Ocean and Earth Science, National Oceanography Centre Southampton

Martha Gledhill

BSc, MChem, PhD

Primary position:
NERC Advanced Research Fellow


The University of Southampton
Dr Martha Gledhill's photo

BSc Marine Chemistry, University of Liverpool (1991)
PhD Chemical Oceanography, University of Liverpool (1995)
Post doctoral researcher, Department of Biological Sciences, University of Plymouth (1995)
Lecturer and Senior Lecturer, Department of Environmental Science, University of Plymouth (1997)
UK Royal Society Relocation Fellow (2005)
NERC Advanced Research Fellow (2007)


The University of Southampton's electronic library (e-prints)


Pižeta, I., Sander, S.G., Hudson, R.J.M., Omanović, D., Baars, O., Barbeau, K.A., Buck, K.N., Bundy, R.M., Carrasco, G., Croot, P.L., Garnier, C., Gerringa, L.J.A., Gledhill, M., Hirose, K., Kondo, Y., Laglera, L.M., Nuester, J., Rijkenberg, M.J.A., Takeda, S., Twining, B.S. and Wells, M. (2015) Interpretation of complexometric titration data: An intercomparison of methods for estimating models of trace metal complexation by natural organic ligands. Marine Chemistry, 173, 3-24. (doi:10.1016/j.marchem.2015.03.006).
Gledhill, Martha, Achterberg, Eric P., Li, Keqiang, Mohammed, Khairul N. and Rijkenberg, Micha J.A. (2015) Influence of ocean acidification on the complexation of iron and copper by organic ligands in estuarine waters. Marine Chemistry (doi:10.1016/j.marchem.2015.03.016). (In Press).
Gledhill, Martha, Gerringa, Loes J.A., Laan, Patrick and Timmermans, Klaas R. (2015) Heme b quotas are low in Southern Ocean phytoplankton. Marine Ecology Progress Series, 532, 29-40. (doi:10.3354/meps11345).
Hogle, Shane L., Barbeau, Katherine A. and Gledhill, Martha (2014) Heme in the marine environment: from cells to the iron cycle. Metallomics, 6, (6), 1107-1120. (doi:10.1039/C4MT00031E).
Gledhill, Martha, Achterberg, Eric P., Honey, David J., Nielsdottir, Maria C. and Rijkenberg, Micha J.A. (2013) Distributions of particulate Heme b in the Atlantic and Southern Oceans - implications for electron transport in phytoplankton. Global Biogeochemical Cycles, 27, (4), 1072-1082. (doi:10.1002/2013GB004639).
Hawkes, Jeffrey A., Gledhill, Martha, Connelly, Douglas P. and Achterberg, Eric P. (2013) The stabilisation and transportation of dissolved iron from high temperature hydrothermal vent systems. Earth and Planetary Science Letters, 375, 280-290. (doi:10.1016/j.epsl.2013.05.047).
Honey , David J., Gledhill, Martha, Bibby , Thomas S., Legiret, François-Eric, Pratt , Nicola J., Hickman, Anna E., Lawson, Tracy and Achterberg, Eric P. (2013) Heme b in marine phytoplankton and particulate material from the North Atlantic Ocean. Marine Ecology Progress Series, 483, 1-17. (doi:10.3354/meps10367).
Gledhill, Martha, Hassler, Christel S. and Schoemann, Veronique (2013) The environmental bioinorganic chemistry of aquatic microbial organisms. Frontiers in Microbiology, 4 (doi:10.3389/fmicb.2013.00100).
Hawkes, Jeffrey A., Gledhill, Martha, Connelly, Douglas P. and Achterberg, Eric P. (2013) Characterisation of iron binding ligands in seawater by reverse titration. Analytica Chimica Acta, 766, 53-60. (doi:10.1016/j.aca.2012.12.048).
Gledhill, Martha and Buck, Kristen N. (2012) The organic complexation of iron in the Marine Environment: A review. Frontiers in Microbiology, 3 (doi:10.3389/fmicb.2012.00069).
Mohamed, Khairul N., Steigenberger, Sebastian, Nielsdottir, Maria C., Gledhill, Martha and Achterberg, Eric P. (2011) Dissolved iron(III) speciation in the high latitude North Atlantic Ocean. Deep Sea Research Part I Oceanographic Research Papers, 58, (11), 1049-1059. (doi:10.1016/j.dsr.2011.08.011).
Mawji, Edward, Gledhill, M., Milton, J.A., Zubkov, M.V., Thompson, Anu, Wolff, George A. and Achterberg, Eric P. (2011) Production of siderophore type chelates in Atlantic Ocean waters enriched with different carbon and nitrogen sources. Marine Chemistry, 124, (1-4), 90-99 . (doi:10.1016/j.marchem.2010.12.005).
Salter, I., Kemp, A.E.S., Lampitt, R.S. and Gledhill, M. (2010) The association between biogenic and inorganic minerals and the amino acid composition of settling particles. Limnology and Oceanography, 55, (5), 2207-2218. (doi:10.4319/lo.2010.55.5.2207).
