Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | er- ff Bac- levels 2 Baculo- CO ) were sub- p 2 Discussions , which secretes a Biogeosciences ects of ongoing ocean acidi- ff Amphisorus levels (580 to 770 µatm) but be , and H. Kawahata 2 2 Amphisorus hemprichii CO p (580 and/or 770 µatm) and decreased 2 , and CO 1810 1809 p , A. Kuroyanagi 3 levels from 260 to 970 µatm. Cultured individuals were 2 CO , which secrete a hyaline shell and host diatom symbionts, is generally expected to reduce rates of calcification by reef p , A. Suzuki 2 Calcarina gaudichaudii 1,2 CO , p level (970 µatm). Net calcification of erent responses among the three species are possibly due to di 2 ff Calcarina CO p and , M. Hikami 1 control system. Living clone individuals of three foraminiferal species ( . These di ects of ocean acidification on 2 2 ff CO CO This discussion paper is/has been under review for the journal Biogeosciences (BG). Please refer to the corresponding final paper in BG if available. Department of Physics and EarthAtmosphere Sciences, and University Ocean of Research the Institute, Ryukyus,Geological The Okinawa, Survey University Japan of of Japan, Tokyo, Kashiwa, National Japan Institute of Advanced Industrial Science and (near 1000 µatm). at a higher porcelaneous shell and hosts dinoflagellatep symbionts, tended to decrease atences elevated in calcification mechanismsfor (in calcification) particular, between the hyaline and specificcation porcelaneous carbonate by taxa, the species and foraminiferal used hosts tofindings and links suggest photosynthesis between by that calcifi- theforaminifers ongoing algal with ocean endosymbionts. hyaline acidification Our shellsunfavorable at might to intermediate favor those symbiont-bearing with either reef hyaline or porcelaneous shells at higher maintained for about 12 weekstemperature, in light an indoor intensity, flow-through and systemter photoperiod. under and constant After weight water the ofulogypsina experiments, each the cultured shell diame- specimenincreased were under measured. intermediate Net levels of calcification of carbonate producers in coralcan exceed reefs, that produce of high-Mg aragonitecoral produced calcite reefs by to shells, corals, the whose makingresults decreasing them solubility of carbonate the culture “first saturation experiments responder” state performedfication in to of on assess the seawater. the calcification Here of e p symbiont-bearing we reef report foraminifers using a high-precision gypsina sphaerulata jected to seawater at five Ocean acidification (decreases in carbonaterising ion atmospheric concentration and pH)calcifying in organisms, response to withLarge, potentially algal severe symbiont-bearing implications benthic for foraminifers, coral which reef are ecosystems. important primary and Abstract Biogeosciences Discuss., 8, 1809–1829, 2011 www.biogeosciences-discuss.net/8/1809/2011/ doi:10.5194/bgd-8-1809-2011 © Author(s) 2011. CC Attribution 3.0 License. 1 2 3 Technology (AIST), Tsukuba, Japan Received: 2 February 2011 – Accepted:Correspondence 17 to: February 2011 K. – Fujita Published: ([email protected]) 25 FebruaryPublished by 2011 Copernicus Publications on behalf of the European Geosciences Union. E calcification of symbiont-bearing reef foraminifers K. Fujita 5 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | 2 ect of ocean acidification -enriched air through the ff 2 1 mm in diameter) are shelled > ect marine calcifying taxa, with potentially , a large, dinoflagellate symbiont-bearing ff ; Kuroyanagi et al., 2009). Recent studies level (Morse et al., 2006). Therefore, reef ] or pH (Bijma et al., 1999; Bijma et al., 2002; ner et al., 2008; Kuroyanagi et al., 2009; Ries − 2 1812 1811 ff 2 3 will rise further, up to a partial pressure of 500– CO 2 p Marginopora control system to assess the e 2 C tracer techniques of reef foraminifers have also shown that CO 14 p ects of ocean acidification on calcification of diverse large, algal ff Marginopora kudakajimensis However, the e During calcification, foraminifers are able to elevate the pH at the site of calcification Culture experiments with reef calcifying organisms such as corals, coralline algae, pH by adding anseawater, acid though the or latter base, would better ratherand reproduce the than the ocean’s present by response. anthropogenic bubbling Therefore, changes using in CO a this high-precision study, we conductedon a calcification culture of experiment symbiont-bearing reef foraminifers. symbiont-bearing and reef-dwellingone benthic species foraminifers ( hashave been shown assessed that in thevaries only response both within of and marine amongal., species calcifying 2009). (e.g. Moreover, organisms Fabry, in 2008; to