Mosquito-control spraying questioned after Gulf barramundi fail to spawn for two years
Feb 5 2018
A remote Queensland Gulf community is concerned their local council’s mosquito control program could destroy the local barramundi industry after the hatchery failed to produce spawn for almost two years.
Spraying to stem mosquito numbers and mosquito-borne viruses such as dengue and zika are carried-out worldwide, and recently in Townsville, Rockhampton and Torres Strait islands.
According to the Carpentaria Shire Council, the barramundi hatchery at Karumba had not produced successful spawn since at least April 2016 until recently, when mosquito spraying was halted for two months.
Local fisherman Mathew Donald is among those concerned about the impacts of mosquito spraying on the fishing and tourism industries across north Queensland.
“If the hatcheries stopped stocking the rivers and the fisherman kept fishing the way they were, then the barramundi stocks would obviously just decline,” he said.
“The professional fishermen would have to move on, the tourists would stop coming to Karumba because of the lack of barramundi there. It would just destroy the place.”
Carpentaria Shire Mayor Jack Bawden told the ABC there were two successful spawns around the time the spraying was stopped, which prompted council to further investigate the effects of mosquito spraying.
“Whether that is a 100 per cent reason for it we still don’t know for sure. That’s why there’s more investigations happening,” he said.
Mr Bawden said the Council suspended mosquito spraying two weeks ago and have called in an environmental health officer for advice.
He said he only became aware of the issues just recently and it was an issue the present council inherited from the previous administration.
“I’ve decided looking into it myself. You’re actually told not to use it [spray] around aquaculture and environments like that because it’s detrimental to marine life,” he said.
Despite the council’s efforts, local fishermen are worried the impact goes beyond the local hatchery.
The chair of the Gulf of Carpentaria Commercial Fishermen’s Association, Shane Ward, said he was concerned about the impact on the hatchery and environment.
“Their suspicion why the last couple of spawns haven’t worked is because of the mosquito spraying and they can’t prove otherwise, so we’re a bit concerned that spraying could also impact the habitat around Karumba,” Mr Ward said.
“The local environment is what we’re concerned about because Karumba is built right on the wetlands, with mangroves almost right up to the back of some of the houses.”
The Council used a chemical called Twilight ULV Mosquito Adulticide Concentrate to manage mosquitos, which according to the material safety data sheet published on their website poses many ecological risks.
“This product is toxic to bees. Very toxic to aquatic organisms, may cause long-term adverse effects to the aquatic environment,” the document said.
While fishermen were comforted by the recent spraying suspension, some believed the council did not act quickly enough.
“That’s quite disgusting that they would keep spraying something like that around Karumba when fishing is the only reason for Karumba,” Mr Donald said.
“They should’ve been on to that a hell of a lot earlier.”
Mayor Bawden said he assured the community the Council was working to resolve the issue.
“Be patient. We’re trying to do the right thing by everyone, and at the same time get a sustainable fishery going in Karumba,” he said.