BEIJING -- The State Oceanic Administration (SOA) on Wednesday disclosed the findings of a nationwide survey on land-based sources of marine pollution.

A total of some 9,600 such sources, including about 740 rivers, 7,500 sewage outlets and 1,350 emergency flood outlets, were identified in the survey.

Among the sewage outlets, only 8 percent were licensed, and about one-quarter were established in ecologically sensitive areas such as protection zones, off-shore wetlands and fisheries, according to the SOA.