A creeping “invasion” has been threatening to smother one of Wales’s most popular lakes. Lagarosiphon major, also known as curly waterweed, is an invasive aquatic plant that can rapidly grow and spread - potentially dominating and “smothering” lakes.

It is from South Africa and is so bad that it was put on the EU’s List of Invasive Alien Species in 2016. This means it’s against the law to sell this plant or throw it away in nature.