Bramble Bay is the most environmentally degraded part of Moreton Bay.[1] Because the bay is so close to the urban populations of Brisbane and Redcliffe the collection of shelled marine animals such as oysters, scallops and limpets is banned.[2] Fishing within bay's closed waters, risks on the spot fines at all times under Queensland's closed water fishing regulations.[2]
Bramble Bay flows into Hays Inlet to the north-west, and Pine River flows into Bramble Bay to the south-west. Some definitions place the mouth of the Brisbane River and the Boondall Wetlands in Bramble Bay.[1] This would also place the mouths of a number of smaller creeks south of Shorncliffe, including Cabbage Tree Creek (formerly Tighgum Creek), Nundah Creek and Kedron Brook, within the Bramble Bay catchment.[3]
Water quality
Both rivers flowing into Bramble Bay carry high loads of nutrients and suspended sediments.[1] Water in the bay is very turbid. At times two sewerage plumes from the rivers are visible in Bramble Bay.[1] The residence time for Bramble Bay, that is, the period of time that a parcel of water remains at a particular location, is 59 to 62 days, the longest for any part of Moreton Bay.[1]
In 2009, the annual Healthy Waterways Partnership Report Card rated Bramble Bay an F from a previous C.[4] The rating deteriorated because of an increase in phytoplankton and nitrogen concentrations, as well as decreases in water clarity and salinity.[5]
During the past the bay contained large areas of seagrass which attracted feeding dugongs, however there are no seagrass beds in the bay today.[1] This is due to a lack of sunlight reaching the seabed.[6]
