Appendix G. an Overview of Programs Across the Northern Territory (NT) for Monitoring

Appendix G. An overview of programs across the Northern Territory (NT) for monitoring, assessing and reporting estuarine condition.

Condition element / What monitoring/assessment is undertaken or planned? / Thresholds for ascertaining element status and/or invoking management response? / How is monitoring data summarised and reported? / Comments/References /
Pressures/threats/
vulnerability / No explicit monitoring and reporting of pressures. / NA / NA
Water chemistry / Little to no regular monitoring of water quality (WQ) in estuaries across much of NT, though recent baseline condition assessments across the ‘Top End’ have included WQ in estuarine reaches.
WQ monitored regularly throughout Darwin Harbour since 2008. 151 sites in Darwin Harbour estuary monitored during 2012; includes quarterly measurement of a range of parameters (e.g. dissolved oxygen (DO), total suspended solids (TSS), chlorophyll-a (chl-a) and various nutrients) across selected sites in wet and dry seasons. / Monitoring data for four indicators (TSS, DO, chl-a and nutrients, i.e. NOx, NH3, total nitrogen (TN), total phosphorus (TP), filterable reactive phosphorus (FRP)) from Darwin Harbour are compared to local water quality objectives (WQO), which account for natural spatial variability among harbour regions.
Data indicate compliance when the median value for an indicator is less than the relevant WQO (or when DO saturation is 80-100%).
Exceedance of WQO invokes an investigation of the underlying cause(s).
Refinement of scoring and underlying WQOs has enhanced ability of grades to distinguish between naturally occurring variability and human impacts on WQ; grading system is statistically defensible, relevant to management and easily understood by the public (DLRM, 2012). / Darwin Harbour WQ summarised as annual Report Cards since 2009.
Reporting and mapping of WQ monitoring outputs for the four key indicators, across multiple regions of the Inner Harbour, Outer Harbour and Tidal creeks.
Water quality grades (A‒E) assigned for each region based on number of WQ indicators meeting desired WQO.
Report cards clearly communicate the key monitoring outputs to the community. An accompanying supplement provides supporting technical information and a more detailed analysis of WQ, including pH, temperature and salinity (Maraud, 2013; Fortune, 2014). / DLRM (2012, 2013, 2014).
Maraud (2013).
Forune (2015).
Department of Land Resource Management (DLRM) now annually collates results from a range of monitoring programs it conducts, as well as those of other government agencies and the private sector, to report on the overall health of Darwin Harbour.
Phytoplankton / Chl-a monitored in conjunction with WQ across selected sites in Darwin Harbour.
Phytoplankton samples collected monthly, June 2010 ‒June 2012, from four sites in the Elizabeth River Estuary (East Arm of Darwin Harbour); provide reference data for assessment of any future impacts on WQ. / Chl-a data evaluated for compliance with local WQOs, as above. / Technical report.
Narrative description of survey results and/or future monitoring plans may accompany Report Cards (e.g. Drewry et al., 2010; Fortune and Drewry, 2011; DLRM, 2013, 2014). / Dostine (2013).
Survey results indicate that intensive, annual monitoring of phytoplankton composition is not required for Darwin Harbour but should be considered at estuarine sites vulnerable to water pollution, e.g. in the upper estuaries.
Sediment / No current monitoring programs.
Darwin Harbour baseline sediment survey, July-December 2012; c. 300 surface sediment samples from intertidal flats and two tidal creeks were analysed for metals/metalloids and nutrients. / Survey aimed to provide comprehensive reference data and assist in the development of sediment quality guidelines for the estuary
Comparison of sediment metal/metalloid levels with ANZECC and ARMCANZ (2000a) guidelines; four samples exceeded the high-level arsenic guideline, above which toxicity effects are possible. / As for phytoplankton. / Munksgaard et al. (2013).
