Pacific oyster mortality syndrome(POMS)
First steps towards integrated management within infected estuaries
Richard Whittington, Paul Hick, Olivia Evans, Navneet Dhand, Ana Rubio & Ika Paul-PontFaculty of Veterinary Science - University of Sydney
Oysters Tasmania meeting Smithton 18th October 2014
The plan
1. POMS in Europe2. Australian POMS situation3. Research
– from spat rearing to on-farm grow-out, – priorities to plug remaining gaps– how this links to the POMS breeding program
4. Request for farmers to help collect data
1. POMS in Europe
History of POMS“Summer mortality” in Pacific oysters
Country Year Age group Mortality Cause
Japan 1960’s adult variable unknown
USA 1980’s all variable unknown
France 1980’s young variable OsHV-1
OsHV-1 occurs in USA, Japan, and some European countries, without mass mortality
“Summer mortality” in Pacific oystersCountry Year Age group Mortality Cause
Japan 1960’s adult variable unknown
USA 1980’s juvenile variable unknown
France 1980’s juvenile variable OsHV-1
France 2008 larvae, spat massive OsHV-1 microvar
UK, Ireland, Spain >2008 larvae, spat massive OsHV-1 microvar
New Zealand April 2010 spat and adult massive OsHV-1 microvar
OsHV-1 occurs in USA, Japan, and some European countries, without mass mortality
What is OsHV-1 uvar?
• It is a marine herpesvirus• not related to human herpesvirus • cannot infect warm blooded animals• no risk to human health
• There are two important marine herpesviruses • abalone herpesvirus• ostreid herpesvirus
– OsHV-1 reference strain – the original strain– OsHV-1 microvar (uvar) – a new mutant strain
Baie de ArchachonAugust 2012
Oysters in France
The French experience
Impact of POMS in France since 2008
Response1. big players produce 10x more spat and
grow the 10% that survive 2. market price has increased3. focus is on a breeding program
– private hatcheries, mass selection– government program, selection based
on lab challenge with OsHV-1 and three species of vibrio
50% of the industry has been lost, especially small farmers
government compensation exists
incentive to reduce losses?
“Summer mortality”
Larvae < 1 month:
all dead
Spat / Juvenile <18 months:
>90% dead
Adults > 18 months:
10-40% dead
whoi.edu
POMS behaviour in Europe
Seasonal pattern of OsHV-1 µvar
2009 – Disease progresses from south to north in summer as water temperatures increases
France since 2008
French research - IFREMER
• Breeding program
• POMS remains a huge issue in 2014, 6 years after it emerged and despite millions of Euros spent in research
• Research will be ongoing
Dr Tristan Renault
2. Australian POMS situation
Port Jackson – Sydney HarbourNov 2010
Botany Bay – Georges RiverNov 2010
0
50
km
POMS in Australia 2010 to 2013
Broken Bay – Hawkesbury RiverJan 2013
Commercial production abandoned
Hawkesbury - Sequence of events 2013
Day 1 - 21st Jan• 10 am – first mortality in spat• 5 pm - mass mortality event • 7pm - samples delivered to DPI
Day 2 - 22nd Jan• Outbreak investigation commenced• Broken Bay Oyster Association
– voluntary quarantine of river– supported an outbreak investigation
• 7pm DPI lab confirmed POMS
Mullet Creek
Day 3 - 23rd Jan• 10 million dead oysters• $3 million loss locally• $0.6 million hatchery loss• Casual staff laid off• Banks called in debt
Day 7- 28th Jan• Businesses, boats, equipment sold
Day 8 – 29th Jan• Minister visits affected oyster growers
Real time outbreak investigation
1. Passive surveillance to monitor spread• farmer observations of mortality
2. Active surveillance• identify risky oyster movements in last 2 weeks• whole river survey to identify infected bays/leases• detailed assessment of all dead stock• water tests
1st question. Where?
Broken Bay Oysters, Hornsby Shire Council, University of SydneyCurrent as at 7 February
29 Jan
15 Feb
Index case21 Jan
24 Jan
29 Jan
25 Jan
2nd question. Who died?
Extreme mortality
Moderate to high mortality
3rd question. When?
