Vacations with a disgust factor Algae slime spoils bathing fun on the Adriatic

It sounds good in Italian: mucillagine. But the gooey foam can completely ruin a dip in the sea. The hoteliers in Rimini & Co. hope that the plague will soon be over. And not just them.

All in all, the Adriatic, the stretch of Mediterranean between Italy and the former Yugoslavia and Albania, is now one of the more peaceful seas. There is no comparison with the Atlantic or the Pacific, for example, which can become very violent. At the moment, however, it does take quite a bit of effort to get into the water at one point or another in the Adriatic. This is not so much due to the waves, but rather to the Algae slime.

On various beaches in Italy, but also in Croatia or Slovenia, a slippery, slippery foam is floating on the surface this year, sometimes more, sometimes less thick, interspersed with small bubbles. Sometimes there are only small patches with lots of space in between, but sometimes it forms a dense carpet. The color varies from white to yellow to brownish. Those who mean it kindly say coffee brown. According to unanimous scientific opinion, the mucus is not harmful to health. It is certainly not toxic.

Take a shower once or twice after a dip in the sea

The plague began a few weeks ago in the north, in the Gulf of Trieste. Other cities have since been affected, such as Ravenna, the tourist stronghold of Rimini and Ancona, even further south. On the city beach there, a survey by Italy's public television station Rai revealed almost unanimous agreement: you can definitely get into the water, but you absolutely have to take a shower afterwards. "Sticky", says one of the locals. Others complain that it makes their skin tingle.

People here have experience with algae slime - or "sea snot", as some call it. In the late 1980s and early 1990s, it was already bad. Mucillagine, as it is called in Italian, spoiled the summer business for several years in a row. The disgust factor was also quite high in 2006/07. So far, however, everything has always been over again after a few days or weeks. Now, in the high season, the worries are of course particularly great. Those who earn their money from holidaymakers prefer not to talk about algae slime at all.

"Dirty sea" centuries ago

But the phenomenon is actually much older than mass tourism. One of the first people to demonstrably notice it was the Cistercian monk Paolo Boccone. The passionate botanist noted "remains of intertwined and interwoven fibers covered with slime" on the beaches off Venice in the Adriatic as early as 1697. The term "mare sporco" ("dirty sea") has been used in specialist literature for a century and a half. Old photos from the early days of tourism show men in swimsuits and women with hats and umbrellas holding their noses because of the stench on the beach.

In all this time, however, no one has yet found a convincing explanation as to why the Adriatic Sea - not elsewhere, by the way - sometimes produces such slime and is then spared for longer periods of time. It is suspected that particularly hot summers with the resulting high water temperatures in the relatively small sea favor the growth - in other words, climate change? Marine biologist Roberto Danovaro from the University of Ancona told the daily newspaper "La Repubblica": "The Adriatic has become a tropical sea. We are now at the level of the Maldives, only without the tropical color."

Tropical temperatures cause algae to bloom

A few days ago, the water temperature was actually measured at 30 degrees - almost like a bathtub. This is when some types of algae multiply particularly well. It is also suspected that the heavy rainfall this spring has washed an unusually large amount of water into the sea, which contributes to the algae bloom. What is certain is that Italy's longest river, the Po, is flushing enormous amounts of fertilizers, pesticides and faeces from agriculture into the Adriatic. "When all these factors come together, a few hundred algae can become hundreds of millions within a few days," says Danovaro.

In addition to tourism, there is another industry that suffers in particular: fishing. Because of the slime, some smaller boats can no longer get out to sea at all: the propellers can't cope. If they can, mechanical parts often have to be painstakingly cleaned of the slime. In addition, the nets are repeatedly damaged. The industry association Fedagripesca therefore called for help from the state and the appointment of an expert commission this week.

Despite all the complaints, marine biologist Danovaro is optimistic: all in all, the Adriatic is less polluted today than it was 40 years ago, he says. Researchers have also discovered that the algae slime is currently virtually melting in many places and dissolving into white flakes - a sign that bacteria in the sea are in the process of decomposing it. Perhaps even before the large numbers of holidaymakers arrive.