More than 100 fishermen filed a lawsuit against the Chinese unit of US energy giant ConocoPhillips Tuesday, demanding 490 million yuan (US$77 million) compensation following oil spills in Bohai Bay earlier this year.

A ship cleans up the leaking oil near the platform C in the Bohai Sea, China. [CFP]

The 107 Hebei Province fishermen took the legal action in a maritime court in neighboring Tianjin City, claiming ConocoPhillips China seriously damaged the local fishery industry, Zhao Jingwei, an attorney representing the fishermen, told the Xinhua news agency.

The two spills that began in June in the Penglai 19-3 oil field, in which ConocoPhillips is the operator with a 49 percent stake, unleashed thousands of barrels of oil and oil-based drilling fluids into the bay, a major fishing region off China's northeast coast, polluting an area of up to 6,200 square meters, according to China's maritime regulator. China's CNOOC Ltd owns the remaining 51 percent of the field.

Citing its investigation, the State Oceanic Administration last month blamed the defects in CNOOC's management and production for the spills, saying it violated protocols and failed to take precautionary measures when there were high risks of a spill. The fishermen claimed the oil spills killed sea cucumbers, scallops and other seafood they raised.

Zhao said he was confident the case would be accepted, as the investigation conducted by maritime authorities and the responses from the Ministry of Agriculture backed up the fishermen's claims.

CNOOC couldn't be reached for comment yesterday.

The Ministry of Agriculture said that oil contamination could affect the growth of shellfish and lead to massive deaths, according to the Economic Information Daily.

The SOA, which called the spills "the most serious marine ecological incident in China," also has said it was hiring lawyers to sue ConocoPhillips for ecological damage.

The first oil spill was discovered near platform B of the Penglai 19-3 field on June 4 and the second leak was at platform C on June 17.

According to industry officials, authorities have slowed or put on hold environmental impact assessment approvals for new wells near the Penglai field, effectively slowing drilling in the area.