Date Sites Sample size OsHV-1 qPCR
26-Oct-11 M,P 30 Negative
7-Dec-11 M,P 30 Negative
19-Dec-11 M,P 30 Negative
4-Jan-12 M,P 30 Negative
18-Jan-12 M,P,R,K 30 Negative
15-Feb-12 M,P,R,K 30 Negative
15-Mar-12 M,P 30 Negative
20-Apr-12 M,P 30 Negative
10-May-12 M,P 30 Negative
5-Jun-12 M,P,R,K 30 Negative
3-Aug-12 M,P,R,K 30 Negative
20-Sep-12 P 30 Negative
1-Oct-12 P 30 Negative
12-Oct-12 P 30 Negative
18-Oct-12 M 21 Inconclusive
19-Oct-12 P 30 Negative
26-Nov-12 M,P 30 Negative
13-Dec-12 M 30 Inconclusive
26-Dec-12 M,P 30 Negative
7-Jan-13 M,P 30 Inconclusive 4 Positive 1 M
21-Jan-13 M,P 30 Positive
2-Feb-13 P 30 Positive
15-Feb-13 P 30 Positive
21st Jan13
18th Oct 12
26th Oct 11
3 months
Sentinel oysters (6 pools of 5) each time
4th question. How did it spread?
• Within the river system?1. local oyster movements
• within 2 days of the onset of the outbreak (i.e. on or after Jan 19th)• incubation period < 10 days (oysters moved 19th Jan died 29th Jan)
2. tide and current (16 km upstream tidal movement)
• To the Hawkesbury?1. Oyster movements?
• no record of any, except certified OsHV-1 negative spat2. Oceanic source?
• tiny amount of virus arrived October 2012• massive dose arrived between 17th and 19th January 2013
– incubation period for mass mortality 2-4 days
Connectedness
US Navy 1943
Connectedness
Thirroul Beach NSW 2011Driftwood carrying oyster shell Thirroul Beach NSW 2014
Pumice (origin New Caledonia) carrying oyster spat
Connectedness
3. Targeted research on POMS
Research objective – “to continue farming around POMS”
• What factors drive the disease?• Can we exploit them?
Breakthroughs needed for:1. Hatchery production 2. Spat rearing3. Growout –juveniles/adults
Broken Bay Hawkesbury River Control site until 2013
Botany Bay Georges River Infected since 2010
10 Km
New South Wales
SYDNEY
Bruce Alford – Broken Bay Oysters
Len Drake – Endeavour oystersResearch sites
POMS research sites
Georges River tray trials 2011-2012
Spatial pattern:Non uniform transmissionUneven mortality
Percent mortality:
Georges River tray trials 2011-2012
30
1 2
3 4
5 6
7 8
9 10
11 12
13 14
15 16
55 67
50 97
47 97
18 74
8 92
8 42
13 33
3 24
OsHV-1 is not evenly distributed in water - it is attached to something
plankton vector hypothesis
Georges River field trials 2011-2012 and 2012 2013
A
B
C
It might be possible to get OsHV-1 out of seawater
November 2011
November 2011
February 2012
n=2000 spat/treatmentFlow rate= 5L/min/tank
No food supplyDaily sampling / mortality check
Co-funding: FRDC, University of Sydney, Tasmanian Oyster Research Committee, Oysters Australia through Seafood CRC
Hatchery/Safe spat rearing trials 2013 and 2014
10,000 L holding tanks
Submersible pumps
Floating basket with control spat
Safe spat rearing500 spat
Filtered water
Filter + UV
Aged water
Control water
Trial 1 Trials 2-7
Daily filter clean
Daily spat examination
4157
741
578
4157
941
580
4158
141
582
4158
341
584
4158
541
586
4158
741
588
4158
941
590
4159
141
592
4159
341
594
4159
541
596
4159
741
598
4159
941
600
4160
141
602
4160
341
604
0%
20%
40%
60%
80%
100%
2nd safe spat rearing trial - 30 Oct 2013
River controlUpweller controlFilter 100/5 µmAged waterFilter 100/5 µm + UV
Date
Cum
ulati
ve m
orta
lity
Safe spat rearing trials 2013 and 2014
Safe spat rearing:• Age seawater for 48 hours before use, or• Filter seawater to 5 micron
Hatchery-Safe spat rearing trials 2013 and 2014
Mortality %
When is it safe to put spat in the estuary?
