Strawberry boom is a drain on Spain
The strawberry has always been one of the most prized tastes of summer. But meeting the growing demand for this favourite fruit - in Britain, Germany, France and beyond - is putting great strain on the environment in Spain.
Spain is the biggest exporter of strawberries worldwide, with an industry worth more than 400m euros (£345m) a year, which supports around 50,000 jobs. Intensive agricultural methods mean the fruit can be grown all year round.
Nine out of 10 strawberries are exported to Europe. Germany imports more than a third of Spanish production, closely followed by France.
But the "red gold", as some Spaniards call it, has transformed not only European supermarket shelves, but also the landscapes of southern Spain.
Driving through the fruit-farming area close to the town of Lucena del Puerto in Huelva, the land is lush and green.
Domes made out of white plastic sheets spread as far as the eye can see. Beneath them are strawberries. This region accounts for almost 90% of production in Spain.
But there is not enough water to supply this huge industry. According to the local water agency, as many as half of all strawberry farms in this region are taking water illegally.
The conservation group World Wide Fund for Nature (WWF) says there are more than 1,000 illegal boreholes in the area, pumping water from deep underground.
But that water is also what feeds one of Europe's most important wetlands, the Donana National Park.
Wildlife at risk
Donana is home to rare species like the Iberian lynx, and settled by migratory birds from Africa. It has been designated by Unesco as a World Heritage Site and a biosphere reserve.
Its marshes are fed by underground aquifers. But the water supplied by one of the main streams has fallen by half in the last 30 years.
"This is a very important threat, because water is important for all in the park - for animals and even for vegetation," says Dr Carmen Diaz Paniagua, from Donana's research station.
Spain is a country already facing severe pressure on its water supplies. Droughts, water shortages, and forest fires have been rife in recent years.
But illegal water use has long been ignored - largely because of pressure from local mayors who see only the economic benefits, says Felipe Fuentelsaz, local officer for WWF.
"There are a lot of boreholes and they have not been closed in the last few years because strawberries create jobs," he says.
"WWF wants a sustainable plan. We need to work with the fact that there are strawberries in the area - but at the moment the amount of land cultivated is far too much.
"We need to reduce it in order to make the soil sustainable, preserve the aquifer and create a balance between agriculture and the environment in Donana National Park."
Lack of will
Juan Manuel Lopez, Huelva's Environment Authority delegate, says it will take time to come to an agreement between farmers and environmentalists.
"I wouldn't call it illegal extraction of water. It's a transitional period toward legalisation and land reorganisation," he said.
"We are going to close more than 900 boreholes and bring water from elsewhere so we can keep the Donana aquifer untouched.
"There are jobs here. We cannot put an end to people's lifestyle overnight."
Freshuelva, the association representing the majority of strawberry farmers here, declined to be interviewed.
But farmers who play by the rules - like Juan Maria Rodriguez, manager of Flor de Donana - blame the authorities for not enforcing the law.
"Of course it bothers us that there are farmers who water their crops illegally. But the fact that there are people who know about it and don't stop it is more disturbing," he says.
"They are a minority and there are many people doing a good job in Huelva. Actually the farmers have been asking the government to put order in all this for five years now."
But where local authorities have failed, consumers themselves may be able to make a difference.
Some of those strawberries shipped all over Europe are organic - and therefore subject to tight production controls - including criteria on water use.
In Switzerland, for instance, the organic market share is 5.7% and rising strongly.
Bio Suisse, the federation of Swiss organic farmers, impose tight criteria on Spanish strawberries sold in Europe to label them as biological agriculture.
Hans Remseir, head of quality assurance for Bio Suisse, the federation of Swiss organic farmers, says the consumer appreciates the difference.
"For the consumers trust in what they buy is more and more important. They want to know there is a traceability of the product, that it is not an anonymous product made against all social and environmental principles," he says.
Organic strawberries can sometimes be twice as expensive - but Mr Remseir says that is often not a problem for the Swiss consumer.
"In Switzerland, food buying represents only 5% of income, so price is not that relevant for making decisions."
In the UK and other countries, however, almost 10% of income is spent on food and drink - meaning the consumer is much more sensitive to price.
In the last two years, sales of organic products in Britain have fallen by 6% and 13%.
In tough economic times, one of the first cuts European householders make is to their budget for groceries.
But while consumers seem willing to loosen their ethical concerns while under financial pressure, their taste for strawberries appears undimmed.