February 2020 - a month of fish kills and fish rescues in New South Wales

In the 2008 fish kill, North Creek was habitable and provided safe haven for many fish.

Doesn’t look like that’s going to happen this time. pic.twitter.com/RkNAAKxDp7

— Keith Williams (@Captainturtle) February 17, 2020

The Northern Star, 18 February 20120, pp 1-2:

Dr Matt Landos, a local veterinarian who specialises in aquatic species, recently warned of a potential fish kill. 

He previously said the long, dry spell had led to a build-up of monosulfidic black ooze in agricultural drains within the catchment. The drains were built long ago to empty wetlands to open land to farming. 

On Sunday, he took his son to North Creek to find his prediction had come true. “Nineteen years on from the first major kill, and the science on drainage and wetland restoration sits largely gathering dust, waiting for action to fix our landscape,” he said. 

“The solution is to pay our farmers to restore drained wetlands.” A spokesperson for the NSW Department of Primary Industries said DPI Fisheries had investigated fish death events at Rocky Mouth Creek and North Creek. 

“Mullet, bream and whiting are the main species impacted, the spokesperson said.“The suspected cause of the current events is due to critically low dissolved oxygen levels.”

Earlier in the month on 7 February at Fine Flower Creek in the Clarence River catchment there was a report of approximately 150 to 200 dead fish including Mullet and Perch. Likely cause being low dissolved oxygen within an isolated pool receiving minimal inflows.

Further down the coast on 11 February at Clybucca Creek in the Macleay River estuary there was a report of thousands of dead fish including Garfish, Mullet, Blackfish, Silver Biddy, Flathead, Bream and Whiting. Recent rainfall events have caused flooding of the backswamp system resulting in deoxygenated and low pH water, killing fish upstream and downstream of the gates.

That same day at Killick Creek, Kempsey, there was also a report of thousands of dead fish including Yellowfin Bream, Mullet, Longtail Eels and Flathead. Stressed fish were observed gasping at the water surface indicating low dissolved oxygen levels present. Cause was episodic rainfall events that caused short and sharp flow. This can cause a rapid reduction in dissolved oxygen levels due to large volumes of organic material entering the river system.

On 5 February Cockle Creek at Teralba, Lake Macquarie there was a report of  hundreds of dead Mullet. Likely cause being low dissolved oxygen within an isolated pool receiving minimal inflows.

16 February at North Creek, Prospect and Chickiba Lakes at Ballina saw a report of thousands of dead fish including Bream, Leather Jacket and Trumpeter. Cause unknown.

By 18 &19 February the Richmond River had suffered two fish kill events. The first at Woodburn Bridge when hundreds  of mullet died due to the reduction in dissolved oxygen (DO) levels caused by significant rainfall/flooding event on floodplain, followed by hot weather, leading to discharge of large volumes of critically low DO water entering the waterway via creeks and drains.The second at the East Wardell Boat Ramp with a report of hundreds of dead fishing including Bream, Flathead, Garfish, Whiting, Mullet, Herring ranging from 10cm to 40cm. The cause was a reduction in dissolved oxygen (DO) levels caused by significant rainfall/flooding event on floodplain, followed by hot weather, leading to discharge of large volumes of critically low DO water entering the waterway via creeks and drains.

Also on 19 February at Alumny Creek, South Arm and Shark Creek in the Clarence Valley there were reports of thousands of dead fish including mullet and eels, due to the reduction in dissolved oxygen (DO) levels caused by significant rainfall/flooding event on floodplain, followed by hot weather, leading to discharge of large volumes of critically low DO water entering the waterway via creeks and drains.

A total of 24 fish kill events occurred in NSW coastal catchments in February 2020, while there were 6 fish kill events in the Murray-Darling Basin involving the death of many hundreds of dead wild fish.

See: NSW Dept. Primary Industries (DPI), Fish Kills in NSW for full details.

In order to save as many fish as possible from the record-breaking drought, bushfires and post-fire water pollution after rainfall, rescues have taken place in the Gwydir, Border Rivers, Macquarie, Lachlan, and Upper Murray catchments in the Murray-Darling Basin, and in the Clarence and Richmond River catchments on the coast.

Threatened fish species were captured and relocated to areas where these fish would have a greater chance of surviving or sent to government hatcheries and Taronga Western Plains Zoo where they will form the backbone of captive breeding programs.

DPI Fisheries states it has rescued more than 5,000 native fish from all corners of the state, since operations began in September 2019 with the rescue of Murray Cod, Golden Perch and other native fish species in the drying Menindee Lakes.

Those fish rescued to date include: approximately 1,630 Olive Perchlet, 740 Southern Pygmy Perch, 292 Oxleyan Pygmy Perch, 107 Southern Purple Spotted Gudgeon, 98 Eastern Freshwater Cod, 79 Silver Perch and 34 Eel-tailed Catfish and, sadly only 9 Macquarie Perch.

Community members are encouraged to report sightings of threatened fish to help identify where actions may be required to prevent fish deaths and, to report any fish deaths or observations through the Fishers Watch phoneline on 1800 043 536. 

For more information or to report a threatened species, download the FishSmart app, phone the Fishers Watch phone line on 1800 043 536, or visit www.dpi.nsw.gov.au/fishing.