RRRD0037: Pesticide dynamics in the Great Barrier Reef catchment and lagoon: management practices in the sugarcane industry (37)

Stephen Lewis TropWATER, James Cook University

Jon Brodie, Aaron Davis, Dominique O’Brien, Mark Silburn, Melanie Shaw, Rai Kookana, Danni Oliver, Rob Milla, Andrew Negri, Craig

Thornton, Bob Packett, John Armour, Rachael Smith, Michael Warne.

Glasshouse trial

•  Applications split into 3 mixes to limit possible effects on soil microbes on eight different soil types

•  Mix 1:

–  Velpar (diuron/hexazinone) –  Stomp (pendimethalin) –  Gramoxone (paraquat/diquat) –  2,4-D amine

•  Mix 2: –  Gesapax (atrazine/ametryn) –  Dual Gold (S-metolachlor) –  Glyphosate

•  Mix 3: –  Soccer (metribuzin) –  Flame (imazapic) –  Balance (isoxaflutole) –  Krismat (trifloxysulfuron sodium

and ametryn)

Glasshouse trial

Ametryn

Interim results: Soil half lives/dissipation rates

Field trials: Burdekin •  Dissipation rates of diuron,

ametryn, atrazine, metribuzin, imazapic, isoxafluotole, glyphosate, 2,4-D, fluroxypyr, metolachlor and pendimethalin

y = 3.5711e-0.05x R² = 0.77732

y = 7.6584e-0.042x R² = 0.78278

0.1

1

10

100

0 10 20 30 40 50 60

8A furrow Ametryn

Atrazine

Pesticide Mix Average Soil half life (days)

Burdekin field dissipation half-life

PPDB half life

Diuron 1 53 69 89 Hexazinone 1 270 XX 105 Pendimethalin 1 38 27 90 Tebuthiuron 1 XX XX 400 2,4-D 1 20 9.4 10 Atrazine 2 40 24 29 Ametryn (in gesapax)

2 24 17 37

Ametryn (in krismat)

3 35 14 37

Metolachlor 2 21.5 15 21 Glyphosate 2 32 7.8 12 Imazapic 3 530 16 232 Isoxaflutole 3 XX 2.6 1.3 Metribuzin 3 79 17 19 Trifloxysulfuron 3 XX XX 63.5

Paddock-scale: Management

•  What management practices are effective in reducing herbicide runoff losses in sugar cane? 1.  rate/spot/banding 2.  choice of product

•  replace PSII residuals with knockdown •  replace PSII residuals with emerging herbicides

3.  trash – source or reduce? 4.  control infiltration/runoff?

Rainfall simulation trials Mackay, Burdekin,

Bundaberg

SRDC brew: glyphosate, fluroxypyr and 2,4-D DNRM brew 1: atrazine, ametryn, diuron, isoxaflutole, metribuzin & K Br DNRM brew 2: atrazine, ametryn, metolachlor, imazapic, pendimethalin

K & Br as controls

Mackay 2012 2,4-D, Glyphosate

Note X = % area sprayed Spraying must have been OK or this would not work!!

Metolachlor, Diuron

Pendimethalin (Stomp), Isoxaflutole (Balance), Imazapic (Flame)

y  =  122.82xR2  =  0.9303

0

50

100

150

0% 20% 40% 60% 80% 100%

%  Sprayed

Concen

tration  (ug/L)

Metolachlor

Diuron

y  =  5.8383xR2  =  0.7859

0

20

40

0% 20% 40% 60% 80% 100%

%  Spray

Concen

tration  (ug/L) Isoxaflutole

Pendimethalin

Imazapic

y  =  138.44x  -­‐  11.652R2  =  0.8186

R2  =  0.5936

0

50

100

150

200

0% 20% 40% 60% 80% 100%%  Sprayed

Concen

tration  (ug/L)

2,4  D

Glyphosate

Linear(Glyphosate)

•  Mackay 2011 rainfall simulation

0%

1%

2%

3%

4%

5%

6%

Runo

ff  load

   %  of  loa

d  in  soil  &

 trash

Shielded  sprayer  used  for  banded  applica3on  of  herbicides.  

Danni  Oliver  10    |  

Shield restricting spray to raised beds only

My call on this for herbicide management is that banded/ shielded spraying is ‘Best’ B practice where ‘weed seeker’ would be ‘Aspirational’ A practice

Results  -­‐  Load  

Danni  Oliver  11    |  

Highly significant difference in loads moving off-site from banded treatments compared with conventional for both atrazine and diuron. 60% decrease in atrazine and diuron applied in banded treatments vs conventional but ~90% decreased in total average load moving off-site.

