Thames salmon return could be down to improved water quality

The return of salmon to the River Thames in London could be down to improvements in water quality and not restocking efforts, it has been claimed.

According to new research published in the journal Biological Conservation, habitat restoration and the steady improvement of water quality could be far more important than simply introducing exogenous species to rivers that have seen a drop in fish populations.

The researchers behind the study, from the University of Exeter, claimed that while the re-introduction of fish is the quickest way to replenish ecosystems it may not be the most effective.

Dr Jamie Stevens, co-author of the study, said: "Perhaps our paper shows that if your yardstick for showing recovery is the presence of Atlantic salmon then the best way to ensure that is to make sure that you get the environment right."

Recently, the Environment Agency pointed out the ten biggest threats to water quality in the UK's lakes and rivers include non-native shrimp and water primrose.

Posted by Lauren Steadman