In recent years the Pool came under attack by the invasive weed Crassula helmsii.
Crassula helmsii | Crassula tetragona | Crassula ovata | Crassula muscosa |
In the UK the non-native species Crassula helmsii and Myriophyllum aquaticum, which cause considerable practical problems in protecting freshwaters, are both escaped invasive species from garden ponds.