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In remote Ontario, a network of lakes is dedicated to bold ecological manipulations.Research there has helped explain algal blooms and acid rain. As the unique outdoor lab turns 40, some wonder whether it is past its prime

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In 1966, fisheries scientist Waldo Johnsonhad a big idea. Algal blooms were plaguingLake Erie, and the Canadian governmenthad created the Freshwater Institute tostudy the problem. Johnson, as the new

director, proposed topollute several smalllakes intentionally tof igure out exactlywhat was going on. Ifresearchers manipu-lated the entire lakeecosystem, he argued,

they might be able to mimic what happensin nature and find some answers.

The government agreed, setting asidedozens of remote lakes for research. Theworld-renowned facility that resulted, theExperimental Lakes Area (ELA), changedthe face of freshwater ecology, ushering inan era of what researchers there call“extreme science.”

Over the decades, ELA researchers andcollaborators from around the world haveconducted more than 50 massive experi-ments, including building dams and settingup fish farms. In a practice that would surelyraise eyebrows elsewhere, they have dumpedtoxic metals, synthetic hormones, and otherpollutants into pristine lakes. “Everyone hasthe same reaction: ‘I can’t believe they letyou do that,’” says ELA’s chief scientistMichael Paterson, a zoologist with Canada’s

Department of Fisheries and Oceans (DFO),which runs the facility. “We use these lakesthe way medical researchers use white mice.”

ELA was pivotal in fingering phosphorusfrom detergents as the culprit in algal blooms,and experiments in lakes there providedcompelling evidence of the harm caused byacid rain. U.S. and Canadian environmentalpolicies were forged in part on the strengthof ELA’s science. “It’s hard to overstate the

impact they’ve had,” says James Elser ofArizona State University (ASU), Tempe.

Forty years later, ELA still hosts first-rate science, say many ecologists. With$13 million of infrastructure, finely charac-terized lakes, and decades of baseline data,the site can tackle problems few others can.All is not rosy, however. Researchers com-plain that government bureaucracy has longlimited the lab’s full potential, although thismay change with a new arrangement forfunding. Half of the staff scientists there arenearing retirement, and recruiting top talentcan be a challenge. As ELA celebrates its40th birthday, even some of the lab’s oldhands wonder aloud whether the place is duefor some rejuvenation.

Young bloodIn many ways, the stars were aligned whenJohnson sketched out plans for the outdoorlab, which became useful for studyingmuch more than eutrophication. In 1967, apair of technicians was sent out to find anarea with many lakes of various sizes,remote enough to be pristine yet within300 kilometers of Winnipeg, where theFreshwater Institute was located. Flying byplane and helicopter, the technicians namedhundreds of lakes, simply giving themsequential numbers. Eventually, 46 lakes in17 small watersheds were selected.

The setting is ideal. The lakes and sur-

OnlineHear more abouthow ELA’s lakes

are altered and probedon Science’s podcast.

sciencemag.org

“...the single

most powerful

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limnology.”

—JAMES ELSER

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www.sciencemag.org SCIENCE VOL 322 28 NOVEMBER 2008 1317

rounding pine forests rest on granitebedrock, so there is little groundwater,which means the lake chemistry is relativelysimple to study. And the diversity of thelakes’ sizes and depths makes for an excep-tionally versatile ecological lab.

Limnologist Jack Vallentyne, hired fromCornell University, was put in charge ofassembling a crack team of scientists. Herecruited respected experts from Japan,Poland, Italy, and other countries, as well as“hot, young blood,” as he called the youngermembers of the team. In his bid to persuadescientists to move to Winnipeg and endurelong, cold winters, Vallentyne touted theopportunity to do whole-lake experimentson a scale unmatched anywhere else.

In what turned out to be a strategic move,Vallentyne put a young limnologist, DavidSchindler of Trent University in Peterborough,Canada, in charge. In the summer of 1968,Schindler set up a field camp with a few trail-ers and got to work. (Schindler is a member ofScience’s board of reviewing editors.)

