8 C o l u m b i a U n i v e r s i t y RECORD April 19, 2002

A study led by Columbiaresearchers published in the Marchissue of “Wetlands,” the journal ofthe Society of Wetland Scientists,supports observations that the saltmarshes of New York City’s JamaicaBay near John F. Kennedy Interna-tional Airport are eroding rapidly,and in the coming decades may dis-appear altogether with rising sea lev-els as a result of global warming.

In an analysis based on historicalaerial photographs of several of thelarger marsh islands, the scientistsdetermined that 12 percent of thearea’s marshlands had been lost since1959. Amore comprehensive exam-ination showed a 51 percent reduc-tion of island marshes between 1924and 1999, with 38 percent loss ofmarsh vegetation occurring since1974. Some of the smaller islandshave lost up to 78 percent of theirvegetation cover since 1974.

The researchers found evidencethat the rate of loss was acceleratingand probably could not survive theoncoming rise of the ocean. Howev-er, they held out hope that trialrestoration efforts, if begun soon,could stabilize the marshes. Becausethey are literally “drowning in place”from sediment starvation, remedia-tion efforts would likely include theplacement of thin layers of sedimenton the marsh surface, according toEllen Hartig, the lead author and anecologist, formerly at Columbia,now with the Federal EmergencyManagement Agency.

“These efforts have had success inother wetlands,” she said. One majorconcern of the scientists is that theloss of the wetlands in Jamaica Baycould pose a danger to surroundingresidential developments, whichwould be further exposed to floodingfrom storm surges.

Hartig said while the NationalPark Service has been excellent inprotecting the marshlands for the last30 years, in the future the agencyshould take a stronger approach and

adopt a hands-on role in managingthe wetlands. In the past, she said, thethinking was that if the wetlandswere left alone they would naturallythrive.

While measured rates of marshgrass growth appear typical of otherregional wetlands, the distribution ofmarsh grass is rather patchy, withmany bare spots and water-filledpools where normally vegetationwould be found.

“From the air, many of the islandsare so riddled with these pools thatthey resemble Swiss cheese,” saidVivien Gornitz, a geologist and spe-cial research scientist at the GoddardInstitute for Space Studies at Colum-bia.

These features indicate that themarshes are submerging, leading toplant die-off from within. Field workand mapping further substantiate thatsubmergence is more significantthan erosion of the island edges.

As part of a regional report pre-pared for the U.S. National Assess-ment on Climate Variability andChange, a suite of sea-level rise pro-jections based on historical data andclimate models was compared withplausible rates of marsh growth. This

analysis suggests that if enough sed-iment could accumulate on themarshes, the marshes would surviveall but the most extreme cases offuture sea level rise. The fact that themarshes are shrinking even at cur-rent rates of sea level rise (around 3millimeters per year in New YorkCity) suggests that lack of sedimentsis an important cause of the wetlandslosses, said Gornitz.

In addition to Hartig and Gornitz,the study involved other researchersat the State University of New Yorkat Stony Brook and the New YorkState Department of EnvironmentalConservation. Funding was provid-ed by the National Science Founda-tion, the National Park Service, andthe National Aeronautics and SpaceAdministration.

A major cause of the vanishingwetlands in the Queens borough isthe disruption of the flow of waterand the spread of sediment uponwhich marsh grasses depend.Repeated dredging of the bay forshipping channels and to providelandfill for the expansion ofKennedy Airport (built on wetlandsbeginning in 1942 before laws toprotect them) over time has depleted

Global Warming Erodes Wetlands Near Kennedy Airport, Columbia Study Finds

the process of sediment depositionwhich nourishes the wetlands. Thedredged shipping channels act as akind of trap for sediment, preventingthis nourishing material from wash-ing over the marshes and maintain-ing their growth.

Urban development that closedoff stream channels around the bay,waves from recreational boat trafficand heavy grazing by waterfowlcontribute to the erosion of themarshes. In addition, development inQueens and adjacent Kings and Nas-sau County may have diminishedsediment sources upland andblocked sediments deposits fromwashing into the bay after storms.“Further research is urgently neededto establish the causes of marshloss,” said Gornitz.

The researchers warned that atcurrent rates of attrition, Spartinaalterniflora, the dominant marsh

grass, could disappear altogetherwithin the next few decades, yearsbefore the full impact is felt from aprojected one meter rise in the met-ropolitan area sea level due to globalclimate warming. The researcherssuspect that the die-off of this marshgrass plays an important role in themarsh deterioration. An abnormallyhigh population of mussels andapparent encroachment of sea let-tuce may be symptomatic of thetransformation to more marine con-ditions as the marshes drown, orthey could be actively contributingto the grass die-off.

A rise in global temperatures dueto increases in greenhouse gasseswould cause thermal expansion ofocean waters and melting of moun-tain and high-latitude glaciers. Pro-jections call for a sea-level rise ofone meter by the end of the centuryin metropolitan New York. “The fateof the island marshes of JamaicaBay serves as a wake-up call regard-ing the hazards facing other coastalwetlands due to the intertwinedimpacts of human-induced stressesand sea-level rise,” the report stated.

While heavy residential andindustrial development and the con-struction of the airport has dramati-cally shrunk the size of the JamaicaBay wetlands since the earlydecades of the 20th century itremains one of the largest coastalecosystems in New York State. In1972, the remaining marsh islandsand Jamaica Bay Wildlife Refugecame under federal protection as partof the Gateway National RecreationArea, administered by the NationalPark Service. Along the Atlantic fly-way for migratory birds, the saltmarshes are prime nesting and feed-ing sites for many shorebirds,including geese and ducks.

Salt marshes near JFK Airport are eroding rapidly and may disappear altogether due to global warming.

