Over 500 fish have died in the moat around Nunney Castle as a result of fungicide pollution, an investigation by the Environment Agency has established.
Lots of people noticed dead fish in the moat on Friday 10 November and over the subsequent weekend. Within a week more than 250 fish – mainly roach – had died.
Parish Councillor Ron Warwick lives near the castle. He contacted the Rivers Authority and English Heritage, who sent someone down to investigate on Tuesday 14 November.
The Environment Agency declared it a major incident and put up signs warning visitors to the castle not to go near the water – and seek medical help if they do.
The Environment Agency also measured the oxygen levels in the moat, which were fine. No ammonia was detected either.
Flowering algae can also have a detrimental effect on the oxygen levels, but this was not found to be a problem either.
Eventually it was established that a fungicide pollution had most likely caused the mass deaths. The Environment Agency has arranged for the dead fish and weeds to be cleared from the moat.
Further tests continue on both the moat and the Nunney Brook to establish the source of the pollution.
In an update on 24 November, the Environment Agency reported that there was evidence of pollution beyong the moat as yet.