Forum jumps and search engines

Hi all, new person so bear with me,

I've been running webwiz successfully for sometime now, and well, it's great!

Here's my problem

I've just installed a new site level search engine, great too, but it picks up all the topics listed in the forum jumps on the display_forum_threads.asp and display_forum_topics.asp

now this would be fine, except the site is about species of animals, so species searches on the site level search throw up every single topic ever posted..

I can only see one solution, that is to remove the forum jump from these pages, I don't know how to do this, if anyone can tell me or give me another way to hide it from the search engine it would be appreciated - I can't just hide the _forum_threads.asp and _forum_topics.asp as I will also loose relevant hits