The controversial weed killer glyphosate has been detected in the Baltic Sea thanks to a new measuring method, the Leibniz Institute for Baltic Sea Research Warnemuende (IOW) said Monday.

The new method makes it possible to detect both glyphosate and AMPA - the main metabolite of glyphosate - in saltwater samples, according to IOW, which developed the method.

This will make it possible to monitor the levels of pollution it causes to the marine environment.

Glyphosate is one of the most widely used weed killers worldwide. The controversial agent has been detected in streams, rivers, and lakes, but had not yet been detected in oceans.

"The starting point for our current study was the question of whether glyphosate and AMPA actually arrive in the sea - for example through biological degradation and deposition in rivers - or whether it is simply methodological difficulties that have so far prevented detection in marine ecosystems," IOW researcher Marisa Wirth said.

The marine chemist's research has shown that the salt in the seawater actually interferes with the measurement methods previously used.

According to the research institute, the measured concentrations are far below those values that are considered toxic for humans and organisms.

"But we now have a sufficiently sensitive and reliable method with which one can carry out meaningful environmental monitoring in the ocean for both substances," said Wirth.

In December 2017, the European Commission decided to extend its approval for glyphosate by five years.