of the N isotopes to provide basic constraints on
environmental conditions when there are few other
indicators available. Recent and ongoing method
development is greatly improving our ability to
measure diverse N pools in the ocean. This is yielding
a new generation of N isotope studies that promise to
provide geochemical estimates for the rates and distributions of N fluxes in the modern ocean, complementing instantaneous ‘bottle’ measurements of
these fluxes as well as other geochemical approaches.
Fundamental aspects of the oceanic N cycle are still
poorly understood, and the N isotopes provide an
important tool for their study.
See also
Nitrogen Cycle.
Further Reading
Altabet MA (2005) Isotopic tracers of the marine nitrogen
cycle: Present and past. In: Hutzinger O (ed.) The
Handbook of Environmental Chemistry, Vol. 2: Marine
Organic Matter: Chemical and Biological Markers,
pp. 251--294. Berlin: Springer.
Altabet MA and Francois R (1994) The use of nitrogen
isotopic ratio for reconstruction of past changes in
surface ocean nutrient utilization. In: Zahn R, Kaminski
M, Labeyrie L, and Pederson TF (eds.) Carbon Cycling
in the Glacial Ocean: Constraints on the Ocean’s Role
in Global Change, pp. 281--306. Berlin: Springer.
Brandes JA and Devol AH (2002) A global marine fixed
nitrogen isotopic budget: Implications for Holoene
nitrogen cycling. Global Biogeochemical Cycles 16:
1120 (doi:10.1029/2001GB001856).
Casciotti KL and McIlvin MR (2007) Isotopic analyses
of nitrate and nitrite from references mixtures and
application to Eastern Tropical North Pacific waters.
Marine Chemistry 107: 184--201.
Chang CCY, Silva SR, Kendall C, Michalski G, Casciotti
KL, and Wankel S (2004) Preparation and Analysis
of Nitrogen-bearing Compounds in Water for Stable
Isotope Ratio Measurement. In: deGroot PA (ed.)
Handbook of Stable Isotope Analytical Techniques, vol.
1, pp. 305--354. Amsterdam: Elsevier.
Fogel ML and Cifuentes LA (1993) Isotope fractionation
during primary production. In: Engel MH and Macko
SA (eds.) Organic Geochemistry, pp. 73--98. New York:
Plenum.
Fry B (2006) Stable Isotope Ecology. New York: Springer.
Galbraith ED, Sigman DM, Robinson RS, and Pedersen TF
(in press) Nitrogen in past marine environments.
In: Bronk DA, Mulholland MR, and Capone DG (eds.)
Nitrogen in the Marine Environment.
Goericke R, Montoya JP, and Fry B (1994) Physiology
of isotope fractionation in algae and cyanobacteria, In: Lajtha K and Michener R (eds.) Stable
Isotopes in Ecology and Environmental Science, 1st
edn.,
pp. 187--221. Oxford: Blackwell Scientific
Publications.
Macko SA, Engel MH, and Parker PL (1993) Early
diagenesis of organic matter in sediments: Assessment
of mechanisms and preservation by the use of isotopic
molecular approaches. In: Engel MH and Macko SA
(eds.) Organic Geochemistry, pp. 211--224. New York:
Plenum.
Michener R and Lajtha K (2007) Stable Isotopes in
Ecology and Environmental Science, 2nd edn., New
York: Wiley-Blackwell.
Montoya JP (1994) Nitrogen isotope fractionation in the
modern ocean: Implications for the sedimentary record.
In: Zahn R, Kaminski M, Labeyrie L, and Pederson TF
(eds.) Carbon Cycling in the Glacial Ocean: Constraints
on the Ocean’s Role in Global Change, pp. 259--279.
Berlin: Springer.
Needoba JA, Sigman DM, and Harrison PJ (2004) The
mechanism of isotope fractionation during algal nitrate
assimilation as illuminated by the
15
N/
14
N of
intracellular nitrate. Journal of Phycology 40: 517--522.
Owens NJP (1987) Natural variations in
15 N in the
marine environment. Advances in Marine Biology 24:
390--451.
Peterson BJ and Fry B (1987) Stable isotopes in ecosystem
studies. Annual Review of Ecology and Systematics 18:
293--320.
Sigman DM, Granger J, DiFiore PJ, Lehmann MF, Ho R,
Cane G, and van Geen A (2005) Coupled nitrogen and
oxygen isotope measurements of nitrate along the
eastern North Pacific margin. Global Biogeochemical
Cycles 19: GB4022 (doi:10.1029/2005GB002458).
Wada E (1980) Nitrogen isotope fractionation and its
significance in biogeochemical processes occurring in
marine environments. In: Goldberg ED, Horibe Y, and
Saruhashi K (eds.) Isotope Marine Chemistry,
pp. 375--398. Tokyo: Uchida Rokakudo.
