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VENICE, ITALYWith a few expert motions ofhis oar, Fabio Carrera sends the long batlaboat gliding around a corner in this maze ofcanals. Suddenly, a dim patch of stars is theonly light and the gentle swish of water the

only sound. The experience evokes acenturies-old past, when Venicewas one of the most powerfulcity-states in the Western world.But times have changed. Oneclue is the outboard motors pro-truding from beneath the tarps ofmoored boats. Another comes inthe approach to the tunnelbeneath Santo Stefano Church.

Although it is low tide, Car-rera has to stoop to clear themoist stone ceiling. At hightide, this passage is completely

inaccessible, says Carrera, anurban information scientist andnative Venetian who now divideshis time between WorcesterPolytechnic Institute in Massa-chusetts and his watery home-town. Elsewhere in the city, theacqua alta overflows the streets,fills the ground floors of build-ings, and nibbles away at bricksand plaster.

New Orleans isnt the onlycoastal city threatened by en-croaching waters. Little by littleeach year, Venice is being swal-lowed by the sea. Although this has been aproblem since the Middle Ages, an accel-erating rise in sea levels linked to globalwarming has turned the sporadic floodingfrom a nuisance into a looming catastro-phe. Crisis already hit once, in 1966, whenmost of the citys streets were submergedunder a meter of water. After 3 decades ofdebate, construction has now begun on aseries of enormous tidal gates to defendthe city. The $5 billion plan is controver-sial, with some critics arguing for differ-

ent protective measures and others pre-dicting that the coming decades of sea-level rise will render the gates obsolete(see sidebar, p. 1979).

But theres good n ews as well. The

Venice problem has made the city a hot

spot for scientif ic research, and theres noshortage of questions to tackle. Every timewe focus on one aspect of the practicalproblem, we discover another gap in ourknowledge, says Pierpaolo Campostrini,an electrical engineer who directsCORILA, the organization that orchestratesVenices scientific activities. Venice is pro-viding other coastal cities with insights onwhat global climate change looks like at thelocal level. The city and its lagoon have alsobecome a model system for studying how

physical, biological, and urban processinteract in a marine setting.

If Italys Ministry of Education, Univesities, and Research has its way, Venicwill soon receive 1.5%$60 million

the $5 billion allocated for the tidal gateCity officials hope that the f ivfold increase in national fundinfor basic science institutionwill attract young people bcreating more academic anhigh-tech jobs in a city whopopulation is rapidly shrinkinBut whether science can revitaize the city or save it from thencroaching sea remains aopen question.

At the battlefront of climate

changeZipping across the chalkgreen water in a motorboaCampostrini points out 16th century stone fortress wiwindows half-submerged. Itnot enough to estimate sea levas a global average, he sayDetermining a particular cityriskand what to do about itrequires an understanding of hoclimate change plays out locallEven so, Venice is a microcosof the larger changes takinplace, says Trevor Davies, a

atmospheric scientist at the University oEast Anglia in Norwich, U.K.

For instance, Venices record of sea-levchange is now the most comprehensive ithe world. Modern records of watermarks gback to the late 19th century, and researcherare finding ways to push the data farthback in time. A Venetian tradition of paining scenes with the help ofcamera obscurprojections, the pinhole predecessor to photography, has left researchers with accurately scaled images of the green algae lin

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News Focus

Complex interactions. A computer model, overlaid on a satellite image,divides the Venice Lagoon into thousands of interacting triangles to enablestudy of its processes, such as water flow and sediment transport.

Like New Orleans,Venice is slowly subsiding. Several decades and$10 billion of research have not settled the debate overwhat to do aboutthe Venice problem, but studies of the citys famed lagoon are pro-viding insights for other coastal cities on pollution and climate chang

A Sinking CityYields Some Secrets

Like New Orleans,Venice is slowly subsiding. Several decades and$10 billion of research have not settled the debate overwhat to do aboutthe Venice problem, but studies of the citys famed lagoon are pro-viding insights for other coastal cities on pollution and climate chang

A Sinking CityYields Some Secrets

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on walls that mark the average high-waterlevel. A team led by Dario Camuffo, a cli-matologist at the University of Padua, Italy,has used them to extend sea-level recordsback another 300 years. Archaeologists aregoing back to the Middle Ages by estimatingwater levels based on the buried remains offormer walls and bridges. And geologists areestimating the local sea level 2000 years agoby dating the remains of salt

marsh plants that once pokedabove the water.

To fit these data into the globalpicture, researchers must alsoaccount for Venices steady sink-ing due to a combination of mov-ing continental plates and com-pressing sediments. The effect ofa little Ice Age that hit Europe inthe Middle Ages appears as aspike in sea levels even higherthan today, whereas the levels atthe time of the Roman Empirewere about 1.5 meters lower. The

most troubling trend, says geo-physicist Alberto Tomasin of theUniversity of Venice, is that sea levels haverisen rapidly over the past 50 years.