our Ries previous ocean et study acidification al., (Kuroyanagi et 2009; al., Ridgwell 2009), et we controlled the Dissard et al., 2010;shell Lombard et weight al., and 2010). diameter)benthic Calcification foraminifer, of (measured is as reduced incrementsture as of experiments pH using becomes lowerthe (Kuroyanagi carbon et uptake al., ratioand 2009). is calcium, and Cul- dependent decreases on whenlower pH the than pH those and or of concentrations the the concentrations of present of seawater inorganic (ter these carbon Kuile elements et are al., 1989). (vesicles or seawater vacuoles)et by al., one 2009; unit de abovemore Nooijer seawater energy et pH to al., elevate (Erez, 2009). thevious 2003; intracellular In culturing pH, Bentov acidified results leading have seawater, to indicated foraminifers aforaminifers reduce would that decrease with shell require in decreasing weights calcification. [CO of Pre- both planktonic and benthic ocean acidification. of reef carbonates inbenthic the foraminifers future (defined (Hoegh-Guldbergprotists as et that mature al., are individuals 2007). hostone of to Large, the reef-dwelling algal primary endosymbiontsLanger producers (Lee, et and 1998; al., carbonate producers 1997; Hallock,magnesium in calcite 1999). Hohenegger, coral (HMC; 2006; reefs They Raja Fujitaof (Hallock, are et and aragonite 1981; al., Fujimura, at 2005), 2008), aforaminifers the with secreting similar solubility high-magnesium high- seawater of calcitereef which shells can calcifying may be exceed organisms the that to “first the responders” decreasing among saturation state of seawater caused by severe implications for marine ecosystems such as coral reefs (Kleypasmolluscs, et and al., foraminifers 1999). suggestcalcification that (e.g. ocean Gattuso et acidification al., will 1998;et Ku adversely al., impact 2009), their leading to a reduction in coral-reef biodiversity and the net accumulation 1000 µatm by theinto end the of surface ocean the changescarbonate century seawater ion chemistry, (Meehl concentration, resulting et and inhydrogen increases decreases al., ions. in in 2007). It pH the will and concentrationsrespect This also to of lead calcite absorption bicarbonate and to and of aragonite, amarine two CO decrease calcifying common in organisms forms the of (Orrganisms saturation calcium et is carbonate state al., strongly secreted of dependent 2005). by on seawatering the with Calcification that carbonate of saturation ocean state marine acidification of will calcareous seawater, adversely suggest- or- a The oceans have takenleased up into about the atmosphere one-thirdthe over of Intergovernmental the Panel the past on anthropogenicScenarios Climate 200 yr carbon (SRES), Change (Sabine atmospheric dioxide (IPCC) CO et re- Special al., Report 2004). on Emission According to 1 Introduction 5 5 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | N, C) ◦ 0 and Am- 2 ). Be- 05 ◦ 1 − s level was ¨ ottger and 2 individuals dissolution are host to 2 − 2 is continually 2 CO Calcarina gau- , respectively). northeast of Ikei p Ehrenberg, 1839 CO is dissolved in sea- p 2 Calcarina 100 µmol m Amphisorus ∼ and Calcarina Amphisorus in each culture cage was ad- 2 and erences in characteristics within ff , and CO p is host to dinoflagellate endosymbionts (beta). Amphisorus hemprichii Baculogypsina are imperforate and appear porcelaneous (Parker and Jones, 1860), concentration in the air by mixing CO β E) on 26 April and 22 May 2009, and levels. Calcarina 0 2 2 , 1814 1813 00 Baculogypsina ◦ concentration) into the filtered (pore size, 1µm) CO control system developed with the cooperation of are commonly found in high-energy reef-flat envi- p 2 2 Amphisorus are perforate and have a hyaline (i.e. clear, glassy) CO N, 128 Amphisorus (alpha) and 0 p erent ff α 23 control system ◦ 2 Baculogypsina gas through the seawater, and a constant CO 2 Calcarina p Baculogypsina and and Baculogypsina sphaerulata ect of genetic variability on the experimental results. For more detailed ff d’Orbigny in Ehrenberg, 1840, and on a reef moat along the Oudo coast, south of Okinawa Island (26 E) on 28 May 2009. Collected individuals were maintained separately in small 0 Calcarina 42 ◦ Baculogypsina ¨ After a few weeks, these adult individuals reproduced asexually. Juveniles of the uger (1990) and Hohenegger (1994). dilution-air (dried air withseawater. a low CO subjected to seawater with di justed by bubbling CO maintained by a high-precision Kimoto Electric Co., Ltd. (Osaka,and Japan). measurement This towers (height, system 1.78 is m),water composed into of by which CO gaseous bubbling CO it frommonitored the in bottom the of equilibrated the airadjusted as flowing towers. needed out The by