-2000

0

2000

4000

6000

8000

10000

12000

14000

0 2 4 6 8 10 12 14

Load

mg

Time after flow started (hours)

Diuron load

Conventional Rep 1

Conventional Rep 2

Banded Rep 1

Banded Rep 2

-5000

0

5000

10000

15000

20000

25000

0 2 4 6 8 10 12 14

Load

mg

Time after flow started (hours)

Atrazine load

Conventional Rep 1

Conventional Rep 2

Banded Rep 1

Banded Rep 2

Monitoring: Partitioning studies: Mackay 2012

Mackay  2012  BareTotal  &  dissolved

0.00

0.05

0.10

0.15

0.20

Glyphosate

AMPA

2,4  D

Fluroxypyr

Ametryn

Atrazin

e

Diuron

Imazapic

Isoxaflu

tole

Metolachlor

Metrib

uzin

Pendim

ethalin

Runo

ff  conc/  spray  rate

Relative risk of herbicides in the sugar industry

•  Risk = Likelihood × Consequence •  Rainfall simulation trials provide a

‘likelihood’ of amount of herbicide to run off a paddock (relative to diuron)

•  Relative toxicity to diuron based on EC50 values for aquatic plants and for algae (phytoplankton)

•  Divide relative differences in toxicity and runoff

Consequence

Herbicide Product Algae 72 hr EC50

Aquatic Plants 7

day EC50

Average for GBR species

Predicted GBR

Atrazine Many generic 22 1.0 10 11 Diuron Many generic 1.0 1.0 1.0 1.0 Hexazinone Many generic 5.4 3.9 4.4 4.7 Ametryn Many generic 1.3 0.55 0.76 0.94 Metolachlor Dual Gold 21148 2.3 N/A 2.3* Propazine 67 48 N/A 57 Pendimethalin Stomp 2.2 0.66 N/A 0.66* Isoxaflutole Balance 44 0.87 N/A 0.87* Imazapic Flame 19 N/A N/A 10** Metribuzin Soccer 7.4 0.44 N/A 4 Trifloxysulfuron sodium Krismat 2.4 0.03 N/A 0.03* Glyphosate Many generic 1630 656 N/A 656* Paraquat Gramoxone 0.09 2.0 N/A 0.09* Asulam N/A 15 N/A 15* Tebuthiuron Grassland 19 7.4 13 13 2,4-D Many generic 8963 32 N/A 32* Fluoxypyr Many generic 18444 672.0 N/A 672* *Based on the lowest value; **Half the 72 hour EC50 algae relative toxicity value

Relative risk

Herbicide Predicted GBR toxicity

Maximum EMC detected in

paddock runoff (100% applied)

Risk relative to diuron based on predicted toxicity and runoff

potential

Burdekin relative

risk

Atrazine 11 260 5.7 3.9 Diuron 1.0 130 1.0 1.0 Hexazinone* 4.7 141 4.3 10 Ametryn 0.94 210 0.58 0.5 Metolachlor 2 190 1.6 1.2 Propazine 57 N/A N/A N/A Pendimethalin 0.7 7.7 11 11 Isoxaflutole 1 15 8 4.8 Imazapic 10 21 62 47 Metribuzin 4 180 2.8 1.9 Trifloxysulfuron sodium 0.0 N/A N/A N/A Glyphosate 656 30 2843 721 Paraquat 0.1 0.1 130 281 Asulam 15 N/A N/A N/A Tebuthiuron** 13 105 16 N/A 2,4-D 32 180 23 12 Fluoxypyr 672 10 8736 6989

*Masters et al. (in press); **Thornton and Elledge (in press)

Healthy Humans in a Healthy Environment

Linking Grab Sampling with Passive Sampling Summer project, Honours project and PhD project of Andrew Novic (if scholarship is

funded)

COLLABORATION between Entox and JCU (Jon’s team); Dom O’Brien, Stephen

Lewis, Aaron Davis et al

Sub-catchment scale: Monitoring •  15 min samples collected for herbicide

analysis over ~34 hours straight through the torrential rain that occurred in January 2013

•  Then event got too big (~ 2 m over bridge) and had to call off second and third nights