Rising sea level isnt the only way cli-mate change is affecting the city. Venice is aperfect natural lab for studying these effects,says Davies, because changes in weatherpatterns are amplified as changes in thefrequency and severity of flooding events.Davies and Isabel Trigo, a climate scientistat the University of Lisbon, Portugal, havebeen teasing apart the different factors thatcause the flooding.

The first task has been a postmortem ofthe 1966 disaster. Even without globalwarming, Venice would be prone to flooding,both because it was built only a couple ofmeters above the water and because of thecitys location at t he end of the narrowAdriatic Sea. The mountains to the north cre-ate low-pressure systems that suck the waterlevel higher up around the lagoon, and windtends to blow in from the sea, piling the waterhigher. And because of the shape of theAdriatic, sometimes swells generated bystorms in the Mediterranean fall in phasewith the tides, doubling the load of water thatrushes into Venices lagoon. These factors allconspired in 1966, causing the second tide ofthe day to push into the lagoon before thefirst could drain out, swamping the city.

With these mechanisms mapped out,Davies and Trigo are f inding that climatechange can also have a protective effect at thelocal level, at least in the short term. Venicewould be in much deeper trouble by now, saysDavies, were it not for a northward drift of theAtlantic storm track over the past 40 years, atrend linked to global warming. As a knock-oneffect, storms in the Mediterranean have

become less severe, likely saving the city frommore 1966-style catastrophes. What happensif climate change nudges the Atlantic circula-tion farther off track is hard to predict. Bystudying Venice, says Davies, you can start todraw out these subtle effects.

Deep knowledge of a shallow lagoon

In the past 3 decades, Rome has spent morethan $10 billion studying and coping withthe Venice problem. In comparison,Italys national research foundationreceives about $1 billion per year. By themid-1990s, people began saying that theVenice funding was a torta, a giant cakefree for the taking, recalls Philippe Pypaert,an environmental scientist at the UnitedNations Educational, Scientific, and Cul-tural Organizations European science

bureau in Venice. In 2000, the newly estalished CORILA began reining in the proects by controlling the flow of funds anorganizing projects under a few broagoals. Things are under much better cotrol now, says Pypaert.

Still, Campostrini says that climate changand flooding arent Venices only problemThe citys art and architectural treasurrequire protection and restoration, and theare environmental threats to the surroundinlagoon, which is a bustling seaport and one Europes largest protected wetlands.

To help understand the troubles beseting the lagoon, scientists of every stripe abuilding a model that can not only hethem manage the fragile environment balso shed light on the physical and biologcal aspects of a wetland. This is our ult

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CREDIT:MOSE

Holding Back the SeaUnderstanding climate impacts is useful. But the goal is to protect Venice. Dams would dothe trick, says Campostrini, but the city would lose its income as a port and the lagoowould die without the daily tides. Injecting water into the underground aquifer that wanearly drained 40 years ago would lift the city, but uneven rising could also destroy it.

The compromise solution, called MOSE, is a series of 78 hollow, 300-ton steel gatesThe gates will sit flat underwater at the lagoons three inlets.But in anticipation of a flood

air will be pumped into the structures to

make them stand upright and block tides upto a meter higher than those of 1966. Dredging has begun for the massive concrete foundations, but they wont be operationabefore 2011.

The two questions hanging over MOSE arehow often they will be used and how high sealevels will rise. By official estimates, the gatewill be needed only two or three times a yearBut critics say it could be as often as 50enough to make the lagoon a sewagecontaminated swamp. And if the worst-casscenario of a 1-meter sea-level rise by 2100comes true, the gates could be useless.

Outsiders opinions are as mixed as thosof Venetians. Something like the MOSE gatesare needed because controlling tidal surges ithe only solution, says Caroline Fletcher, acoastal scientist at the University of Cam

bridge, U.K. But building gates is not enough, according to John Day, an ecologist aLouisiana State University in Baton Rouge who, until 2 years ago, led a long-term study othe Venice lagoon.Day says his study, one of many supported by national funds devoted toVenice, revealed that returning the flow of diverted rivers back into the lagoon would noonly deposit sediments to compensate for subsidence but also would support lush wetlandvegetation that would act as a buffer to slow the surges.With this natural defense, says Daythe gates would not be needed nearly as often. Venices situation is unique, as is NewOrleanss,he says,but they share the long-term problem of subsidence and wetland loss.Day contends that the consortium of industrial partners behind the MOSE projec

[doesnt] want to hear about natural versus engineered solutions.Meanwhile, some Venetians argue that the entire debate has fallen far from the markThe take-home lesson from all this, says Fabio Carrera, an urban information scientiswho divides his time between Venice and Worcester Polytechnic Institute in Massachusettsis that the cheapest solution is to stop global warming, but no one seems to be talkingabout that. J.B

N E W S F O C U

From below.The MOSE gates will rest under-water until floods are predicted and air isforced into their interiors.

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mate goal, says Roberto Pastres, a marinescientist at the University of Venice, but itseasier said than done.

