Chamber and committees

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:

1. Total samples of all scallops tested: i) 1,050 ASP; ii) 322 PSP, and iii) 77 DSP.
2. 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.

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.

The Food Standards Agency has advised me that toxins accumulate to differing levels in the different edible parts of the scallop. Proportionate toxin levels in the gonad are likely to be considerably greater than in the white meat. Testing an amalgam of white meat and gonad mashed together will therefore lead to a lower result than the current gonad only test. As it is possible to consume only the gonad, it is the result of the gonad test which must be used to ensure the protection of public health.

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.

The gonads from 10-12 scallops are used to provide a sample for analysis for algal toxins, never a single gonad. Even after spawning there is sufficient material present from 10-12 scallops to permit analysis.

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.

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.

The Food Standards Agency has advised me that amnesic shellfish poisoning is caused by phytoplanktonic algae creating blooms which are fed upon by bivalve molluscs such as scallops. The growth of these causative organisms is cyclic, therefore the poisoning also tends to be cyclical. However, given the relatively short period over which monitoring for ASP has been carried out, there is insufficient evidence from which to derive specific seasonal trends in the occurrence of amnesic shellfish poisoning.

The Food Standards Agency aim to place a Food and Environment Protection Act (FEPA) Order as quickly as possible to ensure public safety. To help minimise delay, a draft Order is prepared by the Scottish Executive Solicitor's Office Legal Service while ministerial clearance for the Order is sought. Communications between parties involved in the making of FEPA Orders has been improved through more efficient use of email and fax, though ways of making further improvements continue to be investigated. Some improvements have also been possible with regard to the statutory process, which help avoid the potential problems of FEPA Orders expiring during parliamentary recess.

Samples collected as part of the routine monitoring programme are sent to the FRS Marine Laboratory Aberdeen (FRS MLA) by first class post in containers provided for the purpose. Samples arrive within two days of posting. Samples are collected by chartered fishing vessels over fairly large areas. Samples may be caught and kept aboard the boat for 2-3 days before being landed. Once landed, they are immediately collected by FRS MLA staff and transported to Aberdeen. Testing is generally initiated on the day MLA receive the sample.