Water Quality in the Great Barrier Reef Catchments

Pressure in a world heritage area: water quality in the Great Barrier Reef catchments

Thursday, 1st June 2017- Ryan Turner, LuWQ 2017 The Hague

Reinier Mann, Rohan Wallace, Richard Gardiner, Rachael Smith, Rae Huggins, Belinda Thomson, Ben Ferguson, David Orr, Olivia King, Cassandra Taylor, Shane Preston, Jackson Shanks, Sarah Simpson, Michael Warne

Water Quality and Investigations - Department of Science, Information Technology and Innovation, Australia

Great Barrier Reef

World Heritage Area: • Worlds larges coral reef • 2300 km long – 70 to 250 km wide – 3000 reefs – 900 islands • 35 catchments – 500 000 km2 • ~$6 billion to the Australian economy. • ~66 000 jobs • Outstanding universal values Great Barrier Reef - threats

Climate change

Coastal Direct Development use

Poor water quality from land based run-off Reef 2050 Long-Term Sustainability Plan

• Overarching framework for protecting and managing the Great Barrier Reef • Australian Government’s response to the recommendations of the UNESCO World Heritage Committee. • Vision: “To ensure the Great Barrier Reef continues to improve on its Outstanding Universal Value every decade between now and 2050 to be a natural wonder for each successive generation to come.” Reef Plan - history

Reef Plan 2013 - Targets abstract #101 Paddock to Reef program abstract #37

We’re monitoring the changes in We’re taking water samples and monitoring nutrients and We‘re doing marine monitoring and management practice adoption sediments (44 sites) and pesticides (27 sites) modelling to understand the condition to give our best understanding of what to produce pollutant loads data, track long-term trends in water of inshore marine ecosystem health. is really happening on the ground. quality and provide data for modelling. We’re assessing indicators of water quality and changes in the condition, We’re monitoring the water quality We’re using remote sensing to monitor changes in the extent of key catchment indicators of extent and recovery of seagrass and from the on-farm paddock experiments coral. to provide data for modelling and wetlands, ground cover and riparian vegetation. We’re also information back to landholders. monitoring the condition of wetlands.

We’re doing paddock scale modelling We’re doing catchment scale modelling for 35 catchments to to build knowledge on the estimate the average annual pollutant effectiveness of specific farming loads of dissolved inorganic nitrogen, particulate nitrogen, management practices in improving particulate phosphorous, sediment and water quality. pesticides. Catchment Monitoring sites

Across five natural resource management regions

44 sites for sediment and nutrients

27 sites for pesticides

Varying land use, geology and topography

Dynamic climate

Monitoring • Diffuse contaminants • Event conditions • Ambient conditions

Samples collected by • Automated samplers • In-situ probes • Turbidity (EXO2) • Conductivity (EXO2) • Nitrate (SUNA, TRiOS) • Grab sampling • Passive samplers • Acoustic Doppler Current Profiler Quality Assurance & Quality Control

Quality Assurance Framework Procedures Methods Training MERI framework Quality Control Trip blanks Field blank Quality control solutions Duplicates Blind laboratory checking

Water quality monitoring results Results: Water Quality Parameters

Total Suspended Solids Total Nitrogen Particulate Nitrogen Total Phosphorus Particulate Phosphorus Dissolved Inorganic Nitrogen Dissolved Organic Nitrogen Dissolved Inorganic Phosphorus Dissolved Organic Phosphorus Pesticides (57 Compounds) Load calculations

• The timing of the sampling should address the pre-defined objectives of the program. i.e. LOADS • Water quality varies during different stream flow conditions • Sampling frequency during an event should average 10 -12 samples • Minimum 4 on the rise and 3 on the fall • Distributed over all stages of the event • Weekly to maximum monthly during ambient conditions • Pesticide concentration can exhibit an independent relationship to discharge Load calculations Water Quality Water Quantity Sediments, Nutrients, Pesticides River Flow X

Beale ratio: Average load (linear interpolation of concentration)

 1 LQ  1  n  l  N lq  c j  c j1 Load  Q   Load   q  q  1  2Q  j   1  j1 2  2   N q  Reef Plan - 2013 Scientific Consensus Statement The main source of excess nutrients, fine sediments and pesticides from Great Barrier Reef catchments is diffuse source pollution from agriculture.

The main land uses contributing pollutant loads are: • rangeland grazing for sediment, • rangeland grazing and sugarcane for total nitrogen and total phosphorus, and • cropping (sugarcane) for dissolved inorganic nitrogen and photosystem II inhibiting pesticides. Reef Plan measuring towards the goal & targets (priorities) Average annual flow ML Cape York 2104511 1228130 3% 981895 Daintree 1619886 2% 1% 289077 2% Mossman 314490 0% 0% Barron 2188642 3% Mulgrave-Russell

16865874 Johnstone 22% 3160622 Tully 4% Murray

Herbert

HaughtonRiver 9547604 13% Barratta Creek* 2885556 4% 503929 Burdekin River 1% Black, Ross, Don rivers 811523 1% Fitzroy River 2296334 2993926 3% 4% Fitzroy other

Proserpine River 2896237 4% O'Connell River

3559701 Pioneer River 5% 14525803 Plane Creek* 19% 4842916 Burnett River 6% 1547917 2% Burrum, Baffle, Kolan 143106 247505 0% Mary River 0% In ten years > 120 million tonnes of anthropogenic sediment

