Great Barrier Reef Catchment Loads Monitoring Program Report Summary 2015–2016 The Great Barrier Reef Catchment Loads Monitoring Program is a large-scale water quality monitoring program conducted along the east coast of Queensland. It provides measures of annual loads (mass) of total suspended solids and nutrients (nitrogen and phosphorus) from 14 priority basins that discharge to the Great Barrier Reef. For 12 of these priority basins annual pesticide loads and summed annual toxic loads of pesticides are also described. This program is part of the Reef Water Quality Protection Plan (Reef Plan), and the Paddock to Reef Integrated Monitoring, Modelling and Reporting Program (Paddock to Reef Program). It also provides loads data to validate and calibrate catchment models, which assist in evaluating progress towards the water quality targets of Reef Plan. This summary outlines the monitored loads data for 2015–2016. Great Barrier Reef Catchment Loads Monitoring Program 1 Monitoring sites Rainfall Thirty-five basins along the east coast of Total rainfall was average to very much Queensland flow into the reef lagoon. A total of below average in the monitored catchments of the 26 sites were monitored within 14 of these basins Wet Tropics, Burdekin, Fitzroy and Burnett Mary (Figure 1). These consist of 17 end-of-catchment1 regions (Figure 2). The monitored catchments in sites and nine nested sub-catchment sites that the Mackay Whitsunday region received average were monitored for total suspended solids and rainfall whereas the monitored catchments in nutrients. A subset of 15 end-of-catchment sites the Cape York region received average to above and two nested sub-catchment sites across 12 average rainfall during the monitoring year. basins were monitored for pesticides, including the five photosystem II inhibiting pesticides, ametryn, atrazine, diuron, hexazinone and tebuthiuron. Monitoring sites Rainfall deciles 2015–2016 *# End-of-catchment Highest on record * ± # ± Nested sub-catchment Very much above average (90–100) (! Town bove average (70–90) Watercourses Average (30–70) Marine park boundary Below average (10–30) NRM region boundary Very much below average (0–10) Monitored catchments Lowest on record *# *# Great Barrier Reef catchments NRM region boundary ! !I ( COOKTOWN (! COOKTOWN Monitored catchments NRM REGIONS Marine park boundary I. CAPE YORK Normanby River *# Monitoring sites *# *# Barron River (! CAIRNS II. WET TROPICS (! (! * # CAIRNS Town * # *# * Mulgrave River # III. ACKAY HITSUNDAY * # M W *#(! *#(!*# * # INNISFAIL # Russell River *# * INNISFAIL *# IV. BURDEKIN *# Johnstone Rivers !II V. FITZROY Tully River *#(! INGHAM *#(! INGHAM Herbert River VI. BURNETT MARY ! ( TOWNSVILLE (!TOWNSVILLE *#*#*#(! AYR *#*#*#(! AYR * # (! BOWEN *# (! BOWEN Haughton River (! * # #PROSERPINE (! Barratta Creek * *# *#PROSERPINE Burdekin River *#(! *# MACKAY *#*#(! MACKAY OConnell River Pioneer River !III Sandy Creek !IV * # !V *#(! *#(! * # ! ROCKHAMPTON *#! ROCKHAMPTON EMERALD ( *# BUNDABERG *#(! ! BUNDABERG *#( Fitzroy River * # * # * # *# *# Burnett River !VI *# *# *# Tinana Creek Mary River 0 50 100 200 300 400 0 50 100 200 300 400 ilometers ilometers Figure 1 Natural resource management regions, catchments and sites Figure 2 Queensland 2015–2016 rainfall deciles with respect to long-term monitored in 2015–2016. mean rainfall. 1 End-of-catchment sites are defined as sites located at the lowest point in a river or creek where the volume of water passing that point can be accurately measured. Great Barrier Reef Catchment Loads Monitoring Program 2 River discharge Total suspended solids During the 2015–2016 monitoring year, annual The combined monitored annual load of river discharge in all monitored catchments was total suspended solids during the 2015–2016 less than the long-term average. monitoring year was 1800 kt (Figure 4). The In the Normanby, Mulgrave, Russell, Johnstone main contributing catchments were the Burdekin and Tully catchments, annual discharge was (700 kt) and Fitzroy (670 kt) catchments which between 61 per cent and 89 per cent of the generated 39 per cent and 37 per cent of the long-term average. In the Sandy and Pioneer combined monitored total suspended solids catchments, the proportion of annual discharge load, respectively. The remaining catchments to average long-term discharge was 55 and contributed less than 25 per cent of the combined 57 per cent, respectively. In all other monitored monitored annual total suspended solids load. The catchments, the annual discharge was less than lowest monitored annual total suspended solids half the long-term average. load during the 2015–2016 monitoring year was in Tinana Creek catchment (0.17 kt). Annual discharge in the Mary (24 per cent), Barron (24 per cent), Burdekin (18 per cent) and O’Connell (8 per cent) catchments was very low compared to the long-term average. &%% '*%% +%% .