Penalized by duplicate content?

[Tz_Seo]

Hello,

I am in a very weird position. I am managing a website(EMD) which a part of it dynamically creates pages. The former webmaster who create this system though that this would help with SEO but I dought!

The thing is that now the site has about 1500 pages which must look duplicate but are they really duplicate? Each page has a unique URL but the content is pretty much the same: one image and a different title with 5-8 words.

There is more: All these pages are not accessible by the users but only for the crawlers!!! This URL machine is a part of a php - made photo gallery which i never understood the sense of it!

The site overall is not performing very well in SERP, especially after Penguin, but judging by the link profile, the Domain authority, construction (ok besides that crazy photo gallery) and content, it never reached the position it should have in the past.

The majority of these mysterious pages - and mostly their images - are cached by Google and some of them are in top places to some SERP - the ones that match the small title on page - but  the numbers are poor, 10 - 15 clicks per month.

Are these pages considered as duplicated, although they are cached, and is it safe for the site just to remove 1500 at once?

The seomoz tools have pointed some of them as dups but the majority not!

Can these pages impact the image of the whole site in search engines?( drop in Google and has disappeared from Yahoo and Bing!)

Do I also have to tell Google about the removal?

I have not seen anything like it before so any comment would be helpful!

Thank you!

[Tz_Seo]

Mat,

There was a massive production of pages in the mid October 2011 and there was a drop in traffic around November - there was a panda update then.

The problem is that for that the certain niche there is always a small drop for the site concerning Oct, Nov and Dec so it is not so clear to judge!

[matbennett]

Hard to say without knowing the detail of what is on the pages. However it sounds like a perfect set-up for a site to be hit my the Panda updates to me. This is exactly what Panda was built for!

It could be worth checking your traffic levels alongside the dates on this page for a good idea of what changes have already impacted on your site: http://www.seomoz.org/google-algorithm-change  (I like to put those dates in as events on Google Analytics).  However, even if you haven't yet been hit by this I'd suggest you are risking it.

If you have a lot of "thin content" pages then this can impact on the whole site. Generated pages are probably the quickest way to hit such problems.

You don't need to inform google that you have removed them.  Just remove the pages and be sure that it either returns a 404 error or does a 301 redirect to the most logical (not thin) page.