View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by UNH Scholars' Repository University of New Hampshire University of New Hampshire Scholars' Repository Faculty Publications 8-1-2000 Flux of nutrients from Russian rivers to the Arctic Ocean: Can we establish a baseline against which to judge future changes? R. M. Holmes B. J. Peterson V. V. Gordeev A. V. Zhulidov M. Meybeck Université de Paris See next page for additional authors Follow this and additional works at: https://scholars.unh.edu/faculty_pubs Recommended Citation Holmes, R.M., B.J. Peterson, V.V. Gordeev, A.V. Zhulidov, M. Meybeck, R.B. Lammers, and C.J. Vorosmarty (2000) Flux of nutrients from Russian rivers to the Arctic Ocean: Can we establish a baseline against which to judge future changes? Water Resources Research, 36:2309-2320. This Article is brought to you for free and open access by University of New Hampshire Scholars' Repository. It has been accepted for inclusion in Faculty Publications by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. Authors R. M. Holmes, B. J. Peterson, V. V. Gordeev, A. V. Zhulidov, M. Meybeck, Richard B. Lammers, and Charles J. Vorosmarty This article is available at University of New Hampshire Scholars' Repository: https://scholars.unh.edu/faculty_pubs/150 WATER RESOURCES RESEARCH, VOL. 36, NO. 8, PAGES 2309-2320, AUGUST 2000 Flux of nutrients from Russian rivers to the Arctic Ocean: Can we establish a baseline against which to judge future changes? R. M. Holmes,• B. J. Peterson,• V. V. Gordeev,2 A. V. Zhulidov,3 M. Meybeck,4 R. B. Lammers? and C. J. V6r6smartys Abstract. Climate modelspredict significantwarming in the Arctic in the 21st century, whichwill impact the functioningof terrestrialand aquaticecosystems as well as alter land-oceaninteractions in the Arctic. Becauseriver dischargeand nutrient flux integrate large-scaleprocesses, they shouldbe sensitiveindicators of change,but detectionof future changesrequires knowledge of currentconditions. Our objectivein this paper is to evaluatethe current state of affairswith respectto estimatingnutrient flux to the Arctic Oceanfrom Russianrivers. To this end we provideestimates of contemporary(1970s- 1990s)nitrate, ammonium,and phosphatefluxes to the Arctic Oceanfor 15 large Russian rivers.We rely primarily on the extensivedata archivesof the former SovietUnion and current RussianFederation and comparethese values to other estimatesand to model predictions.Large discrepanciesexist among the variousestimates. These uncertainties must be resolvedso that the scientificcommunity will have reliable data with which to calibrateArctic biogeochemicalmodels and so that we will have a baselineagainst which to judge future changes(either naturalor anthropogenic)in the Arctic watershed. 1. Introduction M. Meybeck and A. Ragu, Rivers Dischargesto the Oceans: An Assessmentof SuspendedSolids, Major Ions and Nutri- Earth's temperatureis predictedto rise 1ø-3.5øCin the next ents, book draft, United Nations Environment Programme, century,with evengreater increases in the Arctic [Houghtonet 1995] (hereinafter referred to as Meybeck and Ragu, book al., 1996]. This temperature increaseis expectedto impact draft, 1995) (see also Global EnvironmentalMonitoring Sys- numerousaspects of the Arctic system,including the extent of tem (GEMS-Water), United Nations Environment Pro- permafrostand ice-coveredregions, the amount and distribu- gramme,www.cciw.ca/gems/), there hasbeen little criticaleval- tion of precipitation,and the productivityand biogeochemistry uation of the published values. We will derive nitrate, of terrestrialand aquaticecosystems [Chapin et al., 1995;Anisi- ammonium,and phosphateflux estimatesfor 15 Russianrivers mov and Nelson,1996; Hobble et al., 1998;Serreze et al., 2000]. that enter the Arctic Oceanusing a previouslyunavailable data All of thesechanges will affectriver dischargeand nutrientflux set and compareour estimateto model predictions[Seitzinger to the Arctic Ocean, which in turn may impact Arctic Ocean and Kroeze,1998] and to other data. We will concludethat in processes[Aagaard and Carmack,1989; Broecker, 1997; Ander- spite of the extensivedata set, it is currentlynot possibleto son et al., 1998]. Becauseriver dischargeand nutrient flux quantifyriverine nutrient flux to the Arctic Ocean with suffi- integratelarge-scale watershed processes, they shouldbe early cient confidenceto establisha contemporarybaseline. We will and accurateindicators of climate changein the Arctic. arguethat the scientificcommunity must soon resolve the remain- Detectionof future changesrequires knowledge of current ing uncertaintiesso that we do not squandera powerfuloppor- conditions.In this paper,we assesscurrent (1970s-1990s) nu- tunityto detectthe impactof dimatechange on theArctic system. trient flux from Eurasia to the Arctic Ocean. We focus on Russianrivers becausethe majority of riverine input to the Arctic Ocean comes from Russia.Although several sources 2. Description of Data Set report nutrient concentrationsand fluxes for RussianArctic During the Sovietera the Russianwater qualitymonitoring rivers[Alekin and Brazhnikova, 1964; Tarasov et al., 1988;Smir- systemwas among the mostextensive on Earth. However,prior nov, 1994; Gordeev et al., 1996; Gordeevand Tsirkunov, 1998; to the 1990s,scientists (Russian and otherwise)were unableto access,analyze, or publishthe officialwater qualitydata of the •The EcosystemsCenter, Marine BiologicalLaboratory, Woods former SovietUnion (FSU), largelybecause of political and Hole, Massachusetts. ideologicalreasons [Zhulidov et al., 1998].Such restrictions no 2p.p. ShirshovInstitute of Oceanology,Russian Academy of Sci- ences, Moscow. longer exist, but many of the data remain inaccessible.For 3Centrefor Preparationand Implementationof International example,data are often storedin notebooksinstead of digital Projectson TechnicalAssistance, Rostov-on-Don, Russia. form, and thesenotebooks are not necessarilycentrally located 4Laboratoriede G6ologieAppliqu6e, CNRS, Paris. but insteadmay reside in regionallaboratories. SComplexSystems Research Center, University of NewHampshire, Durham. Owing to these complications,use of the Russiannutrient data has been limited, and their fate has been uncertain be- Copyright2000 by the American GeophysicalUnion. causerecent economicand political instabilityin Russia has Paper number2000WR900099. lead to closureof laboratoriesand the potentialloss of data. In 0043-1397/00/2000WR900099 $09.00 order to help preservethe data set of the FSU and to estimate 23O9 2310 HOLMES ET AL.: NUTRIENT FLUX FROM RUSSIAN RIVERS TO THE ARCTIC OCEAN Arctic Ocean East Siberian Sweden Laptev•• Sea Barents.• Sea Se•a• KaraSeaTaymyr Peninsula Sea of Okhotsk China Kazakstan Mongoli___•Japan Figure 1. Map of Eurasia showingrivers in the United Federal Servicefor Observationand Control of EnvironmentalPollution (OGSNK/GSN) data set and their approximatewatershed boundaries. Discharge stationsare shownby opencircles, and nutrientstations are givenby crosses.Consult Table 1 for stationnames and coordinates.As is apparent, rivers in the OGSNK/GSN data set encompassmost of the Eurasian watersheddraining into the Arctic Ocean,with notableexceptions in the RussianFar East and on the Taymyr Peninsula.River codesare asfollows: 1, Onega;2, SevernayaDvina; 3, Mezen'; 4, Pechora;5, Ob'; 6, Nadym; 7, Pur; 8, Taz; 9, Yenisey;10, Anabar; 11, Olenek; 12, Lena; 13, Yana; 14, Indigirka; and 15, Kolyma. nutrient flux to the Arctic Ocean from Russian rivers, we have whereas rivers in eastern Siberia typically have about 50 compiled and digitizedthe data archivesof the FSU and the monthswith data entries.Sample concentrations reported as current RussianFederation for 15 Russianrivers entering the below detectionlimit (BDL) were treated as zero, whichmay Arctic Ocean.The data comefrom samplesthat were collected lead to a slight underestimationof nutrient flux. and analyzedas part of the Unified Federal Servicefor Ob- Mean monthlyriver discharge(Figure 2), obtainedfrom the servationand Control of EnvironmentalPollution (OGSNK R-ArcticNet database (www.R-arcticnet.sr.unh.edu)(R. B. prior to 1992 and GSN from 1992 onward). We will refer to Lammers et al., An assessmentof the contemporarygauged these data as the OGSNK/GSN data set. river dischargeand runoff in the Pan-Arctic region, submitted The 15 river basinsrepresented in the OGSNK/GSN data to Journalof GeophysicalResearch, 2000) (hereinafterreferred set nearlyspan the >5000 km width of Russia(Figure 1) and to as Lammerset al., submittedmanuscript, 2000), is usedto include three of the world's 13 largest rivers by discharge compute monthly nutrient fluxes.In many but not all cases, [Shiklomanov, 1993]. Watershed areas range from -50- R-ArcticNet dischargedata are availablefor the nutrient sam- 3000 X 103 km2 (Table1). The nutrientdata set consists of pling stations(Table 1). When dischargedata are not available time'series of ammonium,nitrate, and phosphateconcentra- at the nutrient station,data from the closestdischarge station tions for the 15 Russianrivers, with samplesgenerally being are used.Annual river dischargeat the R-ArcticNet stations, collected at the downstreammost station that was free of tidal for the rivers representedin the OGSNK/GSN nutrient data influence.The periodsof recordfor nutrientconcentrations in set,ranges from 13.3to 577.3km3/yr (Table 1). individualrivers typically