Scientists at BioResearch, Ireland's National Diagnostics Centre in NUI Galway, have developed a laboratory cell culture-based system to test for toxins in shellfish. They predict the system could become a routine alternative to the animal testing methods currently used.
The system determines the presence of powerful toxins, okadaic acid and azaspiracid.
Quality control and food safety have become a priority for the molluscan shellfish industry here, which was worth £34 million in exports last year. Testing for toxins is obligatory before sale for human consumption. The bioassay procedure, using biological materials like live animals, tissues or cells, is the standard method used in most EU countries, Canada, the USA and Japan for the past 20 years.
However, the Irish shellfish industry is keen to develop a range of alternative, faster biochemical-based tests to detect toxins, stated Dr Tony Forde of the National Diagnostics Centre. The new cell culture test system is being evaluated by Bantry Bay Mussels Ltd, one of the State's largest shellfish exporters, for in-house quality control.
Phycotoxins, a type of toxin produced naturally by certain plankton on which shellfish feed, present a major challenge worldwide to the shellfish sector and there is no reliable predictor model to warn of possible danger. Weekly monitoring of some 80 bays around this coastline where shellfish is produced aims to look out for any of three regular toxins which are of no harm to the animals themselves but can cause a health risk for consumers.
Temporary closure of bays when national and EU limits are exceeded is a regular occurrence, and it is estimated that it can cause losses of up to £1 million in bad years - such as 1994/1995. Only last week, four bays were closed to scallop harvesting in the west, north-west and south-west, following discovery of amnesiac shellfish poisoning (ASP).
The BioResearch Ireland team hopes that its method will be given the official seal of approval for routine testing in the EU. Mr Micheal O Cinneide, head of the Marine Institute's marine environmental division, has welcomed the progress. The institute has provided up to £78,000 in funding for this project under the EU Marine Research Measure for 1998-99. Based on success to date, it has agreed additional funds next year for a joint research project involving BioResearch Ireland, the industry and the Marine Institute itself.