from seawater controlling the the measurement CO tower surface and used, tagged as populations 2.3 High-precision Clone individuals of the three foraminiferal species were placed into culture cages and Shaker, Wave-PR, TAITEC Inc., Saitama,were Japan). maintained In under contrast, stagnant conditions onfound a in flat relatively shelf, calm because they reef-moatals are were environments commonly not (Hohenegger, fed 1994). during These maintenance, individu- and the culture mediumclone was populations changed were weekly. kept underuntil the the same experiments conditions were asspecies started. the under adults To experimental for determine conditions, 4 di to two 6 clone weeks populations of each species were Petri dishes filledunder with a natural natural light:dark seawater cyclecause at near a room window (light temperature intensity, ronments (approximately (Hohenegger, 1994), 25 these species weremotion maintained produced under continuous by water using a continuous-action shaker (approximately 30 rpm; in vitro 127 phisorus clude the e information on the taxonomy, biology,Kr and ecology of these species, see R 2.2 Maintenance until asexualAdult reproduction individuals just before asexualduring reproduction low (agamont tide or on shizont) nearshoreIsland, were reef Okinawa, collected flats: Japan (26 appearance, whereas those of (i.e. shiny, white, and smoothdiatom like porcelain). endosymbionts, whereas (Lee, 1998). In addition, theseally three during species spring have and been observed summerasexually to (Sakai reproduced reproduce and asexu- Nishihira, clone 1981; individuals Hohenegger, 2006). can Thus, be used for culture experiments to ex- dichaudii (hereafter referred toThese as species are commonlywest found Pacific on (e.g. macrophytes Hohenegger,bonate on 1994) producers coral-reef and in flats are their in2006; environments important (e.g. the Fujita primary Sakai north- and producers and Fujimura,magnesium Nishihira, and 2008). 1981; calcite car- Hohenegger, (HMC; Shells approx. ofof 10 all Mg mol%; three species Saraswati are et composed al., of 2004). high- Shell walls 2.1 Target species Three species offor large, this study: algal symbiont-bearing benthic foraminifers were selected 2 Materials and methods 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | C), ◦ 0.7 ± , which have erences were ff levels (approx- 2 CO p Calcarina levels were prepared for 2 and CO p levels. When significant di 2 Baculogypsina . Before the start of experiment, another 40 levels grew more than twice as large as the β CO 1816 1815 2 erence (HSD) test. These statistical analyses p ff and CO two clone populations). Seawater within the culture p erence between each pair of means was analyzed α ff × ), and photoperiod (12 h). During the culture experi- 1 erent − ff s than shell diameter, as reported by Kuroyanagi et al. (2009) 2 − 2 CO p erence is partly because shell diameter does not exactly reflect three- erences among the five ff ff of the culture medium was adjusted to one of five 2 CO p At the end of the experiment, the cages were removed from the water baths and The as well. This di dimensional shell growth, in particular in were performed with JMP 7.0.2 (SAS Institute Inc.) 3 Results All individuals cultured atinitial di individuals during the experimental periodcorrelated (Figs. with 1–3). shell Shell diameter, but weight the wasmore statistical positively analysis dependent indicated on that shell weight was The shell diameter and weight data(ANOVA) sets for were di analyzed by one-way analysisobserved of variance within a datawith set, a the di Tukey’s Honestly Significant Di The shell diameter andsured. shell The shell weight diameter of (theber each average and of initial the that and maximum crossingmeasured cultured diameter to the from individual the the first was nearest final at mea- cham- software 0.001 mm the (Photomeasure, on center Kenis microscope Inc., photographs ofthe using Osaka, the nearest image Japan). test 0.1µg analysis and usingElectron Shell perpendicular a Corporation). weight microbalance to was (Thermo it) measured Cahn was to C-35 microbalance,2.6 Thermo Statistical analysis the start of the experimentfor (hereafter, comparison “initial with individuals”) the were cultured also individuals. randomly selected 2.5 Measurements than 2.5% for each population. Twenty individuals from those preserved in ethanol at selected randomly for measurements,not excluding grow dead or had individuals no (i.e. protoplasm). those that Mortality did during the experiments was very low, less (from 6 July tolight 30 intensity September (60 2009) µmol m ments, at filamentous a algae constant attaching water tobiweekly the temperature with surfaces (28.5 brushes. of