The State Oceanic Administration (SOA) said over the weekend that water samples taken from the East China Sea where the oil tanker Sanchisank met the first-level standards of China.

The official response comes amid continuing concerns that the condensate oil from the sunken ship might endanger the marine ecology.

SOA staff took 20 water samples near where the tanker carrying 136,000 tons of highly volatile condensate oil went down on January 14. The samples taken between Saturday afternoon and Sunday morning show that oil concentration in the sampled seawater is lower than 50 milligram per liter, said the SOA.

The result shows that the water quality in the sampled region met first-level standards, Wang Yamin, a professor at Shandong University's School of Oceanography, told the Global Times.

Samples taken on Friday and Saturday also meet the country's first-level standards, SOA said in a separate statement released on Saturday.

China's seawater quality standards implemented in 1982 states that the first-level standard is suitable for maritime fishing, nature protection zones and endangered marine organisms.

The SOA also noted that there remains a thin film of oil about a kilometer from where the Sanchisank.

Ma Jun, director of the Institute of Public and Environmental Affairs told the Global Times earlier that condensate oil, a kind of ultra light oil on the Sanchi, differs from other types of crude oil and is poisonous to marine life.