As well as impacting our lives, it comes with no surprise that our aquatic wildlife is heavily affected by their presence. Growing up to 20cm a day(in prime conditions), the dense rafts not only take up a large amount of space but they shade out the most vital energy source – the Sun – leading to:
- Reduction in the chance of photosynthesis by plants in and around water
- Reduction of oxygen in water, negatively affecting fish, plants and invertebrates such as dragonflies that need a good quality source of water to breath as well as survive.
It gets worse for the fish as the excessive growth blocks the waterway and smothers the water in silt, leaving the fish in river gridlock and the latter destroying their spawning habitats – truly a fish’ and fisherman’s nightmare!
It doesn’t stop there. Once winter arrives, the pennyworts die and decompose en masse, adding excessive nutrients, or eutrophication, into the river, snuffing out oxygen to create an inhospitable swamp – except for the floating pennyworts (and algae) that is.