A new survey shows a growing number of candidates — 22 million in the United States — are finding work using their social networks. Among those networks, Facebook trumped LinkedIn and Twitter, with 48 percent of all job seekers using it to hunt for an employment opportunity in the last year.

Jobvite’s Social Job Seeker Survey 2011 indicated that job seekers are uncovering a lot of ways to interact online, said Anne Murguia, vice president of marketing for Jobvite, a social recruiting platform and sponsor of the survey.

Those online activities include adding their profiles to job applications, doing job searches in their networks, contacting recruiters and potential employers, sharing job opportunities with one another, as well as asking for and giving referrals and career advice.

“They’re using social networks in a lot of diverse and interesting ways,” she said. “As corporate recruiters, we need to keep that in mind as we’re thinking of how we can most effectively engage people there.”

According to the nationwide survey of 1,200 workers, one in six workers reported an online social network led them directly to a job. That’s a total of 22 million workers, up from 14.4 million in 2010.

“People are getting more competitive in terms of their job search activities and more people are tuning in to the fact that the social networks can be a great place to find work,” Murguia said.

Among the big three networks, Facebook comes out on top. Among job seekers, defined for this survey as people either actively or passively looking for their next job, 84 percent have a social media profile on Facebook, followed by Twitter (39 percent) and LinkedIn (35 percent).

Murguia said Facebook’s higher volume is likely due to the higher number of users (800 million-plus, according to recent estimates), rather than a unique job-seeking advantage offered by the network.

While the overall numbers are lower for LinkedIn and Twitter, a higher proportion of job seekers are actively engaged with them as job-seeking and professional networking tools. Eighty-eight percent of LinkedIn users and 71 percent of Twitter users used those sites for job hunting, compared to 63 percent for Facebook.