Marine Biophysics Unit

Independent New Investigator: Satoshi Mitarai
Research Theme: Marine Environmental Science

Abstract

Marine Biophysics Unit will develop forecasting system for the coastal ocean circulation processes around Okinawa and implement a validated connectivity assessment tool, coupling available modeling and observation techniques. This modeling tool will i) help marine biologists and geneticists estimate rates of gene flow among sites, ii) enable public agencies to build and evaluate marine protected areas based on population connectivity, and iii) provide marine ecologists with a modeling system for predicting the global and long-term dynamics of the marine ecosystem. Marine Biophysics Unit was established on Sep 1, 2009 when Satoshi Mitarai joined OIST.

1. Staff

1.1 Researchers

Satoshi Mitarai (Independent New Investigator, September 2009–)
Taichiro Sakagami (Technical staff, February 2010–)
Masako Nakamura (Researcher, March 2010–)

1.2 Administraters

Shizuka Kuda (Secretary, February 2010–)
Yukiko Murabayashi (Research coordinator, July 2011–)

1.3 Internship students

Emile Trimoreau (September 2010–February 2011)
Flora Vincent (July 2011–December 2011)

2. Collaborations

2.1 Larval dispersal of coral reef species

K. Sakai (University of the Ryukyus) *
D. Siegel, R. Warner and J. Caselle (University of California, Santa Barbara)
P. Barbar (University of California, Los Angeles)

2.2 Larval dispersal of hydrothermal vent species

T. Maruyama, Y. Fujiwara, Y. Furushima and H. Watanabe (Japan Agency for Marine-Earth Sci. and Tech.)
S. Beaulieu (Woods Hole Oceanographic Institution)

2.3 Regional ocean circulation modeling

J. McWilliams, J. Molemaker and A.Shchepetkin (University of California, Los Angeles)
E. Gross and O. Flinger (Stanford University)
Y. Uchiyama (Kobe University)

2.4 Okinawa coastal ocean observing system

S. Monismith and J. Koseff (Stanford University)
A. Genin (Hebew Universirty of Jerusalem)
L. Legendre (Laboratoire d'Oceanographie de Villefranche)
J. Mitchell (Flinders University)
H. Yamazaki (Tokyo Instutute of Marine Science and Technology)
S. Gallager (Woods Hole Oceanographic Institution)
K. Hirate (Okinawa Prefectural Fisheries and Ocean Research Center)
H. Furukawa, K. Muneda and I. Tedokon (Japan Coast Guard 11th Head Quarter)

* indicates that a joint research agreement has been established.

3. Activities and Findings

3.1 Coastal ocean circulation modeling

We have been developing high-resolution ocean circulation simulation for Okinawa using the Regional Ocean Modeling System. We plan to build three-level nested grids. We are finished with two grids: 1) coarse (12.5 km horizontal resolution) that covers the Pacific ocean and 2) medium (4 km resolution) that covers the north of Philippine, Taiwan, and the Ryukyu islands. We are examining the simulation results against available observation data. We will soon start developing the finest grid (500 m) that covers Okinawa Islands.

3.2 Coastal ocean observations

In collaboration with Prof. Hide Yamazaki, we made field observations along the shore in front of OIST main campus. Using a profiler, we measured and computed physical parameters (temperature, salinity, density, turbidity and chlorophyle a). We also took water samples for Evolutionary Systems Biology Unit (Photo). The aim is to assess marine microorganisms community diversity, dispersal processes and global dynamics. No definitive results have been obtained by now but trials outputs were encouraging.

3.3 Coral larvae under ocean acidification

Ocean acidification is one of the ongoing threads for marine organisms, resulting from the increase level of carbon dioxide in the atmosphere. Ocean acidification may greatly impact larval development and their dispersal ability. We observed transcription levels of heat shock proteins (expressed under stressful conditions to repair damaged proteins) in larvae of a coral species Acropora digitifera under acidified conditions with several different levels.

4. Publications

4.1 Journals

Fiscal year 2009

S. Mitarai, D. A. Siegel, J. R. Watson, C. Dong, and J. C. McWilliams. Quantifying connectivity in the coastal ocean with application to the Southern California Bight. Journal of Geophysical Research–Oceans, 114, Oct. 2009.
H. A. Berkley, B. E. Kendall, S. Mitarai, and D. A. Siegel. Turbulent dispersal promotes species coexistence. Ecology Letters, 13(3):360–371, Mar. 2010.
J. R. Watson, S. Mitarai, D. A. Siegel, J. E. Caselle, C. Dong, and J. C. McWilliams. Realized and potential larval connectivity in the Southern California Bight. Marine Ecology-Progress Series, 401:31–48, 2010.

Fiscal year 2010

K. A. Selkoe, J. R. Watson, C. White, T. Ben Horin, M. Iacchei, S. Mitarai, D. A. Siegel, S. D. Gaines, and R. J. Toonen. Taking the chaos out of genetic patchiness: seascape genetics reveals ecological and oceanographic drivers of genetic patterns in three temperate reef species. Molecular Ecology, 19(17):3708– 3726, 2010.
J. C. Ohlmann and S. Mitarai. Lagrangian assessment of simulated surface current dispersion in the coastal ocean. Geophysical Research Letters, 37, 2010.
Nakamura, M., Ohki, S., Suzuki, A., and Sakai, K. Coral larvae under ocean acidification: survival, metabolism, and metamorphosis, PLoS One 6(1):e1452, Jan 2011.

Fiscal year 2011

Alberto, F., Raimondi, P., Reed, D., Watson, J., Siegel, D., Mitarai, S., Coelho, N., and Serrao, E. Isolation by oceanographic distance explains genetic structure for Macrocystis pyrifera in the Santa Barbara Channel, Molecular Ecology, doi: 10.1111/j.1365-294X.2011.05117.x, May 2011.
Watson, J., Hays, C., Raimondi, P., Mitarai, S., Dong, C., McWilliams, J., Blanchette, C., Caselle, J. and Siegel, D., Currents connecting communities: nearshore community similarity and ocean circulation, Ecology, 92(6), pp.1193-1200, June 2011.

4.2 Books and other one-time publications

Mitarai, S., “Okinawa Marine Eco-system Research Project: OIST’s efforts to create world-class center for research”, Ryukyu Simpo, Feb 2, 2011.

4.3 Oral and Poster Presentations