HOWARD J. SPERO
Department of Geology
University of California; Davis, CA 95616
(530) 752-3307 (Ofc) ; (530) 752-0951 (Fax)
(530) 220-3038 (cell)         spero@geology.ucdavis.edu

EDUCATION

Ph.D.   Biology, University California Santa Barbara 1986
M.Sc.   Oceanography, Texas A & M University 1979
B.A.     Biology-Geology, Magna cum Laude, State University New York at Buffalo 1975

PUBLICATIONS

Pakulski, J. D., A. Baldwin, A. Dean, S. Durkin, D. Karentz, C. A. Kelley, K. Scott, H. J. Spero, S. Wilhelm and W. H. Jeffrey. Scale effects of solar radiation in the marine environmnent: 1. Influence of latitude on the photobiology of heterotrophic bacteria. Aquat. Microbial Ecol (in revision). (75)

Eerkens, J W, Herbert, G.S., J. Rosenthal, and H.J. Spero. Provenance analysis of Olivella biplicata shell beads from the California and Oregon coast using oxygen and carbon stable isotopes. J. Archeological Sci. (Submitted 1/19/05). (74)

Waelbroeck, C, S. Mulitza, H.J. Spero, T. Dokken and T. Kiefer. 2005. A global compilation of late Holocene planktonic δ18O: relationship between surface water and δ18O. Quat. Sci. Rev. (in press). (73)

Russell, A. D., B. Hönisch, H.J. Spero and D.W. Lea. 2004. Effect of seawater carbonate ion concentration and temperature on shell U, Mg, and Sr in cultured planktonic foraminifera. Geochim Cosmochim Acta 68(21):4347-4361. (72)

Fietzke, J, A. Eisenhauer, N. Gussone, B. Bock, V. Liebetrau, Th.F. Nägler, H.J. Spero, J. Bijma and C. Dullo. 2004. Direct measurement of 44Ca/40Ca by MC-ICP-MS using the cool-plasma-technique. Chemical Geology 206:11-20. (71)

Schmidt, M.W., Spero, H.J. and D.W. Lea. 2004. Role of Caribbean salinity variation on North Atlantic thermohaline circulation. Nature 428:160-163. (70). Data available at: http://www.ngdc.noaa.gov/paleo/pubs/schmidt2004/schmidt2004.html

Hill, T.M., J.P. Kennett and H.J. Spero. 2004. High-resolution records of methane hydrate dissociation: ODP Site 893, Santa Barbara Basin. Earth Planet. Sci. Lett. 223:127-140. (69)

Lea, D.W., D.K. Pak, and H.J. Spero. 2003. Sea surface temperatures in the western equatorial Pacific during marine isotope stage 11. In: A. Droxler, R.Z. Poore and L.H. Burckle (eds.): Earth’s Climate and Orbital Eccentricity: The Marine Isotope Stage 11 Question p.147-156. American Geophysical Union Geophysical Monograph 137. (68)

Hönisch, B., B. Bijma, A. D. Russell, H. J. Spero, and A. Eisenhauer. 2003. The influence of symbiont photosynthesis on the boron isotopic composition of foraminifera shells. Mar. Micropaleontol. 49:87-96. (also published in J. Geobiology). (67)

Hill, T.M., J.P. Kennett and H.J. Spero. 2003. Foraminifera as indicators of methane rich environments: A study of modern methane seeps in Santa Barbara Channel, California. Mar. Micropaleontol. 49:123-138. (also published in J. Geobiology). (66)

Gussone, N, A. Eisenhauer, A. Heuser, M. Dietzel, B. Bock, F. Böhm, H. Spero, D.W. Lea, J. Bijma, R. Zeebe and Th. F. Nägler. 2003. Model for kinetic effects on calcium isotope fractionation (δ44Ca) in inorganic aragonite and cultured planktonic foraminifera. Geochim. Cosmochim. Acta 67(7):1375-1382. (65)

