Plankton could be used to signal toxic pollution in the marine environment and warn of human health dangers

Plankton could be used to help warn of future human health problems and pinpoint man-made marine pollution hotspots, according to new research.

Plankton, a diverse group of organisms that live in water, has been collected from oceans around the world as part of a project that began nearly a century ago, in 1931 – the Continuous Plankton Recorder (CPR) Survey, headed by the UK’s Marine Biological Association in Plymouth.

Now a new pilot study by international scientists, focusing on samples collected in the north Pacific between 2002 and 2020, suggests data from the surveys could be used to explore the connection between ocean pollution and rates of chronic illnesses in children and adults, including mitochondrial diseases caused by genetic mutations.

The research team hopes plankton samples could be used to track and curb pollution that leads to human disease.

Robert K Naviaux, professor of medicine, paediatrics and pathology at the University of California San Diego’s School of Medicine, said the findings could explain how exposure to harmful chemicals in the ocean could trigger cell danger response in humans, leading to chronic symptoms.

“We were motivated to explore these new methods by the alarming increase in childhood and adult chronic disease that has occurred around the world since the 1980s,” he said.

“It is my hope that the use of our methods by research groups around the world will reinforce the connection between eco-system health and human health, and provide new tools to monitor how the human chemical footprint has changed over the past century.”

Dr Clare Ostle, CPR research fellow and co-ordinator of the Pacific CPR Survey, said: “All of the samples collected by the CPR Survey are preserved and stored in our biological library. This creates a time capsule of what was in the surface waters at that location and time.”

Samples from the Continuous Plankton Recorder Survey could be used to predict trends in marine pollution and human health. Picture: Marine Biological Association

A variety of technologies were used to assess plankton exposure to man-made chemicals, including pharmaceuticals, persistent organic pollutants such as industrial substances, pesticides, and chemicals derived from plastics and personal care products.

Analysis showed the levels of persistent organic pollutants and the common antibiotic amoxicillin have broadly declined in the north Pacific over the past 20 years.

However, the most polluted samples were taken from nearshore areas closest to human activity where terrestrial run-off and seafood farming were most common.