Greek authorities have started collecting hundreds of thousands of dead fish that poured into a tourist port in the central city of Volos after being displaced from their usual freshwater habitats during flooding last year.

The floating carcasses created a silvery blanket across the port and a stench that alarmed residents and authorities who raced to scoop them up before the odour reached nearby restaurants and hotels.

“It spans kilometres,” city council member Stelios Limnios told Reuters. “It’s not just along the coast, but also in the centre of the Pagasetic Gulf,” he said, referring to the area offshore Volos whose coast is lined with holiday homes.

On Wednesday, trawlers dragged nets to collect the fish that were then dumped in the back of trucks. More than 40 tonnes have been collected in the last 24 hours, authorities said.

Volos mayor Achilleas Beos said the smell was unbearable. During a press conference he blamed the government for not dealing with the problem before it reached his city. He said that rotting fish could create an environmental disaster for other species in the area.

Experts said the problem was caused by historic floods last year that inundated Thessaly plane further north, including rivers and lakes. A net was not placed at the mouth of the river leading into Volos, they said. When the fish met the sea, the saltwater likely killed them.

“They didn’t do the obvious, to put a protective net,” Beos said, referring to government services.

The environment ministry did not respond to a request for comment.

Supreme Court prosecutor Georgia Adelini has also ordered an investigation into the issue.

Ekathimerini report that investigation aims to determine why the dam gate leading from Lake Karla into Pagasitikos Gulf was left open and to identify who made this decision.

“We request that an urgent preliminary investigation be conducted to investigate, among other things, whether the sluice gate leading to the tunnel, which is the sole outlet for the waters of the entire Larissa-Karla plain into Pagasitikos, should have been open,” Adelini’s order stated.

“Further investigation should determine who made the decision to irrigate the aforementioned plain.”

The disaster is the latest impact of extreme weather in Greece that scientists link to climate change, including higher temperatures and erratic rainfall that cause wildfires and flooding.

With AAP via Reuters