the Smallphotosynthesis culture air of cages bubbles the were inside algal removed symbionts, the were cages, removed probably with produced a by pipette. kept cool the until later analysis.with Cultured individuals a were brush picked and from each distilled cage, water, cleaned and air-dried. Of the 40 cultured individuals, 20 were clone individuals of each speciesa were water preserved bath in and ethanol. attachedof Each to 10 cage water the was baths tank placed (five wall treatments in cages with was a circulated suction by cup. fixingture Thus, them there cages in were a containing a path total clone of individuals a were water jet maintained within for the approximately water bath. 12 weeks Cul- 2.4 Culture protocol Each foraminifer culture cage consistedter, of 2.5 a cm) clear with vinyl a hoseclone cell population, (5 cm 40 strainer long; individuals (100 of µm inside eachwere diame- mesh, species put BD (i.e. a Falcon, into total Inc) a ofeach at 120 cage. of individuals each per the end. A cage) two set clone For populations of each five cages for the five imately 260, 360, 580,preindustrial 770, value, and the 970(Meehl µatm, present et Table value, al., 1) 2007), and correspondingtotal respectively. future to alkalinity) Seawater was the values chemistry measured (temperature, estimated predictedcalculating twice salinity, the by pH, a saturation and state IPCC week, of and SRES seawater with the respect averaged to values calcite were (Table 1). used for 5 5 20 15 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | , 2 2 2 α er- P < ff CO CO CO , but 0001 erent 05). 2 . p p p . ff 0001). 0 . 05). In 0 . erences levels of 0 CO 0 ff 2 , individu- p P < P < α of 580 µatm ( P < 2 CO P < 0001 for pop- . β p 0 4 , CO , and = p levels varied both α P < 2 F , at 580 or 770 µatm), , individuals grown at α β CO p erent physiological adapta- ff , individuals grown at a erent Calcarina ff levels β levels in both clone populations. (Ridgwell et al., 2009). Here we 2 levels in population 2 2 levels in the two species with a hya- 01 for population erences in shell weight among di . CO 2 ff 0 CO p CO p p 001 for population CO . 05). In population P < . p 0 0 erences in shell weight among the di level. This result is similar to the findings of 4; ff 1818 1817 2 P < = levels in both populations ( P < F 4; individuals varied from 15 to 25 µg (Fig. 1). Shell 2 CO . One-way ANOVA indicated significant di individuals tended to decrease at elevated p = 05). In population β Emiliania huxleyi . CO 05). Moreover, in both populations, individuals grown F . 0 individuals was generally lower at elevated p 0 levels (Fig. 2). It varied from 30 to 50 µg in population P < 2 P < at 580 and 770 µatm and erent ff 05). Mean shell weights of individuals grown at 770 µatm were CO . p 0 of 580 µatm had significantly heavier shell weights than those Amphisorus Calcarina Baculogypsina , individuals grown at 260 and 770 µatm were significantly heavier 2 α 05). Mean shell weights of individuals grown at a P < . CO 0 ). Tukey’s HSD post hoc test showed that in population p β , as suggested for 2 P < , individuals grown at 580 µatm were also significantly heavier than those β Baculogypsina of 770 µatm had significantly heavier shell weights than those grown at 360 levels in both populations ( CO 2 ). Tukey’s HSD post hoc test of each population showed that individuals grown 2 p β 05). levels in both populations ( . CO Amphisorus Calcarina Baculogypsina CO 2 0 p p 05). In population CO . P < line shell ( compared with that at the present Alternatively, the intra-species variability suggestsor the ecotypes presence within of ations diverse foraminiferal genotypes to species, which havewill di discuss mainly statisticallypopulations significant within results a species. that were common to4.1 the two clone Increased calcification at intermediate Calcification was enhanced at intermediate Experimental results indicate thatby responses the of increment foraminiferal ofamong individuals calcification shell within (measured a weight clone anda population, species. and diameter) between These to two are clone probably di individuals populations due within in to the culture heterogeneity cages of or micro-environments in around water baths (e.g. irradiance levels, nutrient regime). als grown at a grown at 770 orof 970 260 µatm µatm had ( significantly580 heavier µatm shell or weights more ( than thosesignificantly grown lighter at than those grown at other 4 Discussion Mean shell weight of (Fig. 3). One-way ANOVA indicated significantent di for population 3.3 ( higher at intermediate and from 35 to 55 µgin in shell population weight amongTukey’s HSD di post hoc test ofof each population 260 µatm showed that had individuals significantly grown0 heavier at shell a weights thanthan those those grown grown at at 970 µatm 580260 ( and or 580 970 µatm µatm were ( significantly heavier than those grown at 360, 770, or 970 µatm at 260 µatm were foundshell weight to was be not heavier statistically than significant between those these grown two3.2 at treatments. 