Why yes there is skuttle!
First, go to your User Control Panels
(user cp), then click on Edit Options
. The 6th field down allows you to choose Email Notification
, click NO.
You can then click on this link to remove all of your subscribed threads:
(You can also find it on the first page of the USER CP entitled "view all subscribed threads", from there you would be shown the threads and the above link to unsubscribe.)