South African Molluscan Shellfish Monitoring & Control ... · 2011 Shellfish Monitoring Programme...

South African Molluscan Shellfish Monitoring & Control Programme

Annual Report

2011

Custodian:

Shellfish Monitoring Programme Marine Aquaculture Department of Agriculture, Forestry and Fisheries Private Bag X2 Roggebaai Cape Town 8012

Enquiries:

Mr. Mayizole Majangaza, Email: [email protected], Tel: 021 403 7065, Fax: 021 434 2144

mailto:[email protected]

Shellfish Monitoring Programme Annual Report February 2011

i

Contents

ABBREVIATIONS ............................................................................................................................................ 1

INTRODUCTION ............................................................................................................................................. 2

SHELLFISH FARMS STATUS ............................................................................................................................ 2

MONITORING OF HAZARDOUS SUBSTANCES ............................................................................................... 4

MONITORING DATA AND FARM CLOSURES.................................................................................................. 7

Biotoxins.................................................................................................................................................... 7

Paralytic Shellfish Poison (PSP) ............................................................................................................. 8

Diarrhetic Shellfish Poison (DSP) ........................................................................................................... 9

Amnesic Shellfish Poison (ASP) ........................................................................................................... 10

Microbiological Contamination............................................................................................................... 10

Escherichia coli (E. coli) ....................................................................................................................... 10

Salmonella and Vibrio ......................................................................................................................... 11

Heavy metals, Pesticides, PCBs and Radionuclides ................................................................................ 11

COMPLIANCE HISTORY ................................................................................................................................ 13

SHELLFISH MONITORING PROGRAMME PROGRESS ................................................................................... 13

CONCLUSION ............................................................................................................................................... 15

REFERENCES ................................................................................................................................................ 15

Shellfish Monitoring Programme Annual Report February 2011

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FIGURES

Figure 1: Distribution of shellfish farms along the South African coast ....................................................... 3

Figure 2: PSP results for farms to the west of Cape Point ............................................................................ 8

Figure 3: DSP results for farms to the west of Cape Point .......................................................................... 10

Figure 4: E. coli results for farms on the South African Coastline............................................................... 11

Figure 5: Cadmium results for farms to the East & West Coast of Cape Point ........................................... 12

Figure 6: Lead results for farms to the East & West Coast of Cape Point .................................................. 12

Figure 7: Mercury results for farms to the East & West Coast of Cape Point ............................................ 13

TABLES

Table 1: Schedule for testing of hazardous substances ................................................................................ 5

Table 2: Regulatory limit for human health hazards monitored & test laboratories ................................... 6

2011 Shellfish Monitoring Programme Annual Report

1

ABBREVIATIONS

AM Aquaculture Management

ASP Amnesic Shellfish Poisoning

CSIR Council for Scientific and Industrial Research

DAFF Department of Agriculture, Forestry and Fisheries

DoH Department of Health

DSP Diarrhetic Shellfish Poisoning

EOP Environmental Officer Production

EOSP Environmental Officer Special Production

FCO Fisheries Compliance Office

HPLC High-performance liquid chromatography

LCMS Liquid chromatography–mass spectrometry

NECSA Nuclear Energy Corporation of South Africa

NRCS National Regulator for Compulsory Specification

PCB Polychlorinated Biphenyls

PSP Paralytic Shellfish Poisoning

SABS South African Bureau of Standards

SAMSM&CP South African Molluscan Shellfish Monitoring and Control Programme

SANAS South African National Accreditation System

YTX Yessotoxins

HABs Harmful Algal Blooms

http://www.csir.co.za/


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INTRODUCTION

The South African Molluscan Shellfish Monitoring and Control Programme (SAMSM&CP) is a programme

within the Aquaculture and Economic Development Chief Directorate, which falls within the Fisheries

Management Branch of the Department of Agriculture, Forestry and Fisheries (DAFF).

The programme aims to provide the necessary guarantees to local and international markets that the

risk of disease and poisoning through consuming molluscan shellfish is adequately managed and

minimized. To assure that this aim is achieved, the SAMSM&CP is working closely with the Fisheries

Compliance Office (FCO) of DAFF, South African molluscan shellfish farmers, laboratories, National

Regulator for Compulsory Specification (NRCS), Department of Health (DoH) and Municipalities.

The following molluscan shellfish species farmed in South Africa include Haliotis midae (Abalone),

Crassostrea gigas (Oyster), Mytilus galloprovincialis (Mediterranean mussel) and Choromytilus

meridionalis (Black mussel).

