SALT water seeping into a Southend lake through broken valves caused the death of hundreds of eels and carp, an investigation has revealed.

Dead wildlife was spotted floating on the surface of the lake in Southchurch Park East in August, with residents initially fearing it was a sign of a lack of maintenance.

However, an investigation led by Southend Council and Anglian Water has discovered that salt water from the Thames Estuary was leaking into the lake at high tide due to three broken valves in a drainage pipe.

Carp are freshwater fish have very high sensitivity to salt water, which caused the unusual mass deaths. A temporary fix has now been put in place before new valves are installed.

Southend Labour councillor responsible for environment and leisure, Lydia Hyde, said: “It was the salt water that killed off the carp, we did some more investigation and put cameras in the pipe to find that there were three valves used to stop seawater coming into the lake.

“All three had been damaged and in the meantime, there is a temporary measure, much like a balloon that bungs up the pipe and acts as a temporary fix.

“We proved it was salt water and did the fix, to find that all three valves has effectively failed.”

Ms Hyde noted that the fix is temporary while new replacement valves are installed to put an end to the problem.

She added: “We get issues with fish deaths and eel deaths, the lake is quite shallow but what was weird this year was the hundreds of carp all dead from salt water.

“Now we have found out what is going on it will keep these as freshwater lakes.”

Southend environmentalist, Julie Callow, accepts the end of the grim period for the lake but believes the fix comes due to the noise generated by campaigners.

She said: “If they are doing anything now, it is because I have kicked up a stink and Southend against Sewage also kicked up a stink.

“We have had enough and they can’t keep on ignoring these issues. Neighbours were complaining as they were not doing their job.”