Survey identified significant contributions of urban metals/metalloid sources to harbour sediments along its developed eastern side.
Currently unclear how the baseline data from the survey will be built into a future monitoring program.
Habitats and SAV / No current monitoring programs.
Extensive benthic habitat mapping surveys of Darwin Harbour conducted in recent years; aim to support the EIA process and inform the design of future monitoring programs. / N/A
Benthic habitat surveys will provide baseline data for assessing future trends. / Reports on benthic habitat surveys available to the public from 2014.
As above. / Smit et al. (2012).
Currently unclear how the baseline data from these surveys will be built into a future monitoring program, though funding has been secured for a further 4 years of mapping in Darwin Harbour and Bynoe Harbour.
Seagrass Watch community monitoring program, commenced in 2011, aims to measure and track the condition of seagrass meadows in Darwin Harbour. / N/A / As above. / Smit (2011)
Unclear how data from this monitoring are being used to inform management.
Detailed survey of Darwin Harbour mangroves in 1994 (Brocklehurst and Edmeades, 1996). Darwin Harbour Mangrove Monitoring Program; network of 27 undisturbed monitoring sites along 7 transects throughout Darwin Harbour; measurements of species diversity, abundance and community composition, tree health, environmental parameters (e.g. soil salinity, pH & moisture). / Mangrove Monitoring Program provided a baseline of mangrove community condition within Darwin Harbour, and aimed to establish a monitoring framework and standard method for future monitoring. / Darwin Harbour Mangrove Survey (1994) produced a detailed map and inventory of mangrove communities.
Data from the Darwin Harbour Mangrove Monitoring Program was reported via annual reports / Moritz-Zimmerman et al. (2002)
NT Government (2002)
Emphasis on community based mangrove monitoring programs up until 2000. Mangrove monitoring is currently under review, with intentions to develop a long term monitoring program for Darwin Harbour.
Fauna / Extensive fish surveys are informing the design of a fish monitoring program for Darwin Harbour; Baited Remote Underwater Video Surveys (BRUVS) at 14 sites across diverse habitats, plus surveys in mangrove creeks and other fish habitats with poor visibility (Gomelyuk, 2012). / N/A – baseline surveys close to completion. / As for phytoplankton. / Comparable monitoring of fish communities in Bynoe Harbour provides a ‘control’ against which to assess future impacts of recent, major infrastructure projects in Darwin Harbour.
Fisheries continue to undertake BRUVS with a focus on recreational species.
Repeated surveys of estuarine fish fauna have been conducted across numerous rivers of the Kakadu region and other parts of the Top End. These have typically sampled using beam trawls, supplemented by other methods. / N/A – scientific studies not targeted toward management actions. / Technical reports and scientific publications (e.g. Larson, 2002). / Data could provide baseline/reference for future development of broad-scale and long-term monitoring programs.
Dolphin surveys, instigated in 2007, monitor changes in dolphin numbers and distribution; expanded in 2011 to include Bynoe Harbour. / N/A – Unclear how dolphin survey results relate more broadly to estuary condition. / As above. / Griffiths and Palmer (2011).
Palmer (2012).
Funding for a further 5 years of dolphin monitoring has been secured under a recent offset agreement.
Other:
Bioaccumulation / Ongoing (limited) assessments of pollutant bioaccumulation in shellfish, water and sediments of Darwin Harbour; includes metals, toxicants and endocrine disrupting chemicals. / N/A / As above. / Drewry et al. (2010).
Padovan et al. (2011).
Aquatic pests / Monthly monitoring for aquatic pests undertaken at numerous sites in Darwin Harbour (DLRM, 2013). / Presence/absence of pest species. / As above. / Darwin Harbour currently is free of marine pests (DLRM, 2013).
Corals / Limited baseline survey and initial mapping undertaken for Darwin Harbour. Currently no program of monitoring. / N/A / As above. / Griffiths and Smit (2011).

