Efforts were under way July 18 to contain and clean up a large oil slick after pipeline explosions at northeastern China's Dalian Xingang port. Maritime workers on 20 boats were sent to install fencing to stop the spilled oil from spreading further in Dalian's Xingang Harbor. [CFP]

About 1,600 people, including employees at the port and residents within five km of the site, were evacuated and sent to hotels, said Yang Miao, director of a special police force with the Dalian municipal public security bureau. The residents have begun returning to their homes.

According to Maritime Safety Administration, work is ongoing to contain the oil slick to a certain area, mostly by setting up oil fences. Efforts are being made to divert the oil slick from ecological sensitive areas.

Several measures to get rid of the crude oil, such as using oil-absorbing mats and utilizing oil-skimming boats, are being used to recollect the crude oil that spewed into the sea water.

Sometimes, chemical dispersants are used to break down the oil, but this method is the least recommended as their toxicity might harm the fish, and therefore the fishery industry.

Wang Bin, deputy director of the environmental protection department at the State Oceanic Administration, said several hundred vessels are working to skim the oil slick, while local fishermen have also joined the efforts using straw mattresses and fishnets to absorb and collect the crude oil.

"The oil spill has been contained to the port area, where the environmental standard is relatively low, so the impact on the ecology should be quite limited at this stage," Wang said.

Wang Xiaokan, a 32-year-old fisherman, was told Tuesday to help with the cleanup effort.

"I was given oil absorbing mats to collect the oil and plastic sheets to hold it. The oil will then be pumped into big boats and sent back to the company," he said.

Huang Yong, vice-director of local maritime safety bureau, said that more than 800 fishing boats started to help clean up on Monday.

Luan Yujuan, vice-director of the local oceanic and fishery bureau, said 100 more fishing boats joined the effort Monday afternoon.

Wang has been fishing on the Dalian coast for more than 10 years and lives about 500 meters away from where the explosion happened.

"On Friday evening, I heard a big bang and saw black fumes rising from the port area. I did not run away but was evacuated the next morning," he said.

He was worried about his boat and sneaked back Saturday evening to check on it, which luckily was unaffected by the blast. But he and other fishermen are still worried.

Wang said he is not sure about the impact to his fishing business as June, July and August are closed seasons. "But if the oil is not cleaned up and the fish are poisoned, my business will definitely be affected," he said.

An oil spill harms a variety of species, but most notably birds, Ma said. Death is a virtual certainty for affected birds, he said.

In Alaska, after the Exxon Valdez spill in 1989, Exxon power-washed oiled beaches with high-pressure hot-water sprayers. But scientists ultimately determined that this practice was a disaster for the tidal ecology, with clams and other organisms showing much-delayed recoveries on the laundered beaches, compared with oiled beaches that were not cleaned.

Ma's view was echoed in Germany by Silvia Gaus, a biologist at the Wattenmeer National Park along the North Sea, who said few, if any, oil-soaked birds will survive, regardless of the best attempts to clean them and release them back into the wild.

Efforts to catch and clean oil-soaked birds often lead to fatal amounts of stress for them, and the birds will eventually perish from kidney and liver damage, Gaus said.

"According to serious studies, the middle-term survival rate of oil-soaked birds is less than 1 percent," she said. Gaus worked on the environmental cleanup of the Pallas, a wood-carrying cargo ship that spilled 90 tons of oil in the North Sea in 1998. Around 13,000 birds drowned, froze or died due to stress as a result of that spill.