Geoscience Reference
In-Depth Information
Table 6.1
Effects of ocean acidii cation on photosynthesis and carbon i xation in planktonic organisms, comparing rates at pre-industrial/present-day
p CO
2
levels with those at p CO
2
projected for the end of this century.
Group
Response
References
Diatoms
Riebesell et al. ( 1993 ), Burkhardt and Riebesell ( 1997 ), Burkhardt et al. ( 1999 ), Gervais and Riebesell ( 2001 ),
Wu et al . ( 2010 )
Coccolithophores
Buitenhuis et al. ( 1999 ), Riebesell et al. ( 2000 ), Rost et al. ( 2002 ), Zondervan et al. ( 2002 ), Leonardos and Geider
( 2005 ), Feng et al . ( 2008 ), Barcelos e Ramos et al. ( 2010 ), Shi et al. ( 2009 ), De Bodt et al. ( 2010 ), Müller et al.
( 2010 ), Rickaby et al. ( 2010 )
¯
Sciandra et al. ( 2003 )
«
Langer et al. ( 2006 ), Gao et al. ( 2009 )
Dinol agellates
Burkhardt et al. ( 1999 ), Rost et al. ( 2006 )
Cyanobacteria
Barcelos e Ramos et al. ( 2007 ), Hutchins et al. ( 2007 , 2009 ), Levitan et al. ( 2007 ), Fu et al . ( 2008a ), Kranz et al.
( 2009 )
«
Czerny et al. ( 2009 )
Natural assemblages
Hein and Sand-Jensen ( 1997 ), Tortell et al. ( 2002 , 2008 ), Riebesell et al. ( 2007 ), Bellerby et al. ( 2008 ), Egge et al.
( 2009 )
, enhanced;
¯
, slowed down;
«
, unaffected/inconclusive.
Table 6.2
Effects of ocean acidii cation on cell division rate in planktonic organisms, comparing rates at pre-industrial/present-day p CO
2
levels with
those at p CO
2
projected for the end of this century.
Group
Response
References
Diatoms
Riebesell et al. ( 1993 ), Burkhardt and Riebesell ( 1997 ), Burkhardt et al. ( 1999 ), Gervais and Riebesell ( 2001 )
Coccolithophores
Shi et al. ( 2009 ), Rickaby et al. ( 2010 ; Gephyrocapsa oceanica )
¯
Iglesias-Rodriguez et al . ( 2008 ), Langer et al. ( 2009 ), Barcelos e Ramos et al. ( 2010 ), Müller et al. ( 2010 ), Rickaby
et al. ( 2010 ; Coccolithus braarudii )
«
Buitenhuis et al. ( 1999 ), Riebesell et al. ( 2000 ), Rost et al. ( 2002 ), Zondervan et al. ( 2002 )
Dinol agellates
Burkhardt et al. ( 1999 )
Cyanobacteria
Trichodesmium sp.: Barcelos e Ramos et al. ( 2007 ), Hutchins et al. ( 2007 ), Levitan et al. ( 2007 ), Kranz et al.
( 2009 , 2010 )
¯
Nodularia spumigena : Czerny et al. 2009
, enhanced;
¯
, slowed down;
«
, unaffected/inconclusive.
division rate (also referred to as growth rate). While
some studies reported enhanced growth rates at
elevated CO
2
concentrations for diatoms, the cyano-
bacterium
Trichodesmium
, the coccolithophores
E. huxleyi
(only one study) and
Gephyrocapsa ocean-
ica
, and the dinol agellate
Scrippsiella trochoidea
(Table 6.2), most studies on coccolithophores show
no change or a slight decrease in cell division rate in
response to elevated
p
CO
2
. In coccolithophores, a
p
CO
2
/pH-induced decrease in cell division rate
generally concurs with increased rates of produc-
tion of organic carbon (see Section 6.3.1), resulting
in higher carbon cell quota and larger cell sizes at
elevated
p
CO
2
(e.g. Zondervan
et al.
2002 ).
The CO
2
sensitivity of growth and the cell
division rate is generally strongest at
p
CO
2
levels
lower than present-day values, with only small
changes in cell division rate when
p
CO
2
is elevated
above present-day levels (e.g. see Burkhardt
et al.
1999). A decline in growth rate, possibly due to
adverse effects of decreasing pH, has been observed
at
p
CO
2
levels higher than projected for the end of
this century (i.e. >1200 μatm; e.g. Burkhardt
et al.
1999). This effect also becomes evident in the review
of pH sensitivities of a wide range of coastal marine
phytoplankton by Hinga (2002), showing declining
growth rates as pH is shifted from present values to
much higher and much lower levels. As most of the
