terrycrynant's picture

Orange algae

Observed: 19th March 2011 By: terrycrynantterrycrynant’s reputation in Plantsterrycrynant’s reputation in Plantsterrycrynant’s reputation in Plants

Algae which grows in iron rich water which is run off from old mine workings.


No identification made yet.

Species interactions

No interactions present.


John Bratton's picture

Is it alga or ochre, a

Is it algae or ochre, a chemical precipitate?

anonymous spotter's picture

I think it is mostly chemical -

not biological. Mine-water contains a lot of iron, and a typical reaction is that of iron sulphide (pyrites) being oxidised to the sulphate (copperas): this then precipitates as the oxide or hydroxide.
There is usually a high acidity (low pH) and high chloride (salt) content associated with mine-water - these tend to make conditions hostile to most living organisms.

madeleine's picture


Likely to be one of the ferric iron complexes, as noted above. There is a programme of remediation aiming to address many of these mine water issues in Wales - but of course there are many old mines!