Workshop on Conceptual/Theoretical Studies and Model Development including the MODEL Task Team Report; BASS Team Report; REX Task Team Reports

A workshop was convened by the MODEL Task Team and held June 23-28, 1996, in Nemuro, Japan, to develop the modeling requirements of the PICES Climate Change and Carrying Capacity (CCCC) Program. It was attended by over 40 scientists from all member nations of PICES. The principal objectives of the workshop were to • review the roles and limitations of modeling for the CCCC program; • propose the level of modeling required; and • provide a plan for how to promote these modeling activities. Secondary activities at the workshop included organisational meetings of the Regional comparisons (REX) and Basin-scale experiment (BASS) Task Teams, and a symposium by Japan-GLOBEC on “Development and application of new technologies for measurement and modeling in marine ecosystems.” This report serves as a record of the proceedings of this workshop. (PDF contains 89 pages

Do bacteria thrive when the ocean acidifies? Results from an off-­shore mesocosm study

Marine bacteria are the main consumers of the freshly produced organic matter. In order to meet their carbon demand, bacteria release hydrolytic extracellular enzymes that break down large polymers into small usable subunits. Accordingly, rates of enzymatic hydrolysis have a high potential to affect bacterial organic matter recycling and carbon turnover in the ocean. Many of these enzymatic processes were shown to be pH sensitive in previous studies. Due to the continuous rise in atmospheric CO2 concentration, seawater pH is presently decreasing at a rate unprecedented during the last 300 million years with so-far unknown consequences for microbial physiology, organic matter cycling and marine biogeochemistry. We studied the effects of elevated seawater pCO2 on a natural plankton community during a large-scale mesocosm study in a Norwegian fjord. Nine 25m-long Kiel Off-Shore Mesocosms for Future Ocean Simulations (KOSMOS) were adjusted to different pCO2 levels ranging from ca. 280 to 3000 µatm by stepwise addition of CO2 saturated seawater. After CO2 addition, samples were taken every second day for 34 days. The first phytoplankton bloom developed around day 5. On day 14, inorganic nutrients were added to the enclosed, nutrient-poor waters to stimulate a second phytoplankton bloom, which occurred around day 20. Our results indicate that marine bacteria benefit directly and indirectly from decreasing seawater pH. During both phytoplankton blooms, more transparent exopolymer particles were formed in the high pCO2 mesocosms. The total and cell-specific activities of the protein-degrading enzyme leucine aminopeptidase were elevated under low pH conditions. The combination of enhanced enzymatic hydrolysis of organic matter and increased availability of gel particles as substrate supported higher bacterial abundance in the high pCO2 treatments. We conclude that ocean acidification has the potential to stimulate the bacterial community and facilitate the microbial recycling of freshly produced organic matter, thus strengthening the role of the microbial loop in the surface ocean

PICES-GLOBEC International Program On Climate Change And Carrying Capacity: Report of the 2000 BASS, MODEL, MONITOR and REX workshops, and the 2001 BASS/MODEL workshop

Table of Contents [pdf, 0.07 Mb] Executive Summary [pdf, 0.05 Mb] Report of the 2000 BASS Workshop on The Development of a conceptual model of the Subarctic Pacific basin ecosystems [pdf, 0.71 Mb] Report of the 2000 MODEL Workshop on Strategies for coupling higher and lower trophic level marine ecosystem models [pdf, 3.62 Mb] Report of the 2000 MONITOR Workshop on Progress in monitoring the North Pacific [pdf, 1.21 Mb] Report of the 2000 REX Workshop on Trends in herring populations and trophodynamics [pdf, 4.22 Mb] Report of the 2001 BASS/MODEL Workshop on Higher trophic level modeling [pdf, 0.29 Mb] (Document pdf contains 119 pages

Marine Nitrogen Fixation and Phytoplankton Ecology

Many oceans are currently undergoing rapid changes in environmental conditions such as warming temperature, acidic water condition, coastal hypoxia, etc. These changes could lead to dramatic changes in the biology and ecology of phytoplankton and consequently impact the entire marine ecosystems and global biogeochemical cycles. Marine phytoplankton can be an important indicator for the changes in marine environments and ecosystems since they are major primary producers that consolidate solar energy into various organic matter transferred to marine ecosystems throughout the food-webs. Similarly, the N2 fixers (diazotrophs) are also vulnerable to changing environmental conditions. It has been found that the polar regions can be introduced to diazotrophic activity under warming conditions and the increased N availability can lead to elevated primary productivity. Considering the fundamental roles of phytoplankton in marine ecosystems and global biogeochemical cycles, it is important to understand phytoplankton ecology and N2 fixation as a potential N source in various oceans. This Special Issue provides ecological and biogeochemical baselines in a wide range of geographic study regions for the changes in marine environments and ecosystems driven by global climate changes

Biogeochemical modelling of tropical marine ecosystems in the context of climate change

Chinenye Ani used eReefs models to investigate nutrient dynamics and climate change impacts on the Great Barrier Reef (GBR). She found that Trichodesmium is a major source of nitrogen in the GBR and improved the physiological realism of the Trichodesmium submodel of eReefs, which simulates Trichodesmium dynamics in the GBR

Factors controlling organic pollution in Lake Kiba with shallow and semi-closed environment

13301甲第4556号博士（理学）金沢大学博士論文本文Full 以下に掲載：Journal of Nuclear and Radiochmical Sciences 17(1) pp.17-22 2017. Japan Society of Nuclear and Radiochemical Sciences. 共著者：H.T.Bui, S.Nagao, S.Ochiai, K.Fukushi, A.Goto,T.Hasegaw

THE CONTRIBUTION OF INTEGRATED COASTAL MANAGEMENT TO THE SUSTAINABLE DEVELOPMENT OF CHINA’S COASTAL AREA

Ph.DDOCTOR OF PHILOSOPH