Lamlash mussels
Sally Campbell of COAST flags up the fact that mussels in Lamlash Bay have for some time been cited as polluted in the Government’s Food Safety Monitoring report. Malcolm Wheeler, who does the testing for the mussel farm in Lamlash for the government and is therefore is the source of the report, says the mussels are always contaminated at this time of year. They are not lifted till the all clear is given, but Malcolm says, ‘Maybe a warning to people not to pick their own mussels in the summer might be in order.’ He adds, I test monthly for E coli, the present E coli state is A class, which is the safest, and the mussels could be sold now but for the other contaminants. Lamlash Bay is rich in phytoplankton, which produces these contaminates as well as feeding the mussels.’
Sally Campbell agrees, and comments as follows :
It is quite right that they are testing for phytoplankton, which can cause severe reaction in humans, so comes under human health. Of all the places tested around Scotland, many are not closed because the concentration of harmful phytoplankton is lower or absent. This may be because the water is cleaner, thus containing fewer nutrients, or faster flowing. It is well known that concentrations of these are often higher near fish farms, or where farm runoff etc may provide extra nutrients in the water. The Lamlash mussel farm is near burns, farms and a major salmon farm. I don’t know if they test for E. coli, which of course is associated with untreated sewage.
For anyone interested in the scientific details, Sally offers the following explanation of Harmful Algal Blooms
Harmful algae blooms (HABs) are microscopic single-celled plants that live in the sea. HABs is a term used to describe a proliferation, or ‘bloom,’ of single-celled marine algae called phytoplankton. Most species of algae or phytoplankton are not harmful and serve as the energy producers at the base of the food web. While there are thousands of algae species in existence, only a few dozen are known to be toxic. These few toxic species produce potent neurotoxins that can be transferred through the food web, where they affect and even kill the higher forms of life such as zooplankton, shellfish, fish, birds, marine mammals and even humans that feed either directly or indirectly on them.
Five major human toxic syndromes can be caused by the consumption of shellfish contaminated by algal toxins. The increased risks to humans of shellfish (and mussel) toxicity from the prevalence of harmful algal blooms (HABs) may be a consequence of large-scale ecological changes. These could include anthropogenic activities, marine transport and aquaculture, and global climate change. Improvements in toxin detection methods and increased toxin surveillance programmes are positive developments in limiting human exposure to shellfish toxins.
