Processes that threaten the plant include eutrophication, dredging, turbidity, and thermal pollution.

A follow up investigation was conducted by the same institute in November 2001, which included dredging to recover artifacts.

Activities include dredging, repair, and operation of structures and other facilities.

A follow-up investigation was conducted by NIOT in November 2001, which included dredging to recover artifacts and sonar scans to detect structures.

Some suggestions for the harbor, he said, include annual dredging of the spur, dredging farther into the harbor or dredging deeper than six or eight feet.

Examples include dredging and collection of scientific specimens.

Remediation included dredging of six hectares of adjacent riverbeds and removal and treatment of 10,000 m3 of soil.

Possible causes of contamination include dredging that stirs up pollutants in muck; pollution in South America, where birds migrate; lead-based paint on bridges, and lapses in environmental law enforcement, she said.

Man-made impacts in the area include dredging, sewage release and freshwater flooding.

In 2011 the Buffalo River Restoration Project commenced, which includes major dredging to remove contaminated sediment, habitat restoration, and site access projects.