360 µatm, although mean Mean shell weight of weight was relatively heavierOne-way at ANOVA indicated intermediate significantp di ulation at a or 970 µatm ( were significantly heavier thanpopulation those of individualsgrown grown at at 260 970 or µatm 360 µatm ( ( results is focused on foraminiferal shell weight. 3.1 Mean shell weight of subglobular to bilenticular shells with spines. Thus, the following description of culturing 5 5 25 20 15 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | 2 2 in 2 CO ), this p CO p takes up levels. did not in- 2 is reduced in CO p (hyaline species) Amphisorus levels between 580 (750 µatm). Ries et 2 Amphisorus [2856 µatm]) in four of 2 Amphisorus 2 CO p Amphisorus CO CO p Calcarina / levels of around 1000 µatm. p erent result may be due to the 2 usion-limited step. Uptake for ff ff CO levels, indicating that an increased near 1000 µatm p 2 at high 2 (i.e. low pH), an increase in pH above levels might be due to an increased bi- CO 2 CO , calcification in 2 p p CO Baculogypsina CO ¨ uhl, 2000). This alkalinity increase is favor- p levels. This di p 1820 1819 2 usion of bicarbonate, thereby promoting calcifica- Calcarina CO , and suggested by Ries et al. (2009) in coralline ff p and Emiliania huxleyi E. huxleyi ¨ ohler-Rink and K levels. 2 by symbionts might also aid calcification of the host foraminifers be- CO erences in calcification mechanisms between hyaline and porcela- (porcelaneous species) (ter Kuile et al., 1989). p ff − Baculogypsina 3 4 seawater. However, calcification in the two hyaline species at 970 µatm ective in enhancing calcification at treatment level (970 µatm). In porcelaneous species ( ff 2 2 [600 to 900 µatm] and negative at the highest CO CO 2 p and PO p + 4 CO Amphisorus p erent calcification mechanism between In contrast to Photosynthesis by algal symbionts might be enhanced under intermediate Enhanced calcification at intermediate ff This result is consistent within the some findings calcareous of algae enhanced Ries calcification et peaked al. at (2009), who demonstrated that In spite of theneous di species, calcification inhighest all three speciesreduced studied calcification can tended be to explained bythe be the high decreased reduced carbonate at ion concentration the in was also reduced compared with thatbicarbonate at lower ion concentration andmay increased not photosynthesis be of e algal endosymbionts the shell surface dueor to carbonate symbiont ion photosynthesis concentration doesseawater there. at little high Thus, to calcification increase in the alkalinity 4.2 Reduced calcification in seawater at and inorganic carbon for photosynthesis andnot for interfere calcification with in each twoof separate other algal flows (ter endosymbionts that under Kuile, do above the saturating 1991). shell irradiance surface of contributes However,surrounding up the to seawater to photosynthetic an (K 0.2 pH activity increaseable units, in for which imperforate pH increases species, the which take totalseawater. up alkalinity However, carbonate in of ions seawater the for with calcification high directly from bon concentration of theneeded present to seawater measure (ter photosynthetic Kuile rates of et algal al., symbionts 1989), at furthercrease various significantly studies at are intermediate di photosynthesis by isolated in situ diatom symbionts is saturated at the inorganic car- red and calcareous green algae. Although experimental results have suggested that levels. Foraminifers with algal symbiontsforaminifers in have clear, several nutrient-deficient advantages environments over (Hallock, non-symbiotic sis 1999). by The algal photosynthe- symbionts providesbecomes host foraminifers a with substantial source photosynthate, of which as energy NH for calcification.cause such The metabolites removal can of interferehancement with host of crystal metabolites calcification formation by such (ter photosynthesisRodrigues Kuile has et et been al., also al. 1989). demonstrated (2008) En- by in Iglesias- cytoplasm, but is first concentratedcles as or carbonate in seawater an vacuoles) inorganicThus, (Erez, carbon an 2003; pool increased Bentov (i.e. bicarbonate vesi- etthe ion al., culture concentration 2009; medium associated may de with enhance Nooijertion. di increased et al., 2009). carbonate ion concentration and/or tobionts. increased photosynthesis According by the to algal teris