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Despite the loss of the Duke from the USAP program,At the time of the initial 3-year charter agreement inAntarctic scientists have reason to be optimistic about1985, the Duke was operated by Carino Shipping Ltd.,the future. A new ice-strengthened research vessel (classSt. John's, Newfoundland (CAnada-RIeber-NOrway, aABS A-l), Laurence M. Gould (71m, 3400 LT displacewholly-owned subsidiary of Rieber Shipping A/S),ment), has replaced the Duke for an initial five-yearand sailed under a Canadian flag with a predominantcharter in December 1997. The R/V Laurence M. Gould isly Canadian crew. In 1989, the vessel was reflaggedoperated by Edison Chouest Offshore, Galliano,Norwegian international, and from that point on sheLouisiana for the USAP under a subcontract withsailed largely with a Norwegian crew supplementedAntarctic Support Associates. Those sometimes exoticwith Chilean cooks, messmen, oilers and able-bodiedNorwegian entrees and vintage Chilean Cabernets (limseamen. In the shadows of Nansen, Amundsen, Larsen,ited to 3 oz. per dinnerandotherfamousmeal) have given wayNorwegian explorers,to red beans, rice, andthe officers and crew ofCoca Cola as the scienthe R / V Polar mthemselves over themoved from the Rieberyears by dedication andto the Chouest vesseldetermination in purcharter agreement.suit of their science support mission.The initial charterThe Drake Passagerequirement was for theAccordingtotheR/V Polar Duke to perAntarcticPilot,"navigaform austral summertion in the Southernresearch and resupplyOceanis rendered diffitasks similar to thosecultbysea ice, suddenassigned previously toviolentand unprethe R/V Hero. Her firstdictablechanges inseason-threecruisesweather,anunusuallybetween Punta Arenas,highproportionof danChile, and the AntarcticgerousshoalsrisingPeninsula from Januaryprecipitouslyfromdeepto April 1985-conformedwater,largeseasandto this minimal expectaswells,instabilityofthetion. However, by thecompassathighlatiend of her first year, the Figure 2: The R/V Polar Duke is an ice-strengthened vessel with accommodationsJbrinadequatecapabilities of the R/V 26 scientists. Diesel propulsion and thrusters fore and aft provide excellent maneuver- tudes,chartsandlackof naviPolar Duke were chal- ability and station keeping. Photo by Reiber Shipping A/S.gationalaids."It goeslenged by a rare eresearch cruise (L. Quetin, Chief Scientist) (see Parfit,great care when navigating in these waters." Despite all1986), which was followed by a second winter cruisesafety precautions that are routinely taken, work induring her third field season (June to July 1987). The sucAntarctica is still very hazardous. The R/V Polar Dukecess of these winter expeditions established what evenand the entire U.S. Antarctic Program pride themselvestually became a year-round science mission in theon their excellent safety records to date.Antarctic Peninsula (Table 1). Since 1988-1989, the PolarA major obstacle, if not impediment, for science operDuke has typically spent 275-300 days at sea per annumationsin the Peninsula region of Antarctica is the Drakein support of USAP science programs, and during thePassage.This malevolent portion of the global ocean,1989-1990 operating year she was at sea for 339 days.locatedbetweenCape Horn to the north and the SouthThis extended season was due, in part, to her support ofShetlandIslandsto the south (Figure 1, A and B) is,an interdisciplinary expedition from Palmer Station towithoutadoubt,oneof the most inhospitable places onthe Ross Sea and her first ever port call at McMurdoEarth.Althoughonrareoccasion the Drake Passage isStation (Figure 1A). In June 1995, the R/V Polar Duke leftsunnyandcalm,itusuallyis quite the opposite. Stormsthe southern hemisphere, temporarily, to deliver a shipmoveinamoreorlesscontinuoussuccession from westment of hazardous wastes to the U.S. mainland for finaltoeastatalatitudeofapproximately60 S in the Pacificprocessing and disposal. The bright sunny skies andsectoroftheSouthernOcean.Overcastsky and lowwarm seas that accompanied her on her journey acrossbarometricpressures( 985mb)arepossible;gales arethe equator thawed the decks and gained her the served nickname, "R/V Solar Duke."10Oceanogrophy Vol. 12 No. 2/1999

