Sa Trinxa beach bar is located on the kind of white sandy beach that Ibiza is famous for. During the summer season, palm fronds hang from the roof, dance music pulses from the speakers and lithe, young beachgoers drop by for a late lunch and cold Spanish beers.

But like many of the island's open air venues, Sa Trinxa has recently found itself having to fall in line with tough new regulations.

This year, the bar was told it would have to turn down the music, and a limiter was installed to control the volume.

"People come here because of the music," says manager Álvaro. "I like quiet places on my day off but this is Sa Trinxa."

Image caption Álvaro has worked at Sa Trinxa for 12 years

The Ibizan authorities say that music in open air venues like Sa Trinxa must be capped at 65 decibels (dB) - slightly louder than a normal conversation but quieter than most vacuum cleaners.

Andreas Simon is part of a community group called Musica Si, or "Yes to Music", that's been set up to fight the changes.

He shows me a video that the group is sharing on social media. It points out that the average sound of traffic noise is 70dB, while an airliner landing reaches a volume of 110dB.

Mr Simon says the authorities came to install a music limiter in one beach bar in the town of San Antonio at 7am one morning.

Although the bar was empty and the music was off, the limiter showed a reading of 72dB. "The owner asked, 'So who do you fine? The sea or the waves or the wind?'"

Mr Simon says the authorities' blanket approach to regulation isn't working. "What we ask for is a specific solution for every venue. [If] one venue has no neighbours, it can have louder music.

"The government here wants to make people understand that music is noise. Music is not noise, music is a part of the culture. There has to be a reasonable solution because without music, this island is dead."

Marta, an Ibizan DJ who performs under the stage name Hofmann Lalióparda, agrees. She says that small venues located away from residential areas shouldn't be subject to the same rules as super clubs like Ushuaïa.

"They want to stop everything," she says. "But we're bringing together different groups to join forces. Musicians, painters and people who love the arts. We're going to fight against these rules that are being imposed upon us. The little bit of culture this island has left is fast disappearing."

Image copyright Eva Montero Fotógrafa Image caption DJ Marta says people are going to fight the new regulations

Illegal parties

Last year, 3.2 million tourists visited Ibiza. Across the four Balearic Islands of Ibiza, Formentera, Majorca and Menorca tourism accounts for 45% of GDP and a third of all jobs.

But balancing the tourism sector with the needs of local residents is proving increasingly difficult.

When a socialist coalition took control of Ibiza's governing council in 2015, reining in tourism was central to their manifesto.

Image caption Tourism makes up almost half of Ibiza's economy, though visitor numbers fell this summer

Vicente Torres Ferrer is Ibiza's director of tourism. He says there is no problem with loud music in closed clubs and that Ibiza has "the best discos in the world", but when it comes to outdoor venues the residents must be considered.

"We know that music is very important for our offer in Ibiza, we don't want to stop that. The problem comes when we have illegal parties in private villas or music till very late at night in open places."

Mr Torres Ferrer says modern audio equipment can be used to keep music inside a venue, at a lower volume.

"If you have a terrace and you just have one unit hanging from a wall, you have to play the music very strongly so that it arrives at the last table.

"But if you have four units in a certain way, then the music doesn't go away. You can hear the music a little bit but it's very low."

'Not enough police'

Other changes are being made to tone down the island's image as a party destination. Bars in San Antonio's West End drinking strip now close at 3am instead of 5am.

"The early closing doesn't mean that San Antonio doesn't want nightlife. If you want to continue having a party, you can move to the discos and continue celebrating your fiesta there," says Mr Torres Ferrer.

Image caption Some say closing bars early has caused more problems than it's solved

But many say the earlier curfew has simply pushed revellers on to the streets, and the real problem with San Antonio is a lack of police.

Carlos is a taxi driver and an Ibizan native. "There are so many drug dealers and there are not enough police in the street," he says.

Martin Makepeace agrees. He moved to Ibiza from the UK in 1991 and describes himself as a prominent businessman in the San Antonio area.

"[Closing bars early has] caused more problems than it's solved. It's put thousands of people on the street earlier. At the end of the day, it's the crime on the streets that's the problem."

I ask him about reports of prostitution and mugging in San Antonio.

"It's true. There are gangs around who are intent on causing these kinds of problems," he says but argues it would be easy for the authorities to stamp out that behaviour if they wanted to.

Image caption Ibiza needs to balance the needs of both residents and tourists, says Martin Makepeace

"Ten more police on the street on a nightly basis would solve more or less anything, but unfortunately they're not able to do that."

Spending cuts

So why aren't there more police? Ibiza's tourism director Vicente Torres Ferrer lays the blame squarely with the former government in Madrid and the budget cuts applied by then-Prime Minister, Mariano Rajoy, in the wake of the 2008 financial crisis.

"We had this economical problem all over the world, but Spain in particular had a very big problem," he explains.

"So they made very strong restrictions in order to contain the money spent by public administrations."

Ibiza has asked the new government in Madrid to allow it to spend more on basic services and employ more police.

The island has also cracked down on accommodation sites, in an attempt to bring spiralling rental costs under control.

It's now illegal for tourists to rent apartments on the island, while houses or villas can be rented only if property owners obtain a licence.

Island exodus?

Despite the changes, pressure is building for more to be done. A local group called Prou! - Catalan for "Enough!" - has 8,000 Facebook members.

The group aims to "defend and protect" Ibiza from over-tourism and the crime, illegal construction and environmental damage it says comes with it.

Image caption The island is famous for its beaches and its party scene

Yet some locals are running out of patience. Taxi driver Carlos says some of Ibiza's 140,000 permanent residents are considering leaving the island for good.

"Many local people who've lived here for the last 40 years, we're thinking about leaving because we don't like this Ibiza for our children," he says.

In the last 10 years, many have left Ibiza to start new lives on Majorca or the Spanish mainland, he adds.

The changes to music venues, bar opening hours and caps on accommodation do seem to be having an effect - tourist numbers were down 4% for the month of July and 3% in August, compared with last year.

San Antonio businessman Martin Makepeace says the island is grappling with the age-old problem of how to balance the needs of residents and tourists.

"It's a chicken and egg situation. Without the residents you haven't got the tourists; without tourists, you haven't got the residents. We've got to find a compromise."

Listen to Vivienne's full report from Ibiza on Business Daily.