An orange substance seen in Douglas bay has been identified as an algae bloom.

The Department of Environment, Food and Agriculture said the algae has bloomed as a result of high light levels, nutrients and calm waters.

A DEFA spokesman added: ’Although it isn’t harmful itself, it may result in decomposition smells and swimming around it should be avoided.’

Earlier today, a large number of jellyfish were spotted in the bay. DEFA identified these as ’moon jelly aurelia aurita which feed on small plankton, including algae’.

Winds and tides can lead to a concentration of both of these organisms coming together.