High levels of shellfish toxins have been found in three sealochs.
East Loch Tarbert (Sound of Scalpay), Loch Stockinish in Harris and Loch Seaforth are affected.
The comhairle warns that eating shellfish such as mussels, cockles or razor fish from these areas may pose a risk to human health.
Notices to warn the public and casual gatherers will be posted at various locations on the shore.
Commercial shellfish harvesters in these areas have been contacted by the comhairle and steps taken to postpone harvesting until algae levels subside.
It is a sensible precaution to avoid eating shellfish from these areas until further notice said the council.
The comhairle is monitoring the situation and will remove warning notices when it improves.
High levels of shellfish toxin in Lewis and Harris sealochs
19 June 2017