Fears for river derwent fish
After 18 months of waiting, anglers have expressed relief that the clean-up on the Stoke Brook and River Derwent has at last begun. However, concerns still remain about the long-term effects of heavy metals which have now entered the food chain, despite the Environment Agency's (EA) claims to the contrary.
In a press release issued on the 16th June 2008, the EA stated that Food Standards Agency (FSA) tests on Derwent fish samples showed no impact of heavy metals on the river's food chain. However, the EA's own surveys, which have now been obtained by the Anglers' Conservation Association (ACA), show that lead, cadmium and zinc levels in aquatic plants in the Stoke Brook - which took the brunt of the pollution - have risen significantly compared to reference sites.
Far from suggesting that the heavy metals are not a problem, the Agency's tests support an independent expert's report commissioned by the ACA, which demonstrates that high levels of heavy metals have spread to aquatic insects.
The EA has also revealed that the FSA - which did the testing on fish from the Derwent - discarded samples taken in February 2008 because the tissues had been contaminated by high levels of lead in the fish intestines during analysis.
Some of the fish sampled in the most recent tests are thought to be trout taken from the river just days after restocking had been carried out and were therefore unlikely to be contaminated. This raises serious doubts over the validity of the tests carried out by the FSA on the Agency's behalf and adds to the concerns of the anglers.
This problem would have been greatly reduced if the EA had used its powers to start the removal of silt by last winter, as recommended by the polluter's own consultants. Anglers are now asking if the EA's determination to quash reports of heavy metal build-ups might be related to this delay.
ACA Executive Director Mark Lloyd said: "The ACA is very concerned that the Environment Agency appears to be doing its very best to persuade people that there is no transfer of heavy metals into the food chain when its own data, and those gathered by respected independent experts, all point to the fact that lead, cadmium and zinc are accumulating in plants and spreading to invertebrates. The only reason we don't know for sure about levels of these toxins in fish is that the Agency's fish sampling has been sporadic, has involved small samples and in one case the results were discarded."
"The risks from the metal levels in insects eaten by fish - lead in particular - remain until remediation is complete. Detailed fish tissue analysis of metals by the Environment Agency needs to be on-going," commented Dr Nick Everall, the independent aquatic eco-toxicologist who produced the report into heavy metals in invertebrates in the Derwent.
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