Current SEA Research

Results from two decades’ worth of studies on plastic in the oceans

An area of plastic debris was first observed in the North Atlantic Ocean in the early 1970s, but in recent years, a similar area of plastic debris in the Pacific Ocean has received the most media attention.

Sea Education Association (SEA) has been studying both debris fields – in the North Atlantic for the nearly 30 years, and in the North Pacific the past eight. The plastic debris is usually collected by plankton nets towed along the sea surface. This method, although widely used in oceanographic studies, may underestimate the concentration of plastic in the upper ocean because winds and currents mix the plastic debris into deeper waters.

SEA’s work has shown that the concentration of plastic in the western North Atlantic is similar to that found in the North Pacific’s better known “Great Pacific Garbage Patch”. The plastic tends to accumulate in a relatively well-defined region determined by the ocean currents. The length of the data set allows SEA scientists to examine whether or not the amount of plastic in the North Atlantic has changed over time, during a period when the production and disposal of plastic waste have significantly increased.

The plastic debris – consisting primarily of polyethelene, polypropylene, and polystyrene – is less dense than water, therefore it floats at or near the surface. The plastic particles are generally small - no bigger than your smallest fingernail - with a mass less than that of a paper clip. Their size makes these pieces difficult or impossible to see by eye from the deck of a ship in all but the calmest of sea conditions.

Basic questions remain about plastics in the ocean - how far across the Atlantic and Pacific Oceans can the plastic be found? How does the plastic affect the ocean environment, including animals ranging from microscopic plankton to the biggest marine mammals? Plastics at SEA: North Atlantic Expedition will begin to find some answers.