Stupid Science For Earth-Day – Oysters And CO2

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I expected to see something dumb to be paraded out to “celebrate” Earth-Day, and I wasn’t disappointed. Here is an article decrying the effect of increases in CO2 on oysters of the future:

“The average pH of ocean surface waters has decreased by about 0.1 unit — from about 8.2 to 8.1 — since the beginning of the industrial revolution,” the scientists said in noting earlier research. Moreover, models project “an additional 0.2-0.3 drop by the end of the century, even under optimistic scenarios,”

…testing used lab seawater with present-day CO2 ocean concentrations, as well as lab seawater that used higher CO2 levels that scientists say could occur by 2100.

In the higher CO2 environment, the larval shells at day 9 of their growth were 16 percent smaller than those reared in the present-day seawater conditions.

A week later, the difference was 41 percent and the smaller oysters never caught up.

You might be thinking: “Sonic…. You’re an idiot! This sounds really bad! Oysters are disappearing!”

The MSNBC article reinforces that fact:

Worldwide, oysters have already been impacted by development along coastlines — 85 percent of shellfish reefs have been lost, taking with them valuable services like filtering water and creating natural buffers from storms and even boat wakes.

“Oysters have gone extinct in many areas, especially in North America, Australia and Europe,” said David Garrison, director of the National Science Foundation’s biological oceanography program, which funds Gaylord’s research.

It may be very bad, and I’m not going to quibble with the extinction of oysters as being a bad thing. But there are two bits of info missing from this story that would prove to be relevant.

First, ocean pH can be shown to have decreased since the beginning of the industrial revolution, and since most of the man-made CO2 increases have come in the last fifty years, in fact the largest increase has been from 1940 to the present, most of the 0.1 change has happened within one human generation. So oysters should already be getting small, right?

Are they?

You would think that there should already be proof, but there doesn’t seem to be. Even in the lengthier Scientific Daily article, that gives more details of this experiment, there is no mention of the current effects in the environment; no proof that what is expected is already being seen in the real world, i.e. not in the lab, but out there in the ocean. The article does go on to note:

Globally, 85 percent of shellfish reefs have been lost, making oyster reefs one of the most severely threatened marine habitats on the planet.

“Shellfish reefs in some places are at less than 10 percent of their former abundance,” says Garrison. “Oysters have gone extinct in many areas, especially in North America, Australia and Europe.”

OK. But that is a non-sequitor, since the decline in oyster populations are not due to increases in CO2 and Global Warming. In fact:

Oysters have supported civilization for millennia, from the ancient Romans to railroad workers in California in the 1880s. In the 1870s, eastern oyster reefs extended for miles along the James River in Chesapeake Bay. By the 1940s, they had largely disappeared.

Scratch Global Warming / man-made increases in CO2 as the culprit, as the bulk of the increase in ocean acidification occurred after 1940.

Here is a study of Caribbean water chemistry that shows that the pH of those ocean waters are more variable than thought, with dramatic seasonal variations. Yet, in the area they monitored for four years, there appears to be no direct evidence that these dramatic changes are having any effect. I expect this same result of natural variability will be discovered in other ocean environments as well. Even in this highly touted study on the affects of acidification on various shellfish, they cannot show any real-world consequences of the effect.

Here is another problem with this line of lab research. The shellfish / oyster larvae are moved from one pH level environment to another in a very short time period. The lifecycle of an oyster and similar creatures spans, from egg fertilization to full-grown breeding adult, about one month. Not only does the Caribbean study show the adaptability of shellfish and coral, but those are changes that occur sometimes over the lifetime of a single generation. How many generations shellfish will have lived and died, and in the process, adapted to a very small change of pH from 8.1 to 7.9 in 100 years?

2 Comments to “Stupid Science For Earth-Day – Oysters And CO2”

  1. By M Gardner, June 19, 2011 @ 8:17 am

    happened on your site. Excuse me but the life cycle of an oyster from egg to reproductive adult is NOT one month. Google the Horn Point Lab Oyster Hatchery and look up “life cycle. “

  2. By Sonicfrog, June 19, 2011 @ 3:25 pm

    I stand corrected. It’s about one to three years. But that doesn’t invalidate my point. The oysters born into the higher pH environment will have had millions of generations to slowly adapt to a higher pH, not just one or two.

    PS. I’m glad you brought this to my attention, and welcome to the pad I call my internet home.

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