Penrhyn Estuary in Botany Bay provides habitat for migratory birds protected by State and Federal legislation.
The Port Authority implemented rehabilitation and expansion works of Penrhyn Estuary and monitored these works between 2012 and late 2018. This included measuring and report on water quality within the estuary, migratory shorebird numbers, seagrass colonisation, benthic invertebrate concentrations in the estuary substrate and the area and quality of the saltmarsh habitat.