NATIONAL Parks and Wildlife services have closed the upper catchment on the Bellinger River as a precautionary measure in the wake of the turtle mortality event.
The closure is in New England National Park including Brinerville and the order is in force until further notice.
Incident Controller and NPWS Senior Wildlife Management Officer, Geoff Ross, said the closure is to minimise the potential threat of introducing any potential pathogen into the pristine environment of this section of park until the cause and extent of the problem in the lower catchment has been determined.
"People are asked to cooperate and help ensure all possible precautionary measures in order to protect wildlife including in the national park," he said.
"Assessment teams have begun monitoring the river upstream of Thora, mapping the possible the extent of the area where turtles have been affected.
"Hygiene protocols have been developed specially for this response and are required to avoid the potential to spread any disease pathogen until more is known.
"Affected turtles found to date are suffering apparent blindness leading to inability to feed and subsequent starvation."
The Environment Protection Authority (EPA) inspected the Bellinger River at four key locations when the situation was first reported.
No pesticides, including organochlorines, organophosphorous and pyrethroids, or hydrocarbons were detected at any of the four sample sites.
The NPWS is working closely with Bellingen Shire Council, Taronga Zoo, Department of Primary Industries, Wildlife Health Australia (WHA), the Environment Protection Authority (EPA) and WIRES as well as local community members.
"To help prevent potential spread of whatever may be causing the problem people are advised to report sick turtle sightings.
"They should not enter the water, handle the turtles or try to capture any turtles in the Bellinger River.
"If people are using canoes or other water craft it is recommended that these are washed down with warm soapy water and thoroughly dried after use.
"Avoid using in other waterways if at all possible."