Environmental values
Sale Common is one of only two remaining freshwater wetlands in the Gippsland Lakes system. It provides sheltered feeding, breeding and resting habitat for a large range of waterbirds, including the Australasian bittern.
Dowd Morass is a large, brackish wetland that regularly supports rookeries of colonial nesting waterbirds including Australian white ibis, straw-necked ibis, little black and little pied cormorants, royal spoonbills and great egrets.
Heart Morass is also a large brackish wetland, with open expanses providing shallow feeding habitat for waterbirds including black swans, Eurasian coots and a variety of ducks.
Together, the lower Latrobe wetlands function as a diverse and complementary ecological system. Colonial nesting waterbirds breed among swamp paperbark trees at Dowd Morass in spring. Migratory shorebirds feed on the mudflats that are exposed as the wetlands draw down and dry over summer. Waterfowl and fish-eating birds use openwater habitat at the wetlands year-round. The wetlands also support threatened vegetation communities including swamp scrub, brackish herbland and aquatic herbland.
Recent conditions
Climatic conditions in the lower Latrobe wetlands’ catchment varied throughout 2019–20. Total rainfall was below average, but there were still some significant rain events that increased river levels throughout winter and spring 2019, particularly from the Latrobe River catchment, and they caused minor overbank flooding in late spring 2019 and again in late autumn 2020. The VEWH’s entitlement for the lower Latrobe wetlands is not limited in volume, and regulator gates may be opened opportunistically based on water height in the Latrobe River at Swing Bridge.
Heart Morass, Dowd Morass and Sale Common were allowed to draw down in 2018–19 to allow the die-off of aquatic vegetation, promote nutrient cycling and allow terrestrial grasses and sedges to establish. Overbank flows in late winter and early spring 2019 partly refilled the wetlands. Environmental water was subsequently delivered as required (and when salinity in the Latrobe River estuary was not too high) to maintain water quality and habitat for aquatic and terrestrial animals, and to support the growth and flowering of semi-aquatic vegetation. Complete and near-complete fills were achieved at Dowd Morass and Heart Morass respectively in 2019–20, and a partial fill was achieved at Sale Common. A flushing flow was delivered to Heart Morass in spring 2019 to export salts and sulfates. Water levels at all wetlands were drawn down partially over summer to expose mudflats, which created feeding opportunities for wading birds and oxygenated soils to promote seed germination. High rainfall in late April and May 2020 caused minor flooding, allowing deliveries of freshwater to the lower Latrobe wetlands again in autumn.
Some water was retained in Dowd Morass and Sale Common to maintain habitat for Australasian bittern and other significant waterbirds that were observed at these sites during summer. Maintaining this habitat will likely be a priority throughout 2020–21.