nutrient input; light), net primary productivity (NPP), disturbance (coastal human population density), and fisheries (fisheries biomass loss). We mapped pressure data at 10 km resolution for both current (roughly 2010-2020) and future (typically 2041-2060, or midcentury) pressure intensities, with focus on the SSP2-4.5 and SSP5-8.5 scenarios. We estimate how these pressures will impact marine habitats based on their overlap with current distributions of 20 marine habitats and the unique vulnerability of each habitat to each pressure. The SSP2-4.5, “Middle of the road” scenario approximates current climate policy, whereas the SSP5-8.5, “Fossil-fueled development” is considered an “extreme counterfactual scenario” in which CO2 emissions double by midcentury.
All data are available from KNB and the scripts are located on GitHub.
All raster data are 10 km resolution, in Mollweide Coordinate Reference system.
We include several zipped files of data: (1) github_repo_stressors-1.zip is the contents of the GitHub repository that includes R scripts and data used for all calculations; (2) habitat_maps includes 20 .tif files of the habitat data used in the analysis and metadata; (3) pressures_raw includes 60 .tif files of raw (i.e., unscaled) pressure data and metadata; (4) pressures_rescaled includes 48 .tif files of rescaled pressure data (the raw heat index files get collapsed when rescaling) with values all between 0 (no pressure) and 1 (highest pressure), and metadata; (5) impacts_by_pressure includes 40 .tif files that describe the cumulative impact for each pressure across all habitats, at this step, the surface and benthic oxygen as well as the surface temperature and benthic temperature data are combined into a single pressure layers (i.e., reduced-oxygen and ocean-warming); (6) cumulative_impact includes 4 files describing the cumulative impact averaged across all habitats within each pixel.
Previously, we had mapped the yearly cumulative impact of human activities on global oceans from 2003 to 2013. We found that our impact is increasing for the majority of the ocean (59%). Most of the increase was due to climate change but also from fishing, land-based pollution, and shipping.
*Citation: Halpern, B.S., Frazier, M., Afflerbach, J., Lowndes, J.S., Micheli, F., O’Hara, C., Scarborough, C., Selkoe, K.A., 2019. Recent pace of change in human impact on the world’s ocean. Sci Rep 9, 11609.
The data from this analysis are available from KNB, with a package for each stressor (link to the KNB package by clicking the “Data package name”).
All raster files are .tif format and coordinate reference system is mollweide wgs84.
| Category | Data package name | Description |
|---|---|---|
| Cumulative impact | Cumulative impacts | The cumulative impact of all 14 stressors on 21 marine habitats |
| Land-based | Organic chemical pollution | relative intensity of organic pollution due to pesticide runoff from land-based applications |
| Land-based | Nutrient pollution | relative intensity of nutrient pollution due to fertilizer runoff from land-based applications |
| Land-based | Light pollution | relative magnitude of light pollution in coastal environments |
| Land-based | Direct human disturbance | magnitude of direct human interactions on coastal and near-coastal habitats, such as trampling |
| Climate | Sea level rise | magnitude of increasing sea level due to increasing atmospheric CO2 levels from human influences |
| Climate | Ocean acidification | magnitude of decreasing aragonite saturation state due to increasing atmospheric CO2 levels from human influences |
| Climate | Sea surface temperature | frequency of extreme temperature events relative to a historical baseline period |
| Fisheries | Commercial fishing - pelagic low-bycatch | tonnes of pelagic fisheries catch using low bycatch gear types, standardized by Net Primary Productivity |
| Fisheries | Commercial fishing - pelagic high-bycatch | tonnes of pelagic fisheries catch using high bycatch gear types, standardized by Net Primary Productivity |
| Fisheries | Commercial fishing - demersal non-destructive high-bycatch | tonnes of demersal fisheries catch using nondestructive, but high bycatch, gear types, standardized by Net Primary Productivity |
| Fisheries | Commercial fishing - demersal non-desctructive low-bycatch | tonnes of demersal fisheries catch using nondestructive and low bycatch gear types, standardized by Net Primary Productivity |
| Fisheries | Commercial fishing - demersal destructive | tonnes of catch using demersal destructive gear types, standardized by Net Primary Productivity |
| Fisheries | Artisanal fishing | tonnes of artisanal fisheries catch standardized by Net Primary Productivity |
| Shipping | Shipping | relative intensity of global shipping traffic |
Each data package includes:
Raw stressor intensity rasters for 2003 to 2013. These rasters are created using scripts located in the ‘stressors’ folder of the ‘impact_acceleration’ Github repository.
Rescaled stressor intensity rasters for 2003 to 2013. Raw stressor intensities are rescaled to values between 0 and 1, using either known or estimated ecosystem thresholds or upper quantile values from the distribution of global stressor intensity values across years. These rasters are created using scripts located in the ‘stressors’ folder of the ‘impact_acceleration’ Github repository.
Impact rasters for 2003 to 2013 which describe the impact of the stressor based on the vulnerability of 21 marine ecosystems to the stressor. The impact of the stressor is estimated by multiplying the stressor’s intensity by the corresponding ecosystem vulnerability where the ecosystem occurs. The average impact of each stressor, across all ecosystems, is estimated by summing the stressor-by-ecosystem vulnerability combinations and dividing by the number of ecosystems within each cell. These rasters are created using scripts located in the ‘impacts’ folder of the ‘impact_acceleration’ Github repository.
A trend raster describing the average annual change in impact from 2003 to 2013. This raster is created using scripts located in the ’trend’ folder of the ‘impact_acceleration’ Github repository.
The Cumulative impact package includes:
Ecosystem rasters describing the location (1 if present, otherwise NA) of 21 global marine ecosystems. These rasters are the same as used in previous years, with the exception of seaice. The seaice raster was created using a script located in the ‘habitats’ folder of the ‘impact_acceleration’ Github repository.
A vulnerability matrix describing the vulnerability of each ecosystem to each stressor, with values ranging from 0-4.
The impact_acceleration-1.0.zip GitHub repository with the code used to generate, analyze, and visualize data.
The code to create and analyze these data is available from Github: https://github.com/OHI-Science/impact_acceleration
We mapped the change, using both 2008 and 2013 data, in cumulative impacts to global marine ecosystems from fishing, climate change, and ocean- and land-based stressors (Halpern et al. 2015). Seven data packages are available from KNB:
supplementary data habitat data and other files
raw stressor data 2008 and 2013
stressor data rescaled by one time period 2008 and 2013, scaled from 0-1
stressor data rescaled by two time periods 2008 and 2013, scaled from 0-1
pressure and cumulative impacts data 2013, all pressures
pressure and cumulative impacts data 2008 and 2013, subset updated for both time periods
change in pressures and cumulative impact 2008 to 2013
Description of data: Raw stressor data -> rescaled stressor data (values rescaled to be between 0-1) -> pressure data (stressor data after adjusting for habitat/pressure vulnerability) -> cumulative impact (sum of pressure data) -> difference between 2008 and 2013 pressure and cumulative impact data.
All raster files are .tif format and coordinate reference system is mollweide wgs84.
The original project for mapping the cumulative human impact to marine ecosystems (Halpern et al. 2008) additionally has 4 packages of data, with the main cumulative impact data available along with several nested datasets available within that page.