non-native water plants

[juggler]

We have been talking about non-native fishes in our waters. How irresponsible the owners are to be releasing them etc.

What about non-native water plants? How invasive are they? Any sightings? Any concerns?

I used to think it is not right to put non-native water plants into our waters. But then I look around at all the land plants and trees our National Parks Board have planted. So many of them are not native.

Feel free to share your thoughts. Thanks.

[bclee]

Unless they grow like weeds choking out all other plants, they pose less of a problem compared to animals IMO.

Non-native animals may disrupt the food chain or introduce new diseases to which native species have no defense against(I don't know whether it happens for plants).

Plants being at the bottom of the food chain cause much less of a disruption of the food chain.

BC

[vinz]

Water lilies are not native. Neither are lotuses. We've spotted Blyxa Japonica at Upper Pierce Reservoir. I'm sure Budak and rattle off a whole long list of non-native plants he has spotted.

Non native plants are less of problem because they seldom affect humans directly. Plant diseases are unlikely to cross the gap over to animals (including humans), but the diseases could infect other native species.

Given that we pour our tank water in our sewage/drainage system, I think its probable for plant spores/plantlets to escape into our waterways.

[budak]

Blyxa japonica is actually native (japonica is a misnomer, as the plant is pan-Asian), but in truth, there are few places in Singapore where water plants (native or non-native) thrive, so it's hardly an issue. Some may, however, recall the havoc wrecked by Salvinia (native to South America) in local reservoirs in the 60s and 70s, when these floating ferns spread like wildfire, choking off waterways and costing a bomb to clear. Water hyacinths do similar damage across the world.

On the roadside and even in the middle of reserves, non-native plants already abound (rain trees, Draceanas, mimosas, African tulips, dumbcanes etc). It's probably too late to do much.