Breitbarth, E., Achterberg, E.P., Ardelan, M.V., Baker, A.R., Bucciarelli, E., Chever, F., Croot, P.L., Duggen, S., Gledhill, M., Hassellov, M., Hassler, C., Hoffmann, L.J., Hunter, K.A., Hutchins, D.A., Ingri, J., Jickells, T., Lohan, M.C., Nielsdottir, M.C., Sarthou, G., Schoemann, V., Trapp, J.M., Turner, D.R. and Ye, Y. (2010) Iron biogeochemistry across marine systems - progress from the past decade. Biogeosciences, 7, (3), 1075-1097. (doi:10.5194/bg-7-1075-2010).
Curtis-Jackson, Philippa K., Massé, Guillaume, Gledhill, Martha and Fitzsimons, Mark F. (2009) Characterization of low molecular weight dissolved organic nitrogen by liquid chromatography-electrospray ionisation-mass spectrometry. Limnology and Oceanography: Methods, 7, 52-63.
Mawji, Edward, Gledhill, Martha, Milton, James A., Tarran, Glen A., Ussher, Simon, Thompson, Anu, Wolff, George A., Worsfold, Paul J. and Achterberg, Eric P. (2008) Hydroxamate siderophores: occurrence and importance in the Atlantic Ocean. Environmental Science and Technology, 42, (3), 8675-8680. (doi:10.1021/es801884r).
Mawji, Edward, Gledhill, Martha, Worsfold, Paul J. and Achterberg, Eric P. (2008) Collision-induced dissociation of three groups of hydroxamate siderophores: ferrioxamines, ferrichromes and coprogens/fusigens. Rapid Communications in Mass Spectrometry, 22, (14), 2195-2202. (doi:10.1002/rcm.3604).
Braungardt, Charlotte B., Achterberg, Eric P., Gledhill, Martha, Nimmo, Malcolm, Elbaz-Poulichet, Francois, Cruzado, Antonio and Velasquez, Zoila (2007) Chemical speciation of dissolved Cu, Ni, and Co in a contaminated estuary in southwest Spain and its influence on plankton communities. Environmental Science and Technology, 41, (12), 4214-4220. (doi:10.1021/es063042h).
Gledhill, Martha (2007) The determination of heme b in marine phyto- and bacterioplankton. Marine Chemistry, 103, (3-4), 393-403. (doi:10.1016/j.marchem.2006.10.008).
Kawakami, S.K., Gledhill, M. and Achterberg, E.P. (2006) Production of phytochelatins and glutathione by marine phytoplankton in response to metal stress. Journal of Phycology, 42, (5), 975-989. (doi:10.1111/j.1529-8817.2006.00265.x).
Kawakami, S.K., Gledhill, M. and Achterberg, E.P. (2006) Determination of phytochelatins and glutathione in phytoplankton from natural waters using HPLC with fluorescence detection. Trends in Analytical Chemistry, 25, (2), 133-142. (doi:10.1016/j.trac.2005.06.005).
Gledhill, M., McCormack, P., Ussher, S., Achterberg, E.P., Mantoura, R.F.C. and Worsfold, P. (2004) Production of siderophore type chelates by mixed bacterioplankton populations in nutrient enriched seawater incubations. Marine Chemistry, 88, (1-2), 75-83. (doi:10.1016/j.marchem.2004.03.003).
Biscombe, A., Nimmo, M., Gledhill, M. and Achterberg, E.P. (2004) An automated monitor to determine trace metal particle/dissolved interactions in natural waters. Analytica Chimica Acta, 521, 69-76. (doi:10.1016/j.aca.2004.05.066).
Hanrahan, Grady, Gledhill, Martha, House, William A. and Worsfold, Paul J. (2003) Evaluation of phosphorus concentrations in relation to annual and seasonal physico-chemical water quality parameters in a UK chalk stream. Water Research, 37, (15), 3579-3589. (doi:10.1016/S0043-1354(03)00265-3).
Hanrahan, G., Ussher, S., Gledhill, M., Achterberg, E.P. and Worsfold, P.J. (2002) High temporal and spatial resolution monitoring using flow injection with spectroscopic detection. Trends in Analytical Chemistry, 21, 233-239.
Hanrahan, Grady, Gledhill, Martha, House, William A. and Worsfold, Paul J. (2001) Phosphorus loading in the Frome catchment, UK. Journal of Environmental Quality, 30, (5), 1738-1746.
Hanrahan, G., Gledhill, M., Fletcher, P.J. and Worsfold, P.J. (2001) High temporal resolution field monitoring of phosphate in the River Frome using flow injection with diode array detection. Analytica Chimica Acta, 440, (1), 55-62. (doi:10.1016/S0003-2670(00)01395-7).
Gardolinski, P.C.F.C., Hanrahan, G., Achterberg, E.P., Gledhill, M., Tappin, A.D., House, W.A. and Worsfold, P.J. (2001) Comparison of sample storage protocols for the determination of nutrients in natural waters. Water Research, 35, 3670-3678. (doi:10.1016/S0043-1354(01)00088-4).