ELA’s original mission was to examinethe problem of eutrophication. The pressingquestion in the late 1960s was which nutri-ent triggers excessive algal growth. Studiesin small tanks done elsewhere had yieldedconflicting data. Some scientists thought theculprit was phosphorus, principally in deter-gents and sewage; others thought it might benitrogen from fertilizer and sewage, or car-bon, or perhaps even trace metals.

In a now-famous experiment (Science,24 May 1974, p. 897), the team divided Lake226 with a plastic curtain and added phos-phorus to one half. When it turned a distinc-tive murky green, they had their answer. Itwas an aerial photograph from this experi-ment that largely persuaded policymakers tophase out phosphorus from detergents. “Ithink that’s the single most powerful image inthe history of limnology,” Elser says. WhenSchindler took the results—and the photo—to govern-ment hearings in Canada andthe United States, he put ELAon the map as a hub of innova-tive, policy-relevant research.

Next, Schindler tackledone of the most contentiousissues of the day, acid rain. In aseries of experiments con-ducted between 1976 and1988, researchers added sulfu-ric and nitric acid, pollutantsthat lead to acid rain, to Lake

223 and others. The resultsshowed that the pristine eco-system began to suffer at signif-icantly less acidic conditionsthan electric utilities main-tained. They also demonstratedharm cascading through thefood web, with planktonspecies disappearing andfish not reproducing—ashad been seen in lakesalready damaged by acidrain. One of the key contri-butions of ELA, points outecologist Gene Likens ofthe Cary Institute of Eco-system Studies in Mill-brook, New York, was that itprovided experimental evi-dence that helped convinceskeptics of observational studies. Schindlerand his colleagues were also able to performexperiments showing that lakes would slowlyrecover when the pH returned to normal.

Once again, Schindler made the rounds ofgovernment offices and congressional hear-ings in Canada and the United States with hisdata and images—this time starving troutwhose prey had died and species that hadvanished. Although ELA was by no meansalone in studying acid rain, many saySchindler’s ability to communicate sciencein simple, homespun terms—he appearedwidely on television and in newspapers andmagazines—helped spark stricter regula-tions on power plants. In 1990, the U.S. Con-gress passed major amendments to the CleanAir Act that helped reduce acid rain (Science,6 November 1998, p. 1024).

They were heady times. The federal gov-ernment and other funders were generous,and the researchers who flocked to the siteeach summer were essentially given freerein. True, there were a few rules, Schindlerrecalls. For example, once an experimentended, the lake had to be restored to its orig-inal condition. Other than that, “in the early

days, we could do pretty well what wepleased,” he says. The camaraderie wasstrong. “It was nirvana when I got there,”recalls John Rudd, who first arrived at ELAas a graduate student in 1972. Researchersworked full-time, brainstorming late into thenight. “We lived our science together, weekafter week,” says Rudd.

Ecology’s supercolliderBut change was afoot. In 1979, the FisheriesResearch Board, which had been run mostlyby university scientists, was dissolved; theFreshwater Institute and ELA were trans-ferred to DFO. The move put departmentofficials, not scientists, in charge and even-tually had a large impact on the direction ofthe research, says Schindler.

DFO’s primary focus was on marinerather than freshwater issues, and ELA grad-ually lost its favored status. Raising fundsfor experiments became increasingly hard.“We’d always fall through the cracks,”Schindler recalls. Fed up, he left for the Uni-versity of Alberta, Edmonton, in 1989.

Also at about that time, a few officials withthe province of Ontario began to look askance

Probing below. Floating traps collect aquatic insectson lake 375, part of the research infrastructure at ELA.

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Dam impact. Flooding wetlands showed that reservoirs can release greenhouse gases and mercury.

BEFORE AFTER

Rising star. David Schindler, shown in1979 and today, was ELA’s first director.Many credit ELA’s reputation to his2 decades of leadership.

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NEWSFOCUS

at ELA’s practice of dosing the lakes with onepollutant after another. One example in partic-ular sticks in the craw of Robert Hecky, whotook over as director after Schindler.