References

ANZECC, ARMCANZ, 2000. National Water Quality Management Strategy: Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Environment and Conservation Council, and Agriculture and Resource Management Council of Australia and New Zealand. Commonwealth Government, Canberra.

Brocklehurst, P., Edmeades, B., 1996. The Mangrove Communities of Darwin Harbour, Technical Report No. R96/7. Department of Lands, Planning and Environment, Darwin.

DLRM – Department of Land and Resource Management, 2012. Darwin Harbour Region Report Card 2012. Department of Land Resource Management, Palmerston, NT.

DLRM – Department of Land and Resource Management, 2013. Darwin Harbour Region Report Card 2013. Department of Land Resource Management, Palmerston, NT.

DLRM – Department of Land and Resource Management, 2014. Darwin Harbour Region Report Card 2014. Department of Land Resource Management, Palmerston, NT.

Dostine, P.L., 2013. Phytoplankton communities of East Arm in Darwin Harbour. Report number 03/2013D. Department of Land Resource Management, Palmerston, NT.

Drewry, J., Dostine, P.L., Fortune, J., 2010. Darwin Harbour region, other projects and monitoring 2010. Department of Natural Resources, Environment, the Arts and Sport. Report No 25/2010D. Palmerston, NT.

Fortune, J., 2015. Supplement to the 2014 Darwin Harbour Region Report Card. Report No. 01/2015D. Aquatic Health Unit, Department of Land Resource Management, Palmerston, NT.

Fortune, J., Drewry, J., (Eds.), 2011. Darwin Harbour region research and monitoring 2011. Department of Natural Resources, Environment, the Arts and Sport. Report number 18/2011D. Palmerston, NT, Gomelyuk, V., 2012. Assessment of Darwin Harbour fish communities using baited remote underwater video station (BRUVS). Report to Department of Land Resource Management, Darwin.

Griffiths, A.D, Palmer, C., 2011. Monitoring plan for coastal dolphin species in Darwin Harbour. Department of Natural Resources, Environment, the Arts and Sport, Palmerston.

Griffiths, T., Smit, N., 2011. Coral reefs of Darwin Harbour – monitoring the rainforests of the sea, in: Fortune, J., Drewry, J., (Eds.), 2011. Darwin Harbour region research and monitoring 2011. Department of Natural Resources, Environment, the Arts and Sport. Report number 18/2011D. Palmerston, NT, pp. 4‒5.

Larson, H.K., 2002.Report to Parks Australia North, on estuarine fish monitoring of Kakadu National Park, Northern Territory, Australia. Museum and Art Gallery of the Northern Territory, Darwin, NT.

Maraud, N., 2013. Darwin Harbour Water Quality: Supplement to the 2013 Darwin Harbour Region Report Card. Report No 12/2013D. Aquatic Health Unit, Department of Land Resource Management, Northern Territory Government.

Moritz-Zimmerman, A., Comley, B, Lewis, D., 2002. Darwin Harbour Mangrove Monitoring Methodology Technical Manual. Land Monitoring Series No. 3, Report No. 25/2002. Department of Infrastructure, Planning and Environment, Darwin, NT.

Munksgaard, N.C., Kaestli, M., Gibb, K., Dostine, P., Townsend, S., 2013. Darwin Harbour Baseline Sediment Survey 2012. Charles Darwin University, Darwin, NT.

NT Government, 2002. Mangrove Management in the Northern Territory. Department of Infrastructure, Planning and Development, Northern Territory Government, Darwin, NT.

Padovan, A., Munksgaard, N., Alvarez, B., Parry, D., Gibb, K., 2011. Elevated metals in the tropical sponge, Spheciospongia vagabunda, in Darwin Harbour, in: Fortune, J., Drewry, J., (Eds.), 2011. Darwin Harbour region research and monitoring 2011. Department of Natural Resources, Environment, the Arts and Sport. Report number 18/2011D. Palmerston, NT, p. 16.

Palmer, C., 2012. Marine vertebrates of Darwin Harbour, in: Smit, N., Penny S.S, Griffiths, A.D., (Eds.), 2012 Assessment of Marine Biodiversity and Habitat Mapping in the Weddell region, Darwin Harbour 2012. Report to the Department of Lands, Planning and Environment. Department of Land Resource Management, Palmerston, pp. 42‒52.

Smit, N., 2011. Seagrass monitoring, Seagrass-Watch in Darwin Harbour, in: Fortune, J., Drewry, J., (Eds.), 2011. Darwin Harbour region research and monitoring 2011. Department of Natural Resources, Environment, the Arts and Sport. Report number 18/2011D. Palmerston, NT, p. 12.

Smit, N., Penny, S., Griffiths, T., 2012. Assessment of Marine Biodiversity and Habitat Mapping in the Weddell Region, Darwin Harbour. Report to the Department of Lands, Planning and Environment. Department of Land Resource Management, Palmerston, NT.

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