Shellfish

Since biblical times, algal blooms have been recorded in the sea and inland waters. The so-called ‘red tides’ have been recorded all over the world. Algal blooms are caused by phytoplankton which grow rapidly when certain conditions occur, usually increased water temperature and/or light. About 40 types of phytoplankton are poisonous.

Algal blooms are important in Shetland because the toxins produced by the algae, accumulate in shellfish like scallops and mussels, causing ill health in people, ASP (amnesic shellfish poisoning), DSP (diarrhoetic shellfish poisoning) and PSP (paralytic shellfish poisoning).

The Food Standards Agency has a monitoring programme implemented through local Environmental health departments. Shellfish harvesting areas may be restricted or closed to commercial harvesters if toxin levels are found to be above prescribed limits. Latest monitoring data, and advice on which areas are restricted or closed is available on the FSA website.

A link to Food Standards Agency website can be found on the Useful links page.

For further information on Diarrhoeic Shellfish Poisoning please contact Environmental Health on 01595 744800