ELA scientists had been adding cad-mium, a metal released from smelters andcoal-fired power plants, to Lake 382 to seewhether provincial regulations were tightenough to protect aquatic organisms. A few years after Schindler left, Ontario’sthen–minister of environment halted thatwork, forbidding ELA scientists from addingany more cadmium. “They threatened to shutdown the whole ELA if we didn’t stop,”recalls a still-outraged Hecky—despite thefact that power plants were emitting greaterconcentrations of cadmium on a regularbasis. Hecky says he soon realized that plansto add polychlorinated biphenyls to the lakesweren’t going to fly, either.

The nadir came in 1996, when the federalgovernment tried to shut ELA during around of belt-tightening. Hecky resigned inprotest. Scientif ic societies such as the

American Society of Limnology andOceanography rushed to ELA’s defense, andthe lab was saved. ELA is secure now,assures Robert Lambe, DFO’s regionaldirector in charge of the Freshwater Insti-tute. “It’s not in the crosshairs.”

But the years have taken a toll, say scien-tists inside and outside ELA. Old-timers saythat DFO grants are smaller and harder tocome by now. “The federal money to con-duct experiments has dried up,” Rudd says.A long-term experiment on flooding of wet-lands may have to be shut down if funds torepair the dam can’t be found.

The biggest impact has been the declinein staffing; the number of DFO scientistsworking full-time at ELA has fallen byabout half since the early 1990s, to six today.Researchers from other institutions stillflock to the lab with the spring thaw,although now it tends to be graduate stu-dents and technicians rather than professorswho stay the whole summer, Rudd says.

In terms of technological prowess, ELA

remains unmatched. Over the years, DFOreplaced the dented trailers with comfort-able dormitories and a first-rate laboratory.ELA is still “the supercollider of ecology,”says Schindler. In a recent experiment togauge the impact of freshwater aquacul-ture, for instance, researchers had to build a12-ton cage on the ice of Lake 375 in–30°C weather. Every spring, starting in2003, the cage was stocked with 10,000rainbow trout that had to be trucked in fromnearly 1900 km away. There are not manyplaces in the world with ELA’s combinationof experience setting up big infrastructureand onsite research capacity, as well asdetailed background records and referencelakes, notes DFO’s Cheryl Podemski, whoran the experiment.

Perhaps the most ambitious experimentof the past decade is METAALICUS (seesidebar, p. 1319), in which researchersadded isotopes of mercury to Lake 658 andits watershed for 7 years in a row. The goal isto f igure out how the pollutant moves

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Full palate. For 40 years, researchers have conducted a broad range of experimentsin 58 lakes reserved for research (some shown above). Among others, they have

manipulated food webs; examined the effects of habitat disruption, such as removalof lake vegetation; and studied the impact of caged aquaculture.

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through the ecosystem and builds up in fish.The f inal dose of mercury was added in2007, and now team members are keepingtabs on water quality and aquatic life.

Next?

Other experiments at ELA have finished theiractive phase as well. In 2007, all the fish wereremoved from the aquaculture operation forthe last time. Now researchers are watching tosee how the lake returns to its natural state.That’s also the case with ELA’s endocrine dis-rupter study. Over 3 years, researchers addedsynthetic hormones to Lake 260 to study theeffects of birth-control pills in wastewater. Athormone concentrations currently found inmunicipal wastewater, minnow populationscrashed, they found, in the first ecosystem-scale study to show the impact of these pollu-tants on fish populations.

But now, for the first time in ELA’s storiedhistory, no major lake manipulations are ondocket. Part of the reason no big manipula-tions are planned is that half of the staff scien-

tists are about to retire, says Paterson, who is“terrified” of the looming brain drain. But heis heartened by a new alliance with Environ-ment Canada that he hopes will bring newfunds to ELA and enable scientists to broadenthe scope of their research again.

One key issue ELA ought to be immersedin is climate change, Paterson concedes. Infact, Rudd and Schindler tried to sell the ideaof studying climate change to DFO in the

1990s, but there was no interest, they say;DFO officials felt it wasn’t within the depart-ment’s mandate. “For the first time, there’s amajor widespread problem that’s going on thatwe’re not [studying] at ELA,” says Rudd, whoretired in 2002 but continues to work onMETAALICUS. ASU’s Elser and others sayELA could have been more aggressive sincethen. “It helps to have senior leadership thatcan knock heads,” Elser says.

