Fish kills signal repeat warning for habitat action
OzFish, Australia’s fish habitat charity, is receiving numerous reports from the public of a fish kill in the Richmond River, at Ballina in Northern New South Wales.
The member organisation has received messages and photos overnight from locals who report thousands of fish gasping for air, or washing up dead, following the recent cyclone and flooding.
OzFish CEO Cassie Price said “blackwater” is the likely cause. “Blackwater is caused by flooding washing organic material into waterways. This strips oxygen from the water as it decomposes, suffocating fish and other aquatic wildlife.”
Photos provided show dead flathead, bream, whiting, prawns and other marine life washed up on shore, and videos show dying fish gasping on the shoreline. OzFish have also received reports of mud crabs and eels walking out of the water to escape smothering.
Ms Price said OzFish volunteers are out testing and monitoring water quality.
“The results aren’t good. Healthy water should have at least 5mg of oxygen per litre. Fish experience distress when it falls below 4mg per litre, and start to die at 2mg a litre. In Richmond River today, the dissolved oxygen levels are almost nil, sitting at 0.4 mg a litre.”
Ms Price said she fears that this could repeat earlier large large-scale fish kills and decimate the resilience of local fisheries.
“Urgent action must be taken to prevent further fish kills, and build resilience into our waterways.”
Ms Price said restoring local swamplands that border the Richmond would reduce the severity of the black water events, and fish kills.
“Healthy swamp bordering rivers acts as a sieve, or a filter, that reduces the blackwater from entering the waterway.”
“Restoring the Tuckean Nature Reserve to a more natural hydrological regime would mean that much of the swamp would process the flood water, so that significantly less blackwater enters the lower Richmond after events like this.”
She encouraged the public to record any dead fish they discover and share the information with the charity.
“Community can capture a lot of information in a lot of places, very quickly, which is we’re calling for assistance.”
“Record a pin drop or geo reference of your location, estimate the number of fish, take note of any key species you can identify, and take photos and videos. Send it through to us at [email protected].”
“This data will give us an evidence base that can assist in navigating the approvals pathways to restore areas of known blackwater production, like the Tuckean Swamp.”
Media
To learn more, get high-resolution images and video, or arrange an interview with Cassie Price, email [email protected].
About OzFish
OzFish is a not-for-profit member organisation that partners with fishers and the broader community to invest time and money into the protection and restoration of waterways, counteracting decades of degradation with projects in habitat restoration, re-snagging, riverbank planting, clean-ups, fishways, shellfish reefs and educational and community capacity building programs – www.ozfish.org.au.