The shellfish farms are monitored by the SAMSM&CP for human health hazards such as biotoxins,

microbiological organisms, heavy metals, pesticides, polychlorinated biphenyls (PCBs) and radionuclides.

Should the regulatory limit for any of the hazardous substances or organisms be exceeded the farms are

temporarily closed for harvesting until the contaminant reaches acceptable limits.

SHELLFISH FARM STATUS

There were 19 shellfish farms monitored by the SAMSM&CP during 2011 of which 9 of the farms were

to the west of Cape Point and 10 farms to the East of Cape Point (Figure 1). The farms to the west of

Cape Point included 3 abalone farms, 2 mussel farms and 2 oyster farms. The farms to the east of Cape

Point included 8 abalone farms and 3 oyster farms. One of the mussel farm on the west of cape point

also culture oysters and one of the oyster farms culture mussels.


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Figure 1: Distribution of shellfish farms along the South African coast

Most abalone farms were land based and one abalone farm was sea based. The abalone on land based

farms are grown in tanks and the water is pumped into the tanks through free flow and/or recirculation

systems. The oyster and mussel farms were sea-based and grown on ropes suspended from floating

rafts; though on one farm the oysters were grown on racks that were planted into the substrate.

Shellfish farms are susceptible to poor water quality as a result of Harmful Algal Blooms (HABs), sewage,

industrial and domestic contamination. The farms which are at most risk are those situated near

developed areas. Most of the farms in South Africa however are situated in areas that are relatively free

of pollution and have had relatively low incidences of biotoxin concentrations exceeding the regulatory

limit.


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MONITORING OF HAZARDOUS SUBSTANCES

The Microbiological organisms are tested for by the South African Bureau of Standards (SABS), situated

in Rosebank, Cape Town and Swift laboratories situated in Claremont, Cape Town. The tests included

E. coli, Salmonella species and Vibrio species. SABS is accredited for salmonella and Vibrio and in the

process of being accredited for ISO 16649-3 for testing E. coli. Swift is South African National

Accreditation System (SANAS) accredited for SANS 6596 method for testing Vibrio and accredited for

SANS 6179 and ISO 16649-3 methods for testing Salmonella and E. coli respectively.

The biotoxins were tested for at the Council for Scientific and Industrial Research (CSIR) in Rosebank,

Cape Town. The biotoxins monitored include Paralytic Shellfish Poisoning (PSP) toxins, Diarrhetic

Shellfish Poison (DSP) toxins and Amnesic Shellfish Poisoning (ASP) toxins. PSP toxins were tested using

the Mouse Bioassay, DSP toxins were tested using Mouse Bioassay and Liquid Chromatography–Mass

Spectrometry (LCMS) and ASP toxins were tested on the High-performance liquid chromatography

(HPLC) instrument.

Various farms in Saldanha Bay, on the West Coast also submitted samples to Cawthron Institute in New

Zealand to test for lipophilic toxins, which include DSP toxins. This was necessitated as the Mouse

Bioassay is too sensitive for yessotoxin and gives a positive result for the DSP test if the concentration is

as low as 2 to 3 mg/kg. The actual trigger level for the Mouse Bioassay yessotoxin must still be

confirmed. DAFF has recently procured a LCMS that is being operated by CSIR. The LCMS will improve

South Africa biotoxin monitoring capabilities and reduce the number of false DSP positives as well as

provide actual concentrations of biotoxins.

Other hazardous substances monitored include heavy metals (lead, mercury and cadmium), pesticides

and PCBs. These are monitored by SABS in Pretoria. Radionuclides are tested for by NECSA in Pretoria.

The test methods that the labs employ are stipulated in the SAMSM&CP and the methods used are

SANAS accredited or the labs are working towards accreditation. The methods have however all been

validated. These hazardous substances and microbiological organisms were monitored at the frequency

depicted in Table 1.