Just predicting how the water behaves ismind-boggling. Water flow alters thelagoons shape by moving sediments, whichthen changes the flow, and so forth. Add tothat feedback loop the many urban and bio-logical influences, and the hopeful modelerfaces an impossibly complex system, says

Giampaolo Di Silvio, a hydraulic engineerat the University of Padua.

Fortunately, the researchers alreadyhave enormous amounts of information,from the movement of sediments to the dis-

tribution of sea life. The Venice lagoon isthe best stu died in the world, says DiSilvio. One of the big questions to beanswered with the final model, of course, ishow the lagoon will react to the new tidalgates. But it will also help scientists aroundthe world study how pollutants are shuttledthrough marine systems and the factors thatlead to oxygen-choking algal blooms. Themodel may also help answer fundamental

questions involving biodiversity and nutri-ent transport in sea-land systems.

Turning Venice into a science meccacould also save it from a ruinous brain drain.Venice is in danger of becoming a dead

city, like a museum, says Carrera. Driveaway by the high waters and high prices, thpopulation has plummeted from 150,000 the 1950s to 64,000 today. Nearly half of thcitys income now comes from the 14 milion tourists who flock to Venice each yeawith most of the rest coming from port trafic. We desperately need more young peple, says Campostrini, and one way attract them is to build up the university an

high-tech sectors. Otherwise, Venice maend up being saved from the sea but abadoned by its own people.

JOHN BOHANNO

John Bohannon is a writer in Berlin, Germany.

N E W S F O C U S

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Tulane University biochemis tArthur Lustig is still reeling fromHurricane Katrina. He spent4 days hunkered down in his NewOrleans lab before being evacu-ated by helicopter, then anothermiserable night in a shelter. Hishouse was likely lost to flooding,and hes not sure whether the

20 yearsworth of yeast strains heuses to study telomeres survivedthe power outage.

But things could be a lot worse.Showered with invitations fromcolleagues around the country,Lustig is now living with his wifesfamily in Chicago and working atNorthwestern University, with labspace for his four students and onepostdoc. Its a traumatic time. ButI think most of us have a positive attitude thatwe can get over this, Lustig says.

Thousands of scientists face similar chal-lenges. The flooding that displaced NewOrleans residents after Katrina slammed intothe Gulf Coast on 29 August exiled facultymembers, graduate students, and postdocsfrom a half-dozen institutions in NewOrleans. Thanks to Internet message boardsand cell phone calls, many are regrouping intemporary labs and office spaces at otheruniversities. People have been really won-derful. They realize [Katrina] is a hugeimpact on careers, says Arthur Haas, chairof biochemistry and molecular biology at theLouisiana State University (LSU) Health

Sciences Center in NewOrleans. Scientific soci-eties have also rushed tohelp, posting Web sitesfor those who havent yetfound spots (www.aaas.org/katrina).

For some, the disruption may be short-lived. Tulane medical school off icials hope toget a handle soon on mold in air conditioningducts, the main obstacle to reopening build-ings in their now-dry part of the city. Butmany researchers have already enrolled theirchildren in schools el sewhere and dontexpect to return until January, when univer-sity classes resume. Although they are tryingto view the forced exile as a minisabbatical,

its hard to be too optimistic about theresearch. Will it slow us up competitivelAbsolutely, says Lustig.

Against all odds, researchers did wh

they could to preserve their research mateals. In the days after the storm, researchefrom Tulane and LSU ventured back by botruck, and helicopter with armed guardstop off the liquid nitrogen covering storacontainers and retrieve samples hastiordered by priority. Tulane gene-theracenter director Darwin Prockop organizedconvoy from Baton Rouge on 10 Septembto salvage their National Institutes of Hea(NIH)funded adult human stem cell banwith staff lugging 36-kg Dewars up foflights of stairs to collect racks of vials.

Tulane scientists saved transgenic mi

but had to euthanize most other animals; LSanimal caretakers destroyed or loto flooding about 8000 animalsfour vivariums, says Joseph Moschbaecher, vice chancellor facademic affairs at LSUs HeaSciences Center. Also lost at Tulawere freezers of blood and urisamples, including those from tBogalusa (Louisiana) Heart Studwhich has followed thousands children since 1972 to tease oheart disease risk factors. Itnational tragedy, says Paul Whton, Tulane senior vice president f

health sciences.Other scientists fear that mold h

destroyed animal and plant collections built over decades. Tulane ecologist Lee Dysneaked back and put desiccant and mold kilin drawers containing preserved insects. Unversity of New Orleans (UNO) butterfly expPhil DeVries and his wife, systematist CaPenz, fear a severe toll on 30 yearswork: pserved butterflies, hundreds of photographs,well as rare identification books and countlefield notebooks. Physical scientists, for th

Displaced Researchers Scramble

To Keep Their Science GoingDespite huge personal losses, New Orleans scientists are hurrying to recreate their labsand lives with some help from the government

After Katrina

Rescue mission. Staff from Tulanesgene-therapy center bring Dewars ofliquid nitrogen to retrieve adult stemcells from flooded research labs.

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