People > Dr Darren Clark

Dr Darren Clark

Microbial Ecologist

Contact Details

+44 (0)1752 633100 (switchboard)

drcl10/04/2020 11:12:07@pml.ac.uk

Dr Darren Clark is a Microbial Ecologist with interests in pelagic biogeochemistry and phytoplankton physiology. Darren is especially interested in pelagic nutrient cycling and the role that marine microbes play in the various associated processes. This has involved both ship and laboratory based research. Ship-based activity has included campaigns to various areas of the global ocean including the temperate shelf seas surrounding the UK, the open oceans of the oligotrophic Atlantic gyres, the highly productive western boundary upwelling regions and the polar seas of the Arctic and Antarctic.

Darren has been involved with programmes such as UK-SOLAS and AMT, and the Ocean Acidification programmes MedSea and UKOA. He is also involved with the recently funded Shelf-Seas Biogeochemistry programme which will focus on nutrient cycles and carbon-export in the Western shelf-break and Celtic sea region. Darren’s laboratory based research activity focuses on the use of culture techniques to investigate aspects of phytoplankton physiology, notably how cells acclimate to changes in environmental conditions and use cellular resources. This information is pertinent to model development, both at the cellular and ecosystem levels. Darren is at present a member of the NERC peer-review college.

Projects

Microbial carbon pump in a changing ocean: building models for the future

Contact: Dr Luca Polimene

This project will conduct laboratory experiments to provide the physiological information and understanding needed to develop the first ever model...

Pathways and emissions of climate-relevant trace gases in a changing Arctic Ocean (PETRA)

Contact: Dr Andy Rees

The Arctic Ocean is a rapidly changing environment, with rising temperatures leading to an ongoing decline in sea ice and shifting conditions for...

Other key projects

SSB - Shelf Seas Biogeochemistry: this recently funded NERC programme involves a series of research cruises in UK shelf sea waters and is presently underway. The programme has adopted a multidisciplinary approach to the investigation of nutrient cycling processes and carbon export.

UK-OA: The NERC funded Ocean Acidification programme has involved 3 ship-based research cruises to the temperate shelf seas (2011), the Arctic (2012) and the Antarctic (2013). A ship-based bioassay approach was used to investigate changes in biological and chemical characteristics of incubated seawater samples under simulated ocean acidification conditions.

MedSeA: The European Union funded ocean acidification programme in which a multi-disciplinary approach to mesocosm studies has been used to investigate the influence of simulated ocean acidification conditions on natural microbial communities of the Mediterranean Sea.

UK-SOLAS: The international SOLAS programme (Surface Ocean-Lower Atmosphere) aimed to examine gas exchange processes between the ocean and atmosphere at a number of contrasting oceanic regions. N-assimilation and regeneration rate processes were investigated in relation to trace metal availability (INSPIRE) and during a lagrangian study of an upwelled plume (ICON).

Atlantic Meridional Transect (AMT): N-cycling investigations have been conducted during AMT cruises, most recently focusing on depth profiles of nitrification rates within the photic zone of the transect.

Carbon, nitrogen and phosphorous partitioning in marine phytoplankton: A NERC funded research project. The relationship between nutrient availability, elemental cell composition and environmental pH was investigated. Specifically, these studies were used to investigate how the process of basification (an increase in environmental pH driven by prolific phytoplankton growth) can influence the composition of phytoplankton cells. This data is being used to refine physiological and ecosystem based models.

Selected key publications

Clark DR, Flynn KJ, Fabian H. 2014. Variation in elemental stoichiometry of the marine diatom Thalassiosira weissflogii (bacillariophyceae) in response to combined nutrient stress and changes in carbonate chemistry. Journal of Phycology, 50:640-651.

Clark DR, Brown IJ, Rees AP, Somerfield PJ, Miller PI. 2014. The influence of ocean acidification on nitrogen regeneration and nitrous oxide production in the northwest European shelf sea. Biogeosciences, 11:4985-5005.

Flynn KJ, Blackford JC, Baird ME, Raven JA, Clark DR, Beardall J, Brownlee C, Fabian H, Wheeler GL. 2012. Changes in pH at the exterior surface of plankton with ocean acidification. Nature Climate Change, 2:510-513.

Rees AP, Brown IJ, Clark DR, Torres R. 2011. The Lagrangian progression of nitrous oxide within filaments formed in the Mauritanian upwelling. Geophysical Research Letters, 38:L21606.

Clark DR, Miller PI, Woodward EMS, Rees AP. 2011. Inorganic nitrogen assimilation and regeneration in the coastal upwelling region of the Iberian Peninsula. Limnology and Oceanography, 56:1689–1702.

Flynn KJ, Clark DR, Xue Y. 2008. Modelling the release of dissolved organic matter by phytoplankton. Journal of Phycology, 44:1171-1187.

Clark DR, Rees AP, Joint I. 2008. Ammonium regeneration and nitrification rates in the oligotrophic Atlantic Ocean: Implications for new production estimates. Limnology and Oceanography, 53:52-62.

Yool A, Martin AP, Fernández C, Clark DR. 2007. The significance of nitrification for oceanic new production. Nature, 447: 999-1002.

Clark DR, Rees AP, Joint I. 2007. A method for the determination of nitrification rates in oligotrophic marine seawater by Gas Chromatography/Mass Spectrometry. Marine Chemistry, 103:84-96.

Clark DR, Fileman T, Joint I. 2006. Determination of ammonium regeneration rates in the oligotrophic ocean by Gas Chromatography/Mass Spectrometry. Marine Chemistry, 98:121-130.

Opportunities at PML