Japan Geoscience Union Meeting 2015

Presentation information

Oral

Symbol B (Biogeosciences) » B-BG Biogeosciences & Geosphere-Biosphere Interactions

[B-BG21] Material cycles in tropical- subtropical coastal ecosystems

Wed. May 27, 2015 9:00 AM - 10:45 AM 304 (3F)

Convener:*Atsushi Watanabe(Department of Mechanical and Environmental Informatics Graduate School of Information Science and Engineering Tokyo Institute of Technology), Chuki Hongo(Department of Physics and Earth Sciences, Faculty of Science, University of the Ryukyus), Toshihiro Miyajima(Marine Biogeochemistry Group, Division of Ocean-Earth System Science, Atmosphere and Ocean Research Institute, The University of Tokyo), Chair:Chuki Hongo(Department of Physics and Earth Sciences, Faculty of Science, University of the Ryukyus), Toshihiro Miyajima(Marine Biogeochemistry Group, Division of Ocean-Earth System Science, Atmosphere and Ocean Research Institute, The University of Tokyo)

9:00 AM - 9:20 AM

[BBG21-01] The role of coral mucus in the material cycle in reef ecosystems

*Ryota NAKAJIMA1 (1.Department of Marine Biodiversity Research, JAMSTEC)

Keywords:Scleractinian corals, mucus, zooxanthellae, bacterial degradation, particle trap, trophic structure

It is well known that corals release transparent and mucoid organic matter (coral mucus) to the ambient seawater. This mucus release is important for various physiological functions of corals such as defense against stress, particle trap and cellular metabolic regulation. Coral mucus is mainly composed of carbohydrates, proteins and lipids, of which most are dissolved organic matter and thus utilized by heterotrophic bacteria and incorporated into the microbial loop. A fraction of the mucus, with its high molecular weight and sticky properties, captures large amounts of particulate organic matter in the seawater, forming large organic aggregates which are efficiently assimilated into higher trophic levels. Thus, coral mucus is incorporated into reef organisms in a variety of processes and functions as an important organic energy source in reef systems. This paper reviews some types of mucus forms, chemical composition and production rates of mucus, and the contribution of mucus to material recycling and heterotrophs from biogeochemical and ecological perspectives and the possible loss of reef biogeochemical processes and functions by ecosystem degradation due to global climate change and anthropogenic impact.