Table 1: Schedule for testing of hazardous substances

West of Cape Point East of Cape Point

Hazardous Filter Feeder Non – Filter Filter Feeder Non – Filter

http://www.csir.co.za/


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Substances feeder Feeder

Biotoxins

PSP coursing

toxins

48h or twice a

week for multiple

harvesting

2 weeks 1 month 1 month

DSP Coursing

toxins

1 week 1 month 2 weeks 1 month

ASP 1 month 1 month 1 month 1 month

Microbiological Organisms

E. coli 1 month 1 month 1 month 1 month

Salmonella 1 month 1 month 1 month 1 month

Vibrio 1 month 1 month 1 month 1 month

Other Hazardous substances

Heavy Metals Annually Annually Annually Annually

Pesticides Annually Annually Annually Annually

PCB Annually Annually Annually Annually

Radionuclides Every 3 years Every 3 years Every 3 years Every 3 years

The routine monitoring of farms was based on the potential levels of contamination and in terms of

biotoxins, the location on the farm relative to Cape Point. There tends to be substantially more

upwelling systems to the west of Cape Point resulting in higher incidences and concentrations of

Harmful Algal Blooms (HABs) and concomitant biotoxin accumulation in the shellfish. The classification

status of the farm was also considered when designing a monitoring programme.

When any of the hazardous substances or microbiological organism concentrations exceeds the

regulatory limit (Table 2), the laboratories inform the SAMSM&CP office in the form of a red alert. The

red alert requires that the lab phones the staff SAMSM&CP office responsible for farm closures and

sends an email indicating the test result. The SAMSM&CP office then warns the farm not to harvest until

the test result has been confirmed.

If the result is confirmed to exceed the regulatory limit the farm is temporarily closed and the relevant

stakeholders are informed accordingly. The farm is also temporarily closed if shellfish are not tested in


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accordance with the SAMSM&CP. The farm is reopened only when the concentration of the hazardous

substance is below the regulatory limit (Table 2) and/or the programme is complied with.

Table 2: Regulatory limit for human health hazards monitored and test laboratories

Hazardous Substances Regulatory Limit Laboratories

Biotoxins

PSP toxins < 0.8 mg PSP/kg edible flesh CSIR

okadaic acid, dinophysistoxins,

azaspiracids, pectenotoxins and

yessotoxins

Death of 2 out of 3 mice in 24 hours is

considered a positive result (Regulation (EC)

No 2074/2005) (Mouse Bioassay)

CSIR

Okadaic acid group toxins: OA, DTX

1, DTX 2 & DTX 3 and

Pectenotoxins group toxins: PTX 1

& PTX 2

≤ 0.16 mg okadaic acid equivalents / kg edible

flesh (Commission Regulation (EC) No

853/2004). (EU-RL* LC-MS/MS method)

(Commission Regulation (EC) No 15/2011)

CSIR

Yessotoxins group toxins: YTX, 45

OH YTX, homo YTX, and 45 OH

homo YTX

≤ 8 mg yessotoxin equivalents / kg edible flesh

(Codex). (^Liquid Chromatography Mass

Spectrometry (EU-RL LC-MS/MS method)


CSIR

Azaspiracids group toxins: AZA1,

AZA2 and AZA3.

≤ 0.16 mg azaspiracid equivalents / kg edible

flesh (Commission Regulation (EC) No

853/2004). (^Liquid Chromatography Mass

Spectrometry (EU-RL LC-MS/MS method)


CSIR

ASP ASP < 20 mg DA/kg edible flesh CSIR

Microbiological Organisms

E. coli <230/100g edible flesh SABS & Swift

Salmonella absent SABS & Swift

Vibrio spp absent SABS & Swift

Other Hazardous substances

Heavy Metals Lead: < 1.5 mg/kg edible flesh

Mercury: < 0.5 mg/kg edible flesh

SABS


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Cadmium: < 3.0 mg/kg edible flesh

Pesticides < 0.05 mg/kg SABS

PCB < 0.02 mg/kg SABS

Radionuclides < 600 Bq/kg NECSA

The criterion for reopening depends on the contaminant that is present on that particular farm. As an

example when the farm is temporarily closed due to biotoxins, the farm is required to submit three

consecutive samples to CSIR lab for analysis of the contaminant. The samples should be taken over a

period not exceeding two weeks and samples may not be taken on the same day. If all three samples are

below the regulatory limit, the farm will be reopened. When the farm is closed due to other contaminants,

the farm is reopened when the contaminant is below the regulatory limit.

MONITORING DATA AND FARM CLOSURES

Data has been captured and analysed for marine aquaculture farms along the South African Coast. The

biotoxins were analyzed separately for two regions viz. west of Cape Point and east of Cape Point. The

other hazardous substances were analyzed for the coast as a whole.

There were 26 farm closure notices sent to shellfish farms by the SAMSM&CP office in 2011. West of

Cape Point there were 19 notices issued and 7 notices were issued for farms to the east of Cape Point.

