I joined the Bangor University as Professor of Marine Biology, later to be Professor of Marine Biogeochemistry. My original training was as an industrial biochemist but on graduating I rightly came to the view that oceanography offered more interesting challenges than food technology. My entry into oceanography was enabled by a Post Doctorate fellowship at Woods Hole Oceanographic Institute. From there I moved to the then just formed department of Oceanography at Southampton University; where I remained for some 17 years. Then followed 2 year spells at the Bigelow Lab in Maine and as Professor of Marine Microbiology at the University of Gothenburg, before taking up the post at Bangor. On retirement I was awarded emeritus professor status.

E-mail: oss074@bangor.ac.uk

ResearchGate

My initial research interest was in the dynamics of DOC and its composition as food for marine bacteria. This led me to be one of a group of people who drove through the new and the present paradigm of the role of bacteria in the planktonic food web. From this my interest broadened to overall heterotrophic metabolism - respiration. To enable this work I developed an ultra high precision analytical method for the analysis of oxygen concentrations in seawater and the group I assembled became leaders in this field. This work led on to the question of the balance of metabolism (photosynthesis versus respiration) in the oceans and I played a leading role in the debate over purported ocean heterotrophy. Recently, I have developed an interest on the physiology and biochemistry of micro-algae in relation to their potential for biomass and biofuel production. 

I have co-edited and published a number of books, the most recent being: Phytoplankton Productivity: Carbon Assimilation in Marine and Freshwater Ecosystems" (2002), "Respiration in Aquatic Ecosystems" (2005) and "Marine Ecology - Processes, Systems, and Impacts" (2005). 

I have an interest in the interplay between art and science and organised a highly successful Art Exhibition "Plankton as an Artistic Inspiration" at the Feb 2007 Ocean Sciences Meeting of the American Society for Limnology and Oceanography in Santa Fe.

2016

• CyhoeddwydVisionary, heretic, genius or charlatan? The remarkable Ernst Haeckel
  Evans, D., Gruber, E. & Williams, P., 5 Awst 2016, Yn: Ocean Challenge. 21, 2, t. 28 37 t.
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

2015

• CyhoeddwydArt forms from the Abyss: Ernst Haeckel's images from the HMS Challenger Expedition
  Williams, P. J. L., Evans, D. W., Roberts, D. J. & Thomas, D. N., 1 Medi 2015, 1 gol. Munich, London New York: Prestel Publishing Ltd. 143 t.
  Allbwn ymchwil: Llyfr/Adroddiad › Llyfr

2007

• CyhoeddwydMetabolic response of oligotrophic plankton communities to deep water nutrient enrichment.
  McAndrew, P. M., Bjorkman, K. M., Church, M. J., Morris, P. J., Jachowski, N., Williams, P. J. & Karl, D. M., 5 Maw 2007, Yn: Marine Ecology Progress Series. 332, t. 63-75
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
• CyhoeddwydPartitioning of organic production in marine plankton communities: The effects of inorganic nutrient ratios and community composition on new dissolved organic matter.
  Conan, P., Sondergaard, M., Kragh, T., Thingstad, F., Pujo-Pay, M., Williams, P. J., Markager, S., Cauwet, G., Borch, N. H., Evans, D., Evans, D. & Riemann, B., 15 Maw 2007, Yn: Limnology and Oceanography. 52, 2, t. 753-765
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

2006

• CyhoeddwydAn Appreciation of Alfred C. Redfield and his Scientific Work.
  Williams, P. J., 1 Rhag 2006, Yn: Limnology and Oceanography Bulletin. 15, 1, t. 53-70
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
• CyhoeddwydProkaryotic respiration and production in the meso- and bathypelagic realm of the eastern and western North Atlantic basin.
  Reinthaler, T., Van Aken, H., Veth, C., Aristegui, J., Robinson, C., Williams, P. J., Lebaron, P. & Herndl, G. J., 1 Mai 2006, Yn: Limnology and Oceanography. 51, 3, t. 1262-1273
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

2005

• CyhoeddwydMarine Ecology: Processes, Systems, and Impacts
  Kaiser, M., Attrill, M., Jennings, S., Thomas, D. N., Barnes, D., Brierley, A. S., Polunin, N., Raffaelli, D. & Williams, P. J., 1 Ion 2005, 2005 gol. Oxford University Press.
  Allbwn ymchwil: Llyfr/Adroddiad › Llyfr
• CyhoeddwydRespiration and its measurement in surface marine waters
  Robinson, C., Williams, P. J., Del Giorgio, P. A. (Golygydd) & Williams, P. J. (Golygydd), 1 Ion 2005, Respiration in Aquatic Ecosystems. 2005 gol. Oxford University Press, t. 147-180
  Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
• CyhoeddwydRespiration in Aquatic Ecosystems
  Del Giorgio, P. A. (Golygydd) & Williams, P. J. (Golygydd), 1 Ion 2005, 2005 gol. Oxford University Press.
  Allbwn ymchwil: Llyfr/Adroddiad › Llyfr
• CyhoeddwydRespiration in aquatic ecosystems: from single cells to the biosphere
  Del Giorgio, P. A., Williams, P. J. & Williams, P. J. (Golygydd), 1 Ion 2005, Respiration in Aquatic Ecosystems. 2005 gol. Oxford University Press, t. 267-303
  Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
• CyhoeddwydRespiration in Aquatic Ecosystems: History and Background
  Williams, P. J., Del Giorgio, P. A. & Williams, P. J., 1 Ion 2005, Respiration in Aquatic Ecosystems. 2005 gol. Oxford University Press, t. 1-17
  Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod

2004

• CyhoeddwydInterpreting the colour of an estuary.
  Bowers, D. G., Evans, D., Thomas, D. N., Ellis, K. & Williams, P. J., 1 Ion 2004, Yn: Estuarine, Coastal and Shelf Science. 59, 1, t. 13-20
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
• CyhoeddwydMeters, kilograms, seconds, but no bomb units. A zero tolerance approach to units (with apologies to Lynne Truss).
  Williams, P. J., 1 Meh 2004, Yn: Limnology and Oceanography Bulletin. 13, 2, t. 29-32
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
• CyhoeddwydNet community production and metabolic balance at the oligotrophic ocean site, Station ALOHA.
  Williams, P. J., Morris, P. J. & Karl, D. M., 1 Tach 2004, Yn: Deep Sea Research Part I: Oceanographic Research Papers. 51, 11, t. 1563-1578
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

2003

• CyhoeddwydGlobal carbon cycle (communication arising): Metabolic balance in the open sea.
  Karl, D. M., Laws, E. A., Morris, P., Williams, P. J. & Emerson, S., 1 Tach 2003, Yn: Nature. 426, 6962, t. 323-326
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
• CyhoeddwydLong-term environmental studies in the Irish Sea: a review.
  Evans, G. L., Hardman-Mountford, N. J., Hartnoll, R. G., Kennington, K., Mitchelson-Jacob, E. G., Shammon, T. & Williams, P. J., 1 Ion 2003, 2003 gol. Unknown.
  Allbwn ymchwil: Llyfr/Adroddiad › Adroddiad Comisiwn
• CyhoeddwydMultivariate techniques to accurately characterise catchments.
  Evans, D. W., Thomas, D. N., Bowers, D. G. & Williams, P. J., 1 Ion 2003.
  Allbwn ymchwil: Cyfraniad at gynhadledd › Papur
• CyhoeddwydPhysical and anthropogenic effects on observed long-term nutrient changes in the Irish Sea
  Evans, G. L., Williams, P. J. & Mitchelson-Jacob, E. G., 1 Awst 2003, Yn: Estuarine, Coastal and Shelf Science. 57, 5-6, t. 1159-1168
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

2002

• CyhoeddwydInorganic nitrogen assimilation by the picoplankton and whole plankton in a coastal ecosystem.
  Rodrigues, R. M. & Williams, P. J., 1 Tach 2002, Yn: Limnology and Oceanography. 47, 6, t. 1608-1616
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
• CyhoeddwydPhytoplankton Productivity - Carbon assimilation in marine and freshwater ecosystems
  Williams, P. J., Thomas, D. N. (Golygydd) & Reynolds, C. S. (Golygydd), 1 Ion 2002, 2002 gol. Blackwell Publishing.
  Allbwn ymchwil: Llyfr/Adroddiad › Llyfr

2001

• CyhoeddwydComparisons of plankton activity at 59°N and 37°N during two Lagrangian drift experiments in the North Atlantic in June and July 1996.
  Joint, I., Williams, P. J. & Savidge, G., 1 Ion 2001, Yn: Deep Sea Research Part II: Topical Studies in Oceanography. 48, 4-5, t. 1043-1061
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
• CyhoeddwydHeterotrophic bacterial utilization of nitrogenous and nonnitrogenous substrates, determined from ammonia and oxygen fluxes.
  Rodrigues, R. M. & Williams, P. J., 1 Tach 2001, Yn: Limnology and Oceanography. 46, 7, t. 1675-1683
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
• CyhoeddwydInterdecadal variability of nutrients in the Irish Sea.
  Evans, G. L., Williams, P. J. & Mitchelson-Jacob, E. G., 1 Ion 2001, 2001 gol. Unknown.
  Allbwn ymchwil: Llyfr/Adroddiad › Adroddiad Comisiwn
• CyhoeddwydInterdecadal variability of nutrients in the Irish Sea.
  Evans, G. L., Williams, P. J. & Mitchelson-Jacob, E. G., 1 Ion 2001, 2001 gol. Unknown.
  Allbwn ymchwil: Llyfr/Adroddiad › Adroddiad Comisiwn
• CyhoeddwydPrimary productivity of planet earth: biological determinants and physical constraints in terrestrial and aquatic habitats.
  Geider, R. J., DeLucia, E. H., Falkowski, P. G., Finzi, A. C., Grime, J. P., Grace, J., Kana, T. M., La Roche, J., Long, S. P., Osborne, B. A., Platt, T., Prentice, I. C., Raven, J. A., Schlesinger, W. H., Smetacek, V., Stuart, V., Sathyendranath, S., Thomas, R. B., Vogelmann, T. C. & Williams, P. J. & 1 eraill, Woodward, F. I., 1 Rhag 2001, Yn: Global Change Biology. 7, 8, t. 849-882
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

2000

• CyhoeddwydMicro-heterotrophs and the Dynamics of Dissolved Organic Material.
  Williams, P. J. & Kirchman, D. J. (Golygydd), 1 Ion 2000, Microbial Ecology of the Oceans. 2000 gol. Wiley–Liss, t. 542
  Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
• CyhoeddwydNet accumulation and flux of dissolved organic carbon and dissolved organic nitrogen in marine plankton.
  Sondergaard, M., Williams, P. J., Cauwet, G., Riemann, B., Robinson, C., Terzic, S., Woodward, E. M. & Worm, J., 1 Gorff 2000, Yn: Limnology and Oceanography. 45, 5, t. 1097-1111
  Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid
• CyhoeddwydNet production and Respiration
  Williams, P. J., Hanson, R. B. (Golygydd), Ducklow, H. W. (Golygydd) & Field, J. G. (Golygydd), 1 Ion 2000, The Changing Ocean Carbon Cycle: A midterm synthesis of the Joint Global Ocean Flux Study. 2000 gol. Cambridge University Press, t. 37-60
  Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod