Humans Now Major Force in Coastal Ocean Chemistry

Global analysis finds human-made chemicals make up significant portion of organic matter in coastal oceans

Mar. 17, 2026 at 3:14am

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A global analysis of over 2,300 seawater samples from more than 20 field studies around the world indicates that human-made chemicals make up a significant portion of organic matter in coastal oceans. The study, led by researchers at the University of California, Riverside, found that industrial chemicals, many of which are rarely monitored, are far more abundant and widespread than previously recognized, even in remote and pristine marine environments.

Why it matters

This study provides a comprehensive look at the extent of human chemical influence on the world's oceans, which can have significant implications for marine ecosystems, carbon cycling, and overall ocean health. The findings highlight the need for greater monitoring and understanding of the long-term ecological impacts of these ubiquitous anthropogenic compounds.

The details

The researchers analyzed seawater samples collected over a decade from coastal regions across the Pacific, Atlantic, and Indian Oceans. They found that in coastal environments, median levels of human-made organic molecules reached up to 20% of the total, compared to about 0.5% in the open ocean. In extreme cases, such as river mouths impacted by untreated wastewater, the figure exceeded 50%. Overall, 248 human-derived compounds made up a median of ~2% of the total detected signal. While pesticides and pharmaceuticals were expected to be most concentrated near shorelines, the study found that industrial compounds, including substances used in plastics, lubricants, and consumer products, dominate the anthropogenic chemical signal in the ocean.

  • The seawater samples were collected over a decade, from various coastal regions around the world.

The players

Jarmo Kalinski

A postdoctoral researcher in Daniel Petras' group at the University of California, Riverside.

Daniel Petras

An assistant professor of biochemistry at the University of California, Riverside.

Mingxun Wang

An assistant professor of computer science at the University of California, Riverside.

University of California, Riverside

A doctoral research university that conducted the study.

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What they’re saying

“For decades, scientists have tracked plastic debris floating on the ocean's surface and measured rising temperatures that signal climate change. But another, largely invisible human footprint has been accumulating in the sea: thousands of synthetic chemicals. Even in places we consider relatively pristine, we found clear chemical fingerprints of human activity. The extent of this influence was surprising.”

— Daniel Petras, Assistant Professor of Biochemistry

“There was virtually nowhere we sampled that showed no human chemical influence.”

— Jarmo Kalinski, Postdoctoral Researcher

“Industrial chemicals make up the bulk of the human chemical signal we're seeing.”

— Jarmo Kalinski, Postdoctoral Researcher

What’s next

The researchers acknowledged that this analysis serves as a first overview, and detailed targeted analyses with precise quantification are still needed to fully understand the long-term ecological impacts of the cumulative chemical concentrations in the ocean.

The takeaway

This study highlights the widespread and often overlooked presence of human-made chemicals in the world's oceans, even in remote and supposedly pristine marine environments. It underscores the need for greater monitoring and research to understand the implications of this chemical pollution on marine ecosystems and the overall health of the global ocean.