The first thing I noticed about the wetlands was the noise (in a good way). While it looks like a quiet, tranquil area from a distance, the once you start walking you'll notice the sounds of various birds and frogs. The wetlands are home to a large number of birds, some migrating from as far away as Japan.
The only thing I'd advise is to keep an eye on younger children around the water. Most of the wetlands are fenced, however there are sections (eg. near the wooden bridge at the Tuckfield end) where the area around the water is unfenced. The Geelong Council website also advises to keep an eye out for snakes during the summer months.