Forest rangers have been clearing away dozens of sacks of cannabis production waste that were illegally dumped on the border between Groningen and Drenthe at the weekend.

Between 70 and 100 bags were found on Monday in the De Onlanden nature reserve, Bart Zwiers of the Dutch Society for Nature Conservation (Natuurmonumenten) said.

‘It costs a ton of money to clear up this mess,’ he said, adding that Natuurmonumenten had reported the illegal dumping to police.

Zwiers said the part of the problem was the Dutch approach to cannabis, which outlaws production and wholesale of the drug even though small quantities are allowed to be sold in licensed ‘coffeeshops’.

‘What we want is for people to be able to take this rubbish to the local recycling station,’ he said.

‘This dumping is the result of political choices. In many countries the legalisation of soft drugs works fine, but here nature pays the price.’

The rubbish includes plants, compost, drainpipes and polystyrene packaging. The latter in particular can be fatal for birds, Zwiers said.

‘It gets into their stomachs and can’t get out. The result is that they think they’ve had enough to eat, don’t go looking for food and starve to death.’