Lecture: Microbial Regulation of Biologically Mediated Ocean Carbon Pumps: Patterns, Processes and Limitations 

Lecturer: Prof. Richard B. RIVKIN, Memorial University of Newfoundland, Canada 

Time: 10am, Dec 5, 2016  

Location: Meeting Room 205 of Administration Building   

Abstract:   

Anthropogenic activities influence a suite of oceanic properties, including temperature, circulation patterns, and nutrient inputs and their distributions. These activities in turn can alter biogeochemical processes and fluxes that influence marine food webs and ecosystem services, e.g. the biologically mediated ocean carbon pumps, fisheries and other renewable marine resources. The first step in the biologically mediated carbon pumps is the transfer of atmospheric CO2 into the ocean where it is taken up by phytoplankton, organic carbon is synthesized, and a portion of it is transferred to pelagic and benthic food webs (i.e. a regional ecosystem service). Some of the organic carbon can be sequestered in the deep ocean or sediments after being exported from the surface, or sequestered by transformation into long-lived dissolved organic compounds (i.e. a global ecosystem service). Marine carbon export and sequestration currently takes up about 50% of the anthropogenic CO2 and is hence among the most globally important earth-ecosystem services provided by the oceans. A large fraction the energy and carbon transformations occurring in the ocean are mediated by autotrophic and heterotrophic microbes and hence these organisms have a central role in mediating essential ecosystem services. This seminar will present an integrated view of how these small yet important organisms interact to influence ocean carbon cycles and ultimately climate processes 

Introduction of Lecturer:    

Richard RIVKIN is a University Research Professor in the Department of Ocean Sciences at Memorial University of Newfoundland. His research interests and expertise are broadly interdisciplinary with active research in biological oceanography, aquatic and systems ecology, phytoplankton and microbial physiology and ecology and oceanic biogeochemistry. At the global-scale, Professor RIVKIN has characterized the basin-to-global scale distributions of bacterial and autotrophic processes and properties in order to assess and model organic carbon cycling, remineralization and export in the upper water column of the World Ocean. At the molecular- to individual-scale, Professor RIVKIN has evaluated the relationship between adaptation and succession in planktonic communities by studying the relationships between structure and diversity of bacterial assemblages and physiological and ecological characteristics of the microbial community. These fundamental ecological and evolutionary questions are critical to understanding changes in microbial community structure, and relate to metabolic, ecological and physiological changes in the bacterial community that may reflect environmental and climate forcings. During the course of his 35+ year career, Professor RIVKIN has led largescale research expeditions to the Antarctic, Arctic, North Atlantic, Sargasso, Caribbean, North Pacific, Labrador Sea, Beaufort Sea and the Canadian Arctic Archipelago. In addition to basic research programmes, Professor RIVKIN has pursued applied research areas such as studies on invasive species in ballast water, and the effects of shellfish aquaculture and offshore oil production on microbial dynamics, marine habitats and ecosystem carrying capacity. The research from these projects and programmes are described in >140 peer-reviewed papers, including 11 papers published in the journals Science and Nature and >275 published abstracts and presentations.