Darwin Harbour in good health
Westra Van Holthe, Willem
Country Liberals
Media Releases for 12th Assembly 2012 - 2016; Media Releases; ParliamentNT
2015-03-04
Darwin
Made available by via the Publications (Legal Deposit) Act 2004 (NT)
English
Oceans; Marine life
Northern Territory Government
application/pdf
Issued as a Media Release
Northern Territory Government
https://hdl.handle.net/10070/254788
https://hdl.handle.net/10070/528215
https://hdl.handle.net/10070/528211; https://hdl.handle.net/10070/528213
34 Shoal Bay 2014 5.7 Shoal Bay The area is a shallow embayment with a number of sandbars along the coastal fringe and entrance to tidal creeks. Shoal Bay receives sediments and nutrient loads from the Howard River catchment during the wet season. A number of smaller mangrovelined creeks flow to Shoal Bay, these include King, Mickett and Buffalo Creeks. Figure 10 summarises the results of water quality parameters measured at the Shoal Bay monitoring sites. Table 11 reports median values and 20th-80th percentiles (compliance), minimum and maximum values of the data measured. Table 11 - Summary of water quality parameters measured in Shoal Bay One water quality parameter (dissolved oxygen) measured did not comply with the WQOs: Water quality at the Shoal Bay monitoring sites is in very good condition. Dissolved oxygen (DO) can fluctuate widely over short temporal scales particularly with changing tides. Elevations above guidelines can be associated with the natural variation observed in the region. Revision of water quality objectives is needed to better accommodate this natural variation. Sometimes elevated DO can be associated with high algal biomass (Chlorophyll-a). Indicators Water Quality Objectives Shoal Bay min-max 20th-80th percentiles and (median) pH 7.0-8.5 7.6-8.2 7.8- 7.9 (7.8) Dissolved oxygen (% saturation) 80100 97.1-129 100-119 (107) Suspended solids (mg/L) <10 0.4-26.8 1.23 Chlorophyll a (g/L) <1 0.1-11.5 0.2 No (g/L) <10 8-26 12 Ammonia (g/L) <20 2-10 4 Total nitrogen (g/L) <440 90-370 140 Total phosphorus (g/L) <20 5-47 5 Filterable reactive phosphorus (g/L) <10 1-11 2 2014 rating B 34