Microplastics may be changing the colour of the Great Pacific Garbage Patch
Satellite data from the last 20 years shows a brightening in blue and green wavelengths in the North Pacific Ocean.
Scientists have found that tiny plastic particles in the North Pacific Ocean may be altering how sunlight scatters, creating a blue-green tint. According to a report by the Times of India, research published in the journal Communications Earth & Environment suggests these particles have caused a subtle colour shift detected by satellites over two decades.
Ocean optics specialist Shea Cheatham of the University of Bergen in Norway, along with researchers Daniel Koestner and Børge Hamre, analysed satellite records from 2002 to 2022. They observed a statistically significant brightening in blue and green wavelengths near the Great Pacific Garbage Patch.
The researchers first studied how microplastics absorb and scatter light before comparing those properties to natural materials like minerals and phytoplankton. Their models suggested the effect could appear at concentrations similar to those found in the patch, which is roughly twice the size of Texas.
While natural factors like mineral dust or phytoplankton can change ocean colour, researchers noted that dust levels at a nearby station remained steady. Cheatham said the team initially felt disbelief and checked two other satellite datasets to confirm the signature matched their models.
To confirm if microplastics are the root cause, the team intends to take optical measurements of seawater samples from inside the patch. Cheatham stated that they will need to quantify the microplastics present to fully answer the question.
The researchers cautioned that microplastics are likely to enter the base of the marine food web. Cheatham noted that the only way to reduce microplastic pollution at present is to prevent it from entering the water.