1. A system for mapping a thermocline in a body of fluid, comprising: at least one thermocline detection and monitoring module (TDMM); a persistent data storage module; and a plurality of distributed sensors, including intelligent sensors, connected with the at least one thermocline detection and monitoring module and the persistent data storage module by one or more control-level programming and communication methods, wherein the at least one thermocline detection and monitoring module is configured to monitor the thermocline at sampling intervals to collect and fuse measurement data from the plurality of sensors to capture thermocline changes as events, correlate measurement data and events, store measurement data in the persistent data storage module along with previously acquired measurement data for comparison and tracking, characterize the thermocline as a function of spatial location, depth, and time, create and maintain reports that describe the thermocline characteristics, status, trends, and provide multimodal notifications of events to different users.