Holocene coastal paleo-environments of Western Victoria

Microfossils for mid to late Holocene sediments present within the Kelly’s Swamp wetlands have been used to infer temporal landscape change. The abundance of freshwater ostracods and coastal foraminifera within a perched peat sample dated to have formed approximately 1,875 years BP, suggest the Kelly’s Swamp wetlands was once a freshwater coastal lagoon. The microfossils collected from younger sediments, dated to approximately 1,800 to 1,600 years ago, indicate that there was a shift into a swampier and more brackish aquatic environment. The youngest surface (soil) sediment layer in this region reflects drainage works since European settlement, which transformed these wetlands into pasture for agricultural purposes. The dominance of the benthic foraminifera, Ammonia beccarii within all the sediment samples, alongside the general low abundance of ostracod microfossils suggests that pre-European settlement swamp environments in this region experienced dominantly dysoxic (low oxygen) aquatic conditions.