If I am not mistaken when the user requests to reminder the password (I forgot my password) the system calls to write nick name and email
This is often a problem for many users especially when they have multiple accounts in many sites

Could when requesting the user to reminder the password (I forgot my password), to can put only one of these. or Nick name or the email. not both
It would be easier and will not lose users for thisl reason
It is natural and useful to the password reminder the page to have the CAPTCHA