"Poor water quality in our coastal lakes is likely to continue, without significant rainfall," she said. 

The statement comes after NSW DPI Fisheries staff attended the site on Wednesday, February 27 and observed up to 1000 dead fish along a section of Lake Cathie. The area was isolated from the main body of the lake. 

The Camden Haven Courier was sent video by a Lake Cathie resident, which captured the dead fish on Tuesday, February 26.

The NSW DPI spokesperson said the main species were juvenile mullet and a smaller number of bream.

"The suspected cause is related to the very low water levels at Lake Cathie and the resulting isolation of pools," she said. 

"These pools are then susceptible to high water temperatures and low dissolved oxygen."

The spokesperson said DPI Fisheries will continue to work with council on monitoring Lake Cathie. 

The community is reminded to report any observations of fish kills to Fishers Watch by calling 1800 043 536.

Port Macquarie-Hastings Council says Lake Cathie continues to be safe for recreational use despite increasing concerns from members of the public.