Ostracodes (Class Crustacea) have long held place as one of the major groups of useful microfossils in stratigraphy, evolutionary biology, and paleoecology. Ranging in time from the Ordovician Period to the present day, these microscopic crustaceans have proven time and time again their value in applied geology and environmental studies. The non-marine ostracodes of the late Cenozoic Era (including modern populations) have been shown to be particularly useful in the fields of paleoclimate and paleohydrology, and much of that success can be traced to the research efforts of Rick Forester of the United States Geological Survey (USGS). Rick passed away quite suddenly in March of 2014, following his early retirement from the USGS in 2005. This issue of Hydrobiologia will provide the reader with a view of the scope of his research interests, which were primarily in the areas of applied uses of ostracode records to solve problems in late Cenozoic paleoclimate and paleohydrology in North America. He frequently worked with specialists in diatoms and pollen, as well as hydrologists, hydrogeologists, and isotope geochemists, and these papers reflect his interests in these areas. His astonishingly extensive knowledge of geology, physical chemistry, statistics, and paleontologymade him a unique figure in the geosciences, and his loss is deeply felt by his many colleagues. Rick studied modern and Late Cenozoic distributions of non-marine ostracodes for their value in solving paleoclimatic and paleohydrologic problems. He was the founder of the public access database ‘‘NANODe’’ (www.kent.edu/nanode), a non-marine ostracode biogeographical database with species and associated hydrochemical data from about 600 sites in the United States, now also available through the public access multi-proxy database Neotoma (www. neotomadb.org). In paleoclimatic and paleoenvironmental research, a biological ‘‘proxy’’ is a taxon with known modern environmental tolerances and biogeographical distribution, and which also has a significant Guest editors: Alison J. Smith, Emi Ito, B. Brandon Curry & Patrick De Deckker / Multidisciplinary aspects of aquatic science: the legacy of Rick Forester