NITROGEN ISOTOPES IN THE OCEAN 563
environmental conditions when there are few other
indicators available. Recent and ongoing method
development is greatly improving our ability to
measure diverse N pools in the ocean. This is yielding
a new generation of N isotope studies that promise to
provide geochemical estimates for the rates and distributions of N fluxes in the modern ocean, complementing instantaneous ‘bottle’ measurements of
these fluxes as well as other geochemical approaches.
Fundamental aspects of the oceanic N cycle are still
poorly understood, and the N isotopes provide an
important tool for their study.
See also
Nitrogen Cycle.
Further Reading
Altabet MA (2005) Isotopic tracers of the marine nitrogen
cycle: Present and past. In: Hutzinger O (ed.) The
Handbook of Environmental Chemistry, Vol. 2: Marine
Organic Matter: Chemical and Biological Markers,
pp. 251--294. Berlin: Springer.
Altabet MA and Francois R (1994) The use of nitrogen
isotopic ratio for reconstruction of past changes in
surface ocean nutrient utilization. In: Zahn R, Kaminski
M, Labeyrie L, and Pederson TF (eds.) Carbon Cycling
in the Glacial Ocean: Constraints on the Ocean’s Role
in Global Change, pp. 281--306. Berlin: Springer.
Brandes JA and Devol AH (2002) A global marine fixed
nitrogen isotopic budget: Implications for Holoene
nitrogen cycling. Global Biogeochemical Cycles 16:
1120 (doi:10.1029/2001GB001856).
Casciotti KL and McIlvin MR (2007) Isotopic analyses
of nitrate and nitrite from references mixtures and
application to Eastern Tropical North Pacific waters.
Marine Chemistry 107: 184--201.
Chang CCY, Silva SR, Kendall C, Michalski G, Casciotti
KL, and Wankel S (2004) Preparation and Analysis
of Nitrogen-bearing Compounds in Water for Stable
Isotope Ratio Measurement. In: deGroot PA (ed.)
Handbook of Stable Isotope Analytical Techniques, vol.
1, pp. 305--354. Amsterdam: Elsevier.
Fogel ML and Cifuentes LA (1993) Isotope fractionation
during primary production. In: Engel MH and Macko
SA (eds.) Organic Geochemistry, pp. 73--98. New York:
Plenum.
Fry B (2006) Stable Isotope Ecology. New York: Springer.
Galbraith ED, Sigman DM, Robinson RS, and Pedersen TF
(in press) Nitrogen in past marine environments.
In: Bronk DA, Mulholland MR, and Capone DG (eds.)
Nitrogen in the Marine Environment.
Goericke R, Montoya JP, and Fry B (1994) Physiology
of isotope fractionation in algae and cyanobacteria, In: Lajtha K and Michener R (eds.) Stable
Isotopes in Ecology and Environmental Science, 1st
edn.,
pp. 187--221. Oxford: Blackwell Scientific
Publications.
Macko SA, Engel MH, and Parker PL (1993) Early
diagenesis of organic matter in sediments: Assessment
of mechanisms and preservation by the use of isotopic
molecular approaches. In: Engel MH and Macko SA
(eds.) Organic Geochemistry, pp. 211--224. New York:
Plenum.
Michener R and Lajtha K (2007) Stable Isotopes in
Ecology and Environmental Science, 2nd edn., New
York: Wiley-Blackwell.
Montoya JP (1994) Nitrogen isotope fractionation in the
modern ocean: Implications for the sedimentary record.
In: Zahn R, Kaminski M, Labeyrie L, and Pederson TF
(eds.) Carbon Cycling in the Glacial Ocean: Constraints
on the Ocean’s Role in Global Change, pp. 259--279.
Berlin: Springer.
Needoba JA, Sigman DM, and Harrison PJ (2004) The
mechanism of isotope fractionation during algal nitrate
assimilation as illuminated by the
15
N/
14
N of
intracellular nitrate. Journal of Phycology 40: 517--522.
Owens NJP (1987) Natural variations in
15 N in the
marine environment. Advances in Marine Biology 24:
390--451.
Peterson BJ and Fry B (1987) Stable isotopes in ecosystem
studies. Annual Review of Ecology and Systematics 18:
293--320.
Sigman DM, Granger J, DiFiore PJ, Lehmann MF, Ho R,
Cane G, and van Geen A (2005) Coupled nitrogen and
oxygen isotope measurements of nitrate along the
eastern North Pacific margin. Global Biogeochemical
Cycles 19: GB4022 (doi:10.1029/2005GB002458).
Wada E (1980) Nitrogen isotope fractionation and its
significance in biogeochemical processes occurring in
marine environments. In: Goldberg ED, Horibe Y, and
Saruhashi K (eds.) Isotope Marine Chemistry,
pp. 375--398. Tokyo: Uchida Rokakudo.
NITROGEN ISOTOPES IN THE OCEAN 563