Atlantic Ocean has not lost 90% of its plankton
CLAIM: Plankton in the Atlantic Ocean is 90% gone.
AP’S ASSESSMENT: False. This claim is based on a misrepresentation of a limited survey that reviewed water samples for plankton in a section of the Atlantic Ocean. The lead author told The Associated Press it was inaccurate to suggest his research reported that 90% of Atlantic Ocean plankton was gone. Experts who study global marine life say that if 90% of plankton in the Atlantic Ocean were gone, there would be severe collapse in the ecosystem as a whole.
THE FACTS: Climate change is significantly disrupting the world’s oceans, but experts say it hasn’t caused 90% of the Atlantic Ocean’s plankton to die out, as grim online posts have falsely claimed in recent days.
The misconception emerged last week, after the Scottish newspaper The Sunday Post reported on an Edinburgh-based research team’s efforts to sample seawater in one section of the Atlantic Ocean, slightly north of the equator.
The newspaper described the research as finding that 90% of Atlantic plankton had vanished. It used the headline, “Our empty oceans: Scots team’s research finds Atlantic plankton all but wiped out in catastrophic loss of life.”
However, a closer look at the research, which has not been peer-reviewed, shows it was a limited survey in an area of the Atlantic Ocean at 15 degrees north latitude. It was conducted by the Global Oceanic Environmental Survey, which describes its plankton research as a “citizen science” project.
A report on the group’s findings explains the research team developed its own filter to collect its samples instead of using standard plankton trawls. It said the survey involved 13 vessels that all recorded the same results.
Howard Dryden, a marine biologist and the lead author of the research, explained in an email to the AP that the Sunday Post story should have said there has been a 90% decline in plankton in the equatorial Atlantic Ocean.
“Unfortunately, there was a breakdown in communication with the Sunday Post who wrote and printed the story,” Dryden wrote. “I didn’t have a chance to fact check prior to publication.”
The Sunday Post has updated its story and headline to reflect that the research was limited to the equatorial Atlantic Ocean.
However, the newspaper denies misrepresenting the research and stands by its reporting. Sunday Post editor Jim Wilson told the AP in an email, “We accurately reported Dr Dryden’s research. Our headline might have been more specific about the geographical limits of that research but the story was clear and would have left no fair-minded reader confused.”
Dryden acknowledged that his team’s sample size limited its research, and said the group had plans to sign with a university to prepare a report that could be peer reviewed. He said the findings “should be verified by a second independent study.”
Independent experts who research plankton said it was false to conclude, as many social media posts did, that 90% of Atlantic plankton had been wiped out.
“Categorically no, this is not true,” said David Johns, head of the Continuous Plankton Recorder Survey, which has taken monthly samples across multiple routes in the north Atlantic and north Pacific for the last 70 years.
“We have over a ¼ million samples and we have used a consistent methodology throughout that time giving us a unique time series of plankton distribution and abundance in large areas of the worlds oceans,” Johns told the AP in an email. “We have not seen this drop.”
Johns said his survey has seen changes in plankton species in response to climate change, with cold-loving species moving northwards and warmer water plankton taking their place. But, he said, if there were a 90% drop in plankton populations, it would be “immediately apparent to everyone” because all sea creatures depend on plankton.
He said many factors can dramatically affect findings in a survey like this, including the time of day a sample is collected, since many types of zooplankton, or animal species of plankton, come to the surface at night while descending to deeper waters during the day.
“So if you took a sample in the surface waters in nice sunny weather, in a great many areas of the ocean, particularly the open ocean, there would be virtually nothing there,” Johns said. “That’s normal.”
James Sullivan, executive director of the Harbor Branch Oceanographic Institute at Florida Atlantic University, agreed that claims that 90% of Atlantic plankton had vanished were inaccurate.
Reporting such changes in a worldwide ecosystem or ocean basin “takes an incredible amount of science and work,” he said.
“Our oceans are having a hard time with global warming, there’s no doubt about that,” he said. “But it’s not that simple to say, you know, 90% of their life has disappeared.”
This story has been updated to add comments from the editor of The Sunday Post.
This is part of The Associated Press’ ongoing effort to fact-check misinformation that is shared widely online, including work with Facebook to identify and reduce the circulation of false stories on the platform. Learn more about fact-checking at AP.