A researcher with the butterfly protection organisation De Vlinderstichting has received death threats over a report into pesticides found in Natura 2000 areas.

According to the foundation, the threat was sent to the scientist’s home address and has been reported to the police.

“For security reasons, the original post and the report were taken offline,” the group said in a statement.

The study measured the presence of pesticides in Natura 2000 areas, a network of vulnerable EU-protected environments. Regulations to protect Natura 2000 zones have forced the Netherlands to drastically cut nitrogen compound emissions from cattle farming, leading to angry farmers’ protests.

Fifty-one different types were found in ten areas and the research also found that insect populations had declined in several locations. Even pesticides banned for decades, including as DDT, were found.

The report was the first phase of the research and will be used in further studies.

Threats against researchers has been on the rise in recent years. A report last year found that from November 2022 and December 2023, security measures had to be put in place for scientists or staff members of universities more than fifty times.