Fish kill a mystery
By KEN SAPWELL
A MULTI-agency investigation is under way in a bid to determine the cause of a massive fish kill in the Cudgera Creek at Hastings Point this week.
Officers from the Department of Fisheries, the Environment Protection Agency and Tweed Council converged on the creek yesterday to conduct water quality tests and post-mortems on some of the hundreds of fish, eels and crabs found dead on the banks of the creek.
They are trying to determine whether the fish kill - in the wake of this week's torrential downpour - is a result of acid-sulphate or chemical run-off from surrounding farms.
Local resident Graham Dennis, who works at the Hastings Point general store, said he was alerted to the kill on Wednesday morning by fishermen returning from the beach.
"From the bridge to the mouth both sides of the bank were lined with dead or dying fish," Mr Dennis said yesterday.
"I've been here for 20 years and I've never seen anything like it before. They were mainly flathead and small eels, but there was also plenty of trevally and black bream.
"The pelicans and seagulls were having a field day.
"I know there would have been plenty of fresh water pouring into the creek, but that's happened before and it's never resulted in a kill like this."
Mr Dennis said that the water appeared normal but did have an orange tint to it. A spokesman for the NSW Department of Fisheries said they were working with the Tweed Council and Environmental Protection Agency to determine the cause.
NSW Fisheries maintains a database of fish kills in NSW. It contains some 750 records dating back to the early 1970s.
Since the mid 1980s there has been around 20 to 50 kills reported to NSW Fisheries each year, whereas prior to 1987 less than 20 kills per year were reported.
The change in reporting rate has been attributed to improved awareness and better reporting arrangements rather than an increase in the number of kills that have been occurring.
Relatively more kills occur in summer, with the main contributing factor appearing to be higher water temperatures and consequently lower dissolved oxygen levels.