A part of my John Everett series – read more: 0/I – II.0 – II.5 – II.75 –  III.0 – III.3 – IV.0 – IV.4 – IV.8 – V – VII – VIII – Full Report 

Part V of John Everett’s testimony (“Is this bad or good or just different?”) repeats several claims that we’ve already seen to be simply incorrect:

Little Rock Lake, site of a famous acid rain study. Image from Google Maps; sauceclick.

The only new evidence he presents in this section regards a different pH problem: acid rain.

“During the acid rain issues in the 1980s, a lake basin in Wisconsin was deliberately acidified (with EPA and NSF funding) to a pH of 4.7 then allowed to recover. ‘Some species were decimated and others thrived, but the sum-total of life in the lake stayed the same.’ This is a level of acidification 1,000 X the worst-case scenario for the oceans. It provides a clue as to what a 2X change might be.”

His reference for this claim is this news item from ScienceDaily. To clarify, when Little Rock Lake was ‘allowed to recover’, acidification was halted and its pH was allowed to rise to its previous levels. The news item is reporting on the slow recovery, which only took place once the acidification ceased. Dr. Everett presents a quote from this news item, which would seem to suggest that things were just fine in the acidified lake. In fact, the quote in its entirety refers to the lake’s recovery, rather than its acidified state:

“In the end, [study directer Thomas] Frost says, the lake showed a remarkable resilience by returning to its pre-disturbance conditions. [...] ‘The entire ecosystem of the lake is much more resilient than individual species,’ he says. ‘Some species were decimated and others thrived, but the sum-total of life in the lake stayed the same.’ ”

In fact, it seems that Dr. Everett has selected the only part of this news item which DOESN’T point to the critical importance of pH in lakes. Some choice bits he doesn’t mention:

“’We found that the pH levels had a controlling but indirect influence for nearly every biological factor in the lake,’ says Frost. ‘The nature of the food web changed completely.’ ”

“Sport fish in the lake, such as bass and perch, survived the change but the offspring of fish were unable to survive. The zooplankton in the lake, a critical part of the food chain, underwent a complete revolution. Some once-rare zooplankton took over the lake, while once-dominant species almost vanished. ”

“The acidified lake became almost crystal clear in the process, and ultraviolet light penetration increased, he says. Chemical changes helped a long, filamentous algae nicknamed “elephant snot” to spread across the lake bottom. “

“Mercury in fish increased with acidification, but study of the lake’s recovery has shown that mercury deposition has declined recently. ”

“The study also demonstrated that what was intended as a single, isolated stress, acid rain, actually created other stresses on the health of the ecosystem.”

So the results of this lake acidification experiment don’t support Dr. Everett’s rosy outlook for oceanic pH changes. It’s not clear why he cited it, unless he just wanted a optimistic soundbite. It’s also not clear why he’s comparing saltwater and freshwater ecosystems. He does so elsewhere in his testimony, writing in part III:

“….in lakes the limiting pH is about 5 for the presence and good health of crustaceans, snails and insects and fish. This may apply to oceans as well. This is 1000 times more acidic than the oceans of today. [...] If freshwater organisms can form shells at pH of 5-5.5, it is hard to imagine damage at pH 7.8 to all species.”

Both lake and ocean ecosystems are filled with organisms which have adapted to their environments over long time periods. The differences between fresh- and saltwater ecosystems are obvious to any aquarist. (eg, here) It seems risky at best to draw naive analogies between them. I contacted Dr. Carl Watras, coordinator of the Little Rock Lake Experiment. He expressed skepticism about Dr. Everett’s discussion of freshwater environmental pH, and agreed that use of a freshwater acid-rain study is specious, writing “the comparison between lakes and oceans is ‘apples to oranges.’”

The similarity between the two cases, he agrees, is that they both involve environmental pH changing faster than populations and ecosystems can adapt.

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