Schindler agrees that the lab needs aninfusion of fresh blood, especially someonewith a bold vision for ELA’s future who willbattle the bureaucracy for funds. Recruitingthe best and brightest isn’t easy, however;government salaries aren’t competitive withthose at top universities, and DFO can’t evenoffer start-up funding to set up new labs. Butwith three positions that will need to befilled, Paterson will soon be sifting throughresumés. With any luck, he might f indanother Schindler in the bunch—somebodywho can set the course for the next 40 years.

–ERIK STOKSTAD

www.sciencemag.org SCIENCE VOL 322 28 NOVEMBER 2008 1319

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Contaminating a Lake to Save Others

LAKE 658, CANADA—Even at the Experimental Lakes Area (ELA), thebirthplace of “big” ecological experiments, METAALICUS is ambitious. Overthe past 9 years, some 15 principal investigators (PIs) from eight institutionshave joined forces at this remote experimental station (see main text) to teaseapart how mercury in air pollution cycles through the environment. Byadding stable isotopes to Lake 658 and the surrounding watershed,researchers are studying how mercury percolates through soil and into lakes,how microbes make it bioavailable, and the rates at which it accumulates infish. Already, the $15 million project, formally known as the Mercury Experi-ment to Assess Atmospheric Loading in Canada and the United States(METAALICUS), has generated policy-relevant results.

Several attributes made ELA an ideal location for METAALICUS, says one ofits leaders, geochemist David Krabbenhoft of the U.S. Geological Survey inMiddleton, Wisconsin. For one, the relatively low rates of background deposi-tion to the lake made it easier to detect the tiny amounts of mercury iso-topes—just 12.5 grams (a sixth of a teaspoon)—that they added each year.Even more important, the remote location and the history of successfulresearch at ELA lowered the chance of public objections. Just in case, Canadianresearchers held public briefings in Dryden and Kenora, the closest towns.

METAALICUS was years in the planning. After a 3-year pilot project at ELA,the researchers first added isotopes in June 2001, trickling 202Hg throughoutthis 8.3-ha lake by boat. Depositing the other two isotopes—198Hg onto anadjoining wetland and 200Hg onto the surrounding forest—proved far morechallenging. In a nail-biting maneuver, a crop-duster had to fly low overheadrepeatedly, precisely spraying an extremely dilutemist of mercury. Had a droplet of either 198Hg or200Hg drifted into the lake, it would have con-founded the findings.

Within 2 months, 202Hg was detected in fish. Ina paper published in September 2007 in the Pro-

ceedings of the National Academy of Sciences, theteam reported that mercury levels rose by a third in

young yellow perch over the first 3 years ofthe experiment. This suggests that lower-ing industrial emissions of mercuryshould quickly reduce fish contamina-tion in lakes where most of the mer-cury falls directly from the atmos-phere to the water.

The final doses of mercurywere added to the ecosystemlast year. Earlier this fall, acrew of technicians was busylooking for signs of isotopicmercury trickling through theforest soil. Monitoring will continuefor several more years to figure out the rate atwhich the forest soils release mercury after itlands from the atmosphere. “It’s slow, but wecan’t tell you whether it’s 20, 100, 1000 years”for the isotopes to make their way into the lake, says biogeochemist CindyGilmour of the Smithsonian Environmental Research Center in Edgewater,Maryland, a co-PI on a new $570,000 U.S. National Science Foundationgrant to explore the question. The work is crucial, Krabbenhoft notes,because it will provide insights into the impact that past mercury emissionswill have on future fish generations.

METAALICUS is not only the largest experiment in ELA’s history, but it isalso the first that has moved beyond lake manip-ulation, ELA’s original mandate, to manipulationof the surrounding terrestrial ecosystem as well.“Broadening the perspective beyond lakes addsa lot,” says Stephen Carpenter of the Universityof Wisconsin, Madison, and would be an effectiveway to maximize the scientific potential of ELA.“They need to think really, really big.” –E.S.

Trickle down. Researchers are tracking how mercuryin the forest flows into Lake 658.

Straight shot. A crop-duster applied differentisotopes of mercury(black dots) to theupland forest (green)and wetland (red).

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