Plans to drill for oil off the Spanish holiday island of Ibiza have metwith fierce opposition from locals who fear the white sand beaches and marine lifewill be damaged."Everyone is against it here," said Carlos Bravo of the Blue Sea Alliance, an umbrellaorganisation of 50 groups including environmentalists, hoteliers and unions,seeking to halt oil exploration off Ibiza and Formentera, a neighbouring island thatis only accessible by boat.More than 10,000 people, some carrying signs saying "The Mediterranean is not forsale", marched in February through the streets of the capital Ibiza Town against theplanned exploration.Their campaign has the backing of celebrities like US socialite Paris Hilton andBritish model Kate Moss who are regular visitors to Ibiza, one of Europe's top touristdestinations which is famous for its nightclubs and turquoise waters."Ibiza is in danger. It is not a myth, not a metaphor and not an exaggeration. Theisland is facing an ecological disaster," Hilton wrote on her Instagram page earlierthis year.Moss has signed a petition urging the Spanish government not to allow the oil prospecting to go ahead, and posted a photo of herself holding a sign that read"Ibiza Says No" to her 32.8 million Twitter followersThe project dates back to 2010 when British firm Cairn Energy obtained fourexploration licences for the waters around the Balearic Islands, one of which is Ibiza.The company now plans to use seismic imaging, which bounces sound waves off theocean floor, to map pockets of underground oil in the region before it applies for government permits to start drilling.Cairn Energy said it will carry out the seismic imaging over 2,400 square kilometres(930 square miles), an area roughly the size of Luxembourg, 53 kilometres (32 miles)from Ibiza."The company is currently at the very early stages of assessing whether to explorefor hydrocarbons," it said in a statement, before adding that the seismic imagingwill take place "at a time when any impact will be at a minimum, most likely in thewinter months".- Noise threatens marine life -Environmentalists warn the sonic shocks used in seismic imaging are a threat tomarine life.The deep waters around the Balearic Islands are home to the endangered bluefintuna, the striped dolphin, the long-finned pilot whale and sperm whales."Cetaceans are very sensible to noise. This will interfere with their capacity tocommunicate and search for food," said Txema Brotons, the president of Tursiops, aresearch and conservation group based in the Balearic Islands.The seismic imaging will use airguns that produce a loud sound every 10 seconds,round-the-clock, for 75 days, said Bravo of the Blue Sea Alliance."They generate a huge noise level, 10,000 to 100,000 times louder than the engine ofan plane, which seriously harms fish, cetaceans, turtles and invertebrates," saidBravo.Local fishermen fear the seismic imaging will ruin their catches."Cetaceans, fish and their larvae... they are all going to leave," said Pere Valera, thehead of Ibiza's main fishermen's group."We have seen what has happened elsewhere, there was a 70 percent reduction in catches after seismic imaging."- 'Islands' oil is tourism' -Opponents also fear that oil exploration will hurt tourism in Ibiza, the main sourceof revenues for the island which is an UNESCO World Heritage Site."The Balearic Islands' oil is tourism," said the head of the islands' regionalgovernment, Jose Ramon Bauza, who belongs to the conservative Popular Party inpower at Spain's national level.Of all the advanced economies of the OECD grouping, Spain is the most reliant onenergy imports, which account for 99.9 percent of its oil and gas.The Spanish government is looking to reduce this dependence by developing Spain'sown energy production.The Spanish oil industry could create 250,000 jobs and account for 4.3 percent ofgross domestic product within 20 years, according to a report published last monthby consulting firm Deloitte.The report is based on an estimate that Spain has reserves of two billion barrels ofoil.Environmentalists are discouraged by the example set by Spain's Canary Islands,where seismic imaging has already taken place and oil drilling is set to begin laterthis year despite protests by island residents.