Chapters 1 through 4 set the stage for the trend represented in this book; a trend in which more and more of the complexity of real-world systems is recognized and involved in management. The chapters of this section typify the sophistication brought to the process of science in support of management as it is currently implemented in many parts of the world. This sophistication often involves numerous elaborate models and complicated management plans. Such approaches exemplify a focus on ecological processes (e.g., predator–prey interactions, competition, trophic dynamics, and food webs) in which we humans inject ourselves by harvesting fish. Much of this work involves overt recognition of the complexity of natural systems and substantiates our understanding of complexity as a fundamental principle. Complexity is recognized, for example, in lists representing the numerous species with populations in ecosystems affected by human activities such as commercial fishing, pollution, and changes in acidity. Inherent to the factors important to the structure and function of ecosystems are environmental dynamics involving temperature, the circulation of currents, and a wealth of other physical and chemical factors. Such work is crucial to substantiating a variety of principles that are fundamental to progress toward more holistic management.