The world's oceans and waterways are littered with millions of tons of plastic pollution – but scientists in a new study released Thursday say that we should think twice before cleaning them up.

In fact, the scientists warn against using any mechanical cleanup devices to address the global plastic pollution crisis.

This includes cleaning the Great Pacific Garbage Patch, an infamous collection of trash between Hawaii and California that's spurred on the "Ocean Cleanup" project, which uses mechanical means to corral the debris.

Where to focus our attention

Study co-author Richard Thompson of Plymouth University in the U.K. told USA TODAY we should focus 95% of our attention and energy on reducing the flow of plastic trash into the ocean, and only 5% on cleanup.

"At the moment, plastic debris is entering the ocean at a rate far faster than any feasible cleanup," Thompson said. "There is a risk that focusing on clean up will distract attention from the real priorities."

"If we focus on cleanup as a solution to plastic pollution we condemn future generations to continue contaminating the environment and cleaning up as an afterthought," he said.

Study lead author Melanie Bergmann, a marine ecologist at the Alfred Wegener Institute in Germany, used this analogy: "When the bathtub is overflowing, you first turn off the tap before you mop the floor," she said to USA TODAY.

Global treaty would reduce plastic production

In the study, which appeared in the journal One Earth, the scientists say with plastic production projected to triple by 2060, "the most cost-effective and efficient way to prevent further pollution is to reduce plastic production and consumption," according to a University of Plymouth statement.

The study has been published as world leaders prepare to resume discussions on the United Nations Global Plastics Treaty at the upcoming third meeting of the Intergovernmental Negotiating Committee on Plastic Pollution.

"A plastics treaty should foremost reduce plastics production," Bergmann told USA TODAY. "The science shows that this is the most effective and economic lever to reduce plastic pollution."

In the study, the scientists also say that the environmental costs of leaving plastic pollution in the ocean should be weighed against the full environmental and economic cost of plastic removal technologies, and call for clear criteria for such judgments to be incorporated into the treaty, the University of Plymouth statement says.

Surprise find:Marine animals are thriving in the Great Pacific Garbage Patch

Don't rely on mechanical means

Researchers caution that plastic removal technologies used so far have shown mixed success in the amount of waste material they are able to collect, and many have not been tested at all.

"In fact, some have been shown to harm quantities of marine organisms – including fish, crustaceans and seaweeds – that far exceed the amount of plastic captured, meaning their overall impact on the ocean is potentially more harmful than helpful," the University of Plymouth said.

"My team tested one type of clean up device here in Plymouth and showed it removed mainly seaweed and that it captured fish and other marine creatures which were dead when the device was emptied," Thompson said to USA TODAY.

"One type of cleanup I do encourage is hand picking, for example, from beaches," he said. "This can be very effective, and if volunteers take part this helps to raise awareness."

Ocean Cleanup did not immediately respond to USA TODAY's request for comment.