Yes, but so can a lot of fish tanks. a dehumidifier and fan driven vents are a good investment, especially for basement ponds or in areas that are already humid.
As stated above, I would highly recommend a dehumidifier. They are one of the best investments you make when setting up a pond. The nice thing about them is they do provide some heat as well. You can attach a hose directly to the dehumidifier to discard the collected water down the drain.
You can also use good quality bathroom paint and green board (kitchen and bath sheetrock) to help resist the humididty. If mold is going to occur, it will most likely be in corners or any place that is not well insulated (a real problem in the winter for houses up north).
Condensation can also develop on the windows, this can get messy to...
agreeded i have a chronic cough from a mold in my kitchen due to poor circulation in this room once you have it almost impossible to get rid of well worth the investment to go with the advice stated..
Mold is very unhealthy, I also recommend a dehumidifier. Mold can grow on many differnt substrates including wood, cement, drywall, etc. All of these are commonplace in the home and excess humidity will fuel this problem.