This is Ian Sanders who is studying the breakdown of organic sediments in the Frome - at least that is what I think he is doing - he promised to let me have more information soon.

He told me that the River Water Crowfoot (Ranunculus fluitans) acts a a sort of compost heap and if there is too much organic matter then ammonia can be produced which poisons young trout. There has, apparently, been a reduction in the trout population over the last 20 years.

The experiment will continue for several more months with Ian visiting the Frome the first week of each month.

A typical bed of River Water Crowfoot. The white flowers cannot be seen here though they form quite a dense mat further upstream.