Lack of O2 may have killed fish
THREE incidents which have seen dead fish surfacing in waterways in high numbers have been reported in three separate locations in recent weeks.
The latest is in an artificial lake at Burrum Heads where 40 mullet were reported dead on Wednesday.
Officers from the Department of Environment and Resource Management investigated the incident and believe low dissolved oxygen levels in the lake are to blame for the death of the fish.
It is believed the low oxygen levels were caused by organic material such as plants and leaves, which draw oxygen from the water as they break down, being washed from drains into the artificial lake by the recent storms.
Fraser Coast councillor Sue Brooks said the low water level probably also contributed to the death of the fish.
Low water levels were also thought to be behind the death of about 100 fish in a Dundowran lagoon more than a week ago while about 200 fish washed up on the foreshore between Torquay and Scarness on Sunday.
DERM was unable to determine what had killed the fish after testing because of the level of decomposition.
Ms Brooks said the community should be wary of using any type of fertilisers or pumping water out of waterways while water levels were so low.
“It just exacerbates the problem.
“People need to be extra careful in this hot weather.”
Ms Brooks said that trying to retain natural vegetation around waterways would also help the situation as it acted as a filter.
The council is using a pump on a lagoon in Dundowran to try to protect its watery wildlife from a similar fate but Ms Brooks said it was not possible to do that with every waterway in the region.
“We just don’t have enough pumps to do that.
“It is sad to see the fish dying – it is very distressing.
“We’ve gotten a little bit of rain but we need lots more.”