wmartin@brl-smoke.ARPA (Will Martin ) (04/22/86)
Publicity about acid rain indicates that some types of pollution cause rainfall to become acidic enough that lakes which collect such rainfall eventually themselves turn acidic enough to kill off the natural biota and become nearly sterile. How acidic is this? I ask this because of a fact mentioned in the recent PBS National Geographic special on the Okeefenokee swamp -- the statement was made there that this swamp water was "as acid as strong tea". Yet, even though acidic, this area teems with life. Are the lakes damaged by acid rain more acidic than this swamp water? If not, is it just because they are in colder climates that the (seemingly) acid-tolerating lifeforms that flourish in the acid swamp cannot live in these more-northerly acidified lakes? Or could such acid-tolerating biota be introduced into those lakes and create a new ecosystem that could survive the acidification? (And that this would happen naturally, given long enough time, but these areas are sterile now just because the acid-tolerating biota haven't yet been introduced?) Will
fetrow@entropy.UUCP (David Fetrow) (04/28/86)
=====> Begin 202's article <=====
Yet, even though acidic, this area teems (Okee. Swamp)
with life. Are the lakes damaged by acid rain more acidic than this
swamp water? If not, is it just because they are in colder climates that
the (seemingly) acid-tolerating lifeforms that flourish in the acid
swamp cannot live in these more-northerly acidified lakes? Or could such
acid-tolerating biota be introduced into those lakes and create a new
ecosystem that could survive the acidification? (And that this would
happen naturally, given long enough time, but these areas are sterile
now just because the acid-tolerating biota haven't yet been introduced?)
=====> End 202s article <=======
An interesting observation. I'd expect most of the acid tolerating biota
would have a problem with the temperature (and possibly altitude) of Northern
acid damaged lakes. Northern bog biota might be a better choice.
In any case, introducing new species into the wild is an EXTREMELY risky
proposition. Often the response is either totally non-successful or
overwhelming. As a last resort the idea might work but it is not something
to be done lightly.
--
- Dave "Tuttle" Fetrow
Defender of CP/M-80 in a multibyte world
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...and a whole pile of other stufffalk@sun.UUCP (04/29/86)
> Publicity about acid rain indicates that some types of pollution cause > rainfall to become acidic enough that lakes which collect such rainfall > eventually themselves turn acidic enough to kill off the natural biota > and become nearly sterile. How acidic is this? When I was in H.S., we had a class called "Environmental Research" in which we basically learned how to take ecological measurements and do surveys etc. My assigned sampling site was a stream used by a local town to dump their (barely) treated sewage. Not only was it downstream from the sewage plant, but it was also downstream from a Cott beverage plant and an asphault plant. So, we had sewage, sugar and god knows what else being dumped. Anyway, the primary measurement of pollution is coliform bacteria, which is measured in "colonies" per milliliter. Counts of 100 or so are typical for reasonably clean water; counts in the thousands is pretty bad. Well, we typically got counts around half a million or so for this stream. One week however, we got a count of zero. I was really puzzled (I didn't believe for a moment that someone had cleaned it up). My puzzlement lasted about half an hour, and then we got the pH measurement back -- it was 3.0. Anyway, I'm from New York state orginally, and acid rain is a real problem there. In the early days of ecology conciousness, the EPA set up standards for pollution emission that were described in terms of concentrations at a certain distance from smokestacks. The big coal burners in the Detoit area answered this not by cleaning up their act, but by building huge smokestacks so that the pollution would still be airborn when it reached the sampling distance. The results were that all of the sulfer and nitrogen oxides get all the way to NY before they are precipitated out of the atmosphere by the rain (where they become sulfuric and nitric acids respectively) and acidify the lakes. I think the current count is one third of all NY lakes in mountain regions are sterile or becoming sterile because of it. -- -ed falk, sun microsystems
