Oil continues to seep out of the sunken oil tanker Prestige, further threatening coastal areas of northwestern Spain that have already suffered severe damage from the spill. An estimated 33,000 gallons of fuel oil are leaking each day from numerous cracks in the vessel, officials warned yesterday. If unaddressed, the leaks could continue into 2006, said Emilio Lora Tamayo, head of a scientific commission studying the environmental disaster. To stem the tanker’s oily tide, the main cracks could be sealed using a robot or the remaining oil could be pumped out to a platform on the surface, but both options pose major technical challenges. The single-hulled Prestige, which had been carrying 15 million gallons of fuel oil, broke apart and sank about 130 nautical miles off the coast of Spain more than three weeks ago. Cleanup ships have mopped up about 3 million gallons from the sea, but a number of slicks remain and oil continues to move toward the coastline, where it is destroying fisheries, beaches, and the livelihoods of locals. In the wake of the disaster, the European Union last week barred single-hulled tankers that are carrying heavy fuel oil from entering EU ports.