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Cyanobacteria (Blue-Green) Algae

Aquatic cyanobacteria are known for their extensive and highly visible blooms that can form in both freshwater and seawater. The blooms can have the appearance of blue-green paint or scum, but can be other colours as well. These blooms can be toxic.

These can resemble fine grass clipping suspended in the water and when levels of growth are higher, scums can form on downwind shores.

Algal blooms can be toxic and pose a risk to human and animal health. When levels are high, warning signs are put up. For more information, see our Information Sheet, pdf icon Blue Green Algae PH11 [88kb].

Currently Affected Sites

At October 2018, all water bodies (except Linlithgow Loch) are free of cyanobacteria or have levels below the 20,000 cells per ml threshold for taking action. The following water bodies were previously affected:

  • Beecraigs Loch (medium levels)
  • Bowden Springs Fishery (high levels)
  • Linlithgow Loch (high levels)

Concerns or Enquiries

The responsibility to manage algal blooms lies with the owner of the water concerned. However, for enquiries relating to cyanobacteria (Blue-Green Algae), please contact Environmental Health. Environmental Health will assess any action required against the relevant Scottish Government guidance and the Lothian and Fife Cyanobacteria Action Plan.

Linlithgow Loch and Beecraigs Loch 

Linlithgow Loch, owned by Historic Scotland.  Both Linlithgow Loch & Beecraigs Loch have a history of summer and early autumn cyanobacteria algal blooms. A routine inspection and sampling programme is in place to monitor the condition of the water. Suspected blooms should be reported to Environmental Health, which will arrange sampling if necessary. For up to date information on algal levels, see Linlithgow Loch.