The purpose of this book is to reveal the wonderful stories of aquaticscience to a mainstream audience and convey a deeper understanding ofrivers. Learning science always works best with an interactive, hands-onapproach. Thus this book also aims to enable interactive lotic science.Unprecedented advances in data technology are driving novel innovationsin every branch of science, especially environmental sciences. For example,devices smaller than a fist can track temperature, oxygen concentrations, orsalinity levels every minute and send data to scientists over wirelessnetworks in real time. Although such tools might not prove useful to mostnon-scientists, others are fun, informative, and accessible to riveraficionados willing to explore tools online. Agencies tasked with managingecosystems support web applications that allow anyone to map a watershed,track flow levels, or identify organisms living within just about any loticsystem, large or small. Wherever possible, this book briefly introduces suchtools in instructional sidebars.