Researchers in aquatic sciences have long been interested in describing temporal and biological heterogeneities at different observation scales. During the 1970s, scaling studies received a boost from the application of spectral analysis to ecological sciences. Since then, new insights have evolved in parallel with advances in observation technologies and computing power. In particular, during the last 2 decades, novel theoretical achievements were facilitated by the use of microstructure profilers, the application of mathematical tools derived from fractal and wavelet analyses, and the increase in computing power that allowed more complex simulations. The idea of publishing the Handbook of Scaling Methods in Aquatic Ecology arose out of a special session of the 2001 Aquatic Science Meeting of the American Society of Limnology and Oceanography. The edition of the book is timely, because it compiles a good amount of the work done in these last 2 decades. The book is comprised of three sectionsc measurements, analysis, and simulation. Each contains some review chapters and a number of more specialized contributions. The contents are multidisciplinary and focus on biological and physical processes and their interactions over a broad range of scales, from micro-layers to ocean basins. The handbook topics include high-resolution observation methodologies, as well as applications of different mathematical tools for analysis and simulation of spatial structures, time variability of physical and biological processes, and individual organism behavior. The scientific background of the authors is highly diverse, ensuring broad interest for the scientific community.