I noticed that my reps had been lowered and when I checked my profile there were several of my answers which had been removed and reps deducted, and so I wonder what policy requires that and why?
Four of your positively scored answers were deleted last night. However, this was due to the question getting deleted, not anything about your answers specifically.
Two things worth mentioning:
If your posts get to +3 and the post is older than 30 days, then the reputation is kept. That wasn't the case in any of these cases (all posts were <3 scored so age is irrelevant).
Answering questions that are likely to get closed/deleted carries the risk that you will lose reputation when they are inevitably deleted. Not only that, your work is wasted because it's not longer generally accessible. Instead of answering these, action them, you have the reputation to vote to close, use it.
Note that this also works in reverse, if you have a net loss of reputation when a post is deleted then you'll regain that reputation.