The salty Po Delta of Italy harms agriculture, fishing

PORTO TOLLE, Italy (AP) — Drought and unusually warm weather have increased salinity in Italy’s largest delta, where the mighty Po River flows into the Adriatic Sea south of Venice, killing rice paddies along with the shellfish that are a key ingredient in one of the culinary specialties of Italy: spaghetti with mussels.

At least a third of the stock of prized bivalve clams farmed in the Po Delta has died. Plants on the banks of the Po River are withering as they drink water from increasingly salty aquifers, and secondary waterways have dried up, shrinking amphibian and wetland bird homes.

“It is clear that there is a whole system with an ecology that will have permanent problems,” said Giancarlo Madovani, director of the River Basin Authority. The ecosystem includes the Po Delta Park, which together with neighboring lands in the Veneto form a reserve recognized by UNESCO for its biodiversity.

The amount of water entering the delta from the Po River is at an all-time low, reaching just 95 cubic meters (3,350 cubic feet) per second last month, due to drought conditions caused by a lack of winter snow and spring and summer rains. This is one-tenth of the annual average. It has been almost two months since the farmers were able to pump the river water for agriculture.

The impact may be even more permanent, as saltwater washes unrecorded distances inland and seeps into aquifers, underground layers of rock that can hold water.

And while deltas are by definition an exchange zone between fresh and salt water, the movement is becoming increasingly one-way: seawater intrusion inland has increased from two kilometers (just over a mile) in the 1960s and 10 kilometers (six miles) in the 1980s to a staggering 38 kilometers (nearly 24 miles) this year.

“The area around the Po is three meters below sea level, so there is a constant flow of salt water going into the aquifers,” Mantovani said. “So we are not only creating an agricultural problem, a human problem, but also an environmental problem. … This is a perfect storm.”

For clam farmers, excessive salinity, high temperatures and the resulting spread of algae are suffocating the mollusk that is the focus of one of Italy’s favorite summer dishes: Spaghetti alle vongole. And none are more precious than the striped and grooved vongole veraci farmed in the Adriatic Sea.

“You can see the clams suffering,” said Katisusia Belan, who has been clamming for 27 years. “In the afternoon, with this heat, the lagoon dries up. You can drive the tractor through here.’

According to agricultural lobby Coldiretti, this year’s payback could accelerate if the proper exchange of salt and fresh water is not restored. He blames the failure to remove sediment from the delta, which allows oxygen and fresh water to enter the lagoon, for the worsening situation.

Meanwhile, clam farmers worried that more stock could die have rushed to market while they still have molluscs to sell. This abundance has pushed prices down, creating more financial hardship. “There is a double negative effect: extinguishment and lower prices,” said Coldiretti’s Alessandro Faccioli.

Nearby rice farmers are also watching the rise in salinity with increasing anxiety. The rice fields of the Po Delta make up a small part of Italy’s national rice production, which is concentrated in drought-stricken Piedmont and Lombardy closer to the source of the Po River. While the larger producers suffer from a lack of water in their fields, those in the delta suffer from increased salt content, which kills the plants.

Grower Elisa Moretto, who runs a small family business, hopes she can save a third of her crop this year, but that remains to be seen. Whether it can turn a profit depends on other forces, including rising fuel and fertilizer costs.

But the real concern is for the future, if salinity increases and causes permanent damage to aquifers.

“If that happens, everything dies,” Moretto said.

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