Mark, thanks for that question. I've been trying to navigate how to handle this as I've been preparing for these updates. As I look around at various websites in preservation, credit is given in many different ways.
For example, it can be embedded in the image itself, or might contain a watermark. Some sites prevent right clicking. In terms of best visual presentation, a clean image obviously looks best. If every image on the site were to be loaded with watermarks, or credits it could potentially clutter the visual experience for viewers. There are also some more in-depth suggestions for giving credit in a non-visually cluttering ways here:
https://fieldsgraphicdesign.com/wordpress/how-to-credit-stock-photo-nofollow-link-wordpress/#what-your-photo-credit-should-sayI've also noticed some websites, such as EBT's, simply include a disclaimer on the bottom 'all images property of their respective owners.'
I like your suggestion of a link; Perhaps we could have a 'photographers' page on the website that credits photographers who have contributed to the site, along with a 'hallmark' image of theirs from the WW&F, linked to their site, if they have one.
Additional thoughts are welcome!
Best,
Steve