I Always Get These When I Photograph Water Streams

The photo below shows a stream of water from one of the fountains in front of the New York Public Library main branch at 42nd Street. We see many little circular shapes in the stream of water. What is very strange is that I always get such shapes in each session when I photograph little streams of water, which I usually do at home by photographing falling water drops.  Various anomalies such as striped orbs, orb crescents, face-like details and orb holes appear on and off, unpredictably, when I photograph streams of water. But in every session in which I photograph water streams or falling water drops, I always get a great number of circular shapes as we can see in this photo. I would be curious to learn of the experiences of other photographers in this regard.  Is there anyone out there who never gets such an effect when photographing with a flash small streams of water or falling water drops?

Below is a closeup of the right part of this photo: