The study, published in the U.S.-based
Wilderness Medical Society journal, found that fatal attacks had remained roughly stable at about two per year since the 1970s.
"But the number of nonfatal attacks has increased markedly," Manolis said.
Nonfatal attacks increased sharply from about 0.1 per year between 1971 and 1980 to 3.3 per year from 2001 to 2004, according to the study.
The research found that most attacks (81 percent) occurred while the victim was swimming or wading and that all fatal attacks involved water.
Manolis said the dramatic increase in the saltwater crocodile population since the species was protected in the early 1970s was not necessarily responsible for the increase in attacks.
The number of wild "salties" estimated to live in the Northern Territory has jumped from as few as 3,000 in 1971 to more than 75,000 currently.
But he said because the average size of crocodiles had increased over that time, the animals attacking humans had often changed from a small "hatchling" to a four-meter (13-foot) giant weighing hundreds of pounds.
Last month a man was killed by a five-meter (16.5-foot) crocodile while diving near Darwin, five days after a British snorkeler was taken and killed by a croc.
But Manolis does not think culling is the answer.
Name: Saltwater Crocodile, aka Estuarine Crocodile (
Crocodylus porosus)
Primary Classification: Crocodilia (Crocodiles and Alligators)
Location: Southeast Asia and northern Australia.
Habitat: River mouths, lakes, estuaries and shallow coastal waters, especially near mangrove swamps.
Diet: A wide variety of animals, including fish, turtles, mud crabs, snakes, shore and wading birds, buffalo, domestic livestock, wild boars and monkeys.
Size: Up to 23 ft in length and 1 ton in weight.
Description: Gray, brown, black or dark olive in color; white or yellow belly; large head; fairly long, broad snout with deep pores; heavy-set jaw with up to 68 teeth; large, oval, plate-like scales; webbed hind feet; powerful, striped tail with two keels.
Cool Facts: It is the largest reptile in the world, and perhaps the most dangerous. Along with the alligator, it is responsible for more human fatalities per year than any other predator on Earth. Its eyes and nostrils are located on top of its head, which allows it to see and hear prey while partially submerged.
Conservation Status: Common