By Christopher Thompson

Sure, we all know there’s always more fish in the sea. But there’s also plenty more plastic garbage.

Since 1957, scientific gear used to measure plankton in the north Atlantic Ocean has been clogged by plastic trash some 669 times. Almost all of those snarls have occurred since the late 1990s, showcasing how much ocean plastic has skyrocketed in the past two decades.

And since 2000, scientists say the occurrence of plastic entanglement on the gear has increased by around ten times.

Researchers say the study is “the first to confirm a significant increase in open ocean plastics in recent decades.”

Study lead author Clare Ostle of the Marine Biological Association and the University of Plymouth in the U.K. said “what is unique about this work is we have been able to demonstrate the increase in ocean plastic since the 1990s.”

The researchers looked at how much plastic was entangled on devices that record the amount of plankton in the ocean. The devices, known as continuous plankton recorders, are instruments that have been towed over 6.5 million nautical miles in surface waters of the North Atlantic and nearby seas since 1957.

The device takes up about the same space as a marine mammal, so therefore is affected by plastic entanglements in a similar way. According to CNN, the researchers didn’t set out to do a study about plastic pollution. They were initially studying the plankton.

Some of the biggest increases in the types of trash have been in larger plastic items such as bags, rope and netting.

Knowing where plastic tends to concentrate will be important for conservation, Ostle said to National Geographic.

“It’s important for waste management and how we think about tidying up,” she said.

The study was published Tuesday in the peer-reviewed British journal Nature Communications.