AN INVESTIGATION is underway after hundreds of dead fish were found in Penarth Marina.

Officers from Environment Agency Wales and Cardiff Harbour Authority are currently examining the cause of death of approximately 1,000 fish, consisting of Rudd, Roach and Chub.

Fish were also found in the lower reaches of the river Ely and in Cardiff Bay.

Samples of fish were collected on Monday, May 12, and sent to the Environment Agency National Fisheries Laboratory.

Lesions were present on almost all those submitted, an indication of bacterial infection, and post mortem examinations are continuing.

John Harrison, Environment Manager for the Taff and Ely area, said: "As soon as we know the cause we will be better placed to decide what measures we can take to reduce further impacts.

"People are urged not to touch or take away any of the dead fish."

Bacterial lesions are a common feature of spawning stress in Roach.

The examined fish were in spawning condition, and the extent of the mortality suggests that normal spawning stress may have been compounded by other factors, such as fluctuations in dissolved oxygen.

Environment Agency Wales could not rule out the involvement of a fish disease, but said the results of additional tests will be announced as soon as they are available.

Officials did say that average pH at the site close to the mortality has increased over the past month.

Recent increases in temperatures are also likely to have been a contributory factor.

Agency Officers say they will continue to work closely with Cardiff Harbour Authority and Cardiff Council's Environmental Health team to establish the primary cause and manage the clean-up and disposal of the affected fish.

*Anyone wishing to report dead fish can contact Environment Agency Wales in confidence on: 0800 80 70 60