Let's not forget... ocean acidification

It's been a couple of weeks since I mentioned ocean acidification. You'd think that someone, even George Monbiot, might mention it in the context of "Climategate" (which I still reckon will amount to nothing in the long run) as the other big reason why rapid CO2 increase is Not a Good Idea.

So, what's new from the Ocean Acidification blog?:

a. a couple of types of plankton (two species of coccolithophore) show reduced growth under increased dissolved CO2, even when the increase is more gradual than in some of other experiments;

b. another study on 4 different strains of coccolithophore indicates that they respond differently to increased CO2, presumably on a genetic basis. This is possibly a good thing, if you assume the ones that take increased CO2 in their stride replace those that suffer decreased calcification. But it's going to be very difficult to experimentally tell if that is what will happen in the oceans, I would have thought.

c. a report from an unlikely source (iStockAnalyst!) says that the waters off Japan are showing lower pH:

A group of scientists, led by Takashi Midorikawa of the Meteorological Research Institute in Tsukuba, Ibaraki Prefecture, has checked the pH readings of surface seawater off the Kii Peninsula at 30 degrees north latitude that have been made since 1986. They have found that the pH has dropped by 0.04 during this period, a considerable change. Such ocean acidification has been observed elsewhere as well, such as off Hawaii.

It seems that this is the 3rd report of long term (20 plus years) measurements which are indeed showing that ocean acidification is happening as predicted:

a. the Hawaiian study from earlier this year;
b. the Icelandic ocean study, which has just been updated, and
c. now Japan.

While there seems to be a considerable divergence in the actual rate of acidification, water temperatures and other factors presumably have a role.

Still, it seems that the skeptic response that ocean acidification can't happen (or isn't happening,) which seemed to be the position of Ian Plimer and Bob Carter, for example, just isn't sustainable.

4. Here's an interesting report on current work underway with coring coral in the Caribbean to see if growth rates can be correlated to decreasing pH. It will very interesting if they replicate the findings of a study on Australian coral.

5. Cuttlefish (and other cephalopod?) eggs are affected by decreased pH, but it seems unclear whether in a good way or a bad way. (They absorb less cadmium, but more silver.) All kind of complicated, isn't it?