•  Sampled over a 5 day period in total •  Test validity of passive samplers for load

calculations

~ 300 kg Atrazine ~ 20 kg of diuron and metribuzin First time asulam detected in monitoring

Site selection at last workshop…

Davis et al. 2012 e.g. ~20 samples for 2008/09 wet season GBR Loads program 306 samples in large 2010/11 wet season

What we did: polar, non-polar, nutrients

Passive sampling ●  Capture flood and replicate

multiple monitoring deployment scenarios:

●  Before, during and after flood

Grab sampling ●  Captured baseflow, rise, peak

and fall of hydrograph

●  Continuous 15 minute sampling… after bridge flooded some breaks at night because of safety concerns

●  On-site processing (filtering and spiking with standards)

34 hours

31 hours

9 hours

What we found: Lots of data

Assessing  the  risk  of  addi7ve  pes7cide  exposure  in  the  Great  

Barrier  Reef  Stephen Lewis1, Rachael Smith2, Dominique O’Brien1, Michael Warne2, Andrew Negri3, Caroline Petus1, Eduardo Da Silva1,

Daniel Zeh1, Ryan Turner2, Aaron Davis1, Jochen Mueller4, Jon Brodie1

1Catchment to Reef Research Group, TropWATER, James Cook

University Townsville. 2Water Quality and Investigations, Environmental Monitoring and Assessment Science, Science Delivery, Department of Science,

Information Technology, Innovation and the Arts. 3Australian Institute of Marine Science, Townsville

4ENTOX, University of Queensland, Brisbane

A  few  ways  to  examine  ‘addi7ve  risk’’  •  HEQ  equivalent  (toxicity  rela7ve  to  a  ‘standard’  pes7cide)  – HEQ  rela7ve  to  diuron  (PS-­‐II  herbicides  only:  i.e.  single  mode  of  ac7on)  –  current  standard  for  MMP  Cat  1  to  Cat  5  (Kennedy  et  al.,  2012)  

 

•  Mul7ple  substances  poten7ally  affected  frac7on  –   Use  of  Species  Sensi7vity  Distribu7on  data  (Traas  et  al.,  2002)  

Species  sensi7ve  distribu7on  

From: Traas et al. (2002)

Assume  conserva7ve  mixing  of  flood  waters  in  the  marine  environment  

Evidence  for  conserva7ve  mixing  of  PSII  herbicides  in  the  GBR  1.  Direct  plume  studies  (Lewis  et  al.  2009)  2.  Par77oning  data  (PSII  herbicides  

predominately  associated  with  the  dissolved  phase)  (Davies  et  al.  2012;  Bob  Packe_,  unpublished)  

3.  Long  half  lives  of  herbicides  in  seawater  (Andrew  Negri  &  Phil  Mercurio,  unpublished)  

Calcula7ons  based  on  conserva7ve  mixing  (HEQ)  

y = -8.5714x + 36

0

5

10

15

20

25

30

35

40

0 1 2 3 4 5

HEQ

Salinity

So…  If  we  know  the  pes7cide  concentra7ons  at  the  river  mouth  at  certain  7mes  and  the  salinity  of  the  flood  waters  we  can  predict  the  concentra7on  in  the  marine  

environment    Schroeder  et  al.,  2012  

CDOM- salinity relationship

Categories  of  consequence  HEQ  concentra3on   Known  effects  on  keystone  marine  

plants  Ra3ng  

>10  µg.L-­‐1   Coral  bleaching  and  reduced  reproduc7on  

Catastrophic  

2.3  to  10  µg.L-­‐1   Light  adapted  yield  EC50  on  coral  and  seagrass  species  

Major  

0.5  to  2.3  µg.L-­‐1   Light  adapted  yield  EC10  on  coral  and  seagrass  species  

Moderate  

0.1  to  0.5  µg.L-­‐1   Lowest  observable  effect  for  coral  and  seagrass  species  

Minor  

0.025  to  0.1  µg.L-­‐1   No  known  effect   Insignificant  

<  0.025  µg.L-­‐1   Nil   No  risk  

Calcula7ons  based  on  conserva7ve  mixing  (HEQ)  

y = -8.5714x + 36

0

5

10

15

20

25

30

35

40

0 1 2 3 4 5

HEQ

Salinity

2.3

16.3

Acute  categories  based  on  SSD  

Risk category Effect

% of phototrophs to experience

Diuron equivalent

concentration (µg/L)

Minor Effects

Major Effects

5 Catastrophic

Impact is clearly affecting, or could clearly affect, the nature of the ecosystem over a

wide extent. Recovery periods greater than 20 years likely.