endosym- Kuile initially (1991), taken in upphotosynthesis hyaline and (perforate) in for species, the incorporation inorganic into formforate carbon the species; of skeleton instead, are bicarbonate the not two in obligatorily processessource. linked a may In in compete di the per- for the cytoplasm, same algalfor inorganic symbionts photosynthesis. carbon take up Inorganic inorganic carbon carbon for in calcification the is form not of CO taken up directly from the Iglesias-Rodrigues et al. (2008)duction reported in increased calcification the andal. coccolithophore net (2009) obtained primary parabolic pro- calcificationate response patterns (i.e. positivethe at 18 intermedi- benthic marine taxa that they examined. previous culture experiments by Iglesias-Rodrigues et al. (2008) and Ries et al. (2009). 5 5 25 20 10 15 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | . 2 CO ect of levels ff p , 2003. 2 ects. Le ff CO p on calcification , 2010. 2 control system, to 2 Amphistegina lob- CO p ect calcification by the 2 ff CO doi:10.2113/0540115 p C tracer techniques have in- 14 ), they found no optimum pH for ocean, Science, 320, 1020–1022, 2 doi:10.5194/bg-7-81-2010 of 260 to 360 µatm in the three species ex- 2 1822 1821 A. hemprichii CO p , 2009. , 2009. , 2008. , 2008. , Biogeosciences, 7, 81–93, This research was supported by the Global Environmental Research ) was reduced or stopped, implying a disturbance of the metabolic C tracer techniques (ter Kuile et al., 1989) have demonstrated that in 14 Ammonia ectively in seawater at a pH higher than the present level. ff Ammonia tepida (a hyaline, perforate species with diatom symbionts) changes gradually over a pH bearing foraminifera on northwestdoi:10.2113/gsjfr.38.2.117 pacific coral-reef flats, J. Foramin.calcium Res., carbonate 38, saturation of 117–126, 37–46, seawater 1998. on coral calcification, Global Planet. Change, 18, oceanographic proxies, Rev. Mineral. Geochem., 54, 115–149, doi:10.1126/science.1157130 tion bydoi:10.1073/pnas.0904306106 elevating their intracellular pH,and P. Mg/Ca and Natl. Sr/Ca ratios in Acad.with benthic foraminifera calcite: Sci. results from USA, culturing experiments 106, 15374–15378, oceanography: Examples fromSpringer-Verlag, the Berlin, South Heidelberg, Germany, Atlantic, 489–512, 1999. edited by: Fischer,foraminiferal shell G., weight: and comment Wefer, onters “Carbonate G., of ion the concentration Caribbean in Sea”3, glacial-age by p deepwa- Broecker, 1064, W. 2002. S. and Clark, E., Geochem. Geophys. Geosyst., alization process in calcareousdoi:10.1073/pnas.0906636106 foraminifera, P. Natl. Acad. Sci, USA,pact 106, of 21500–21504, the oceanic carbonate system (experimental results), in: Use of Proxies in Pale- Gattuso, J. P., Frankignoulle, M., Bourge, I., Romaine, S., and Buddemeier, R. W.: E Fujita, K. and Fujimura, H.: Organic and inorganic carbon production by algal symbiont- Erez, J.: The source of ions for biomineralization in foraminifera and their implications for pale- Fabry, V. J.: Marine calcifiers in a high-CO de Nooijer, L. J., Toyofuku,Dissard, D., Nehrke, T., G., Reichart, G. and J., and Bijma, J.: Kitazato, Impact of seawater pCO H.: Foraminifera promote calcifica- Bijma, J., Honisch, B., and Zeebe, R.: Impact of the ocean carbonate chemistry on living Bijma, J., Spero, H., and Lea, D.: Reassessing foraminiferal stable isotope geochemistry: im- Bentov, S., Brownlee, C., and Erez, J.: The role of seawater endocytosis in the biominer- their help with shell weight measurements. References T. Ono for his assistance with seawater measurements, and to Y. Yoshinaga and T. Ishimura for We are grateful to Y. Nojiri,and Y. S. Shirayama and Ozaki K. for Sakai their for help their with discussion, the to maintenance A. of Iguchi, the S. high-precision Ohki iments using perforate species the optimumscale), pH but for in calcification ancalcification, is imperforate which between species increased pH ( veryindicate 8.2 steeply that above and reef pH 8.9 8.4 foraminifersmore (NBS e with (NBS scale). both hyaline These and results porcelaneousAcknowledgements. shells canFund calcify of the Ministry of the Environment, Japan (No. B-084, Principal Investigator: Y. Nojiri). Calcification tended to decrease from amined, although not all observations werethat statistically ocean significant. acidification This since result suggests to preindustrial reduce times their has calcification, already as caused suggested reef by foraminifers Kuroyanagi et al. (2009). Culture exper- of around 1000 µatm and highertor (pH of for 7.7 photosynthesis on by the seawater symbiotichost scale) foraminifer. algae, may Another be which cause a may of limiting inCadre fac- reduced et turn calcification al. may