Other than phytophthora being a water mold and in the same classification (Oomycetes) as aquatic water molds, I have never heard it referred to in connection with ponds, fish or aquatic plants specifically. It is a soil borne organism, therefore terrestrial in nature. Can you be more specific with your question?

I searched "phytophthora ponds" w/Google and got plenty of references to it being found in nursery recirculation ponds and so forth. Maybe what you want to know can be found in such as fashion.

Thanks for your responses. The nursery recirculation I think is what I am refering too for the most part. I knew it was a soil borne disease and I nknew it was considered a water mold, but it wasn't making any sense to me in the reference it was being used. Thanks to you guys and your help I now understand what the statement meant in the right context. Thank you and yes I did find a lot of google info.
Thanks Kelly

Presence of water appears to be the basic requirement, with Phytophthora ramorum (cause of sudden oak death) even traveling in airborne water droplets.