b) Forests have died in the Krusne-Hory Mountains of extreme northwest Czech Republic due to air pollution, acid rain, and mobilization of toxic metals
Environmental Problems at the Regional Scale
In the U.S., industry dealt with increasingly stringent ambient air quality standards in the 1960s and 1970s, in part, by building tall stacks. Tall stacks carried the pollution away from the urban area so that people in cities like Gary, Indiana, could breathe again. The pollution was carried to remote locations where we did not fully understand its effects. Mesoscale (regional) pollution resulted in acidification of some lakes and a decline in rural air quality, especially acidic aerosols, fine particulate matter and ozone pollution. Our own mathematical models at the University of Iowa indicated that perhaps a total of 1000-2000 small lakes and streams in the Northeast, Upper Midwest, and southeastern United States became acidified by acid deposition (acid rain).5 Studies culminated in the 1990 Clean Air Act Amendments which were the first to control sulfur oxides and nitrogen oxides due to acid deposition. Possible crop damages and human health effects of this regional pollution are still being assessed.
Local and regional air pollution in developing countries mostly was unabated through the 1980s. In former Czechoslovakia, the Communist government insisted on production without controls, and the environment suffered. (There is infinite demand for a free good.) The "polluter pays" principle was accepted theoretically, but not enforced, and the result was a devastated landscape as shown in Figure 7. Forest die-back has claimed about 200,000 acres in northwestern Bohemia and about half of the forests in the Czech Republic show symptoms of decline.6 We are currently involved in a research project there to determine if agricultural soils and crops have become contaminated with excess toxic metals from regional atmospheric deposition.
Another example of environmental problems at the regional scale is fisheries decline. Beeton 7, in a seminal paper in 1961, catalogued the history of decline of commercial fishing in the Great Lakes, almost one-quarter of the world's fresh water (Figure 8). In the 1800s, changes were already occurring in commercial catch due to habitat alteration of streams and spawning grounds. By the mid-1900s, over-fishing, introduction of foreign species (such as the sea lamprey), and pollution all played important roles. In Lakes Erie, Ontario and parts of Huron, the bottom waters and sediments had become so eutrophic due to water pollution that they lost oxygen which, in turn, killed mayfly larvae and other species at the base of the food chain. Lake Erie was declared "dead" in 1965, about the same time that the Cuyahoga River caught fire in Cleveland. Today, the eutrophication problem has been greatly reduced by control of point source pollution, and sports fishing has recovered by restocking. Still, problems remain. There is a fishing ban on many species of salmon and lake trout due to biomagnification of toxic chlorinated hydrocarbons, principally polychlorinated biphenyls (PCBs), DDT, chlordane, and dieldrin pesticides, chemicals that were banned in the 1970s but are so persistent as to remain with us today.
As humans become more numerous, the threat of local pollution effects become regional. The recent crash of cod and flounder off the George's Bank in New England is reminiscent of what happened 50 years earlier in the Great Lakes.8 (If you are willing to eat dogfish instead of flounder, there is no problem.) The global fish catch is down since 1989, especially on a per capita basis, and there are reports of cod, flounder, and orange roughy (deepwater fish) populations crashing. These effects are primarily due to over-fishing, as humans try to harvest a treasure trove of marvelous protein that is in great demand, but they are failing once again to pay the true cost of replacing those fish once populations are decimated. We can only hope that most of these effects are reversible. Regional environmental problems can become global environmental problems in the absence of governmental sanctions and cooperation.
|Figure 8.Decline of the fishery in Lake Ontario during the period from 1910-1960 (from Beeton, 1969)|
Speech | Acknowledgements | References | About Jerald L. Schnoor
Presidential Lectures Home