Book Section

Devez, A., Achterberg, E. and Gledhill, M. (2009) Metal ion-binding properties of phytochelatins and related ligands. In, Sigel, A., Sigel, H. and Sigel, R.K.O. (eds.) Metallothioneins and Related Chelators. Cambridge, UK, Royal Society of Chemistry, 441-481. (Metal Ions in Life Sciences 5). (doi:10.1039/9781847558992-00441).


Research Interests

Specialism: Marine Biochemistry

Trace metal biogeochemistry

I investigate the distribution of metals in the marine environment and am particularly interested in interactions between organisms and metals. I am currently undertaking research into the way organisms optimise their use and acquisition of iron in the ocean. Iron is an important metal in the marine environment as it limits productivity in approximately 30% of the surface ocean. Specific research projects in this area involve the investigation of bioinorganic iron complexes such as hemes and siderophores. I also work on metal toxicity, investigating the production of compounds (phytochelatins) that maintain trace metal homeostasis in phytoplankton and may thus represent useful biomarkers in contaminated systems.

Hemes in marine bacterioplankton and particulate material

I am pioneering research on hemes in the marine environment. Hemes are intracellular iron containing porphyrins, which make up approximately 40 % of the total iron pool of organisms. Hemes play a critical role in both photosynthesis and respiration, yet despite this little is known about heme levels in marine organisms or their response to variations in ambient iron concentrations. In my lab we are investigating hemes in order to assess their suitability as an indicator of "aneamia" in marine phytoplankton and bacteria, and as an indicator for biological particulate iron in the ocean.

Detection, characterisation and biogeochemistry of iron chelators in seawater

The extent to which organisms take up metals from seawater is known to be affected by metal speciation. Some metals are reduced in availability by complexation with organic matter, while in some cases organic complexants may be released by organisms to increase availability. I am particularly interested in siderophores, high affinity iron chelators used by bacteria to acquire iron in low iron environments. In my lab we develop novel, sensitive and specific techniques using liquid chromatography – mass spectrometry with which to separate, detect and quantify siderophores in seawater.

Other research interests

Other research interests include interactions between marine phytoplankton viruses, their phytoplankton hosts and trace metals. I have also worked on the distribution of amino acids in the dissolved and particulate phase in seawater.

PhD Supervision

Pornsri Mingkwan 

David J. Honey

Khairul Bin Mohamed 

Lizeth Avendano 

Jessica Klar 

Primary research group:  Marine Biogeochemistry

Research project

Iron Isotopes in seawater samples


Laboratory manager, liquid chromatography – mass spectrometry laboratory.

Teaching Responsibilities

SOES3035 Oceanography Research Training


Dr Martha Gledhill
Ocean and Earth Science, National Oceanography Centre Southampton University of Southampton Waterfront Campus European Way Southampton SO14 3ZH United Kingdom

Room Number: NOCS/184/11

Telephone: (023) 8059 9258
Email: m.gledhill@noc.soton.ac.uk