Figure 2. Geoduck clam shell size under different ocean acidification conditions. A) geoduck shell area relative to mean day 0 shell size under three different pH levels, B) geoduck shell area relative to mean day 23 shell size for each treatment during common garden ambient pH exposure, C) geoduck shell area relative to mean day 135 shell size for clams preconditioned to  to three different pH conditions under secondary exposure to ambient or medium pH, and D) geoduck shell area relative to mean day 135 shell size for clams preconditioned to  to three different pH conditions under secondary exposure to ambient or medium pH.