Thank you so much for your response Patrick.

We have no manual actions on the main website and our MOZ spam score is 2/17. Our main website is full of original, good-quality content and we have been very careful to avoid any black hat seo strategies. We have had a professional seo expert audit our site and their feedback has been positive. In short, it seems like we have been doing everything right. We are mindful that the website might be affected by the current market for our industry, but have seen a very noticeable decline in our stats that seem to go beyond the usual market fluctuation backlash.

It is the two subdomains (e-commerce sites) that have duplicate content issues. I probably should have mentioned earlier that the decline coincided with the launch of the subdomains.

Keeping in mind that I am open to the possibility the cause of the decline could be isolated within the main website itself, I nevertheless would like to know if it is possible that subdomains can affect a root domain?

Thanks again for your detailed response - really appreciate it.

Amy