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Larval Growth of Oysters in a Warming and CO2-Accreting World
Thiyagarajan, V. and Ko, G.W.K. 2012. Larval growth response of the Portuguese oyster (Crassostrea angulata) to multiple climate change stressors. Aquaculture 370-371: 90-95.

Citing Lapegue et al. (2004), the authors write that the Portuguese oyster is "an important ecosystem engineer" that is "extensively cultivated" and that lives in significant numbers in the coastal environments of South China, France and Portugal.

What was done
In a number of laboratory studies designed to see how the larval growth stage of this particular species of oyster responds to various "climate change stressors," as they describe them, Thiyagarajan and Ko examined the effects of low pH (7.9, 7.6, 7.4) at ambient salinity (34 ppt) and low salinity (27 ppt), while they say "the combined effect of pH (8.1, 7.6), salinity (24 and 34 ppt) and temperature (24°C and 30°C) was examined using factorial experimental design."

What was learned
In the words of the two researchers, "surprisingly, the early growth phase from hatching to 5-day-old veliger stage showed high tolerance to pH 7.9 and pH 7.6 at both 34 ppt and 27 ppt," while they report that "larval shell area was significantly smaller at pH 7.4 only in low-salinity [italics added]." Then, in the 3-factor experiment, they observed that "shell area was affected by salinity and the interaction between salinity and temperature but not by other combinations [italics added]." And they discovered that "larvae produced the largest shell at the elevated temperature in low-salinity, regardless of pH [italics added]."

What it means
In light of these several positive findings, Thiyagarajan and Ko conclude that "the growth of the Portuguese oyster larvae appears to be robust to near-future pH level (>7.6) when combined with projected elevated temperature and low-salinity in the coastal aquaculture zones of [the] South China Sea."

Lapegue, S., Batista, F., Heurtebise, S., Yu, Z. and Boudry, P. 2004. Evidence for the presence of the Portuguese oyster, Crassostrea angulata, in northern China. Journal of Shellfish Research 23: 759-763.

Reviewed 17 April 2013