Most of the farm closures were due to biotoxins, and a few due to the presence of microbiological

contamination. There were no closures due to other hazardous substances viz. heavy metals, pesticides,

PCBs or radionuclides.

Biotoxins

During 2011, two farms were closed due to non-compliance to the biotoxin testing schedule; otherwise

farms were only closed due to PSP and DSP causing toxins levels exceeding the regulatory limit.

Paralytic Shellfish Poison

The PSP toxin concentrations for all the farms to the west of Cape Point are represented in Figure 2. The

concentrations that exceeded the regulatory limit triggered farm closures. The only farms that were

closed in this region were three abalone farms. As the PSP toxin levels exceeded the regulatory limit

these farms were not allowed to market live product, only processed products where the abalone was


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eviscerated and scrubbed. Some of these farms were closed for sale of live products for approximately

six months during 2011 and were under intensive sampling schedule to ensure close monitoring of PSP

toxin. There was no PSP toxins detected in shellfish farms to the east of Cape Point and as a result no

closures.

Figure 2: PSP results for farms to the west of Cape Point

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

18

-No

v-10

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-Jan-1

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v-11

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-Feb-1

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PSP

(m

g/kg

ed

ible

fle

sh)


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Diarrhetic Shellfish Poison

The mussel and oyster farms in Saldanha Bay tended to experience more DSP closures in 2011. Farm

closures due to DSP were mostly between April and August (

Figure 3). Some of the farms remained closed for about six months.

There were no abalone farm closures due to DSP to the west of Cape Point. On the East of Cape Point

there was only one oyster farm that experienced closures as a result of the DSP toxin tests.

0

0.2

0.4

0.6

0.8

1

1.2

18

-No

v-10

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-Jan-1

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-Ap

r-11

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1

14

-Sep-1

1

03

-No

v-11

D

SP c

on

cen

trat

ion

(M

U)


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Figure 3: DSP results for farms to the west of Cape Point

Amnesic Shellfish Poison

Though low levels of Amnesic Shellfish Poison (ASP) toxins has been detected in mussels in Saldanha

Bay, no shellfish farms were closed due ASP exceeding the regulatory limit. There has been no ASP toxin

detected in abalone to date.

Microbiological Contamination

E. coli, which is used as an indicator species, is used for the classification of growing areas and is

important indicators of sewerage pollution and associated diseases. The farms were all classified as

“Approved” based on the data received. Other microbiological organism data analysed includes

Salmonella and Vibrio. Data for wet storage facilities for the oyster farms are also analysed.

Escherichia coli

In 2011 there were a few farms that were sent closure notices due to E. coli levels exceeding the

regulatory limit. The closures were mostly between April and July (Figure 4) and in some cases appeared

to be associated with high rainfall events.

0

0.2

0.4

0.6

0.8

1

1.2

18

-No

v-10

07

-Jan-1

1

26

-Feb-1

1

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-Ap

r-11

06

-Jun

-11

26

-Jul-1

1

14

-Sep-1

1

03

-No

v-11

D

SP c

on

cen

trat

ion

(M

U)


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Figure 4: E. coli results for farms on the South African Coastline.

Salmonella and Vibrio

Only one farm was sent closures notice due to the presence Salmonella. There was no closure due to

Vibrio species.

Heavy metals, Pesticides, PCBs and Radionuclides

The levels of heavy metal tended to be higher in mussels and oysters than in abalone (Figure 5, 6 & 7);

most of these farms are at Saldanha Bay. Both on the East and west of Cape Point there were no farm

closures due to heavy metals exceeding the regulatory limits (Table 1).

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

18

-No

v-10

07

-Jan-1

1

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r-11

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-Jun

-11

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03

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v-11

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-Dec-1

1

11

-Feb-1

2

Co

nce

ntr

atio

n (

Co

un

t/1

00

g)

Regulatory limit


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Figure 5: Cadmium results for farms along the South African coast

Figure 6: Lead results for farms along the South African coast

0

0.5

1

1.5

2

2.5

Ab

alon

e 1

Mu

ssel 1

Oyster 1

Ab

alon

e 2

Mu

ssel 2

Oyster 2

Ab

alon

e 3

Ab

alon

e 4

Ab

alon

e 5

Ab

alon

e 6

Ab

alon

e 7

Ab

alon

e 8

Ab

alon

e 9

Ab

alon

e 10

Oyster 4

Oyster 5

Co

nce

ntr

atio

n (

mg/

kg)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Ab

alon

e 1

Mu

ssel 1

Oyster 1

Ab

alon

e 2

Mu

ssel 2

Oyster 2

Ab

alon

e 3

Ab

alon

e 4

Ab

alon

e 5

Ab

alon

e 6

Ab

alon

e 7

Ab

alon

e 8

Ab

alon

e 9

Ab

alon

e 10

Oyster 4

Oyster 5

Co

nce

ntr

atio

n (

mg/

kg)


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Figure 7: Mercury results for farms along the South African coast

There were no detectable levels of pesticides, PCB or radionuclide present in any shellfish farms along

the South African Coast.