> 85 > 33 > 16

4 Major Impact is, or would be, significant at a wider level. Recovery period of 10-20 years likely.

66 - 85 10 - 33 7.4 - 16

3 Moderate Impact is, or would be, present at a wider

level. Recovery period of 5-10 years is likely.

10 - 66 0.2 - 10 0.96 - 7.4

2 Minor

Impact is, or would be, not discernible at a wider level. Impact would not impair the

overall condition of the ecosystem, sensitive population or community over a wider level.

1 - 10 0.01 - 0.2 0.2 - 0.96

1 Insignificant

No impact or if impact is or would be, present then only to the extent that it has no discernible effect on the overall condition of

the ecosystem.

0 - 1 0 - 0.01 0 - 0.2

Chronic  categories  based  on  SSD  

Risk category Effect

% of phototrophs to experience

Diuron equivalent

concentration (µg/L))

Minor Effects

Major Effects

5 Catastrophic

Impact is clearly affecting, or could clearly affect, the nature of the ecosystem over a

wide extent. Recovery periods greater than 20 years likely.

> 70 > 20 > 4.6

4 Major Impact is, or would be, significant at a wider level. Recovery period of 10-20

years likely. 40 - 70 5 - 20 1.6 - 4.6

3 Moderate Impact is, or would be, present at a wider

level. Recovery period of 5-10 years is likely.

5 - 40 0.3 - 5 0.21 -1.6

2 Minor

Impact is, or would be, not discernible at a wider level. Impact would not impair the

overall condition of the ecosystem, sensitive population or community over a

wider level.

1 - 5 0.04 - 0.3 0.06 -0.21

1 Insignificant

No impact or if impact is or would be, present then only to the extent that it has

no discernible effect on the overall condition of the ecosystem.

0 - 1 0 - 0.04 0 - 0.06

Mackay Whitsunday region

Mackay  Whitsunday  region  

Mackay  Whitsunday  region  Event Details Risk Assessment

Site Event No

Duration Discharge (GL)

Exposure Type

Risk Category Exposure Coverage Ratio

Mackay-Whitsundays

Pioneer River

1 7 d 19 h 74 Chronic Major 0.4 2* 4 d 23 h 196 Chronic Moderate 1.0 3 13 d 17 h 332 Chronic Insignificant 1.7

Sandy Creek 1 5 d 23 h 44 Chronic Major 0.7

2* 4 d 21 h 60 Chronic Moderate 1.0 3 4 d 11 h 30 Chronic Moderate 0.5 4 3 d 13 h 33 Acute Moderate 0.6

5 4 d 30 Chronic Moderate 0.5

6 7 d 3 h 63 Chronic Minor 1.1

Composite    map  

GIS  analysis  –  areas  of  risk  for  corals  Sum of Area (km2)

Reef Reef Total

Row Labels Major Moderate Minor Insignificant No risk

Cape York 8800 8800

Wet Tropics 30 130 2300 2400

Burdekin 0.5 3000 3000

Mackay-Whitsunday 6.0 18 110 130 2900 3200

Fitzroy 6.2 28 4800 4900

Burnett-Mary 0.7 5.1 280 280

Grand Total 6.0 18 150 295 22000 23000

GIS  analysis  –  areas  of  risk  for  seagrass  Sum of Area (km2)

Column Labels

Seagrass Seagrass

Total

Row Labels Major Moderate Minor Insignificant No risk

Cape York 11000 11000

Wet Tropics 250 740 3900 4900

Burdekin 9.8 6100 6100

Mackay-Whitsunday 57 82 200 84 2.9 430

Fitzroy 0.1 14 5800 5800

Burnett-Mary 45 40 6200 6300

Grand Total 57 82 500 890 33000 35000

Catchment/GBR:  repor7ng  

We should be able to Include herbicides (at least PSII) into GBR report card 4

MMP categrories

Acute (ms-PAF)

Chronic (ms-PAF)

Toxicity to GBR species

Her

bici

de e

quiv

alen

ts (H

EQ

, µg

l-1)

0.01

0.1

1

10

InsignificantMinorModerateMajorCatastrophic

5

4

3

2

1

ms-­‐PAF  (mul7ple  substances  poten7ally  affected  frac7on)  Based  on  SSD  and  mixture  assump7ons  

