Mapping Oil Spills and Offshore Industrial Activities in the northwest Atlantic for Marine Conservation and Management

Overview Anthropogenic activities such as oil pollution, vessel traffic, and artificial light pose growing threats to marine ecosystems across Canada’s Exclusive Economic Zone (EEZ) and adjacent Atlantic waters. Despite their importance, data describing the spatial and temporal distribution of these threats have remained fragmented or difficult to access. To address this gap, we developed a harmonized, high-resolution geospatial dataset covering Canada’s Exclusive Economic Zone (EEZ) and adjacent Atlantic waters. The dataset integrates multiple data sources—including the Integrated Satellite Tracking of Pollution (ISTOP), National Aerial Surveillance Program (NASP), National Environmental Emergency Centre (NEEC), Automatic Identification System (AIS) vessel tracking, and VIIRS satellite observations—into a suite of threat layers representing petroleum pollution, offshore infrastructure, vessel activity, and artificial light exposure. All layers were processed using reproducible workflows and standardized to a 1-km² grid (EPSG:4326). The resulting products, delivered as Cloud Optimized GeoTIFFs (COGs), are openly available via Zenodo and accompanied by comprehensive metadata and processing documentation. The dataset is designed to support cumulative effects assessments, marine spatial planning, conservation prioritization, and environmental response strategies. By providing consistent and reusable data on key marine stressors, this dataset enables more transparent and science-based decision-making. It also offers a foundation for research into cumulative risk to at-risk species, such as the globally threatened Leach’s Storm-Petrel (Hydrobates leucorhous), and contributes to broader marine management efforts under national and international policy frameworks. Included Data • Total datasets: 12 versioned folders (v1.0.0)• File types: 598 TIF files (raster data) Marine shipping data: • Ship light detection • Shipping intensity density • Shipping night light intensity density Offshore petroleum infrastructure: • Platform annual data • Platform monthly data • General petroleum activity data • Detection frequency and total heat metrics (2017-2023) Offshore petroleum pollution: • Petroleum pollution incidents Light pollution: • Night light monthly data Temporal range: • Annual data: variable from 2017 to 2023 • Monthly granularity available for select datasets