Abstract: Modern marine ecology is a rapidly developing discipline characterized by a high degree of interdisciplinary integration of expertise from biology, environmental science, geography, fisheries, and other related fields. Over more than half a century of development, it has undergone a fundamental transformation from the predominantly descriptive “nature-oriented” approach of traditional marine ecology to a “human-sea coupled system” paradigm. Its theoretical foundation is centered on hierarchical integration and process coupling, marking a shift from analyses of single-species distribution or single-factor impacts toward a comprehensive, multidimensional, multi-level, and cross-spherical exploration framework. The discipline has established a multi-scale research system spanning from molecules and cells to individuals, populations, and ecosystems, with the overarching aim of elucidating the structure, function, dynamic patterns, and regulatory mechanisms of marine ecosystems across multiple spatiotemporal scales. The developmental trajectory of the field exhibits the typical characteristics of deepening micro-level investigation, expanding macro-level scope, and strengthening applied research orientation. With the rapid advancement of novel marine observation technologies, molecular biological techniques, and big data applications, the research perspectives of this discipline have been continuously broadened. New concepts and hypotheses have been progressively proposed, and the research paradigm has consequently undergone a transformation. This paper systematically reviews the basic theoretical framework and developmental trajectory of modern marine ecology at multiple levels. It selects a number of representative core concepts and emerging fields, including marine molecular adaptation, the microbial carbon pump, the microbial food web, trophic cascade effects, ecological tipping points, ecological resilience, deep-sea chemosynthetic ecosystems, and marine carbon sinks, and elaborates on their scientific connotations, research status, and unresolved issues. In addition, it summarizes the prevailing academic perspectives both domestically and internationally, identifies current bottlenecks in disciplinary development, and outlines future priority research directions, with the aim of providing a useful reference for further refining and advancing the theoretical system of the discipline.

Key words: Modern marine ecology, Theoretical framework, Marine molecular adaptation, Microbial food web, Microbial carbon pump, Trophic cascade effect, Ecological tipping point, Deep-sea chemosynthetic ecosystem, Marine carbon sequestration