Research

Ongoing Research

Larval Dispersal and Marine Population Connectivity

Quantification of stochastic larval connectivity among marine populations is essential to understand global and long-term changes of marine ecosystems (Siegel et al., 2008). Our primary approach is to quantify dispersal probabilities of marine species in order to learn how far larvae can be transported by oceanic eddies and how quickly and effectively they colonize new sites (Mitarai et al., 2009; Mitarai et al., 2016), and to test these predictions of dispersal with recruitment and population genetic data that define the biogeographic characteristics of selected marine species (Selkoe et al., 2010; Nakamura et al., 2015). By quantifying dispersal patterns, we seek to contribute to marine conservation planning. That is, by optimizing design of marine protected areas, we may be able to help prevent the collapse of vulnerable ecosystems globally (Mullineaux et al., 2018; Levin et al., 2020).

Biological Responses of Coral Reef Species to Turbulent Flows

Biological responses to the changing physical oceanographic environment can have significant consequences for biogeochemical cycling. We study biological responses of coral reef species to oceanic turbulence at individual scales, and quantify their integrated effects on biogeochemical processes at reef scales, based on in situ observations (Rintoul at al., 2022). In order to better understand effects of flows on biology (causality), we also combine ocean observations and flume experiments with living organisms, such as corals and garden eels (Ishikawa et al., 2022). Combined with ocean circulation models, we strive to formulate better estimates of coral-reef contributions to the carbon cycle in the changing environment.

Oceanic Responses to Extreme Forcings by Typhoons

Atmosphere-ocean interactions in tropical cyclones remain a central research topic in oceanography and related disciplines. Extreme forcing by tropical cyclones can cause rapid shifts in marine community structures, including marine microbes in coral reefs (Grossmann et al., 2015; Ares at al., 2020). We deploy ocean observing platforms with a suite of sensors, in order to understand key atmospheric, oceanic, and biological processes, even under extreme weather conditions, including cores of tropical cyclones (Mitarai and McWilliams, 2016). 

In the fall of 2021, the MBU entered a joint research agreement with Nippon Telegraph and Telephone Corporation (commonly known as NTT) to enable real-time monitoring of atmosphere-ocean interactions in fully developed typhoons. We also utilize obtained typhoon observation data to formulate better predictions of typhoon intensification. 

Research Applications

Cooperation with the Japan Coast Guard

As an application of developed research tools, the MBU has been contributing to i) improvement of drift prediction accuracy, and ii) increased sophistication of ocean tide models and ocean current simulations in the sea around Okinawa, through a cooperative agreement with the 11th Regional Coast Guard Headquarters, since March 2012. Ten years of successful cooperation resulted in a commendation from the Commandant of the Japan Coast Guard in 2022. Cooperation with the Japan Coast Guard will be accelerated in the coming decade.  

OIST was recently awarded a Center of Innovation grant by the Japan Science and Technology Agency. As one of the proposed projects of the Center of Innovation program, the MBU will develop an ocean monitoring framework around Okinawa, in collaboration with the Naha Coast Guard Office, which will provide its resources, including patrol vessels, helicopters, airplanes, and divers for the project, when possible. This new cooperative agreement will greatly enhance in situ observations for ongoing and future MBU research projects, while promoting marine-leisure safety around Okinawa, e.g., by providing rip current predictions.