BBpress registration page is attracting a lot of Spam registration

Hi Team ,

I am doing a soft launch for a job portal come forum site - http://www.jumpingladder.com . There is a separate registration for the job portal for both employees and candidates . This automatically adds the user in the forums too. But over the last few days I have seen spammers use the bb press register page and getting into the system. I need to stop them.

Please advise which plugins to use , I tried Stop Spammers and its not really doing anything.

Hoping for a solution.