Spero, H.J., K.M. Mielke, E.M. Kalve, D.W. Lea and D.K. Pak. 2003. Multispecies approach to reconstructing eastern equatorial Pacific thermocline hydrography during the past 360 ky. Paleoceanography 18(1):10.1029/2002PA000814. (64)

Juranek, L. W., A. D. Russell and H. J. Spero. 2003. Seasonal oxygen and carbon isotope variability in Euthecosomatus pteropods from the Sargasso Sea. Deep Sea Res. I 50:231-245. (63)

Zachos, J.C., M.A. Arthur, T.J. Bralower and H.J. Spero. 2002. Brief communication: Tropical SST during greenhouse intervals. Nature 419:897-898. (62)

Bemis, B. E., H. J. Spero and R. C. Thunell. 2002. Using species-specific paleotemperature equations with foraminifera: a case study in the Southern California Bight. Mar. Micropaleontol. 46:405-430. (61)

Spero, H. J. and D.W. Lea. 2002. The cause of carbon isotope minimum events on glacial terminations. Science 296:522-525. (60)

Dekens, P.S., D.W. Lea, D.K. Pak and H.J. Spero. 2002. Core top calibration of Mg/Ca in tropical foraminifera: Refining paleo-temperature estimation. Geochem. Geophys. Geosyst., 3(1):10.1029/2001GC000200. (available at http://www.g-cubed.org). (59)

Lea, D.W., D.K. Pak, P.A. Martin and H.J. Spero. 2002. Reconstructing a 350 kyr history of ice volume using planktonic Mg/Ca and oxygen isotope records from a Cocos Ridge core. Quat. Sci. Rev. 283-293. (58)

Sanyal, A., J. Bijma, H.J. Spero and D. W. Lea. 2001. Empirical relationship between pH and the boron isotopic composition of Globigerinoides sacculifer: Implications for the boron isotope paleo-pH proxy. Paleoceanography 16(5):515-519. (57)

Lea. D.W., D.K. Pak and H.J. Spero. 2000. Climate impact of late Quaternary equatorial Pacific sea surface temperature variations. Science 289:1719-1724. (56)

Schiffman, P, H. J. Spero, R. J. Southard and D. A. Swanson. 2000. Controls on palagonitization versus pedogenic weathering of basaltic tephra: Evidence from the consolidation and geochemistry of the Keanakako’i ash member, Kilauea Volcano. Geochem. Geophys. Geosyst. 1:2000GC000068. (Available at http://www.g-cubed.org). (55)

Bemis, B.E., H.J. Spero, D.W. Lea and J. Bijma. 2000. Temperature influence on the carbon isotopic composition of Orbulina universa and Globigerina bulloides (planktonic foraminifera). Mar. Micropaleontol. 38(3-4):213-228. (54)

Russell, A. D. and H. J. Spero. 2000. Field examination of the oceanic carbonate ion effect on planktonic foraminiferal stable isotopes. Paleoceanography, 16(1):43-52. (53)

Lea, D.W., T.A. Mashiotta and H.J. Spero. 1999. Controls on magnesium and strontium uptake in planktonic foraminifera determined by live culturing. Geochim. Cosmochim. Acta, 63(16):2369-2379. (52)

Spero, H.J., J. Bijma, D.W. Lea and A.D. Russell. 1999. Deconvolving glacial ocean carbonate chemistry from the planktonic foraminifera carbon isotope records. In F. Abrantes and A. Mix (eds.), Reconstructing Ocean History: A Window into the Future. Kluwer Academic/Plenum Pub., N.Y. ,p. 329-342. (51)

Mashiotta, T. A., D. W. Lea and H. J. Spero. 1999. Glacial-interglacial changes in Subantarctic sea surface temperature and δ18O using foraminiferal Mg . Earth Planet. Sci. Lett., 170(4):417-432. (50)

Houston, R. M., B. T. Huber and H. J. Spero. 1999. Size-related isotopic trends in some Maastrichtian foraminifera: methodological comparisons, intraspecific variability, and evidence for photosymbiosis. Mar. Micropaleontol. 36(4):169-188. (49)

