On Oct 3, 1:13*pm, wrote:
In article ,

wrote:
In seawater, most of the dissolved carbon dioxide is in the form of
the bicarbonate ion, rather than in the form of carbonate ion or
dissolved gas.

I'm trying to estimate the growth rate of a range of algae as a
function of dissolved CO2. Can algal photosynthesis use the HCO3- ion
directly? What about the CO3-- ion?

The basic biology books I've looked up only mention CO2, not the
dissolved ionic species, but it occurred to me that if algae had to
rely on CO2 gas then they'd starve to death.

Note that there's an equilibrium in water between carbonate, bicarbonate
and carbon dioxide, so even if the plants have to 'grab' the CO2 as it
forms, they can get it even at seawater pH where it's in very low
concentration. *But since CO2 immediately forms carbonic acid ('hydrogen
bicarbonate') in water, I suspect that even land plants actually use it
in bicarbonate form.

I don't know what the growth-limiting factor is in marine algae in
nature, but IIRC nitrogen is a more important factor than carbon. *
In fresh water, explosive growth of algae is often a sign of urban
or agricultural pollution (e.g. sewage, manure or fertilizer run off)
providing nitrogen.

I would reccomend that you contact the University of Galway Ireland
where there is extensive research going on with salt water algae