Too much duckweed

How Balyang sanctuary used to look before the drought and today's covering of duckweed. from w
At Balyang Sanctuary I was wondering what was the massive amounts of plant-life on the surface of the water - one whole pond covered in pink, the others almost choking in green. An internet search came up with duckweed, some pink, some green.Okay, it's rather obvious isn't it, when the place has many little ducks enjoying the water after the drought.Do ducks eat duck-weed I wonder. Earlier I had rung Parks and Gardens to ask the name of this 'weed' but no-one knowledgable was there - everyone on holidays - or perhaps watching the young men in lycra riding up and down dales and through the streets of Geelong. It's on TV all day today and fun to guess just where/which road is in view. Don't care about the bikes, just the location which is still being advertised as 'Melbourne'.