Two scientists in Sweden were found guilty of misconduct in their high-profile paper outlining the dangers of microplastics on fish published in the prestigious journal Science last year.

Peter Eklöv and Oona Lönnstedt, both of Uppsala University, were found guilty of misconduct in a report capping months of investigation at the school. The pair did not appear to seek ethical approvals for animal experimentation – and some of the trials were never even performed, the investigators found.

“Oona Lönnstedt and Peter Eklöv are guilty of misconduct in research, Eklöv in that he has violated the regulations on ethical approval for animal experimentation, and Lönnstedt in that she has violated the regulations on ethical approval for animal experimentation and because the experiments were not conducted as described in the article in the scholarly journal and are therefore fabricated,” Uppsala announced in their final report.

“The misconduct in research was intentional,” the panel adds in the decision, handed down Dec. 6.

The paper, “Environmentally relevant concentrations of microplastic particles influence larval fish ecology,” was published in June 2016, and garnered a wave of headlines. The duo claimed that young European perch (Perca fluviatilis) were lured to eat microplastic polystyrene particles, which inhibited their growth, changed their behavior, and generally made them less responsive to threats from predators. The larvae actually preferred to eat the plastic, the two scientists wrote in the study.

The study received widespread coverage in newspapers and in scientific publications around the world after its June 3 publication date. But just a little more than two weeks later, on June 20, seven researchers sent an official complaint to Uppsala contending the work could not be real.

A preliminary investigation at the school was released in August 2016, which found no evidence of misconduct.

But a second “expert group” found misconduct in April 2017, and Science retracted the paper the following month.

This final report does not describe what the punishments for the two scientists will be. But the school emphasized the dangers of losing trust in science.

“We take a very serious view of misconduct in research, every such case risks leading to a public loss of confidence in research,” said Vice Chanellor Eva Akesson. “At the same time, it is important to be careful in this type of investigation so that innocent people do not suffer ill effects. I welcome the fact that the situation regarding liability has finally been clarified in this case.”

Eklöv was the supervisor of Lönnstedt, who was a postdoctoral researcher at the time the paper was published last year. Eklöv spoke to Science in the wake of the report, and told the reporter, “I’m very disappointed by my colleague.” Eklöv further told the journalist that the data behind the paper was supposed to be posted online – but Lönnstedt claimed her laptop was stolen shortly after the information was requested by the journal. But he backed off the work, stating “I have never done research on microplastics and I probably never will do research on microplastics.”

Professor Peter Eklöv and Dr. Oona Lönnstedt. Photo: Uppsala University