Biological oceanography
TITLE. The influence of temperature and food source on zooplankton respiration.
PhD project of Raffaella Nobili

SUPERVISOR & CO-SUPERVISOR(S)
Carol Robinson (UEA), Erik Buitenhuis (UEA), Claudia Castellani (SAHFOS, Plymouth)

Phd to be held at the University of East Anglia (UEA) and Sir Alister Hardy Foundation for Ocean Sciences (SAHFOS)

PROJECT DESCRIPTION.

Mesozooplankton make a significant contribution to the marine biogeochemical cycles of carbon and nitrogen through their respiration, excretion and vertical migration. The greatest proportion of the carbon dioxide taken up by phytoplankton during photosynthesis is recycled back to carbon dioxide through the respiration of phytoplankton, bacteria, protists and mesozooplankton. Yet the magnitude and variability of the respiration of each of these plankton functional types is poorly constrained. Ecosystem models parameterise mesozooplankton respiration in terms of .basal. respiration which is related to temperature but independent of feeding and .metabolic. respiration which is proportional to feeding or assimilation. A number of different laboratory and field techniques including microelectrodes and optodes, can be used to measure mesozooplankton respiration at a range of temperatures and food quantity and quality. This PhD project will compare and contrast these different methods in the field and in the laboratory in order to better parameterise respiration of the most ubiquitous mesozooplankton . the copepods. Experiments will also be conducted to assess the potential impact of the predicted effects of climate change: decreasing inorganic nutrient supply, increasing hypoxia and decreasing pH, on copepod growth and respiration. The project will combine laboratory work, open ocean (e.g. Arctic / North Atlantic) fieldwork, data synthesis and modelling, and will benefit from use of the Continuous Plankton Recorder (CPR) Survey.s 80 year dataset of the ecology and biogeography of plankton in the North Atlantic.

Funding: NERC funded studentship with SAHFOS as CASE partner.