Consumers should refrain from buying Spanish strawberries, whose cultivation is having a "catastrophic" impact on wetlands in the south of the country, the World Wildlife Fund warned.

The production of strawberries in Spain is also highly pollutant, resulting in 4,500 tonnes of plastic waste every year and still using a pesticide which is banned in the EU (bromomethane), the statement says.

"By buying Spanish strawberries - on sale in supermarkets from January to April - you are supporting the destruction of the Iberian natural milieu because the impact of this cultivation on the environment is catastrophic," WWF's Paris office said.

Some 95 percent of Spanish strawberries are grown on an area of 5,000 hectares (12,300 acres) around the Coto Donana national park, which is on the UNESCO world heritage list, WWF said.

Irrigation of the farms has reduced flows of fresh water to the Donana marshes by 50 percent and is draining one of the European Union's most important wet zones, WWF said.

Some 40 percent of the farms and 50 percent of the bore holes that feed them have no authorisation, the organisation said.

Nearly 330,000 tonnes of strawberries are produced in Spain every year, of which more than half are exported. Germany and France are the largest importers. [AFP]