Country diary: Dragonflies and trout thrive in the quiet of the river

‘Trees in full, dark summer leaf block out much of the remaining glare, shading the banks.’ Photograph: John Gilbey

The worst of the heat has slipped away into the east, and a wind from the sea is starting to cool the stone of the harbour walls. It is just after low water, and the streamers of seaweed below me are beginning to turn upstream with the flow of the tide.

I follow their lead, crossing the harbour on the wooden footbridge and taking the path inland on the southern side of the Afon Aeron. New, bright thistle flowers erupt from the old stone wall that guards the stream, the stems describing narrow arcs in the breeze. The tidal limit is quickly reached, and even for high summer the level of the river is low. Angular lines of dipping rock strata that form the river bed hold back narrow pools of water, which overflow without vigour at the lowest points.