a (2003) be showed metabolism thatspecies e in low ( pH seawater, pseudopodial emissionactivity of of a hyaline the foraminifer.in Further relation studies to calcification are of needed foraminifers with to algal investigate symbionts metabolic in4.3 activity seawater at high Reduced calcification between 260 and 360 µatm and 900 µatm. Resultsdicated of that culturing the experiments rate using ifera of photosynthetic incorporationrange of (NBS carbon scale) by between(present 6.0 seawater and pH) 9.6, (ter Kuile with et the al., optimum 1989). rate These being results around suggest pH that 8.2 5 5 30 25 20 15 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | , test , 2009. , 2009. , 2006. world, Science, 320, 2 Ammonia beccarii Marginopora vertebralis ect of carbonate ion concentra- ects on doi:10.1130/g30210a.1 ff ff doi:10.5194/bg-6-2611-2009 , Mar. Biol., 137, 473–486, 2000. , 2009. doi:10.1016/j.gca.2006.08.017 1824 1823 and “ocean acidification”: Role of high Mg-calcites, , 2008. 2 CO p , 2007. , 2010. Amphisorus hemprichii and , 2008. ¨ uhl, M.: Microsensor studies of photosynthesis and respiration in larger ¨ uger, R.: Observations on the biology of Calcarinidae (Foraminiferida), Mar. doi:10.1016/j.marmicro.2009.09.003 doi:10.1126/science.1154122 -induced ocean acidification, Geology, 37, 1131–1134, 2 ner, I. B., Andersson, A. J., Jokiel, P. L., Rodgers, K. S., and Mackenzie, F. T.: Decreased ff CO Biol., 106, 419–425, 1990. Wong, C. S., Wallace, D. W. R., Tilbrook, B., Millero, F. J., Peng, T.-H., Kozyr, A., Ono, on large benthic foraminifers: results190–195, from laboratory experiments, Mar. Micropaleontol., 73, J. L., Schlitzer, R.,Anthropogenic Slater, ocean R. acidification D., over Totterdell,organisms, I. the Nature, J., twenty-first 437, Weirig, 681–686, century 2005. M.-F., and Yamanaka, its Y., and impact Yool, on A.: recent calcifying symbiont-bearing benthic foraminifera, Mar. Micropaleontol., 58, 31–44, 2005. J. R.: From laboratoryof manipulations ocean to acidification, Earth Biogeosciences, 6, system 2611–2623, models: scaling calcification impacts abundance of crustose coralline algaedoi:10.1038/ngeo100 due to ocean acidification, Nat. Geosci., 1, 114–117, duction: the role of reef foraminifera, J. Foramin. Res.,deformation: 27, 271–277, 1997. implications for using test deformations as a pollution indicator, J. Foramin. Geochim. Cosmochim. Acta, 70, 5814–5830, Gruber, N., Ishida, A.,fray, Joos, P., Mouchet, F., Key, A., R. Najjar, M., R. Lindsay, G., K., Plattner, Maier-Reimer, G.-K., E., Rodgers, Matear, K. R., B., Mon- Sabine, C. L., Sarmiento, symbiotic foraminifera. I The physico-chemical microenvironmentAmphistegina of lobifera Kitoh, A., Knutti,A. R., J., Murphy, and J. Zhao, M.,Science Z.-C.: Noda, Basis. Global Contribution A., climateIntergovernmental projections, of Raper, Panel in: S. Working on Climate C. Climate Group Change, Change B.,Chen, I edited 2007: Watterson, Z., to by: The I. Solomon, Marquis, the Physical S., G.,Press, M., Fourth Qin, Cambridge, Weaver, D., United Assessment Averyt, Manning, Kingdom Report K. M., and B., New of York, NY, Tignor, the USA, M., 747–845,sediments 2007. and to Miller, rising H. atmospheric L., Cambridge University N.: Geochemical consequencesScience, of 284, 118–120, increased 1999. atmospheric carbon dioxide on coral reefs, tion and irradiance ondoi:10.5194/bg-7-247-2010 calcification in planktonic foraminifera, Biogeosciences, 7, 247–255, Gittins, J. R., Green,E. D. R. V., and H., Boessenkool, K. Tyrrell, T., P.:336–340, Gibbs, Phytoplankton calcification S. in J., a von high-CO Dassow, P., Rehm, E., Armbrust, Res., 33, 1–9, 2003. 71–100, 1998. bonate beach environments, Mar. Micropaleontol., 61, 4–39, 2006. E., Harvell,M., C. D., Iglesias-Prieto, Sale, R.,Coral reefs P. Muthiga, under F., rapid N.,doi:10.1126/science.1152509 Edwards, climate change Bradbury, A. and R. ocean J., acidification, H., Caldeira, Science, 318, Dubi, K.,P. 1737–1742, S. Z. A., Knowlton, N. I: and N., Mar. Ecol., Hatziolos, 15, Eakin, 291–334, M. 1994. C. E.: K., Kluwer Academic Publishers, Dordrecht, Netherlands, 123–139, 1999. Pacific coral reefs, J. Sediment. Petrol., 51, 467–474, 1981. ¨ ¨ ottger, R. and Kr ohler-Rink, S. and K Ries, J. B., Cohen, A. L., and McCorkle, D. C.: Marine calcifiers exhibitSabine, mixed C. responses L., to Feely, R. A., Gruber, N., Key, R. M., Lee, K., Bullister, J. L., Wanninkhof, R., R Ridgwell, A., Schmidt, D. N., Turley, C., Brownlee, C., Maldonado, M. T., Tortell, P., and Young, Kuroyanagi, A., Kawahata, H., Suzuki, A., Fujita, K., and Irie, T.: Impacts of ocean acidification Raja, R., Saraswati, P. K., Rogers, K., and Iwao, K.: Magnesium and strontium compositions of Le Cadre, V., Debenay, J. P., and Lesourd, M.: Low pH e Orr, J. C., Fabry, V. J., Aumont, O., Bopp, L., Doney, S. C., Feely, R. A., Gnanadesikan, A., Ku Langer, M. R., Silk, M. T., and Lipps, J. H.: Global ocean carbonate and carbon dioxide pro- Morse, J. W., Andersson, A. J., and Mackenzie, F. T.: Initial responses of carbonate-rich shelf Meehl, G. A., Stocker, T. F., Collins, W. D., Friedlingstein, P., Gaye, A. T., Gregory, J. M., K Kleypas, J. A., Buddemeier, R. W., Archer, D., Gattuso, J. P., Langdon, C., and Opdyke, B. Lombard, F., da Rocha, R. E., Bijma, J., and Gattuso, J.