Our research focus will be the Lagrangian connectivity of marine ecosystems and sea hazards due to natural or made-made Lagrangian material transports. Specifically, we plan to further develop and apply our new theory and schemes for (i) the study and quantification of biogeochemical coherent structures and Lagrangian connectivity of marine ecosystems, and (ii) the study and mitigation of sea hazards due to stochastic advection and Lagrangian material transports including marine contaminations and spills. To do so, we will employ and improve our schemes and computational systems for probabilistic ocean physical-biogeochemical modeling and forecasting, for predicting Lagrangian Coherent Structures and their uncertainties, and for Bayesian nonlinear Eulerian and Lagrangian data assimilation. We will build upon our experiences, especially those that involved large and collaborative research. Several of our recent MIT-MSEAS methods and software will be used and further developed for the Red Sea Initiative. Our long-term approach is to utilize these known information structures, for robust and accurate Bayesian forecasting, Lagrangian transport studies, data assimilation, and optimal planning of ocean sensing.