% *%% -% '%%% " ,% )% +% &*%% # $ (% $ *% 0 1 )% &%%% '% (% /" '% *%% &% &% " "# % % % ! ! Figure 3 Percentage of average long-term discharge (bars) and Figure 4 Annual monitored total suspended solids loads for annual discharge (blue dots) for 2015–2016. Natural resource 2015–2016. Natural resource management regions are grouped management regions are grouped by colour. by colour. Image: Queensland Department of Science, Information Technology and Innovation Great Barrier Reef Catchment Loads Monitoring Program 3 Image: Great Barrier Reef Marine Park Authority Image: GreatBarrierReef MarinePark seven percentofthecombinedmonitoredload. remaining catchmentseachcontributedlessthan The (540 t)andJohnstone(300catchments. were derivedfromtheFitzroy(1600t),Burdekin nitrogen duringthe2015–2016monitoringyear largest monitoredannualloadsofparticulate The particulate nitrogenwas4100t(Figure5). The combinedmonitoredannualloadof Herbert (270t)andJohnstone(260catchments. (510t),Russell(310Burdekin(280 t), Tully the Fitzroy catchment(680t)withmoderateloadsin load ofdissolvedinorganicnitrogenwasinthe The largestmonitoredannual total nitrogenload. accounted for26percentofthemonitoredannual inorganic nitrogenwas2900t(Figure5),which The combinedmonitoredannualloadofdissolved catchments (Figure5). t),Normanby(910t)andHerbert(840 (1100 Tully also monitoredintheBurdekin(1500t), Fitzroy (3300t)catchmentwithmoderateloads total monitorednitrogenloadwasderivedfromthe Thirty percentofthe t. total nitrogenwas11,000 The combinedmonitoredannualloadof Nitrogen N b) "#)$$$ )%$$ )&$$ *$$$ *+$$ %$$ &$$ '$$ ($$ $ c) " # $% '&& (&& )&& *&& +&& ,&& -&& Natural Resource Management regions are grouped by colour. Natural Resource Managementregionsaregrouped bycolour. nitrogen (b)and particulate nitrogen(c)loadsfor2015–2016. Annual monitored totalnitrogen(a),dissolved inorganic Figure 5 & " #$ &*%% '%%% &%% '%% (%% )%% *%% % ! ! ! a) 4 Great Barrier Reef Catchment Loads Monitoring Program particulate phosphorus. cent ofthecombinedmonitoredannualload catchments eachproducedlessthanfiveper The remaining and Normanby(95t)catchments. Fitzroy (750t),Burdekin(250Johnstone(130t) of particulatephosphoruswerederivedfromthe The largestmonitoredannualloads annual load. 71 percentofthetotalphosphorusmonitored phosphorus was1600t,whichaccountedfor The combinedmonitoredannual load ofparticulate monitored annualloadoftotalphosphorus. contributed lessthanfivepercentofthecombined All remainingcatchments (120 t)catchments. Burdekin (460t),Johnstone(210t)andNormanby Moderate loadswerealsodeliveredbythe contributor beingtheFitzroy(910t)catchment. phosphorus was2300t(Figure6)withthelargest The combinedmonitoredannualloadoftotal Phosphorus Image: Queensland Department of Agriculture andFisheries Image: QueenslandDepartment of a) grouped bycolour. Annual monitoredtotalphosphorus(a)andparticulate (b)loadsfor2015–2016.NaturalResourceManagementregionsare Figure 6 "" #$ &%%% &%% '%% (%% )%% *%% +%% % ! P Innovation and Technology RiveratEuramo.Image:QueenslandDepartmentofScience,Information Tully b) " ## $% (&& ('& )&& *'& +&& '& & ! 5 Great Barrier Reef Catchment Loads Monitoring Program Pesticides The total monitored annual load of the five photosystem II inhibiting herbicides (ametryn, ! atrazine, diuron, hexazinone and tebuthiuron) exported past the monitoring sites were (from largest to smallest): 1000 kilograms (kg) of tebuthiuron; 790 kg of total atrazine; 660 kg of total diuron; 260 kg of hexazinone; and 7 kg of ametryn (Figure 7). Atrazine and diuron were the only photosystem II inhibiting herbicides consistently detected in every monitored catchment. Hexazinone was detected in all catchments except the Haughton and Burdekin catchments. Ametryn was detected in the Mulgrave, Russell, Barratta, O’Connell, Pioneer, Sandy and Tinana catchments. Tebuthiuron was detected in the Haughton, Barratta, Burdekin, O’Connell, Sandy, Fitzroy, Burnett and Mary catchments. Toxic load The toxic load of photosystem II inhibiting pesticides is the sum of the toxic loads of ametryn, %$$ atrazine, diuron, hexazinone and tebuthiuron. The )($ toxic load of a pesticide is its load (mass) multiplied )'$ by a toxic equivalency ( ) factor – this accounts for the relative toxicity of the pesticide compared )&$ to diuron. The monitored annual toxic load of )%$ photosystem II inhibiting pesticides for the end-of- )$$ catchment sites was equivalent to 750 kilograms ($ of diuron (750 kg ). Diuron accounted for diuron '$ 82