Seaweed Responses to Ocean Acidification - Seaweed Biology - page 401

Fig. 19.2 Calcification, linear extension, and primary production in ( a ) Halimeda ,( b ) Penicillus ,
and ( c ) Udotea grown in experimental calcite, boundary, and aragonite seawaters. Rates of
calcification, linear extension, and production significantly increase ( P < 0.05) with increasing
seawater Mg/Ca. Vertical bars are standard errors (From Ries 2009 , with permission of Blackwell
Publishing Ltd)
calcite seas (Fig. 19.2 ). In the calcite sea treatments, however, they were still able to
precipitate aragonite, demonstrating some level of internal control over the poly-
morph of calcite produced. For coccolithophores (calcifying phytoplankton), the
physiological basis of calcification, and its relationship to photosynthesis, is being
elucidated using various physiological and molecular tools (e.g., Brownlee and
Taylor 2004 ); similar approaches need to be applied to calcifying red, green, and
brown seaweeds if we are to better understand how they will be affected by OA.
19.5 Physiological Performance in a High CO 2 World
The sensitivity of seaweeds to OA can be species specific. Their response may
vary depending on their carbon physiology, mode of calcification, morphology
(functional growth forms), and life history. For example, filamentous turf algae
with shorter generation times may be able to acclimate and adapt to the changing
environment faster than large canopy-forming kelp species with a longer generation
time.