COMPLIANCE HISTORY

Most of the farms have complied with the requirements of SAMSM&CP. There were only two farms that

did not comply with the requirements. The main non-compliance was failure to do the required tests

according to the frequency stipulated in the SAMSM&CP. The farms are both complying with the

SAMSM&CP.

SHELLFISH MONITORING PROGRAMME PROGRESS

South African shellfish farmers have accepted the SAMSM&CP and are prepared to comply with its

requirements. Though a few oyster farms have contested the DSP Mouse Bioassay, they have not

provided a suitable alternative to date. DAFF has increased capacity to improve on the effective

management of the programme by appointing two new staff.

0

0.05

0.1

0.15

0.2

0.25

0.3

Ab

alon

e 1

Mu

ssel 1

Oyster 1

Ab

alon

e 2

Mu

ssel 2

Oyster 2

Ab

alon

e 3

Ab

alon

e 4

Ab

alon

e 5

Ab

alon

e 6

Ab

alon

e 7

Ab

alon

e 8

Ab

alon

e 9

Ab

alon

e 10

Oyster 4

Oyster 5

Co

nce

ntr

atio

n (

mg/

kg)


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There is now 3 staff managing the programme, which includes an Assistant Director, an Environmental

Officer Special Production (EOSP) and an Environmental Officer Production (EOP).

In 2011 the SAMSM&CP office identified a gap in phytoplankton monitoring for food safety purposes

with the assistance from the NRCS audit that was conducted. Standard Operation Procedures (SOPs) for

On-farm phytoplankton identification and SAMSM&CP lab phytoplankton monitoring have been

compiled. These SOPs are compiled in relation to the SAMSM&CP manual. The SAMSM&CP staff also

attended phytoplankton identification courses to assist build their capacity. Currently the phytoplankton

monitoring is being implemented and there is progress.

The LCMS for biotoxin analysis that was procured by the DAFF in 2010 to assist famers with effective

analysis of shellfish samples has been fully implemented for testing DSP causing toxins. Currently the

CSIR lab is in progress with the validation of an AOAC method 2005.06 to test for PSP causing toxins on

the Liquid Chromatography Fluorescence Detector (LCFLD). The use of the LCMS has reduced the

overall cost of biotoxin analysis and increase the accuracy of analysis.

The SAMSM&CP staff has improved the working relationship with other stakeholder involved in the

programme. In 2011 several meetings were held to improve working relationships with labs and other

stakeholders. In these meetings there were exchange of ideas that assisted with the improvement of the

office and the stakeholder’s activities, for example improvement of turnaround time for the availability

of results to the SAMSM&CP office and farmers. Some laboratories that were not compliant with the

SAMSM&CP requirements were addressed in these meeting.

According to the SAMSM&CP internal audit and NRCS independent audit, the biotoxin and

microbiological labs and the SAMSM&CP office met more than 60% of the EU requirements for export of

shellfish to the EU countries. The SAMSM&CP office has also assisted the oyster and mussel farmers

towards achieving the export requirements of China.


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CONCLUSION

The SAMSM&CP report for 2011 outlines the status of marine aquaculture shellfish farms and the

programme, a summary of the compliance data and the level of compliance. The 19 farms that are

monitored include abalone, mussel and oyster farms. These farms are monitored by DAFF: Shellfish

Monitoring Programme which implements the South African Molluscan Shellfish Monitoring and Control

Programme (SAMSM&CP).

Though the mussel and oyster farms are more susceptible to contaminant accumulation and have

experienced closures due to PSP and DSP, abalone farms are also susceptible to PSP poisoning,

particularly on the West Coast. There have been a few closures due to E. coli, which appears to be

associated with heavy rainfall periods.

REFERENCES

Department of Agriculture, Forestry and Fisheries (2011) South African Molluscan Shellfish Monitoring

and Control Programme.

South African Molluscan Shellfish Monitoring & Control ... · 2011 Shellfish Monitoring Programme...

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