"Lake Stinko" screamed the headlines of Seattle newspapers back in 1962, as putrefying mats of algae washed ashore on favorite swimming beaches. "Lake Washington Brown," "That's Algae, Not Mud," and "It'll Be There For The Next Ten Years," are all headlines that the Seattle Post-Intelligencer used on July third of that same year. What caused these mucky masses of decaying algal scum, and the resulting level of human alarm, along the shores of Lake Washington, which forms the entire eastern boundary of the city of Seattle?

The answer is a tiny, chain-forming blue-green organism (cyanobacterium) called Oscillatoria rubescens. It appeared in the lake in enormous and unprecedented numbers that year. And amazingly, in one of the West's most famous political responses to an environmental problem, there was no knee-jerk political reaction to the algal blooms that worried thousands of recreationists, property owners, fishermen, and developers: the problem had been anticipated, diagnosed, and tackled four years before it became a real nuisance to anyone. How this happened has become a legend at the interface between public action and scientific ecology....

Thanks to a group of limnologists (scientists who study lakes) at the University of Washington, led by Dr. W. T. Tommy Edmondson, the appearance of a few cells of Oscillatoria in the lake in 1958 led to the prediction that the lake was about to undergo a major change. Furthermore, this science-based prediction led to a remarkable public action that year - the vote to create a special taxing district around greater Seattle called Metro. Edmondson and his colleagues were excited when they saw those first Oscillatoria cells, (which they dipped out of the lake in a beer bottle and identified back in the lab), because the cells were a common early indicator of deterioration in lakes all across Europe and the eastern United States. After that, they thought they knew what would happen next in their own back yard.

Edmondson convinced a voting public that this was a very real risk in Seattle's beloved Lake Washington by using the example of the European lakes, whose nuisance algae began to reach epidemic proportions within a few years after the first appearance of Oscillatoria cells. Moreover, in Seattle, unlike in Zurich and countless other places, it was not too late to do something about it.

The culprit was an expanded source of food for the algae - nutrients in the form of nitrogen and phosphorous, abundant in the treated sewage flowing into Lake Washington from Seattle and its burgeoning suburbs. These nutrients created a bounty for this indicator algal species that had previously been rare or absent in the lake. Not only were the resulting algal blooms a nuisance for people who lived around the lake, but decomposing algae reduced the amount of dissolved oxygen in Lake Washington, which in turn led to major mortality of fish, such as beloved Northwest salmon species.

This response to an excess of nutrients exhibited by Lake Washington and many other lakes is a natural process known as eutrophication. As is the case with many types of environmental problems, humans simply take a natural process and push it to the point where critical components of a system are out of balance. The simplified lesson here is that for some ecological problems that result from human perturbation of ecosystems (in this case an influx of nutrient-rich sewage that increased primary productivity), it is possible to avert or even reverse apparent ecological catastrophes. As the University of British Columbia ecologist Charles Krebs states, "ecological communities, up to a point, can rebound from disturbances."

While Seattle's unwanted nutrients triggered the deterioration of Lake Washington, eutrophication is not the only kind of disturbance that large numbers of humans can create in inland waters. Other lakes in the West are equally threatened by the impacts and demands of urban areas, even those several hundred miles distant. One of the best-known examples is Mono Lake in eastern California, which has changed dramatically in the last few decades due to municipal water needs in far-away Los Angeles. In this case, the damage has been due to diversion of water from rivers and streams that normally feed Mono Lake, leading to a dramatic lowering of the lake's water level and resulting deterioration of the lake as habitat for dozens of bird and invertebrate species.

As with the formation of Metro in greater Seattle, Mono Lake experienced a dramatic public response (in this case, the creation of a non-governmental organization, the Mono Lake Committee) that acted to protect Mono Lake as a local recreational and ecological resource. The difference is that, while Lake Washington was getting too much of a good thing (nutrients), Mono Lake was getting too little of a good thing (fresh water). In each case, the culprit was human intervention in functioning ecosystems without fully considering the consequences of tinkering with them.

While Lake Washington has undergone a dramatic recovery since sewage diversion and is now as clear as it was before the Oscillatoria blooms in the 1960s, the human population around it has increased dramatically in the past two decades and there are many other threats to its health. As with Mono Lake, only a combination of good science and appropriate public action will determine what the multi-use natural resources in the west will look like in the 21st century.

Our understanding of the dynamics of lakes was revolutionized by the long-term studies of Lake Washington by Tommy Edmondson and his research team, which began in 1949 and continue to the present day (Tommy celebrated his 80th birthday in 1996 and still works in his University of Washington laboratory every day). By highlighting the importance of long-term data in making sound environmental decisions, the Lake Washington example contributed to the creation of the Long Term Ecological Research (LTER) Program by the National Science Foundation. LTER projects collect data on ecological events over much longer time scales than most basic research projects. The LTER project is located in Wisconsin; however, data from lakes studied intensively there have been helpful in predicting responses of lakes to external environmental influences in many other parts of the country and the world.

Edmondson and the voters of King County (including Seattle and its suburbs) devised and executed an ingenious plan based on sound ecological principles. They reasoned, that by eliminating from the lake, sources of nutrient-rich sewage (a critical resource for the algae), the murkiness and other problems would go away, leaving a clear and healthy Lake Washington, like the one the Seattle's original settlers found over a century earlier. Based on Edmondson's ecological predictions, and thanks to the creation of Metro, sewage was diverted away from Lake Washington and into adjacent Puget Sound, an arm of the Pacific Ocean that was flushed twice daily by large tides.

Eutrophication

This site, supported by the World Bank, describes some of the economic concerns associated with eutrophication at various international development projects. It also contains a good general discussion of the effects of excess nutrient loading in a variety of freshwater and estuarine habitats.

Limnology

This homepage is from the premier scientific society for limnologists, people who do research on lakes. It contains information on the workings of the society, upcoming meetings, and contents of the society's professional journal - Limnology and Oceanography. The founding editor of this journal, Yvette Edmondson, is married to Tommy Edmondson, the famous Lake Washington researcher mentioned above.

US Long Term Ecological Research Program

This site describes one of the major projects of the US Long Term Ecological Research (LTER) Program, which was established by the National Science Foundation (NSF) to conduct studies on ecosystems lasting well beyond the 3-5 year duration of the typical scientific research project (and its funding).

Mono Lake

This excellent and informative homepage of the Mono Lake Committee, an organization formed in the late 1970s to save California's fragile Mono Lake from a variety of external threats, contains a wealth of information on the ecology, chemistry, geology, and political history of this unusual high-altitude lake.

Blumm, Michael C. and Thea Schwartz. "Mono Lake and the Evolving Public Trust in Western Water." Arizona Law Review 37(3): 701, 1995.

Edmondson, W. T. "Lough Neagh: The Ecology of a Multipurpose Water Resource." Limnology and Oceanography 41(6): 1373, 1996.

Edmondson, W. T. The Uses of Ecology: Lake Washington and Beyond. University of Washington: Seattle, 1991.

Edmondson, W.T. and S. E. B. Abella. "Unplanned Biomanipulation in Lake Washington." Limnologica 19(1): 73, 1988.

Goldman, Charles R. "Primary Productivity, Nutrients and Transparency During the Early Onset of Eutrophication in Ultra-oligotrophic Lake Tahoe, California-Nevada." Limnology and Oceanography 33(6): 1321, 1988.