In Chapter 1 the methodological principles of systemization and visualization of multidimensional ecological information for its operational dissemination among potential users are stated. Their realization results in creation of the geographic-and ecologic model of marine basin as an information base for diagnosis of the marine ecosystem state, estimation of consequences of economic activity, and modelling of its changes with the use of mathematical tools. In Chapter 2 the geographic-and-ecological aspects of mathematical modelling of marine ecosystems, the possibilities and peculiarities of the most adequate models, the Russian hydrodynamic model of oil spills SPILLMOD and hydroecological model of organogenic compound transformation in the sea, are investigated. In the following six Chapters the examples of practical realization of geographic-and-ecological (as information source) and mathematical (as computing apparatus) modelling at the investigations of specific ecological problems associated with consequences of natural hazards and economic activity on aquatory and within the whole Black Sea basin are given.