My blog recently got deindexed from google and I'm hardly getting traffic. But Comment rate is not decreased. Daily I get about 60-70 comments and total visitors per day is 10-20. From where these comments are generated?? Mine is WP blog
Use a spam remover plugin if you do not want spam comments. This one should do the trick. http://wordpress.org/extend/plugins/spam-free-wordpress/
I have a similar problem but I keep deleting the comments, it's okay, right, I mean I don't feel like I need a spam plug-in since all comments are useless...I delete them all. It's a portfolio site I send to employers and employers do not leave comments at all, so I'm good. I think there's an option if you don't want comments, you can close them once and for all.
Agree with flame design. It would be nice if y don't put any comment plug-in to avoid spam. But if you really want to have comments on your blog, use Akismet plug-in to block spam.