Around this time each year for about a decade, the U.S. Department of Agriculture has rounded up Canada geese from parks and airports across New Jersey, herded them into pens, and euthanized them with carbon dioxide.

The process has begun again, and it is set to continue through July as the government fights an overabundance of geese up and down the East Coast, responding to complaints about waste, property damage, and aviation safety.

But the program is not without detractors in the animal-rights community.

"What they're doing in New Jersey is totally unnecessary. It's based upon a lack of understanding of wildlife behavior," said David Feld, director of GeesePeace, which helps communities remove the birds using "nonlethal" methods.

Efforts to cull geese this year have received more attention than in the past, especially in New York City. In January, US Airways Flight 1549 had to execute an emergency landing on the Hudson River after being struck by geese.

In response, the city has asked the USDA's Wildlife Services to capture and kill at least 2,000 geese at city parks and sites within five miles of airports, angering protesters who gathered outside the Port Authority of New York and New Jersey on Tuesday.

Priscilla Feral, president of Friends of Animals, which helped organize the protest, called the culling of residential geese in the hope of improving flight safety a "mean-spirited, inane idea." She pointed to a study by Smithsonian scientists that concluded the geese that hit Flight 1549 were migratory.

"We recognize that there can be people who don't agree with it," USDA spokeswoman Carol Bannerman said. "It would be nice if there were somewhere to take the geese to . . . but in New Jersey, especially, there's not a place to put them."

The USDA doubled the geese it removed in the state from 1,000 in 2006 to 2,000 in 2008, Bannerman said. This year, 20 locations in nine counties, including Burlington, Mercer, and Salem, have requested geese removal.

Officials choose this time of year because geese are molting, or shedding their feathers, and cannot fly.

A primary alternative touted by Feld is pouring corn oil on goose eggs, which prevents them from hatching. This process, he argues, is more effective at stopping the population problem at the source and can discourage the goose who laid the egg from returning.

Bannerman said Wildlife Services had treated 2,000 eggs in more than 300 nests in New Jersey. She said that despite this and other tactics, such as discouraging residents from feeding the geese, it was difficult to make them leave the area, citing research that showed geese moved an average of only 21/2 miles in two years.

Feld countered that if more emphasis had been placed on non-lethal methods, the geese would have been gone by now.

"Because they're not doing appropriate management practices, they've got a program where the only answer is killing them," he said. "It gives people a false sense of security and gives them justification for something they wouldn't have to do in the first place."

Though the U.S. Fish and Wildlife Service released a report in 2002 that set a goal of cutting New Jersey's population of 80,000 Canada geese in half, Bannerman said the USDA's job was not to reach that quota but simply to respond to requests from municipalities and landowners.

For this reason, Tori Perry, a senior cruelty caseworker with People for the Ethical Treatment of Animals, said the group had focused on those requesting the geese removal instead of the government. When a PETA member hears about a removal request, the organization calls the landowner to suggest other methods.

"Most people want to be kind, want to be compassionate," Perry said. "They just need to be educated."

Contact staff writer Matthew Spolar at 856-779-3829 or mspolar@phillynews.com.