My research focusses on marine phytoplankton, tiny single celled plants that live throughout the surface ocean. Collectively they carry out as much photosynthesis as all the plants on land. Phytoplankton are crucial for the Earth's carbon and nutrient cycles and are the base of the marine food web.
Click here for a great movie about phytoplankton and why they're important.

the role of light for phytoplankton biogeography

Phytoplankton species have different characteristics, or traits, which help determine where they survive in the ocean. I am particularly interested in how different species absorb and utilise light for photosynthesis and how this impacts their distributions. I use a combination of field experiments and numerical modelling including in collaboration with the Darwin Project team at MIT.

measuring carbon in the ocean from space

I'm using a novel numerical model to better understand how measurements made from satellites can be used to quantify dissolved and particulate carbon in the ocean. This work is part of a collaborative project called Pools of Carbon in the Ocean (POCO) funded by the European Space Agency in collaboration with PML and the Darwin Project team at MIT. 

the physical controls on phytoplankton in shelf seas

Shelf seas are highly dynamic and are important regions for ocean carbon and nutrient cycles. I explore how phytoplankton growth, physiology and species distributions vary between different shelf sea environments and how they respond to physical forcing such as the tides. I've been part of a number of projects including the UK Shelf Sea Biogeochemistry programme.

Click here for photos and key discoveries... 

phytoplankton distributions and productivity in the Atlantic

The Atlantic Ocean encompasses a variety of conditions from nutrient-poor subtropical gyres to nutrient-rich and highly productive coastal upwelling systems. I've studied how and why phytoplankton species distributions, physiology and photosynthesis vary between these systems via the Atlantic Meridional Transect (AMT) programme. 

phytoplankton photosynthesis and growth

I am interested in how phytoplankton absorb light and use the energy for photosynthesis. I've used a variety of methods, including Fast Repetition Rate fluorometry (FRRF) and carbon fixation by radioisotope techniques, to measure different parts of this processes. This work has contributed to larger projects such as PROTOOL, which assesses the use of FRRF for quantifying primary production.

the CROZet natural iron bloom and EXport experiment (CROZEX)

In large parts of the ocean, phytoplankton growth is thought to be limited by the availability of iron. The CROZEX project explored how iron and light availability affects phytoplankton in the surface ocean and the knock-on affect to carbon export and the deep ocean ecosystem. 

Click here for photos and more...