Globally bacterial contamination of recreational waters is an issue in most major population centres so monitoring levels of bacteria and establishing the source is often required to tell the story.
If we understand the source of bacteria found in recreational waters, resources can be appropriately channelled to resolve or reduce the pollutant. Conservation and restoration of estuaries and recreational water use, needs programs that can assess condition and report on change.
In 2017 TEER tested and trialled a method to detect the major sources of bacteria (enterococci) in the Upper Tamar estuary which tested surface water samples collected monthly. During 2017 we were able to identify bacteria from livestock (sheep and cattle), horses, dogs, birds, stormwater and humans (sewage treatment plants and septic tank systems).
We found that the bacteria formed 2 groups, one group at the very upper limits of the estuary (Kings bridge to Riverside) and the second group moving downstream into the broader parts of the river (Tamar Island to Blackwall). The upper group of bacteria were slightly more dominated by human sources (sewage treatment plants and stormwater) than livestock (sheep, cattle or horses), while the downstream group tended to be more dominated by livestock than humans. We continue to refine these results in 2018.