Uhle, M. E., S. A. Macko, H. J. Spero, D. W. Lea, W. F. Ruddiman, and M. H. Engel. 1999. The fate of nitrogen in the Orbulina universa foraminifera–symbiont system determined by nitrogen isotope analyses of shell-bound organic matter. Limnol. Oceanogr. 44(8):1968-1977. (48)

Bijma, J., H.J. Spero, D.W. Lea. 1999. Reassessing foraminiferal stable isotope geochemistry: Impact of the oceanic carbonate system. In: G. Fischer and G. Wefer (eds.) Use of Proxies in Paleoceanography - Examples from the South Atlantic, pp.489-512, Springer-Verlag, Heidelberg. (47)

Lea, D.W., J. Bijma, H.J. Spero, and D. Archer. 1999. Implications of a carbonate ion effect on shell carbon and oxygen isotopes for glacial ocean conditions. In: G. Fischer and G. Wefer (eds.) Use of Proxies in Paleoceanography - Examples from the South Atlantic, pp.513-522, Springer-Verlag, Heidelberg. (46)

Spero, H.J. 1998. Life history and stable isotope geochemistry of planktonic foraminifera. In: Norris, R. D. and Corfield, R. M. (eds)., Isotope Paleobiology and Paleoecology, Paleontological Society Papers, 4:7-36. (45)

Kirby, M.X., T.M. Soniat and H.J. Spero. 1998. Stable isotope sclerochronology of Pleistocene and Recent oyster shells (Crassostrea virginica). Palaios 13(6):560-569. (44)

Wilson-Fenelli, A., G.T. Chandler and H.J. Spero. 1998. Reliability of benthic foraminiferal calcite as proxy for paleoceanographic conditions: Results from microcosm culturing studies. J. Foram. Res.28:312-320. (43)

Winn, R.D. Jr, H.H. Roberts, B. Kohl, R.H. Fillon, J.A. Crux, A.H. Bouma and H.J. Spero. 1998. Upper Quaternary strata of the upper continental slope, northeast Gulf of Mexico: sequence stratigraphic model for a terrigenous shelf edge. J. Sed. Res. 68(4):579-595. (42)

Rink, S., M. Kühl, J. Bijma and H.J. Spero. 1998. Microsensor studies of photosynthesis and respiration in the symbiotic foraminifer Orbulina universa. Mar. Biol. 131:583-595. (41)

Bemis, B. E., H.J. Spero, J. Bijma and D.W. Lea. 1998. Reevaluation of the oxygen isotopic composition of planktonic foraminifera: Experimental results and revised paleotemperature equations. Paleoceanography 13(2): 150-160. (40)

Buening, N, S.J. Carlson, H.J. Spero and D.E. Lee. 1998. Evidence for the early Oligocene formation of a proto-Subtropical Convergence from oxygen isotope records of New Zealand Paleogene brachiopods. Palaeogeogr, Palaeoclimtol. Palaeoecol. 138(1-4): 43-68. (39)

Spero, H. J., J. Bijma, D. W. Lea and B.E. Bemis. 1997. Effect of seawater carbonate concentration on planktonic foraminiferal carbon and oxygen isotopes. Nature 390:497-500. (38)

Mashiotta, T, D.W. Lea and H.J. Spero. 1997. Experimental determination of Cd uptake in shells of the planktonic foraminifera Orbulina universa and Globigerina bulloides: Implications for surface water paleoreconstructions. Geochim. Cosmochim. Acta 61(19):4053-4065. (37)

Uhle, M.E., S.A. Macko, H.J. Spero, M.H. Engel and D.W. Lea. 1997. Sources of carbon and nitrogen in modern planktonic foraminifera: The role of algal symbionts as determined by bulk and compound specific stable isotopic analyses. Org. Geochem. 27(3-4):103-113. (36)

Chandler, G. T, D.F. Williams, H.J. Spero and G. Xiaodong. 1996. Sediment microhabitats and stable isotope disequilibria phenomenon in microcosm cultured benthic foraminiferal calcite. Limnol. Oceanogr. 41(4):680-688. (35)

