"Marine resource depletion" is a globally pervasive problem historically attributed to overfishing, but research identified another insidious potential culprit, according to National Fisherman.

What's happening?

Although the term "overfishing" may sound self-explanatory, there's some nuance to it; overfishing occurs when stocks are depleted to a point where populations cannot be sustained.

Marine resource depletion has a broader scope, encompassing non-living resources that are exhausted by unsustainable human activities in marine environments

Overfishing remains a serious problem worldwide, according to the UN Framework Convention on Climate Change (UNFCCC). However, the study pointed to a distinct yet difficult-to-detect culprit depleting marine resources: microplastics.

Microplastics have existed since the introduction of plastic in the mid-20th century, but weren't formally identified until 2004. Ensuing research into the impact of microplastics on humans, wildlife, and the environment uncovered a host of adverse effects.

A study conducted by the Monterey Bay Aquarium Research Institute (MBARI) that it called "groundbreaking" zoomed in on the impact of ocean plastic and microplastics on marine food webs. Their findings were extensive and broad, but one specific finding stood out in particular: More microplastics in the ocean originated from consumer waste than from fishing gear.

National Fisherman coupled those findings with information presented in June 2025 by the Mid-Atlantic Regional Council on the Ocean (MARCO).

Marine scientist Meredith Seeley explained that microplastics are known to increase the susceptibility of fish to pathogenic illnesses, and overall, exposure to ocean plastic has "significantly increased [the] rate of mortality" among marine life.

Kieran Kelly isn't a fisherman. He owns Ocean Integrity, a microplastics recovery company, and has long suspected that ocean plastic played a larger role in marine resource depletion.

"I've been saying it for years. Probably at this stage, microplastics and nanoplastics are killing more plants and animals in our oceans than commercial fishing," Kelly observed.

Do you think fracking should be illegal in America? Yes — everywhere 👏 Yes — in most areas 👍 In some areas 🤷 No 👎 Click your choice to see results and speak your mind.

Why do these details matter?

The National Marine Fisheries Service, better known as NOAA Fisheries, has been monitoring the "decrease of the food fishes of the seacoasts and lakes of the United States" since 1871, before commercially viable plastic was developed.

Overfishing antedated "all other pervasive human disturbance to coastal ecosystems, including pollution, degradation of water quality, and anthropogenic climate change," according to research conducted in 2001, presented prior to the identification of microplastics in 2004.

It's well established that commercial fishing is a large contributor to both overfishing and ocean plastic, often in the form of ghost nets and other abandoned or lost pieces of equipment.

Nevertheless, MBARI's samples of microplastics came primarily from activity on land, not in the sea, and Seeley published findings linking increased marine mortality to microplastics in 2023.

What's being done about it?

Efforts to reduce ocean plastic are ongoing, and the NBA even got involved with an initiative to tackle ghost nets.

National Fisherman's article was a reminder that understanding climate issues is the first step toward effecting change.

At an individual level, using less plastic and replacing everyday plastic items is another way to reduce and slow marine resource depletion.

Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.