Cape Horn rollers, are legendary. They can achievelengths of 1 nmi, crest to crest, and reach heights of 25m (Lansing, 1959). As Charles Darwin wrote on firstobserving the Drake's fury in 1833, "The sight is enoughto make a landsman dream for a week about death,peril and shipwreck," or as Patricio Rojas, a cook aboardthe R / V Polar D u k e , recently proclaimed in a pressrelease on Wild Antarctica, "The Drake Passage makesthe living wish they were dead, and makes an atheistbelieve in God!" Every time I make the crossing I thinkabout Shackleton and his men who made a forced crossing of the Drake Passage from Elephant Island to SouthGeorgia in their open, 6m dory, James Caird. That helpsto place m y own misery into a broader and more realistic perspective.Occurrence and Consequenceo f the Ozone H o l eOzone, a triatomic form of oxygen (O3), OCCURS naturally in the earth's stratosphere and elsewhere. Ozone isboth an important oxidant and a precursor for otherreactive compounds, and plays a crucial role in atmospheric photochemistry (Molina and Rowland, 1974;Schnell et al., 1991). Ozone is essential for life on earth;it absorbs both infrared and UV-B (280-320 nm) radiation and, consequently, helps to drive the global circulation of the upper atmosphere. The amount of ozone atany one location on earth is called the "total ozone column" and is expressed as the height of O3 at standardtemperature and pressure measured in 10 .2 m, orDobson units (DU). The amount of 03, present at anygiven time and place is a complex balance betweenSelected Scientific Benchmarksnumerous sources, sinks, and transport processes.It is impossible to review or even mention all of theGeographical, seasonal, and interannual variations inscientific accomplishments of the many investigatorsO3 are both expected and observed.who have conducted research aboard the R/V PolarSuperimposed on these natural O3 dynamics is theD u k e during her 13 years of service. Interested readersdiscovery, by Farman and co-workers, of the episodicare encouragedloss of 03 eachto consult theaustral summerannual reviewover Antarcticaissues of the(Farman et al.,Antarctic1985; SolomonJournal of theet al., 1986). ThisUnitedStatesloss of stratosfor summariespheric O3, theof the results ofso-called "ozonethesediversehole," is attribfield programsuted to O3 de(see Table i for astructionbyfew examples).chlorine radicalsThere are, howvia chemicalever, at leastcatalysis. Thesetwo areas ofreaction mecharesearchthatnisms were firstdeservemendescribed by M.tion not onlyMolina and F.S.because of theirRowlandinsignificance, but1974, researchalso because offor which theytheirmuchlaterwerebroader implica- R/V Polar Duke calls at Pahner Station (64 46'S, 64 '03'W), the U.S. research base in the Antarcticawardedthetions to earth Peninsula. Established in 1968, this station now supports a diverse range of science projects from marine 1 9 9 5 N o b e lbiology to meteorology and upper atmosphere studies. It is also the site of several large penguin rookeriesand ocean sci- and, since 1991, the site of a NSF Long Term Ecological Research (LTER) project.Prizeinences.TheseChemistrytopics include 1)along with P.Antarctic stratospheric ozone depletion, increased surCrutzen, another ozone chemistry pioneer. These naturface ultraviolet solar irradiance, and effects on ecosysal O3-destroying reactions are now known to be stimutem processes; and 2) biogeochemical processes, carlated by release into the atmosphere of manmadebon fluxes, and the structure and function of Antarcticchlorofluorocarbons (CFCs), thereby providing afood webs. Both of these broad research topics havecompelling case study for our direct intervention onbeen studied extensively by investigators workingearth's climate.aboard the R/V Polar D u k e since 1985.During the annual development of the AntarcticOceanography Vol. 12 No. 2 / 1 9 9 911

TABLE 1Selected research programs supported by the R/V Polar Duke during her service to the U.S. National Science Foundation'sAntarctic Program (1985-1997)Project TitleMarine Geology & GeophysicsMarine heat flowPaleoclimate history of southern ChileStratigraphy in Antarctic fjordsMarine geology of Antarctic continental marginsMarine ChemistryParticulate matter fluxCycling of biogenic silicaIron and phytoplankton productionPhysiological ecology of ultraviolet absorbing compoundsHydrocarbons in the Antarctic Peninsula regionMarine BiologyAntifreeze proteins in Antarctic fishesEnergetics of Antarctic krillPhysiology of ice algaeBehavioral ecology of Weddell sealsMicrobial chitin degradationLife history of Antarctic fishesBiology of gelatinous zooplanktonMeteorology/OceanographyMarine sources of sulfate aerosolNetwork for monitoring ultraviolet radiationPhotochemistry of Antarctic watersOzone depletion and phytoplankton biologyCloud condensation nuclei: a link between ocean-sulfate and climateOceanographyTrophic coupling between mesopelagic and sea-ice communitiesLong-term ecological research on the Antarctic marine ecosystemResearch on Antarctic coastal ecosystem