THE DRAMATIC pictures are all too familiar: ugly oil slicks blackening the shoreline, graceful seabirds brought low by coats of foul black goo. Last week they came from the coast of Spain, where the stricken tanker Prestige spilled at least 2 million gallons of fuel oil before sinking to the bottom with the remainder of its 20 million-gallon load. It wasn't supposed to be this way. In the wake of the massive Exxon Valdez spill in Alaska in 1989 and a major spill off the coast of France a decade later, international standards were tightened. Single-hulled tankers like the Prestige are being phased out: By 2015 all oil tankers must have double hulls for extra safety. Older tankers are supposed to meet a more rigorous inspection schedule, and the Prestige is reported to have met its inspection requirements. It will take more investigation to determine precisely what caused the ship to break apart, but in the meantime the disaster tells governments they haven't done enough yet to safeguard oil shipment.

Coastal nations must intensify their efforts to be sure tankers, particularly the oldest ones, are getting adequate scrutiny. European officials suggested last week that some aging vessels are dodging ports known to be rigorous about inspections: If that is happening, countries must work together to stop this evasion. The International Maritime Organization should heed environmental groups' call for wider designation of "no-go" zones, to steer tanker traffic away from particularly significant or biologically rich areas. It might help to require that the heaviest and most environmentally toxic oil, like the Prestige's cargo, be carried only in double-hull tankers. Stronger international efforts also are needed to rein in "flag of convenience" countries that register ships but don't live up to their responsibilities for enforcing standards.

None of these can guarantee against all mishaps: As long as world economies are dependent on oil, oil will be shipped, with a potential environmental price to be paid. Even without big spills, millions of gallons of polluting oil pour into the seas each year from runoff and other sources. But a spill like that from the Prestige exacts a dramatic and lasting toll and demands stronger efforts to avert the next calamity.