mrh@cybvax0.UUCP (Mike Huybensz) (04/29/86)
In article <202@brl-smoke.ARPA> wmartin@brl-smoke.ARPA (Will Martin ) writes: > Publicity about acid rain indicates that some types of pollution cause > rainfall to become acidic enough that lakes which collect such rainfall > eventually themselves turn acidic enough to kill off the natural biota > and become nearly sterile. How acidic is this? Without checking textbooks, I'd say that natural pH's of the subject lakes are around 6 to 8, and the damaging pH's range from 4 to 6. Keep in mind that the pH measurement is the negative log of the concentration: a pH of 5 means a hundred times more hydrogen ions than a pH of 7. > How acidic is this? I ask this because of a > fact mentioned in the recent PBS National Geographic special on the > Okeefenokee swamp -- the statement was made there that this swamp water > was "as acid as strong tea". Tea is a good comparison: the brown color of swamp and bog waters results from the dissolving of tannic acids from leaves (and humic acids from soils.) > Yet, even though acidic, this area teems > with life. Are the lakes damaged by acid rain more acidic than this > swamp water? If not, is it just because they are in colder climates that > the (seemingly) acid-tolerating lifeforms that flourish in the acid > swamp cannot live in these more-northerly acidified lakes? Or could such > acid-tolerating biota be introduced into those lakes and create a new > ecosystem that could survive the acidification? (And that this would > happen naturally, given long enough time, but these areas are sterile > now just because the acid-tolerating biota haven't yet been introduced?) Acid rain doesn't make lakes more acid than some naturally occuring lakes and swamps: the problem is that it does so suddenly, killing off organisms which are not adapted to changes in pH. In general, northern lakes tend to have simpler ecosystems with less biomass than southern. Less biomass means less ability to buffer the environment. Swamps are where (among other things) organic matter carried downstream gets deposited, making them very butrient rich. Acid-tolerant species tend to come from waters with nutrient-rich sources of organic acids. Acidified lakes don't have those nutrients: their acids come from inorganic sources such as rainfall. There tends to be very little natural exchange of species between freshwater rivers, lakes, and streams. Much of the natural distribution of fish, clams, etc. is due to the history of retreat of the last glaciation. It is very unlikely that acid-tolerant fish would spread into acidified lakes naturally; other organisms (such as plants) might be more likely. We could try to construct new ecosystems in the acidified lakes by the introduction of tolerant species. But changing an entire regional fauna as a patch-job for a preventable side-effect of our industry doesn't sound like a wise idea to me. -- Mike Huybensz ...decvax!genrad!mit-eddie!cybvax0!mrh
CJC@PSUVM.BITNET (04/30/86)
Xref: psuvax1 net.sci:729 net.bio:361
>
> Publicity about acid rain indicates that some types of pollution cause
> rainfall to become acidic enough that lakes which collect such rainfall
> eventually themselves turn acidic enough to kill off the natural biota
> and become nearly sterile. How acidic is this? I ask this because of a
> fact mentioned in the recent PBS National Geographic special on the
> Okeefenokee swamp -- the statement was made there that this swamp water
> was "as acid as strong tea". Yet, even though acidic, this area teems
> with life.
I'm sure someone more knowledgable than I could have answered this
question better than I but since I haven't seen any answers...
I've heard that acid rain can sometimes compare to lemon juice or
vinegar in acidity; I drink strong tea all day long with no ill effects
(at least none that I've noticed), but I would not drink more than a
few spoonfuls of lemon juice or vinegar. I understand that the acid in
rain comes in part from sulfur dioxide, and I would not knowingly drink
*any* sulfuric acid, no matter how diluted. Is it relevant that a very
dilute soultion of hydrochloric acid is used to kill life forms in drinking
water? I'm interested in the acid rainfall topic and would appreciate
information from those who know, even if it's just the name of a useful
book.
--Carolyn J. Clark
Bitnet: CJC at PSUVM
UUCP : {allegra, akgua, ihnp4}!psuvax!CJC@PSUVM.BITNET