NASA's Chandra X-ray Observa-tory has found two stars—one toosmall, one too cold—that revealcracks in our understanding of thestructure of matter. These discoveriesby a team of astronomers includingColumbia Professor David Helfandopen a new window on nuclearphysics, offering a link between thevast cosmos and its tiniest con-stituents.

Chandra's observations of starsRXJ1856.5-3754 and 3C58 suggestthat the matter in these stars is evendenser than nuclear matter found onEarth. This raises the possibility thesestars are composed of pure quarks orcontain crystals of sub-nuclear parti-cles that normally have only a fleet-ing existence following high-energycollisions.

By combining Chandra and Hub-ble Space Telescope data,astronomers found that RXJ 1856radiates like a solid body with a tem-perature of 1.2 million degreesfahrenheit (700,000 degrees Celsius)and has a diameter of about sevenmiles (11.3 kilometers). This size istoo small to reconcile with standardmodels for neutron stars—until nowthe most extreme form of matterknown. too small.

"Taken at face value, the com-bined observational evidence pointsto a star composed not of neutrons,

but of quarks in a form know asstrange quark matter," said JeremyDrake of the Harvard-SmithsonianCenter for Astrophysics (CfA) inCambridge, Mass., and lead authorof a paper on RXJ1856 to appear inJune 20 issue of “The AstrophysicalJournal.” Quarks, thought to be thefundamental constituents of nuclearparticles, have never been seen out-side a nucleus in Earth-bound labo-ratories.

Observations by Chandra of 3C58also yielded startling results. A teamcomposed of Patrick Slane andSteven Murray, also of CfA, andHelfand failed to detect the expectedX-radiation from the hot surface of3C58, a neutron star believed tohavebeen created in an explosion wit-nessed by Chinese and Japaneseastronomers in 1181 AD. The teamconcluded that the star has a temper-ature of less than one million degreescelsius, which is far below the pre-dicted value.

"Our observations of 3C58 offerthe first compelling test of models forhow neutron stars cool and, the stan-dard theory fails," said Helfand. "Itappears that neutron stars aren't pureneutrons after all—new forms ofmatter are required."

A teaspoonful of neutron starmaterial weighs a billion tons, asmuch as all the cars, trucks and buses

on Earth. Its extraordinary density isequivalent to that of the nucleus ofan atom with all of the typical spacebetween the atoms and their nucleiremoved. An atom's nucleus iscomposed of positively chargedprotons and neutral neutrons, parti-cles so small that 100 billion trillionof them would fit on the head of apin.

Protons and neutrons are com-posed of even smaller particlescalled quarks, the basic buildingblocks of matter. Enormous atomsmashers are designed to probe theforces between quarks and the struc-ture of the nucleus by smashinghigh-energy beams of nuclei intoeach other and observing the violentaftermath for a fraction of a second.

Drake cautioned that the observa-tions of RXJ1856 could be inter-preted as a more normal neutron starwith a hot spot. Such a model isunder consideration by Fred Walterof the State University of New York,Stony Brook, one of the discoverersof RXJ1856, which was originallyfound in 1996 by the German Roet-gen satellite. However, the hot spotmodel requires a very special orien-tation of the star with respect to theEarth to explain the absence of pul-sations, which would be expectedfrom the hot spot. The probability ofsuch an orientation is quite small.

Cosmic X-Rays Reveal Evidence for New Matter Form

More than 100 scientists andresearchers from Columbia and theCanadian province of Québecengaged in recent discussions on theColumbia campus aimed at build-ing research partnerships in theemerging field of nanotechnology.

The Québec-Columbia Nan-otechnology Symposium, held atDavis Auditorium on April 11,brought together leading scientistsfrom Columbia and research uni-versities in Québec with the inten-tion of forming collaborations onthe frontier of nanoscale research inmany disciplines. Executive ViceProvost Michael Crow told thegathering: “In an era where worldclass science increasingly meansinternational science, we believethat committing to partnerships suchas these will become vital for build-ing and sustaining research pro-grams.”

The discussions were held withparticipants of NanoQuébec, theresearch network founded in 2001by the province’s six research uni-versities: McGill, Montréal, EcolePolytechnique, INRS, a center in thenetwork of the Institut National pourla Recherche Scientifique, at theUniversity of Québec, Laval andSherbrooke. The network has com-mitted $5 million in research fund-ing to nanotechnology.

The intent of the first meetingwas for Columbia and Quebecresearchers to learn where partner-ships are possible. Follow-up meet-

ings are planned to focus in moredetail on promising areas, accord-ing to Jeffrey Brancato, actingdirector of the Columbia Nan-otechnology Initiative.

Columbia is one of six majorresearch universities in the UnitedStates that have been designatedby the National Science Founda-tion as national nanoscale researchcenters. The University receivedan initial U.S. government grant of$10.8 million to support the workof 16 primary researchers for fiveyears in the Center for ElectronicTransport in Molecular Nanostruc-tures. Professors Ronald Breslow,the National Medal of Sciencewinner, and Horst Stormer, aNobel Prize winner in physics, arescientific directors of the center.

More than 50 researchers Uni-versity-wide are engaged innanoscale research, includingthose at Columbia’s Fu Founda-tion School of Engineering andApplied Science, the Health Sci-ences Division and within diversedepartments, such as chemistryand physics. Research involvesthe simulation of biological andinorganic materials; the synthesisand characterization of nanocrys-tals, nanotubes, and low-dimen-sional structures, and the fabrica-tion of small, functional biologicalmachines that detect and movematter through a variety of micro-scopic methods.

—Suzanne Trimel

New Nanotechnology InitiativeLaunched with Province of Québec

BY SUZANNE TRIMEL