WATERMARKS

Ocean plastic, seen from space

Every dot is a sample someone took. Blank ocean is unmeasured, not clean — the shape of this map is research effort as much as pollution.

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Watermarks — prototype

A date-scrubbable view of pressure on the ocean. Drag the timeline: magenta dots are microplastic samples collected up to that date.

How to read this

Two things the map will imply that it does not show.

Density of dots is density of sampling, not of plastic. The straight lines across the Pacific are research cruise transects; the crowded patches off North America and Europe are where funded survey programmes operate. Vast stretches of the Southern Ocean, the South Atlantic and the tropical Indian Ocean are close to empty here — nobody has published measurements from them, which is not the same as finding nothing.

Samples accumulate, so the total only ever rises. Dragging the timeline forward adds every sample collected up to that date and never removes one. The growing count is a record of measurement effort over five decades, not a measure of the ocean getting dirtier — this data cannot answer that question, because the early ocean was barely sampled at all.

Data

Microplastics — Nyadjro, E.; Webster, J.; Boyer, T.; Cebrian, J.; Collazo, L.; Kaltenberger, G.; Larsen, K.; Lau, Y.; Mickle, P.; Toft, T.; Wang, Z. (2025). The NOAA NCEI Global Marine Microplastics Harmonized Database during 1972-04-20 to present (NCEI Accession 0306475). NOAA National Centers for Environmental Information. Dataset. doi.org/10.25921/v8gj-k896. Dedicated to the public domain under CC0 1.0. Filtered here to ocean-water samples and reduced to position, date, density class and concentration — this is altered NOAA data, not the original dataset.
Earth imagery — NASA Earth Observatory. Surface: Blue Marble: Next Generation (December 2004, topography and bathymetry) by Reto Stöckli. Clouds: Blue Marble combined global cloud composite. NASA imagery is not subject to copyright in the United States; recompressed and resized here.
Land / water mask — coastlines rasterised from Natural Earth 1:10m land polygons, which are in the public domain.

NASA and NOAA are named as sources only. Neither endorses this project, Pressing Space, or any product or service. No NASA insignia or NOAA emblem is used.

Monthly figures

Month	Samples to date

Software

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The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

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