A study led by the OKEANOS–University of the Azores Marine Litter team traced 1,577 pieces of fishing-related debris to the United States and Canada, revealing how plastic discarded or lost thousands of kilometers away can travel across the North Atlantic and survive for decades

The ocean remembers what we throw into it. Long after a fishing vessel has returned to harbor, long after a season has ended and even after the people who handled a piece of equipment have forgotten it existed, plastic can continue its own improbable voyage. Carried by currents, exposed to storms, sunlight and salt, it may cross an ocean without passport or boundary until, years or even decades later, it arrives on the shore of another country. In the Azores, researchers have now reconstructed part of one such journey. A new study led by the Marine Litter team at OKEANOS–University of the Azores, based on Faial, has identified plastic debris associated with the North American lobster fishery along Azorean coastlines—physical evidence of a pollution route stretching from the United States and Canada across thousands of kilometers of the North Atlantic.

Researchers recorded 1,577 items, consisting primarily of plastic components from lobster traps, particularly escape devices and identification tags attached to fishing gear. Because some of those tags retained identifying information, scientists were able to accomplish something notoriously difficult in marine-pollution research: trace debris found on distant shores back toward the geographical regions and economic activities from which it originated.

From North America to the Middle of the Atlantic

Among the identifiable tags, 63 percent originated in the United States, and of those American items, 76 percent came from Maine, a state whose coastal economy and cultural identity are deeply connected to lobster fishing. The remaining identifiable material originated in Canada.

The findings give unusual precision to something scientists have long understood more generally: oceanic islands are particularly exposed to marine debris transported over enormous distances by currents. The difficulty has usually been proving where individual objects originated. Plastic fragments rarely arrive carrying their biographies.

Fishing materials can be different.

“Materials associated with fishing, especially those carrying marks or identification codes, provide a unique opportunity to establish a connection between the debris found and the regions and activities that generated it,” explained Dr. Christopher Pham, principal investigator of the study and leader of the OKEANOS-UAc marine litter group, which has conducted research in the field for more than a decade.

In this case, the objects became evidence. A tag designed originally to identify fishing equipment became, years later and thousands of kilometers away, a marker of the movement of pollution across an ocean.

Plastic with a Forty-Year Memory

Perhaps even more striking than the distance traveled is the age of some of the material. The identification tags recovered in the Azores correspond to the period between 1983 and 2023.

The oldest therefore reaches back four decades.

That chronological range demonstrates the extraordinary persistence of plastics associated with fishing activity. Ocean pollution does not necessarily disappear when it leaves sight of the coast where it originated. It can remain within marine systems for decades, moving between currents and coastlines, breaking down or washing ashore far from its original source.

A piece of fishing equipment entering the sea during the early 1980s can thus become an environmental problem for an Azorean island in another century.

Science Built by Many Hands

The research also tells another, quieter story—one about how knowledge is gathered on islands. Much of the underlying material was collected by former Nature Rangers of the Faial Natural Park, demonstrating the importance of cooperation between scientific and environmental institutions.

Later, an OKEANOS-UAc citizen-science campaign brought local communities on Faial and Pico into the collection effort.

That participation matters. Marine litter is an enormous research field in the most literal sense: the coastline is extensive, the ocean immeasurable and debris constantly moving. Scientists cannot be everywhere. Rangers, residents and volunteers walking shorelines can therefore become essential observers of environmental change, transforming ordinary encounters with discarded objects into scientific evidence.

Pollution Without Borders

For Dr. Yasmina Rodríguez, a co-author of the study, the findings provide clear evidence of the transboundary character of plastic pollution in the North Atlantic.

Fishing-related materials originating in the United States and Canada, she noted, eventually reach the Azores thousands of kilometers away. That creates a particular problem for island regions because they must manage marine waste produced far beyond their own jurisdictions—pollution over whose original generation local authorities have little or no control.

It is one of the paradoxes of environmental responsibility in an interconnected ocean. An Azorean municipality can clean a beach. Regional institutions can monitor coastal ecosystems. Researchers can identify and quantify marine litter. Citizens can collect what washes ashore.

But none of them can prevent a piece of fishing equipment from being lost thousands of kilometers away off North America.

The source and the consequence belong to different jurisdictions, while the current recognizes neither.

An International Problem Requires an International Response

For precisely that reason, the study’s authors argue for greater cooperation among countries and continents to prevent plastic fishing materials from entering—and remaining within—the marine environment.

Among the measures identified are improved systems for marking and reporting fishing gear, preventive measures to reduce plastic losses associated with lobster fishing in both the United States and Canada, and better coordinated policies among countries and regions.

The study also demonstrates the scientific value of making fishing equipment identifiable. When markings survive, they allow researchers to reconstruct pathways that would otherwise remain invisible, improving understanding of the origins, dispersal and persistence of marine plastic.

There is a larger lesson here for the Azores. The archipelago may occupy a small geographical space, but its position in the North Atlantic makes its coastlines witnesses to environmental decisions made far beyond the islands themselves. What washes onto Faial or Pico may have begun its journey beside another continent, within another economy and under another regulatory system.

The ocean connects these distant worlds more completely than political maps suggest.

And perhaps that is what the 1,577 objects collected in the Azores ultimately tell us. They are not merely fragments of lobster traps, escape devices and identification tags. They are records of journeys—material evidence that environmental responsibility cannot end at a national coastline.

A lobster trap works in North American waters for a season; its plastic may wander the Atlantic for a generation. Some of these pieces began their journey as far back as 1983, crossed an ocean no one intended them to cross, and eventually arrived on Azorean shores. The sea carried them thousands of kilometers, but it did not make them disappear. It simply delivered one coast’s forgotten plastic to another coast’s future.

Based on a story in Diário dos Açores- Paulo Viveiros, director. Phots from Azores Getaways, Nova Scotia Lobster info and Science News Exploreres.