SYDNEY • The annual beach pilgrimage during the height of summer in Melbourne, Australia's second-largest city, has been threatened by an unsettling phenomenon - shores where the tides are tainted with excrement.

The state of Victoria's Environment Protection Authority (EPA) warned on Monday that heavy rains had washed faecal pollution from rivers, creeks and drains into Port Phillip Bay, on which Melbourne and many adjacent beaches are situated. It advised against swimming at 21 beaches .

However, the agency said yesterday that conditions had improved overnight. Melbourne's Herald-Sun newspaper reported that all 36 bay beaches were suitable for swimming, according to EPA manager of applied sciences Anthony Boxshall.

But Dr Boxshall added that people should still avoid swimming in discoloured water or near storm-water drains, according to the Herald-Sun.

Beaches on the Mornington Peninsula and Geelong, further away from Melbourne along the Port Phillip Bay coastline, were deemed safe for swimming by the EPA yesterday.

"It's poo in all its luxurious forms that is causing the problem," said Dr Boxshall, noting that the waste was from people, dogs, horses, cows, birds and other animals.

Faecal pollution can cause serious health problems, including gastroenteritis.

Dr Boxshall said much of the waste had been washed down the 241km Yarra River, which runs through Melbourne into Port Phillip, affecting the city's bayside beaches the most.

The EPA takes regular water samples and rates Victoria's beaches.

A "good" rating means that the water is suitable for swimming. "Fair" means that rainfall has affected the water. "Poor" means people should avoid contact with it.

Residents said during the New Year holiday weekend that the pollution had deterred them from indulging in a favourite summer ritual.

"When the temperature gets above 30 degrees, Melbournians typically pack the family in the car with food and drink and spend the day at the beach," said resident Sam Riley.

"I was going to take my two young boys to the beach myself over the summer, but now I'm concerned about whether the water is clean."

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