Subject field
Ecology, Marine
Title
Factors terminating the subarctic spring bloom
Project period
Spring or autumn 2025. 15 to 60 ECTS
Background
Return of light irradiance during high levels of inorganic nutrients in late winter initiate the spring bloom in sub-arctic environments. It is a paucity of knowledge about what factors terminate the spring bloom. Both increased temperature, higher excretion of energy and carbon substrates, competition of nutrients with prokaryotes and elevated grazing are potential factors. This has implication for projecting climate change effects on marine primary productivity.
Overall aim
Clarifying the influence of temperature and substrate availability for regulating the extent of the spring bloom.
Research question
Is the spring bloom terminated by increased temperature, higher organic carbon supply or a combination of both?
Method
Data from a full factorial mesocosm experiment and simultaneous measurements from an adjacent field site will be evaluated. Effects of temperature and dissolved cell substrates on phytoplankton biomass, chlorophyll-a and prokaryotic growth will be investigated. The development of the spring bloom from late winter to spring in the field and mesocosm system will be compared.
Workplace
Department of Ecology and Environmental Science and Umeå Marine Sciences Centre (UMF), Norrbyn.
Contact