Comparing  risk  classifica7ons  

MMP categrories

Acute (ms-PAF)

Chronic (ms-PAF)

Toxicity to GBR species

Her

bici

de e

quiv

alen

ts (H

EQ

, µg

l-1)

0.01

0.1

1

10

GBR

MPA

Gui

delin

e Tr

igge

rs

99% 95% 90%

InsignificantMinorModerateMajorCatastrophic

5

4

3

2

1

ms-­‐PAF  (mul7ple  substances  poten7ally  affected  frac7on)  Based  on  SSD  and  mixture  assump7ons  ANZECC  Low  Reliability  Ecosystem  Protec7on  =  0.2  µg/L  

ANZECC  

Add  in  the  guidelines  

Taxa/Species   Dura7on   IC50  (REP)   Reference           Diuron   Atrazine   Hexazinone   Tebuthiuron      

Seagrass                          Z.  muelleri   72  h   2.5  (1.0)   13  (0.19)   4.4  (0.57)   29  (0.086)   This  study*  H.  uninervis   72  h   2.4  (1.0)   18  (0.13)   6.9  (0.35)   30  (0.080)   This  study*                              Coral                          Acropora  millepora   7  d   2.9  (1.0)   47  (0.062)   14  (0.21)       (Negri  et  al.,  2011)  

Seriatopora  hystrix   14  h   2.3  (1.0)   45  (0.051)   8.8  (0.26)   175  (0.013)   (Jones  et  al.,  2003)  

Acropora  formosa   14  h   5.1  (1.0)   37  (0.14)           (Jones  and  Kerswell,  2003)  

Mon:pora  digitata   10  h   5.9  (1.0)   88  (0.067)           (Jones  and  Kerswell,  2003)  

Porites  cylindrica   10  h   4.3  (1.0   67  (0.064)           (Jones  and  Kerswell,  2003)  

Seriatopora  hystrix   10  h   2.9               (Jones  and  Kerswell,  2003)  

Diatom                          

Navicula  sp.   4  h   2.6  (1.0)   36  (0.072)   5.7  (0.46)   94  (0.028)   (Magnusson  et  al.,  2010)  

Cylindrotheca  closteriuma   4  h   4.4  (1.0)   77  (0.057)   6.9  (0.64)   77  (0.057)   (Magnusson  et  al.,  2010)  

Phaeodactylum  tricornutuma   4  h   2.7  (1.0)   34  (0.079)   6.6  (0.41)   51  (0.053)   (Magnusson  et  al.,  2010)  

Phaeodactylum  tricornutuma   2  h   18  (1.0)   45  (0.40)     22  (0.82)       (Muller  et  al.,  2008)  

Green  alga                          

Nephroselmis  pyriformis   4  h   2.1  (1.0)   14  (0.15)   2.4    (0.88)   12  (0.18)   (Magnusson  et  al.,  2010)  

                           

Foraminifera                          

Heterostegina  depressa   24  h   11               (van  Dam  et  al.,  2012b)  

                           

Crustose  algae                          

Neogoneolithon  fosliei   7  d   8.5  (1.0)   180  (0.047)   152  (0.056)       (Negri  et  al.,  2011)  

                           Mean  for  all  species       5.2  (1.0)   54  (0.12)   23  (0.46)   67  (0.070)      MMP  (REPs)                  (1.0)              (0.16)              (0.38)              (0.08)  

Seagrass  toxicity  (YII)  and  rela7ve  equivalent  potency  to  Diuron  (GBR  species)  

*Flores,  F.,  Collier,  C.J.,  Mercurio,  P.,  Negri,  A.P.,  Submi_ed.  Phototoxicity  of  four  photosystem  II  herbicides  to  tropical  seagrasses.  PLoS  ONE.  

 

MMP categrories

Acute (ms-PAF)

Chronic (ms-PAF)

Toxicity to GBR species

Her

bici

de e

quiv

alen

ts (H

EQ

, µg

l-1)

0.01

0.1

1

10

GBR

MPA

Gui

delin

e Tr

igge

rs

99% 95% 90%

InsignificantMinorModerateMajorCatastrophic

10%

Inhi

bitio

n of

ph

otos

ynth

eis

in s

eagr

ass

20%

50%

5

4

3

2

1

ms-­‐PAF  (mul7ple  substances  poten7ally  affected  frac7on)  Based  on  SSD  and  mixture  assump7ons  

GroundTruth  against  founda7on  GBR  species