wavelength-resolved optics and phytoplankton light absorption

Phytoplankton absorb light at different wavelengths depending on the types of light-harvesting pigments they contain. By resolving the full light spectrum in the model we are able to incorporate these characteristics and investigate their importance in driving phytoplankton distributions in the ocean. For example, carotenoid-containing phytoplankton often occur deeper in the water column than phycobillin-containing ecotypes (see model outcomes in the figure). One challenge is to identify how significant the pigment content of the different phytoplankton types is to forming these distributions, compared to other factors such as nutrient requirements or temperature.

Figure caption: An example (1-D) model outcome for the south Atlantic gyre. Each phytoplankton ecotype is defined by a set of stochastically assigned growth parameters and some size-based rules. Each ecotype is also assigned one of four sets of light absorption characteristics. The light absorption characteristics are taken from representatives of 1) a carotenoid-containing eukaryote (P.Euk), 2) a phycobillin-containing Synechococcus (Syn), 3) a high-light strain of Prochlorococcus (HL Pro) 4) a low-light Prochlorococcus (LL Pro).

For more information

  • Hickman, A.E., S. Dutkiewicz, R.G. Williams, and M.J. Follows: Modelling the effects of chromatic adaptation on phytoplankton
    comunity structure in the oligotrophic ocean. Submitted to Marine Ecology Progress Series (Oct 2009).
  • Hickman, AE., Dutkiewicz, S., Williams, R.G., Follows M.J. (2009). Modelling phytoplankton distributions in the ocean: a novel multi-species approach. AGU Chapman Conference on the Biological Carbon Pump. Brockenhurst, UK. Invited presentation