Buening, N and H.J. Spero. 1996. Oxygen- and carbon-isotope analyses of the articulate brachiopod Laqueus californianus: A recorder of environmental changes in the subeuphotic zone. Mar. Biol. 127:105-114. (34)

Sanyal, A., H.G. Hemming, W. S. Broecker, D.W. Lea and H.J. Spero. 1996. Oceanic pH control on the boron isotopic composition of foraminifera: Evidence from culture experiments. Paleoceanography 11(5):513-517. (33)

Spero, H. J and D.W. Lea. 1996. Experimental determination of intraspecific stable isotope variability in Globigerina bulloides: Implications for paleoceanographic reconstructions. Mar. Micropaleontol., 28:231-246. (32)

Billups, K. and H.J. Spero. 1996. Reconstructing paleotemperatures and the carbon isotope geochemistry of the equatorial Atlantic during the last 150,000 years: Results from individual foraminifera. Paleoceanography, 11(2):217-238. (31)

Uhle, M.E., S.A. Macko, H.J. Spero and M.H. Engel. 1996. Nutrient cycling in modern planktonic foraminifera as determined by bulk and compound specific stable isotopic analyses of organisms and their diets. In: J. O. Grimalt and C Dorronsoro (eds.), Organic Geochemistry: Developments and Applications to Energy, Climate, Environment and Human History, A.I.G.O.A. Publ., p. 34-36. (30)

D. Karentz and H. J. Spero. 1995. Response of a natural Phaeocystis population to ambient fluctuations of UVB radiation caused by Antarctic ozone depletion. J. Plankton Res. 17(9):1771-1789. (29)

Billups, K. and H.J. Spero. 1995. Relationship between test size, thickness and stable isotopes in individual planktonic foraminifera from two equatorial Atlantic cores. J. Foram. Res., 25:24-38. (28)

Lea, D.W., P.A. Martin, D.A. Chan and H.J. Spero. 1995. Calcium uptake and calcification rate in the planktonic foraminifer Orbulina universa. J. Foram. Res., 25:14-23. (27)

Lea, D.W. and H. J. Spero. 1994. Assessing the reliability of paleochemical tracers: Barium uptake in the shells of planktonic foraminifera. Paleoceanography 9(3):445-452. (26)

Spero, H. J. and D. W. Lea. 1993. Intraspecific stable isotope variability in the planktonic foraminifera Globigerinoides sacculifer: Results from laboratory experiments. Mar. Micropaleontol. 22:221-234. (25)

Spero, H. J., D. Andreasen and B. Sorgeloos. 1993. Carbon and nitrogen isotopic composition of different strains of Artemia sp. Int. J. Salt Lake Res., 2(2):133-139. (24)

Fitt, W.K., H.J. Spero, J. Halas, M.W. White and J.W. Porter. 1993. Recovery of the coral Montastrea annularis in the Florida Keys after the 1987 Caribbean “bleaching event”. Coral Reefs 12:57-64. (23)

Spero, H.J. 1992. Do planktic foraminifera accurately record changes in the carbon isotopic composition of seawater ΣCO2? Mar. Micropaleontol. 19:275-285. (22)

Lea, D.W. and H.J. Spero. 1992. Experimental verification of barium uptake in individual shells of the planktonic foraminifera Orbulina universa. Geochim. Cosmochim. Acta 56:2673-2680. (21)

Spero, H.J., I. Lerche and D.F. Williams. 1991. Opening the carbon isotope “vital effect” black box, 2, Quantitative model for interpreting foraminiferal carbon isotope data. Paleoceanography 6:639-655. (20)

Spero, H.J., and D.L. Angel. 1991. Planktonic sarcodines: Microhabitat for oceanic dinoflagellates. J. Phycol. 27:187-195. (19)

Spero, H.J. and D.F. Williams. 1990. Evidence for low salinity surface waters in the Gulf of Mexico over the last 16,000 years. Paleoceanography 5:963-975. (18)