ratesHydrothermal vents in the Bransfield StraitsFormation of Antarctic bottom waterEcology of marine Antarctic archebacteriaozone hole, there can be complete loss of O in the lowerstratosphere and up to 50% loss of total column O ,(from typical winter values of 300 DU to springtimeminima of 150 DU) during a period of less than sixweeks generally beginning in late August. The size ofthe Antarctic ozone hole has been increasing since theearly 1980s (Jiang et al., 1996), and this has stimulatedresearch into this important area.Changes in total column 03 concentrations havedirect effects on UV-B irradiance at the earth's surfaceand, hence, implications for UV-B d e p e n d e n t photochemistry and photobiology. Ozone selectively absorbsUV-B and does not alter visible light (400-700 nm);consequently, O: depletion selectively increases UV-Bfluxes. A major body of literature exists on the effects ofUV-B radiation on the physiology and growth of a vari-12Principal InvestigatorL. LawverA. LeventerE. DomackJ.B. AndersonR. DunbarD. Nelson, D. DemasterJ.H. MartinD. KarentzM. KennicuttA. DeVriesR. Ross, L. QuetinC. SullivanJ.W. TestaJ.T. StaleyR. RadtkeR. HarbisonH. BerresheimC.R. BoothK. Mopper, D. KieberR. Smith, B. PrdzelinV. SaxenaK. SmithR. Ross/R. Smith and othersM. Huntley and othersG. KlinkhammerT. FosterE. DeLongety of marine organisms (Voytek, 1990; Hfider andWorrest, 1991), but less is k n o w n about the ecologicalconsequences. An a u t h o r i t a t i v e r e v i e w of presentknowledge has recently appeared (Karentz et al., 1994).In response to a recognized need to obtain more information on the potential ecological impacts of theAntarctic ozone hole, a ground-based scanning spectroradiometer (280-700 n m with 0.75 n m bandwidth) wasd e p l o y e d at Palmer Station in May 1988 as part of theUSAP UV monitoring network to measure the ozonehole in the Peninsula region (Booth et al., 1994). Withthe aid of this instrument, Frederick and Lubin (1994)were able to d o c u m e n t a springtime period of enhancedsolar UV irradiance at Palmer Station that coincidedwith the atmospheric ozone depletion. At the sametime, several important studies were initiated aboardOceanography VoL 12 No. 2/1999

discovered were the mycosporine-like amino acids. Athe R/V Pohzr Duke, and at Palmer Station, the results offield survey of a variety of marine algae and higherwhich have provided new insights into this complexorganisms, also conducted aboard the R/V Polar Dukeand important environmental problem.and at Palmer Station, demonstrated a widespreadHolm-Hansen et al. (1989) were among the first tooccurrence of these natural sunscreensrecognize the importance of UV-B(Karentz et al., 1991). A more recentradiation on rates of photosynthesis . . several important studiescomparison of the effects of UV radiain Antarctic marine phytoplankton.were initiated aboardtion on phytoplankton derived fromSubsequent field studies further docthe R/V Polar Duke,short-term (1 day) versus long-term (2umented a significant UV radiationand at Palmer Station,weeks) incubations revealed that cells(both UV-A and UV-B) inhibition oncan acclimatize and adapt to increasedthe rate of phytoplankton growththe results of whichUV fluxes (Villafafie et al., 1995).(Helbling et al., 1992, 1994). On sunnyhave provided new insightsConsequently,thelong-termdays when total UV radiation wasecological impacts may be less thanhigh ( 10-15 W m2), photosynthesis into this complex and importantenvironmental problem.initially believed. Clearly more studwas increased 200-300 ."o by theies are warranted before any predicremoval of all UV light ( 378 nm)tive ecosystem models can be developed.using selective filters. However, when the total UVradiation was lower ( 10 W m :), more typical of partlyIn addition to these studies on the effects of UV-B radiation on phytoplankton, recent investigations aboard thecloudy days, no effect was observed. They also reportR/V Polar Duke have documented other potentiallyed that UV radiation was more inhibitory toimportant impacts on a variety of populations andmicroplankton (primarily diatoms) than to nanoplankton (primarily flagellates), a result that may have impliprocesses. Bacteria, the primary consumers of dissolvedorganic matter in marine ecosystems, are known to becations for food web dynamics especially consideringsusceptible to UV radiation, and Southern Ocean bactethe important role of microplankton as a food sourceria are no exception. Field studies conducted during thefor Antarctic krill and other large herbivores (HelblingR/V Polar Duke-supported DIMERS expeditionet al., 1994). Because UV-B radiation is rapidlyabsorbed in the