Frogs in Pond

Observation - Frogs in Pond. Description: Our pond is very clean, but today there was an oily scum at one end. The frogs arrived last week. Is the scum associated with the frogs, if so what causes it? If not is it harmful to them and what should I do about it?

Our pond is very clean, but today there was an oily scum at one end. The frogs arrived last week. Is the scum associated with the frogs, if so what causes it? If not is it harmful to them and what should I do about it?