- Asked by: Jamie McGrigor, MSP for Highlands and Islands, Scottish Conservative and Unionist Party
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Date lodged: Friday, 08 September 2000
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Current Status:
Answered by Susan Deacon on 20 November 2000
To ask the Scottish Executive whether it will explain the high performance liquid chromatography testing procedure and in particular how long the testing actually takes and what the margin of error is for this procedure.
Answer
High Performance Liquid Chromatography (HPLC) is used to analyse shellfish samples for domoic acid, the chemical causing amnesic shellfish poison (ASP). The toxin is extracted from prepared samples using aqueous methanol, then partially purified and fully isolated from the purified extract by pumping through an absorbent column within the HPLC machine. Chromatographic techniques separate domoic acid from compounds such as lipids, fatty acids, amino acids etc present in the extract. Finally, the toxin is quantified and identified by ultraviolet spectrometric detection, by comparison with standard reference domoic acid. The procedure meets EU requirements and is United Kingdom Accreditation Service UKAS accredited. The standard deviation of domoic acid analyses undertaken in a recent inter-laboratory comparison exercise covering the UK and Ireland was <12.5%. FRS Marine Laboratory, Aberdeen currently test approximately 100-150 shellfish samples per week for ASP.
- Asked by: Jamie McGrigor, MSP for Highlands and Islands, Scottish Conservative and Unionist Party
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Date lodged: Friday, 08 September 2000
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Current Status:
Answered by Susan Deacon on 20 November 2000
To ask the Scottish Executive what shellfish molluscs other than scallops are tested for toxins.
Answer
Samples of all bivalve molluscs harvested for human consumption are tested for the presence of toxins. The molluscs tested include: mussels, oysters, scallops, queens, razor fish and cockles.
- Asked by: Jamie McGrigor, MSP for Highlands and Islands, Scottish Conservative and Unionist Party
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Date lodged: Friday, 08 September 2000
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Current Status:
Answered by Susan Deacon on 20 November 2000
To ask the Scottish Executive why the scallop is particularly susceptible to toxin contamination while the queen scallop appears to be entirely resistant.
Answer
The Food Standards Agency has advised me that it is not known why some species appear to accumulate toxins more readily than others do. Toxins from the phytoplankton on which the molluscs feed accumulate in the animals. Once the intake of toxin producers ceases, the molluscs metabolise the toxins and eliminate them from their tissues. Scallops appear to have a much slower rate of elimination than other mussels and queens, meaning the toxins are retained for longer periods.
- Asked by: Jamie McGrigor, MSP for Highlands and Islands, Scottish Conservative and Unionist Party
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Date lodged: Friday, 08 September 2000
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Current Status:
Answered by Susan Deacon on 20 November 2000
To ask the Scottish Executive, from each sample collected under the Food and Environment Protection Act 1985, how many (a) scallops and (b) queen scallops have been tested for (i) amnesic shellfish poisoning, (ii) paralytic shellfish poisoning, (iii) dieuretic shellfish poisoning and (iv) other toxins.
Answer
The FRS Marine Laboratory Aberdeen (FRS MLA) has analysed 1,698
samples of bivalve mollusc for paralytic shellfish poisoning (PSP), 1,284 for diarrhetic shellfish poisoning (DSP) and 1,969 for amnesic shellfish poisoning between 1 January and 31 October 2000. This composed of:- Total samples of all scallops tested: i) 1,050 ASP; ii) 322 PSP, and iii) 77 DSP.
- Queens scallops accounted for: i) 81 ASP; ii) 71 PSP, and iii) 72 DSP.
Given the aim to minimise the period for which boxes remain closed through intensifying monitoring as boxes approach safe limits, the Food Standards Agency estimates that some 80% come from areas subject to controls under the Food and Environment Protection Act 1985. No other toxins are monitored.
- Asked by: Jamie McGrigor, MSP for Highlands and Islands, Scottish Conservative and Unionist Party
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Date lodged: Friday, 08 September 2000
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Current Status:
Answered by Susan Deacon on 20 November 2000
To ask the Scottish Executive how many personnel are involved in (a) sample collection; (b) sample transportation; (c) sample testing and (d) result verification in relation to amnesic shellfish poisoning.
Answer
The number of people involved in amnesic shellfish poisoning (ASP) testing varies depending on the source and origin of the samples. Collection involves sea-going staff and cultivation site owners. Transportation may be by air, boat and or road. Scientific staff undertake preparation, analysis and verification of sample results.
