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
20 East Arm 2014 5.3 East Arm A relatively large part of the catchment of East Arm is principally urbanised, and includes the East Arm wharf, marine support services and industrial areas. Treated wastewater discharge to Blessers creek which is in the East Arm reporting area. During the wet season high sediment, nutrient and other pollutant loads are received from urbanised areas. Sediment monitoring has shown there is minor impact from urban land-use, and overall low metal and nutrient concentrations in the sediments (Munksgaard et al. 2013). Figure 7 summarises the results of each water quality parameter measured at the East Arm monitoring sites. Table 7 reports median values and 20th-80th percentiles (compliance), minimum and maximum values of the data measured. Table 7 - Summary of water quality parameters measured in East Arm One water quality parameter (total nitrogen) measured did not comply with the WQOs: Water quality at the East Arm monitoring sites is in very good condition. Dissolved oxygen values were generally lower in upper parts of the area and ypically associated with the immediate area of the discharge point. Similarly nutrients were generally higher in the upper reaches. Indicators Water Quality Objectives East Arm min-max 20th-80th percentiles and (median) pH 6.5-8.5 7.32-8.24 7.7-8 (7.8) Dissolved oxygen (% saturation) 80-100 24.4-113.5 70-92 (81) Suspended solids (mg/L) <10 1.38-46.3 3.8 Chlorophyll a (g/L) <4 0.22-68.4 1.6 No (g/L) <20 3-135 3 Ammonia (g/L) <20 1-333 5 Total nitrogen (g/L) <300 3-2960 350 Total phosphorus (g/L) <30 5-1100 22 Filterable reactive phosphorus (g/L) <10 2-696 6 2014 rating B 20