Foam patterns

The River Skell flows through the Fountains Abbey and Studley Royal estate, entering at the Abbey end (where it was once important to the monastic community as a source of power and food). It is transformed in the middle section into the formal ponds and lakes of the 18th century water gardens, before being released back as nothing more than a stream, which then flows towards Ripon, joining the River Laver before being subsumed into the River Ure. Despite the ongoing rainfall of the last few months, the stream was little more than a trickle, before drying up more or less completely (perhaps flowing underground?) At the final pool, a large amount of foam had formed (perhaps agricultural run-off?) and swirled into patterns that I found quite photogenic.