Processes and Approaches of Coastal Ecosystem Carbon Sequestration (PACECS)

Summary of the project

Ocean is the largest carbon pool on earth, serving as the buffer of global climate change, absorbing about 1/3 of CO2 produced by human activities. Carbon sink captured by marine ecosystem is called the "Blue Carbon Sink" (hereinafter referred to as "blue carbon"), which is one of the most important mechanisms for the sea to store carbon. The initial form of blue carbon is visible plant carbon sequestration in the coastal zone. As a matter of fact, the invisible microorganisms (phytoplankton, bacteria, archaea, and protozoa), which have always been ignored, account for 90% of the marine biomass and constitute the main component of blue carbon. The marginal sea covers one third of the total territory of China, and it is of urgent need to explore the immense potential of carbon sinks. This project aims at the key processes and mechanisms of the carbon sequestration in coastal ecosystems and ways to increase ocean carbon sink.

An increasing carbon sink, on the one hand, refers to increasing the sinking and burial of particle organic carbon (POC) in sediments; and on the other hand, it is about increasing the production of refractory dissolved organic carbon (RDOC) mediated by microorganisms (the overall amount of the RDOC pool is equal to that of CO2 in the atmosphere). This project is comprised of four subprojects. Subproject 1 focuses on community structure and ecosystem function in the carbon cycle, with an emphasis on key processes concerning the POC sinking and the RDOC production. Subproject 2 focuses on physiological and molecular mechanisms of ocean carbon sinks, such as uptake, transformation, and release of carbon-containing chemical compounds by microorganism at the gene and protein levels. This subproject also focuses the impact of human activities and input of terrestrial nitrogen and phosphorus on the above processes. Subproject 3 focuses at re-establishing the evolution process of ocean carbon sinks in geologic history with sedimentary records, which should record organic carbon from burial of sinking POC in sediments studied in subject 1, the RDOC molecules studied in both subproject 1 and 2, and the human activities and input of terrestrial sources studied in subproject 2, and aims at the relationship between ocean carbon sinks and global climate changes in ancient oceans. Based on field investigation, theoretical analysis and historical representation of the subproject 1, 2, and 3, subproject 4 aims at establishing scenario models for carbon sink dynamics under global warming situation, and providing theoretical and technical foundations for engineering ocean carbon sequestration in the future.

The PIs leading this project include a "Minjiang" scholarship professors, a Professor of "Distinguished Young Scientists Program”, a Professor of “Excellent Young Scientists Program”, two Distinguished Professors of the "Thousand Young Talents Program" and "Hundred Talents Program" of Chinese Academy of Sciences. This project is also featured in its interdisciplinary cooperation and integration. Potential breakthroughs are especially expected in the following aspects:

  1. key processes and regulatory mechanisms of ocean carbon sink and its relationship with environment and global climate changes;
  2. an index system for carbon storage including a series of physical-chemical and biological indices and parameters and main core measurements protocols;
  3. demonstrations of increasing carbon sink and engineering carbon sequestration in the ocean.

These outputs will support the sustainable development of marine ecosystem and national carbon emissions trading.

Area of study

Coastal oceans of China. The majority of the regions includes:

  1. from the Yangtze River estuary to the East China Sea;
  2. from the Pearl River estuary to the South China Sea;
  3. the Bohai Sea and the Yellow Sea.

Time Table for activities

July 1, 2016 - June 31, 2021