This book is for people that want to know more about the oceans, its inhabitants, and the ocean processes. The main text of the book describes individual marine ecosystems including offshore open water, benthic, nearshore tropical, nearshore temperate, and nearshore arctic ecosystems. Discussed are some of the basic ecological principles found operating in these and other ecosystems. Examples of specific research efforts are described to illustrate how scientists go about uncovering information about life in the oceans. The examples are drawn from parts of the National Marine Sanctuary Program to emphasize the need for conservation of selected marine areas in the United States. (CW)