• 500 spat placed at multiple sites • every 2 weeks Aug 2013 to May 2014• each lot checked 2 to 4 weeks later• 21 lots all together
Olivia Evans PhD student
39
Georges River – Window of Infection
1
23
4
5 1 = Mangroves2 = Pelican Gut3 = Sylvania Waters4 = Never Fail Bay5 = Lime Kiln Barr6 = Site A7= Site B8 = Site C
C
A
B
40
Mortality Data : Georges River
1
23
4
5 Wild Sites:1 = Oyster Shed Mangroves2 = Pelican Gut3 = Sylvania Waters4 = Never Fail Bay5 = Lime Kiln Barr
Farmed Sites:Site ASite BSite C
August 2013
A
C
B
RESULTS:
41
1
23
4
5 Wild Sites:1 = Oyster Shed Mangroves2 = Pelican Gut3 = Sylvania Waters4 = Never Fail Bay5 = Lime Kiln Barr
Farmed Sites:Site ASite BSite C
September 2013
A
C
B
Mortality Data : Georges River
42
1
23
4
5 Wild Sites:1 = Oyster Shed Mangroves2 = Pelican Gut3 = Sylvania Waters4 = Never Fail Bay5 = Lime Kiln Barr
Farmed Sites:Site ASite BSite C
October 2013
A
C
B
Mortality Data : Georges River
43
1
23
4
5 Wild Sites:1 = Oyster Shed Mangroves2 = Pelican Gut3 = Sylvania Waters4 = Never Fail Bay5 = Lime Kiln Barr
Farmed Sites:Site ASite BSite C
November 2013
A
C
B
Mortality Data : Georges River
44
1
23
4
5 Wild Sites:1 = Oyster Shed Mangroves2 = Pelican Gut3 = Sylvania Waters4 = Never Fail Bay5 = Lime Kiln Barr
Farmed Sites:Site ASite BSite C
December 2013
A
C
B
Mortality Data : Georges River
45
1
23
4
5 Wild Sites:1 = Oyster Shed Mangroves2 = Pelican Gut3 = Sylvania Waters4 = Never Fail Bay5 = Lime Kiln Barr
Farmed Sites:Site ASite BSite C
January 2014
A
C
B
Mortality Data : Georges River
46
1
23
4
5 Wild Sites:1 = Oyster Shed Mangroves2 = Pelican Gut3 = Sylvania Waters4 = Never Fail Bay5 = Lime Kiln Barr
Farmed Sites:Site ASite BSite C
February 2014
A
C
B
Mortality Data : Georges River
47
1
23
4
5 Wild Sites:1 = Oyster Shed Mangroves2 = Pelican Gut3 = Sylvania Waters4 = Never Fail Bay5 = Lime Kiln Barr
Farmed Sites:Site ASite BSite C
March 2014
A
C
B
Mortality Data : Georges River
48
1
23
4
5 Wild Sites:1 = Oyster Shed Mangroves2 = Pelican Gut3 = Sylvania Waters4 = Never Fail Bay5 = Lime Kiln Barr
Farmed Sites:Site ASite BSite C
April 2014
A
C
B
Mortality Data : Georges River
49
1
23
4
5 Wild Sites:1 = Oyster Shed Mangroves2 = Pelican Gut3 = Sylvania Waters4 = Never Fail Bay5 = Lime Kiln Barr
Farmed Sites:Site ASite BSite C
May 2014
A
C
B
Mortality Data : Georges River
50
Hawkesbury River – Window of Infection
1
2
34
5
1 = Patonga2 = Porto Bay3 = Mullet Creek4 = Marra Marra5 = Kimmerikong
51
RESULTS:Mortality Data Window : Hawkesbury River
1
2
34
5
1 = Patonga2 = Porto Bay3 = Mullet Creek4 = Marra Marra5 = Kimmerikong
August 2013
52
1
2
34
5
1 = Patonga2 = Porto Bay3 = Mullet Creek4 = Marra Marra5 = Kimmerikong
September 2013
Mortality Data Window : Hawkesbury River
53
1
2
34
5
1 = Patonga2 = Porto Bay3 = Mullet Creek4 = Marra Marra5 = Kimmerikong
October 2013
Mortality Data Window : Hawkesbury River
54
1
2
34
5
1 = Patonga2 = Porto Bay3 = Mullet Creek4 = Marra Marra5 = Kimmerikong
November 2013
Mortality Data Window : Hawkesbury River
55
1
2
34
5
1 = Patonga2 = Porto Bay3 = Mullet Creek4 = Marra Marra5 = Kimmerikong
December 2013
Mortality Data Window : Hawkesbury River
56
1
2
34
5
1 = Patonga2 = Porto Bay3 = Mullet Creek4 = Marra Marra5 = Kimmerikong
January 2014
Mortality Data Window : Hawkesbury River
57
1
2
34
5
1 = Patonga2 = Porto Bay3 = Mullet Creek4 = Marra Marra5 = Kimmerikong
February 2014
Mortality Data Window : Hawkesbury River
58
1
2
34
5
1 = Patonga2 = Porto Bay3 = Mullet Creek4 = Marra Marra5 = Kimmerikong
March – May 2014
Mortality Data Window : Hawkesbury River
59
Window of infection summaryRIVER First mortality Last mortality
Georges October 2013 April 2014
Hawkesbury October 2013 February 2014
• Risk of mortality is not constant throughout the season• Risk is not the same in different bays or estuaries• It is safe between May and September
What can you do to keep farming during the risky window?
