Evidence suggests aerial surveys of the NSW coastline are an inefficient and expensive way to protect swimmers from sharks, a government report says.
The report into the Shark Meshing (Bather Protection) Program shows less than one shark is spotted for every 100km.
"(This implies) a considerable underestimation of the presence of many of the shark species known to frequent the coastal fringe area," the NSW Department of Primary Industries report said.
"These data corroborate previous survey results suggesting aerial surveys are an inefficient and expensive method to enhance bather protection from potential shark attack."
The report states the results of various studies undertaken over several years raises "serious concerns" about the use of aerial beach patrols as an early warning system for sharks.
A maximum of 100 animal sightings were recorded during 37 flight passes between Stockton and Wollongong, with twice the number of animals being recorded during south-bound flights.
Almost half of the sightings were schools of fish, with just 25 sharks sighted of which 20 were hammerhead sharks.
The study said 38 flights between Seal Rocks and Stockton sighted 102 sharks, the majority of which were juvenile white sharks.