upper 10-20 m of the water column,(Damage In Microorganisms from Environmentaldepending on the amount of dissolved organic matterRadiation in the Southern Ocean; W. Jeffrey, Chiefand other properties, the effective dose of UV radiationScientist) have documented a significant inhibition ofheterotrophic growth and metabolism and measuredis difficult to determine unless relevant complementarymeasurements (e.g., ocean mixing rates) are made atproduction of W-induced photoproducts in bacteriaunder the Antarctic ozone hole. Another effect on bacterthe same time. According to Bidigare (1989), a quantitative assessment of the effects of UV-B enhancemential population dynamics may be via the interactions ofwill require knowledge of 1) the wavelength-depenUV radiation and infectious viruses. Because they lackdent flux of UV-B in the ocean, 2) action spectra for UVDNA repair mechanisms, viruses may be especially susB damage to Antarctic organisms, and 3) depth-depenceptible to ozone hole enhancements in UV-B radiation.dent distributions and residence times of organisms inTo the extent that virus infection is a major control onthe mixed layer.plankton populations, changes in their infectivity ratesBased on the results of their "Icecolors-90" cruise incould influence ecosystem dynamics and carbon fluxes.the Bellingshausen Sea aboard the R/V Polar DukeThe decreased abundances of virus particles observed in(October to November 1990), Smith et al. (1992) reportthe surface waters of the Antarctic Peninsula (Bird et al.,ed that the Antarctic ozone hole has resulted in shifts of1993) are consistent with this model.in-water spectral irradiances that had affected AntarcticMalloy et al. (1997) have recently presented the firstmarine ecosystem processes including a minimumdirect evidence that increased UV-B radiation may6-12 /,, reduction in primary production during thedamage the DNA of higher organisms within a naturalperiod of their observations. However, because thepopulation of Antarctic zooplankton. Studies conductmaximum in enhanced UV-B radiation occurs at a timeed aboard the R/V Polar Duke demonstrated that theof the year (early spring) when phytoplankton produceggs of the Antarctic icefish are susceptible to ozonetion rates are relatively low, the impact on total annualinduced UV-B radiation increases resulting in DNAorganic matter production may be negligible (Holmdamage, identical to that observed in microorganisms.Hansen et al., 1993). The comprehensive field study ofConsequently, enhanced UV-B fluxes may affect recruitSmith et al. (1991) examined not only the short-termment as well as transfer of organic matter to highereffects of increased UV-B radiation, but also the equallytrophic levels. Finally, the increased levels of UV-B radiimportant photoregulatory ecological processes, includation in Antarctic waters may also significantly magnifying UV-A and UV-B induced photoprotectivethe rates of euphotic zone photochemical processes (inmechanisms (see also Pr6zelin et al., 1994). Among theaddition to DNA dimerization), which, in turn, maymost effective photoprotectant organic compoundshave either negative or positive effects on the associat-Oceonogrophy VoL 12 No. 2/199913

flow through microheterotroph (bacterial) and protoed populations. One interesting but unpredictable effectzooplankton (flagellate and ciliate) assemblages. In fact,is the partial photolysis of otherwise refractory diswe can expect our views on the strucsolved organic matter to produceIn 1989, the R / V P o l a r D u k etural complexity of the Antarctic foodlabile, low molecular weight subsupportedfieldresearchwebto expand further as we incorpostances such as pyruvate (Kieber,ratenewecosystem processes current1994). The formation of these labileconducted by personnellyunderinvestigation.The concept ofprecursors could, in turn, stimulatefrom John Martin's trophic bacterial production tenable,these reduced carbon-limited ensive,quantitativestudand potentially, decouple photoauiesofenergyandcarbonflowthroughtotrophic and chemoheterotrophiccontrol primary productionthe entire Antarctic food web still doprocesses. This coupled photochemiin Antarctic ecosystems.notexist. This information is crucialcal-bacterial processing of this largeforunderstandingthestructure and efficiency of thereservoir of organic matter could have a major effect on"bi

University of Hawaii Department of Oceanography Honolulu, Hawaii 96822 USA n 14 May 1997, the research vessel (R/V) Polar Duke departed Punta Arenas, Chile, bound for . ("medevac") on several occasions, earning her well-deserved reputation as the lifeline of the Antarctic Peninsula. In October 1985, the