- Asked by: Jamie McGrigor, MSP for Highlands and Islands, Scottish Conservative and Unionist Party
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Date lodged: Friday, 08 September 2000
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Current Status:
Answered by Susan Deacon on 20 November 2000
To ask the Scottish Executive what contingency plans are in place for sampling for amnesic shellfish poisoning during (a) bad weather and (b) the holiday season.
Answer
The shellfish toxin sampling continues throughout holidays and weekends to ensure that public health is protected at all times. However bad weather will limit the harvesting of samples. Measures are taken to ensure that immediately the weather improves sampling is resumed.
- Asked by: Jamie McGrigor, MSP for Highlands and Islands, Scottish Conservative and Unionist Party
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Date lodged: Friday, 08 September 2000
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Current Status:
Answered by Susan Deacon on 20 November 2000
To ask the Scottish Executive (a) why the areas covered by boxes closed under the Food and Environment Protection Act 1985 are the si'e they are; (b) how often tests are conducted in each box area; (c) how many scallops are sampled from each box area; (d) how often tests are conducted in box areas following closure; (e) what influences the actual sampling point within a box area; (f) whether the Global Positioning Satellite co-ordinates are available for each sample point; (g) whether box area sampling points vary and, if so, in what manner; (h) if half box areas are closed (e.g. Orkney), whether this indicates that samples are collected from more than one location in every box area, and (i) why some box areas remain closed even after readings fall below the safety threshold.
Answer
The size of the boxes used to monitor offshore scallop grounds have to be large enough to ensure public safety and were set using hydrographic information. The boxes were accepted by the EU.
- The EC Directive (91/492/EEC) requires periodic monitoring of live bivalve molluscs. The Food Standards Agency Scotland (FSAS) ensure that Scottish boxes are monitored throughout the year. When algal toxin levels are above the statutory level the frequency of sampling is increased.
- 10-12 scallops are taken as one sample, two of these samples, from separate tows, are taken from each box.
- Following closure of a box by a Food and Environment Protection Act Order, FSAS aim to resample every fortnight until the algal toxin level drops to close to the statutory limit. Thereafter, weekly sampling is requested.
- A commercial dredger that fishes on known scallop grounds within each box undertakes sampling.
- Global Positioning Satellite co-ordinates are not used when sampling boxes off-shore, although the boat involved with the sampling can provide the FRS Marine Laboratory with their position if necessary.
- Samples are collected from known scallop grounds. There may be some variation in sampling points, from trip to trip, within the same relative vicinity.
- Generally two samples are collected from within each box. If land bisects the box additional samples may be collected.
Boxes remain closed until two algal toxin results, below that of the statutory limit, are obtained with at least one week between each result. However there are some cases where boxes remain closed although the toxin level has dropped below the statutory limit, since other algal toxins may have increased in the area thus affecting the same shellfish species.
- Asked by: Jamie McGrigor, MSP for Highlands and Islands, Scottish Conservative and Unionist Party
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Date lodged: Friday, 08 September 2000
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Current Status:
Answered by Susan Deacon on 20 November 2000
To ask the Scottish Executive what the early warning signs are of an outbreak of amnesic shellfish poisoning.
Answer
The early warning sign for an outbreak of amnesic shellfish poisoning (ASP) is the presence of an algal phytoplankton organism called Pseudo-nitzschia. Scallops filter sea water and consume the planktonic organism which in turn causes a build-up of toxin in the shellfish. Scallops containing large quantity of this toxin, if eaten, cause ASP in humans.
- Asked by: Jamie McGrigor, MSP for Highlands and Islands, Scottish Conservative and Unionist Party
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Date lodged: Friday, 08 September 2000
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Current Status:
Answered by Susan Deacon on 20 November 2000
To ask the Scottish Executive whether the severity of winter conditions has any effect on the appearance of amnesic shellfish poisoning.
Answer
There is insufficient scientific data to specify whether the severity of winter conditions has any effect on the incidence of amnesic shellfish poisoning (ASP). The growth of the causative organisms is cyclic, reflecting the spring and autumn planktonic blooms which in turn are caused by fluctuations in temperature, light and nutrients.
- Asked by: Jamie McGrigor, MSP for Highlands and Islands, Scottish Conservative and Unionist Party
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Date lodged: Friday, 08 September 2000
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Current Status:
Answered by Susan Deacon on 20 November 2000
To ask the Scottish Executive how important (i) water chemistry; (ii) nutrient balance; (iii) nitrogen (ammonia and urea); (iv) phosphate, and (v) water temperature are to the propagation of algal blooms.
Answer
I refer the member to the answer given to question S1W-09757.
