Almost all the large shorebird roosts on the southern end of the Great Sandy Strait occur where there are large areas of salt marsh. The exceptions are the roosts out on sand banks in the middle of the Strait and most of these are underwater at the very high tides.
Salt marshes are areas of very low land in the intertidal areas. They are covered with salt tolerant plants and areas of open salt pan. Mangroves often fringe the area further out towards the sea. Wallum vegetation grows where the dry land starts. Salt marshes are covered partially or wholly by water on every tide. When the tide is out the sun shines directly onto the plants and dries everything out. This image showing tidal flows over saltmarsh is from the wikipedia page http://en.wikipedia.org/wiki/Salt_marsh
These extremes of water and temperature have produced a very special and fragile environment. When the plants are putting on new growth they are often bright green but the usual colors are red and brown. The whole area can look very dry and burnt. However, when the tide comes in it looks quite different.
Looking across the Mullens roost site at Cooloola Cove. The foreground shows tracks made by 4wheel drive vehicles - one of the biggest threats to this environment in our area. (Click on images to enlarge them.)
This is part of the same roost site but with the tide in. The water is only a few centimeters deep but enough to cover most of the plants.
An area of salt marsh when the tide was not very high - Red-necked Stints and Red-capped Plovers in the front, Gull-billed Terns behind, and Eastern Curlews in the back.
Red-necked Stints hunting for food among the plants and pools of water.
Salt marsh plants growing with smaller mangroves provide excellent cover for a Pacific Golden Plover