Frozen shellfish combat pollution

Millions of tiny oysters and mussels are being frozen and stored for the future to help combat marine pollution around Britain’s coast.

Until now, testing for pollution using these living indicators could only be done in the summer when the shellfish were reproducing. This new method combines cryogenic technology with a secret recipe of protective natural compounds to keep the tiny shellfish in a state of suspended animation.

Two young scientists have started their own company to develop this revolutionary new technique. Coastal & Marine Biotechnologies (CMB), a spin-out from the Natural Environment Research Council (NERC), is being opened in Plymouth on 7th December by Dr Caroline Jackson, Chair of the European Parliament’s Environment Committee and MEP for the South West.

The new method is inexpensive, reliable, quick and easy to perform at any time of the year. It can be used for routine testing of seas around tourist beaches, on board ships or in response to environmental disasters such as oil spills.

The embryonic shellfish are frozen to a temperature of -196 degrees C -more than twice as cold as any recorded temperature in Antarctica – and stored in special containers that resemble drinking straws.

Research Director, Ian McFadzen, said, ‘At this incredibly low temperature living tissue is normally destroyed. But by carefully controlling the cooling process and adding our special cocktail of protective compounds the animals can survive for at least 50 years in their suspended state.’ The compounds used were originally derived from Arctic and Antarctic organisms and tropical plants.

When testing is done, the tiny creatures are thawed and placed in seawater where pollution is suspected. ‘If they develop and grow normally then the water is clean, but if they die or show deformities that will indicate the presence of harmful pollutants,’ said John Wedderburn, co-founder of CMB.

‘If repeat testing needs to be carried out in the same area over several decades, the same batch of frozen embryos can be used to ensure consistency in the test results.’

The freezing technique can be applied to fish breeding programmes or used to conserve rare or vulnerable species of marine life. These ultra-low temperatures are the same as those used in human IVF (in vitro fertilisation) techniques.