Tom Carver reports from "the site of the world's biggest drink-driving accident"

On 24 March 1989, the Exxon Valdez oil tanker grounded on a reef in Prince William Sound, 40 miles (65 km) off the Alaskan coast.

It dumped 11 million gallons (41.8m litres) of crude oil into the waters and contaminated about 1,300 miles (2,080 km) of coastline.

Its captain, Joseph Hazelwood, admitted drinking vodka before boarding the vessel, but was acquitted of operating a ship while intoxicated.

The captain of the Exxon Valdez had been drinking

The Exxon Valdez spill was not the biggest in the world, but was by far the deadliest to wildlife.

It killed an estimated 250,000 seabirds, 2,800 sea otters, 300 harbour seals, 250 bald eagles, up to 22 killer whales, and an unknown number of salmon and herring.

Ten years on, Prince William Sound looks back to normal, but local fishermen and environmentalists say it is crippled.

Only two species, bald eagles and river otters, have recovered from the spill, according to government scientists who work for the Exxon Valdez Oil Spill Trustee Council.

'No species in trouble'

But Exxon - which has established a $900m fund to settle government damage claims - says the area has suffered no lasting damage.

"The environment in Prince William Sound is healthy, robust and thriving," the company said.

"It is Exxon's position - and that of many independent scientists - that there are no species in [the sound] in trouble due to the impact of the 1989 oil spill."

Activists hope to block Exxon's planned merger with Mobil, until it agrees to pay $5bn in damages.