Modern urban developments have significantly improved over the years, and now take a holistic approach to the wider surrounds. Wetland creation or rehabilitation is now a crucial component of every residential development, and for good reason. These areas are designed as storm water staging areas which enable less stress to be placed on underground pipes during high flow events, filtration of runoff through the use of filtering plants and engineering filtration, and habitat creation for birds and aquatic life.
These manmade ecosystems function much the same way as natural wetlands, which provide staging and filtering zones at the interface between rivers and the sea. When these natural estuarine systems succumb to anthropogenic influences and inputs they often stop functioning as they should which can have far reaching effects on adjoining ecosystems.
Increased sedimentation, nutrient loading, excessive runoff, invasive plant species, invasive animal species, disruption of natural opening and closing cycles, and blocking of channels, can all have serious repercussions on the health and functionality of the system.
It is possible however to reverse and ‘bring back to life’ wetlands which are highly degraded or altered by human land use and influences. One such example is the Mungalla wetlands on the Far North Queensland Coast in Australia. These wetlands are especially important because of their proximity to the UNESCO World Heritage Great Barrier Reef – both ecosystems have evolved together and coexisted over millennia.
Human impacts primarily from the installation of a sea wall in the 1940s slowly removed the salinity from The Mungalla Wetland. This then lead to the collapse of the native fish and plant species, and subsequently lead to an explosion of invasive vegetation. In 2013 this seawall was removed, fish populations have begun to increase; following exotic vegetation removal native vegetation has begun repopulating the estuarine system.
It is hoped that by improving the approximately 13,000 wetlands along the Queensland Coast specifically within Great Barrier Reef catchments that long term positive results in coral health will correlate to estuarine health.
By Craig Pervan