Rob Lampe’s Research

 
Molecular Responses of Phytoplankton in Upwelling Regimes

Coastal upwelling regimes along the eastern boundaries of the Pacific and Atlantic Oceans are the most biologically productive areas of the ocean. These regions are characterized by equatorward wind patterns that cause cold, nutrient-rich water to upwell to the surface and stimulate enormous blooms of phytoplankton. Due to the dynamic nature of upwelling, these phytoplankton communities are subject to tremendous natural variations in abiotic stressors. Upwelled water is naturally high in carbon dioxide and more acidic which quickly changes with photosynthetic activity forming large gradients at the surface. Reduced availability of the essential micronutrient iron can also be limiting to phytoplankton growth in some areas depending on the level of interaction between upwelled water and iron-rich sediment. The end result is a complex biogeochemical mosaic which may be perturbed by climate change.

Phytoplankton in these regions also undergo a ‘conveyer belt cycle’ in which deep subsurface populations are upwelled with the nutrient rich water. This processes forces the community to cope with intense changes in light, but likely provides a substantial seed stock for surface blooms. These blooms are well characterized as being dominated by large chain-forming diatoms. Through a combination of shipboard incubations in the California Upwelling Zone and laboratory-based experiments, we seek to couple levels of gene expression with chemical and physical measurements to address the following research questions:

  1. How do different types of phytoplankton respond to being upwelled, and what is unique to diatoms that allows them to preferentially benefit?
  2. How will phytoplankton responses to upwelling change facing increased pH and iron stresses as a result of climate change?

 
References:

Capone, D. G. and D. A. Hutchins (2013). “Microbial biogeochemistry of coastal upwelling regimes in a changing ocean.” Nature Geosci 6(9): 711-717.

Wilkerson, F.P. and R.C. Dugdale, Nitrogen in the Marine Environment (2nd Edition). 2008. Capone, D.G., E.J. Carpenter, and D.A. Bronk, eds. Burlington, MA, USA: Academic Press: p. 771-807.