The State Oceanic Administration's (SOA) Qingdao office said it had deployed a helicopter and a dozen vessels to make daily patrols in the sea area for the Paralympics sailing events from September 8 to 13.

The same forces were deployed for the Olympics from August 8 to 24, when 400 sailors from 62 countries and regions competed in 11 sailing events in the city, according to the SOA.

The marine authority said that 400 fishing boats will stand by in case of a sudden algae bloom during the Paralympics.

SOA satellite monitoring had detected no large patches of algae in the area since August 23.

The coastal city was hit by a sudden algae bloom that floated from the Yellow Sea in mid-June. The non-noxious algae covered 32 percent of the 50-square km sailing venue at the peak of the outbreak.

For a month, the city government mobilized soldiers and volunteers to clear more than 1 million tons of algae, and built barriers and fences to keep it out of the sailing venue, which was completely cleared on August 1.

The city's quick response to the situation was praised by International Sailing Federation president Goran Peterson.