Based on Kroon et al. (2012) using a 5.5 anthropogenic increase of >144 000 t of sediment 32 Tonnes 3.7 Million dump trucks Average monitored (2006-2015) and modelled loads for total suspended solids (t/y) Cape York 108020 190767 216316 172038 2% Daintree 1% 20662 241460 2% 2% 0% 37838 2% Mossman 0% 101676 89208 234408 371167 27177 1% 1% Barron 2% 3% 0% 729402 16520 79599 Mulgrave-Russell 110930 7% 1% 0% 1% 38947 Johnstone 295783 400424 0% 3% 4% Tully

Murray

Herbert

HaughtonRiver

Barratta Creek*

Burdekin River

Black, Ross, Don rivers 2321743 21% Fitzroy River

Fitzroy other

Proserpine River

O'Connell River 4865240 44% Pioneer River 312396 3% Plane Creek*

Burnett River

Burrum, Baffle, Kolan

Mary River Sediment runoff

Image Dr Andrew Brooks and Professor Jon Olley, Griffith University

Image WWF Australia Alluvial gullies and channel erosion are the most dominant sources of sediment due to grazing pressure and loss of riparian vegetation Sediment runoff

Fine sediments (e.g. silt and clay) travel further into the reef lagoon and can form flocs, which can stress the ecosystem by: •blocking light •smother corals and seagrass •reducing oxygen and pH levels. Average monitored (2006-2015) and modelled loads dissolved inorganic nitrogen (t/y) Cape York

Daintree

Mossman 391 427 51 333 4% 4% 134 Barron 481 1% 4% 1% 55 238 5% 1% Mulgrave-Russell 36 3% 0% 266 Johnstone 3% 475 304 5% Tully 3% Murray 431 Herbert 568 5% 6% HaughtonRiver

Barratta Creek* 731 Burdekin River 8% Black, Ross, Don rivers

Fitzroy River 1340 14% 388 Fitzroy other 4% Proserpine River

O'Connell River

921 Pioneer River 447 10% 5% Plane Creek*

1382 Burnett River 15% 28 Burrum, Baffle, Kolan 0% 82 1% Mary River Nutrient runoff – Wet Tropics Nutrient runoff linked to Crown-of-thorns starfish

Crown-of-thorns starfish (COTS) larvae increase when their food source phytoplankton, is abundant. Generally phytoplankton numbers are low in reef waters, but fertilisers and other compounds can result in increased phytoplankton numbers in the Great Barrier Reef lagoon (courtesy of the Australian Institute of Marine Science) Managing water quality in Australia

National Water Quality Management Strategy (NWQMS) www.environment.gov.au/topics/water/water-quality/national- water-quality-management-strategy

1. Australian and New Zealand Water Quality (1) Guidelines (WQGs)

(2) 2. State WQGs e.g. Queensland

(3) 3. Regional WQGs e.g. Great Barrier Reef What are trigger values?

Risk of harm occurring Action required

Site-specific investigation or Moderate to high risk management action

Trigger Values

Low risk None Consequences of exceedances Three rules of thumb – the greater the exceedance the more severe the biological effects – the longer the duration of consecutive exceedances the more severe the biological effects – the more pulses (repeated exposures) the more severe the biological effects Imidacloprid TVs

Proposed national revision of guidelines ~0.1 µg/L (Smith et al 2014) Canadian water quality guidelines 0.23 µg/L Netherlands environmental risk limits 0.067 µg/L Imidacloprid

• Solublity in water 610 mg l-1

• Koc 132–310 • log Kow ~ 0.57 • Soil half-life 48–997days • Field dissipation half-life 26–229 days • Water half-life 6–41 days

What does this mean? • When imidacloprid is applied to crop soils (as opposed to its domestic / veterinary uses) it becomes highly mobile on contact with water” • Queensland coast has large areas of cane cropping Imidacloprid - Tully River

0.35 2000

1800 0.3

1600

0.25 1400

1200 0.2

1000

0.15 Imidacloprid (ug/L)Imidacloprid 800 (cumecs) Discharge

600 0.1

400

0.05 200

0 0 7/10/2012 7/10/2013 7/10/2014 ms-PAF Discharge Date Seasonal Mann-Kendall Test / Period = 12 / Serial independence / Two-tailed test (Imidacloprid (μg/L)):

Kendall's tau 0.110 S' 670.000 p-value (Two-tailed) 0.003 alpha 0.05 95th percentile imdacloprid (μg L-1) surface water concentration since 2009 1

0.9

0.8

0.7

0.6

0.5

0.4

0.3 Canadian guideline 0.2

0.1 Netherlands guideline

0 1 2 3 4 5 6

Russell River at East Russell Mulgrave River at Deeral Johnstone River* Tully River at Euramo Herbert River at Ingham Barratta Creek at Northcote O'Connell River at Caravan Park Pioneer River at Dumbleton Pump Station (HW) Sandy Ckreek at Homebush Reporting Innovative nitrate sensors Further information

www.reefplan.qld.gov.au Thank you This work is funded by the Queensland Government, Australia www.reefplan.qld.gov.au

My LuWQ 2017 conference trip was funded by: Queensland Government, Australia Queensland University of Technology, Australia James Cook University, Australia