Baseline ecological studies, Lauderdale Quay

Estuarine ecology, wader ecology and water quality baseline field studies as part of the Integrated Impact Statement (IIS) for the Lauderdale Quay proposal in Ralphs Bay

Lauderdale Quay is a proposed waterfront housing and marina development situated in Ralphs Bay, southern Tasmania, and includes 477 residential allotments, 3 commercial lots and a marina with capacity to accommodate 120-140 vessels. The proposal involves dredging and construction of islands and waterways encompassing 86 ha of intertidal sandflat and 61 ha of subtidal habitat. Aquenal was commissioned to conduct estuarine ecology, wader ecology and water quality baseline surveys to compile data on ecological values and environmental issues for the site.

Baseline ecological studies, Lauderdale QuaysBaseline ecological studies, Lauderdale QuaysBaseline ecological studies, Lauderdale Quays

The estuarine ecology baseline study included detailed surveys of the endangered spotted handfish Brachionichthys hirsutus and its habitats, other threatened and protected species, native communities and habitats, and marine pests. Water quality monitoring involved a year-long program of fortnightly surveys of a range of physico-chemical parameters, as well as additional surveying of water turbidity under high wind conditions and stormwater inputs during rainfall events.

The wader ecology component involved a suite of studies at Lauderdale and surrounding sandflat sites in southern Tasmania that have potential ecological links via wader movements. Patterns of diurnal and nocturnal utilisation, nesting habitats, foraging ecology and habitat carrying capacity were investigated. The carrying capacity assessment focused on the dominant resident species, the Pied Oystercatcher Haemotopus longirostris, and utilised an innovative modeling approach to estimate numbers of birds that could be supported by areas of sandflat on the basis of foraging resources. Data input to the model related to foraging behaviour, available invertebrate food resources, sandflat exposure times, and additional wader and environmental parameters. The Lauderdale Quay study represents the first known application of this modeling approach in Australia, and provides a new benchmark for environmental assessment of wader habitats.