Frozen shellfish to combat pollution

Natural Environment Research Centre

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 dynamic young scientists have started their own company to
develop this revolutionary new technique. Coastal & Marine
Biotechnologies (CMB) Ltd., a spin-out from the Natural Environment
Research Council (NERC), is being opened in Plymouth on 7 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 minus 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.

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