No, 90% of plankton in the Atlantic Ocean did not die off

Sea life has been struggling for years because of pollution, overfishing and climate change. A now deleted Instagram post claimed the world’s oceans are in even more trouble.  

The July 21 Instagram post featured an image of the ocean with superimposed text that read "Breaking: Plankton in the Atlantic Ocean is 90% gone."

"In what could be the most disturbing news in ocean conservation, if not human, history — data reveals worse than expected state of plankton (the foundation of life on earth) with a 90% drop in the Atlantic, driving another nail in the coffin of our dying ocean," the text continued.

The Instagram post cited a study released by the Global Oceanic Environmental Survey Foundation, or the Goes Foundation, a Scotland research group that  measures plankton levels in the Atlantic Ocean.

Howard Dryden, a marine biologist and the study’s lead author, was quoted in the Instagram post’s caption saying the Atlantic Ocean was "pretty much dead."

Similar posts have popped up elsewhere on social media.

Scientists have since questioned the study’s validity and the Goes Foundation’s data gathering methods. Dryden has said news outlets and social media have misinterpreted the study.  

The post was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. Instagram is owned by Facebook. (Read more about our partnership with Facebook.)

Plankton come in two groups: phytoplankton and zooplankton.

Phytoplankton are plantlike organisms often found near the water's surface. They can absorb carbon dioxide and produce oxygen.

Zooplankton are animals that include creatures as small as krill and as large as a jellyfish. They stay in deeper waters during the daylight to avoid predators and rise up to the surface at night to feed on phytoplankton. 

The Instagram post took its information and Dryden’s quote from a story about the foundation’s study in a story published July 17 by The Sunday Post, a Scottish newspaper.

The Post's story originally had the headline of "Our empty oceans: Scots team’s research finds Atlantic plankton all but wiped out in catastrophic loss of life," and said the study found a majority of Atlantic Ocean plankton had disappeared over two years because of pollution from toxic chemicals and microplastics.

However, the article did not say that the study collected samples from a limited part of the Atlantic Ocean at 15 degrees north latitude, and that the foundation’s findings have not been peer-reviewed. Dryden told PolitiFact there was a "breakdown in communication with The Sunday Post," and that the newspaper has since updated its story clarifying the scope of the foundation’s study.

"What should have been said was that there has been a 90% decline in the equatorial Atlantic, not the whole Atlantic," Dryden said. "This is still a major finding, because it could mark the beginning of the spread further afield."

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The Goes Foundation described its plankton and pollution survey as an "ongoing Citizen Science project" involving 13 sailing vessels, one manned by researchers for the foundation and 12 others crewed by sailors given monitoring equipment. The crews used custom paper filters to collect water samples. Scientists would later analyze the filters to see whether plankton were in the water.

The crews involved in the survey found only a minuscule amount of plankton.

Dryden said the foundation's findings "should be verified by a second independent study," and that the organization is working on getting its findings peer-reviewed, although that could take two years.  He said the organization felt it had to make the information public as soon as possible because "it is so important for the survival of the oceans and climate change."

Oceanographers and marine biologists contacted by PolitiFact disagree with the study’s methods and findings, saying they have not observed a 90% drop in plankton around the equatorial Atlantic Ocean, or anywhere else.

Mark Ohman, a biological oceanographer at the Scripps Institution of Oceanography at the University of California, San Diego, said the study "does not even begin to meet the standards of peer-reviewed science."

He said the study’s sampling method was "not an appropriate way to take quantitative plankton samples" and led to unreliable results because:

• The sample tubes used by the boats were too small to collect zooplankton in the upper ocean.
• Most soft-bodied zooplankton would be unrecognizable on the filter paper used by the study.
• The study failed to sample most of the open ocean plankton, which are not large enough to be captured by the filter.

The study didn’t specify when and where the samples were taken in the Atlantic, which would affect how much plankton was in the water, Ohman said. And the study failed to highlight plankton’s importance in ocean food webs and in regulating the Earth’s climate and oxygenating the atmosphere, he said.

"This study makes no contribution to understanding of any of those key processes, is rife with distortion and misunderstanding, and completely lacks credibility," Ohman said.

There have also been no widespread changes to the plankton levels in the Atlantic Ocean, said David Johns, head of the Continuous Plankton Record Survey, which was established in 1931 to measure and monitor the ecological health of marine plankton.

"We have analyzed over a quarter-million samples from over 70 years of sampling, and have categorically not seen the declines reported by Dryden, and do not agree with his results," Johns said.

Ohman said there has been no drop in overall zooplankton populations in the northeast Pacific Ocean, and a rise in phytoplankton. The Continuous Plankton Record Survey works with a large network of scientists around the world. None of the scientists has reported seeing the same declines mentioned in the Goes Foundation survey. There have been some plankton population declines that can be attributed to climate change, but not water pollution as mentioned in the survey, Johns said.

"A reduction as mentioned in Dryden’s report would not only be catastrophic, but also immediately obvious," Johns said. "No plankton, no food for higher trophic levels such as fish, whales, filter-feeding shark and seabirds."

An Instagram post claimed 90% of plankton in the Atlantic Ocean had vanished.

The post based its information on a study by the Global Oceanic Environmental Survey Foundation that claimed water samples it took in a part of the Atlantic Ocean showed the dramatic reduction. The organization said its findings could not be applied to the entire ocean, only the specific area from which the samples were taken.

However, marine biologists and oceanographers have several issues with the organization’s sampling method and findings and say they have not seen a dramatic drop in the plankton population. In some cases, these experts say, plankton have been increasing.

If such a dramatic drop in plankton occurred, it would have a disastrous impact on marine life that would have already been observable.  

We rate this False.