Registration Form Fix Requested

My site (www.whatihadfordinnertonight.com) has been flooded with spam registrations. I installed a captcha plugin to try and eliminate bots, but I was still getting dozens of fake registrations per day. What caught my eye was that some had email addresses and some didn’t. I finally went and tried my registration page myself, and it turns out, all one needs to enter is a username… one can skip the email and captcha boxes entirely and send the form, creating a new user in my database.

Since I also have the spam matching plugin installed, I would really like for the form to be required to be fully filled out before it can be submitted so that email addresses to be captured and matched against it before allowing registrations, and rejected if they are spam. And, the ones that don’t fill out an email won’t be allowed to register at all.

This is something that has started over the past several months, and wasn’t a problem before September or so. Can anyone help, please? Thanks in advance.