IT may seem hard to believe if a mozzie gets you in its sights, but Hexham swamp mosquito populations are in decline.
The staged opening of the Ironbark Creek floodgates since 2008 has resulted in an increase in mosquito predators, such as fish and birds.
‘‘There was a big jump [in mosquito populations] in the first year after the floodgates opened, but it’s started to decline since then,’’ Dr Cameron Webb, who records mosquito populations in the swamp several times a year, said.
‘‘The system is slowly starting to return to balance.’’
That balance was upended when the floodgates were installed in the early 1970s with the intention of reclaiming the floodplain for grazing.
It was believed cutting off the area from the Hunter River would result in a drop in the mosquito population.
Instead, all that happened was the salt water mosquitoes were replaced by a fresh water variety.
Today, about 60 types of mosquitoes have been identified in the Hunter estuary system.
‘‘Just because someone near Hexham Swamp gets bitten doesn’t necessarily mean the mosquito came from the swamp, it could have come from as far away as Kooragang Island or Fullerton Cove,’’ Dr Webb said.
The Hunter-Central Rivers Catchment Authority opened another three of the eight floodgates in September last year.
It is planned to open the final two gates in April this year, which will result in the full inundation of the 700-hectare floodplain.
‘‘We are always going to have mosquitoes in summer,’’ Dr Webb said. ‘‘But their numbers are going to fluctuate depending on changes in environmental conditions.’’