Williams, D.F., I. Lerche, H.J. Spero, D.M. Trainor, W.F. Falls, T. Guilderson and K. Kirschenmann. 1989. Modeling of hydrocarbon-related carbon isotopic anomalies in subsurface exploration wells of the northern Gulf of Mexico, p. 337-346. In: D. Schumacher and B.F. Perkins (eds.), Coast Oils and Gases. Proceed. 9th Ann. Res. Conf. SEPM. (17)

Spero, H.J. and D.F. Williams. 1989. Opening the carbon isotope 'vital effect' black box, I: Seasonal temperatures in the euphotic zone. Paleoceanography 4:593-601. (16)

Porter, J.T., W.K. Fitt, H.J. Spero, C.S. Rogers and M.W. White. 1989. Bleaching in reef corals: Physiological and stable isotopic responses. Proceed. Nat. Acad. Sci. 86:9342-9346. (15)

Williams, D.F., R. Ehrlich, H.J. Spero, N. Healy-Williams and A.C. Gary. 1988. Isotopic differences between conspecific foraminiferal morphotypes and resolution of paleoceanographic events. Paleoceanogr. Paleoclimatol. Paleoecol. 64:153-162. (14)

Spero, H.J. and D.F. Williams. 1988. Extracting environmental information from planktonic foraminiferal δ13C data. Nature 335:717-719. (13)

Spero, H.J. 1988. An ultrastructural examination of chamber morphogenesis and biomineralization in the planktonic foraminifera, Orbulina universa. Mar. Biol. 99:9-20. (12)

Jones, D.S., D.F. Williams and H.J. Spero. 1988. More light on symbioses in fossil mollusks: The case of Mercenaria "tridacnoides." Paleoceanogr. Paleoclimatol. Paleoecol. 64:141-152. (11)

Spero, H.J. 1987. Symbiosis in the planktonic foraminifer, Orbulina universa, and the isolation of its symbiotic dinoflagellate, Gymnodinium béii sp. nov. J. Phycol. 23:307-317. (10)

Spero, H.J. and M.J. Deniro. 1987. The influence of symbiont photosynthesis on the δ18Ο and δ13C values of planktonic foraminiferal shell calcite. Symbiosis 4:213-228. (9)

Kokke, W.C.M.C. and H.J. Spero. 1987. Sterol pattern determination as a probe for new species of zooxanthellae in marine invertebrates. Application to the dinoflagellate symbiont of the foraminifer Orbulina universa. Biochem. Syst. Ecol. 15:475-478. (8)

Spero, H.J. 1985. Chemosensory capabilities in the phagotrophic dinoflagellate, Gymnodinium fungiforme. J. Phycol. 21:181-184. (7)

Spero, H.J. and S.L. Parker. Photosynthesis in the symbiotic planktonic foraminifer, Orbulina universa, and its potential contribution to oceanic primary productivity. J. Foram. Res. 15:273-281. (6)

Spero, H.J. 1982. Phagotrophy in Gymnodinium fungiforme: The peduncle as an organelle of ingestion. J. Phycol. 18:356-360. (5)

Bé, A.W.H., H.J. Spero and O.R. Anderson. The effects of symbiont elimination and reinfection on the life processes of the planktonic foraminifer, Globigerinoides sacculifer. Mar. Biol. 70:73-86. (4)

Spero, H.J. and M. Morée. 1981. Phagotrophic feeding and its importance to the life cycle of the holozoic dinoflagellate, Gymnodinium fungiforme. J. Phycol. 17:43-51. (3)

Bé, A.W.H. and H.J. Spero. Shell regeneration and biological recovery of planktonic foraminifera after physical injury induced in laboratory culture. Micropaleontology 27:305-316. (2)

Spero, H.J., D. Hagan and A. Vastano. 1979. An SEM examination of Sagitta tenuis Conant (Chaetognatha), utilizing a special sedation and handling procedure. Trans. Amer. Micros. Soc. 98:139-141. (1)