My thanks to Kat at the EA for updating the Friends on this week’s talk of water quality on the Rivers Shuttle & Cray MH FFCM
On Monday (21/06/21) we were made aware of a fish kill involving several hundred dead fish on the River Shuttle at Bexley Woods. Our Water Quality and Fisheries Officers visited later that morning to investigate. Although there were no obvious signs of pollution present we noted a general discolouration and a recent deposit of silt. Thames Water, who operate the sewerage system, along with their contractors also attended. No issues could be found with the river water nor the nearby sewer network. Unfortunately the source and cause of the fish kill still remains unknown. We are having lab analysis carried out on the river water and the investigation remains open. Whatever caused the fish mortality, is likely to have been flushed downstream and diluted. The remaining fish carcasses will decompose naturally without having a negative impact on water quality.
We have received separate reports of fish in distress on the River Cray near Foots Cray Meadow. This was also attended and water quality readings suggested this was the result of a possible algae bloom and is not related to the River Shuttle incident.
Rivers receive water from many different sources including road and yard drainage. Unknown pollutants may enter drainage networks which flow into local watercourses any time but especially in urban catchments following rainfall. Natural waters can also contain strains of blue-green algae, which can be toxic to humans and animals. We carry out bacteriological testing at designated bathing waters to inform swimmers of risk but not in this area. We are therefore not in a position to comment on whether a watercourse is safe to enter for either humans or their pets.
If you have any further concerns regarding health and safety, we would advise contacting the Environmental Health Team at your local authority who is best placed to deal with these sorts of queries.
Likewise, if you do observe any pollution, please report this through to our incident hotline on 0800 80 70 60.
Katherine Tye | Fisheries Technical Officer
FBG North | Kent and South London