-P.: E Lee, J. J.: “Living sands” – larger foraminifera and their endosymbiotic algae, Symbiosis, 25, Iglesias-Rodriguez, M. D., Halloran, P. R., Rickaby, R. E. M., Hall, I. R., Colmenero-Hidalgo, E., Hohenegger, J.: The importance of symbiont-bearing benthic foraminifera for West Pacific car- Hohenegger, J.: Distribution of living larger foraminifera NW of Sesoko-jima, Okinawa, Japan, Hoegh-Guldberg, O., Mumby, P. J., Hooten, A. J., Steneck, R. S., Greenfield, P., Gomez, Hallock, P.: Symbiont-bearing foraminifera, in: Modern Foraminifera, edited by: Sen Gupta, B. Hallock, P.: Production of carbonate sediments by selected large benthic foraminifera on two 5 5 30 25 20 30 15 25 10 20 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | arg Ω cal Ω Baculogypsina sphaeru- , Science, 305, 367–371, 2 , respectively. The value of 2 29 6.39 4.24 1930 5.3256 3.91 3.53 43 3.18 2.60 2.69 2.11 1.78 1 − ± ± ± ± ± treatment. Standard deviations CO 2 p CO p C ◦ 0.028 261 0.0330.039 360 0.035 580 0.038 774 972 , 2004. ± ± ± ± ± at 25 T 1825 1826 . C) ( µatm) ◦ 2 , 2004. ( . The mean salinity and total alkalinity, which were measured 2 CO p CO p and T (saturation state of seawater with respect to calcite and aragonite) was calculated doi:10.1016/S0377-8398(03)00099-9 Future 1Future 2Future 3 27.5 27.5 27.6 7.926 7.826 7.756 Present 27.4 8.072 Preindustrial 27.5 8.170 Treatment Temperature pH arg Mean physical and chemical conditions in each Ω on the Okinawan reef flat and preliminary estimation of its annual production, in: Pro- and species of symbiont-bearing foraminifera, Mar. Biol., 103, 241–251, 1989. larger foraminifera from a339–349, reef flat at Akajima, Okinawa, Japan,foraminifera, Mar. in: Micropaleontol., Biology 50, demic of Press, Foraminifera, London, Great edited Britain, by: 73–89, 1991. Lee, J. J. and Anderson, O. R., Aca- lata ceedings of the 4th International766, 1981. Coral Reef Symposium, 2, Manila, 18–22 May 1981, 763– T., and Rios,doi:10.1126/science.1097403 A. F.: The Oceanic sink for anthropogenic CO cal are shown for pH repeatedly during the experiments, were 34.4 andfrom 2188 the mol total kg alkalinity and Table 1. Ω ter Kuile, B., Erez, J., and Padan, E.: Mechanisms for the uptake of inorganic carbon by two ter Kuile, B.: Mechanisms for calcification and carbon cycling in algal symbiont-bearing Saraswati, P. K., Seto, K., and Nomura, R.: Oxygen and carbon isotopic variation in co-existing Sakai, K. and Nishihira, M.: Population study of the benthic foraminifer 5 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | erence ff after culture for about after culture for about SE of the 20 clone individuals sampled SE of the 20 clone individuals sampled in ± ± . . Calcarina gaudichaudii β β 1828 1827 Baculogypsina sphaerulata population population (B) (B) , , α α levels. Values are means erent letters above plotted treatment values indicate a significant dif- levels. Values are means ff 2 2 erent letters above plotted treatment values indicate a significant di CO ff CO p p Population Population 05) in shell weight according to Tukey’s HSD post hoc test. Dashed and solid . 0 (A) (A) = Mean shell diameter and weight of α Mean shell diameter and weight of 05) in shell weight according to Tukey’s HSD post hoc test. Dashed and solid lines . 0 = α Fig. 2. 12 weeks at five in each treatment. Di ference ( lines show mean shell diameterexperiment. and weight of clone individuals, respectively, at the start of the ( Fig. 1. show mean shell diameter andexperiment. mean weight of clone individuals, respectively, at the start of the 12 weeks at five each treatment. Di Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | after culture for about SE of the 20 clone individuals sampled ± . Amphisorus hemprichii β 1829 population (B) , α levels. Values are means erent letters above plotted treatment values indicate a significant dif- ff 2 CO p Population 05) in shell weight according to Tukey’s HSD post hoc test. Dashed and solid . 0 (A) = α Mean shell diameter and weight of Fig. 3. 12 weeks at five in each treatment. Di ference ( lines show mean shellexperiment. diameter and weight of clone individuals, respectively, at the start of