• Adults – partial solution– Intertidal culture – raise growing height if you can– Otherwise it is a research priority
• Spat – no solution yet– Remains a research priority
November
May
October
2 month old
7 month old
15 month old
Rack and rail – traysLong-line - basketsFloating - baskets
7,600 - 18,000 oysters 3 ages/sizes
Every oyster examined every 7 to 14 days
Field trials 2011-2012 and 2012 2013
Standard height‘Low’
+300 mm‘High’
Adults and spat 2011-2012 and 2012 2013
Adults
+300 mm high growing height • mortality <50%
Cum
ulati
ve m
orta
lity
(%)
Low
High (+300mm)
Consistent findings were obtained at all 3 sites and in both summers
• No benefit in raising growing height in either baskets or trays• Same results in trays, hanging baskets and floating systems• Spat are just too susceptible – most die
• This remains the biggest hurdle
Spat 2012-2013
Other important observations
• Oysters that survive an outbreak are “immune” and survive the next outbreak
• OsHV-1 can be detected at a low level in some oysters more than 1 month before an outbreak– these are almost certainly the oysters that survive– can we exploit this?
• Age and size – but which is more important?
• Temperature patterns for POMS
France: water temperature and disease
Georges River summer 2012-2013 Sites A, B, CAverage weekly water temperature
31 Jul2012
21 May2013
15oC Mortality in tray and baskets trials2 month period without disease that is not explained by French data
Conclusions1. we need to intepret water temperatures under Australian conditions2. we need to standardise the way we measure water temperature3. we may be able to predict risk periods
Exploitable discoveries from research
1. Removal of virus from water
2. There is a safe window
3. Age and size are important
4. Survivors are “immune”
5. Growing height
• Safe spat rearing
• Normal cultivation possible
• Growout and fattening
This knowledge directly complements the POMS breeding program
May-October: safe period
Novel cultivation practices from the hatchery through to commercial harvest
Integrated approach
Spat - November-May: (year 1)
1. Spat held in OsHV-1 free estuaries, or2. Spat held in safe land-based systems
October
• Spat in the River • Trial fast growing
cultivation systems (FLUPSY)
1. Oysters that reach market size sell2. Other adult oysters high height (<50% will die)
5 months
November
May
October
Adults - November-May (year 2)
Survivors are immune – grow them at standard height
6 months
Safe spat rearing
market
Hatchery
Further research is needed now
November
May
October
Solve problem of spat culture during window of infectionSolve problem of grow-out for farmers who cannot raise growing heightPredict risk periods for Tasmania and South Australia
1. Exploit resistance due to age and size2. Artificially condition spat to survive3. Genetically resistant spat
November
May
October
Proposal to FRDC in current call for new projects
Species diversificationSensitive/Resistant
Dilution effectCash flow
BiosecurityActive surveillance
Quarantine protocolsControl of movements /
transfers
ResearchSelective breedingResistance PO
Other traitsReliable supply
Timeframe
EpidemiologyPathogenicityImmunology
Farming practicesHusbandry techniques
Fast growing systemsDensity
Complementary approaches
STRATEGIESfor POMS
Review business models particularly debt levels to cope with sudden cessation of cash flow
4. Request for help
• 10 farmers from different parts of Tasmania• Temperature probes on oyster leases• Duration – up to 3 years• Inconvenience – a bit• Benefit – knowledge about temperature
profiles relative to estuaries in NSW where we know POMS can occur: risk prediction
Secure yellow cap tube to floor of basket with cable tie
Pool noodle float secured inside basket with cable ties
Basket attached to long line ropein such a way that it is able to floatfreely at all times
Richard Whittington Ms Olivia Evans Dr Navneet Dhand
Dr Ika Paul-PontAnn-Michele Whittington
Anna Waldron Vickie Patten Dr Ana Rubio
The University of Sydney Oyster Team
Alison Tweedie
Dr Paul Hick
Acknowledgements
Funding agencies & collaborators• FRDC, University of Sydney• NSW I&I• Sydney CMA - BBWQIP• Hornsby Shire Council• Siminis Oyster Systems• Tasmanian Oyster Research Committee• Oysters Australia • Shellfish Culture Tasmania
Oyster growers• Broken Bay Oysters - Bruce Alford, John Stubbs,
Rob Moxham, Steve Jones• Endeavour Oysters – Bob, Len and Ted Drake,
Robert Hill and Keith Duggan• Leon and Angela Riepsamen, Grenwell Point
Thank you for your attention