The Special Session 55 “Microbial Carbon Pump: A multidisciplinary focus on origins,cycling and storage of DOM in the ocean” was chaired by WG134 members (Gerhard Kattner, Nianzhi Jiao, Farooq Azam and Steven Wilhelm). It attracted about 100 participants including researchers, young scientists and students at the ASLO Aquatic Science Meeting.
This special session was comprised of a poster session (February 17) and an oral session (February 18).
The ASLO Emerging Issues Workshop included five sessions. The meeting program included discussion on the practice of the MCP, anticipated program/projects to develop and potential MCP joint cruises West Pacific Warm Pool, Bering Sea, Arctic Ocean .
The main issues were discussed by the oceanographers, biologists and chemists during the meeting. Compared with the biological pump, MCP plays a more important role in carbon’s sequestration rather than carbon’s fixation. Membrane potential could be a useful parameter to track the RDOC. Some RDOM could be bio-available but the concentration is too low for organisms to use. The molecular weight in the range of 200-600Da has a positive relationship with depth. The concept of RDOC was initially defined by the biologists and chemists. “Reactivity is important”. Even though it’s hard to put one label on the term, something clear is that: chemists define SLDOC by the removing rate; the term used by microbiologist in incubation experiment, depends on how long the DOC can last for. We can also refer to some phytoplankton bloom data in the past, the “black carbon”, the RDOC/DOC produced from the hydrothermal vent. We can even develop different approaches to measure the unknown RDOC based on the two time-serie stations since differences among RDOC compounds were found in HOT & BAT. Besides, it has been found that in the ocean, there’s carbon-rich external molecular. So the chemical structure origins of organic matters from plants and phytoplankton are very important connection to the molecular characterization of RDOC in the ocean. The importance of MCP is the transformation of DOC by microbes. So it’s important to figure out how much carbon is processed by microbes per year.
(Editing Contact：xjz@xmu.edu.cn)