His focus is on fish ecology, especially as it relates to early life history dynamics in relation to large riverine-floodplain systems. Thorpe has concentrated effort on documenting the environmental phenomena that structure both adult and larval assemblages in warm- and cold-water systems in North America. Thorpe is interested in freshwater invertebrate communities, limnology, and stream ecosystems. He has also worked extensively in the North Pacific Ocean, Gulf of Mexico, and the Atlantic Ocean as a fisheries biologist. These projects have included examining coastal fish populations and by-catch and conducting open surveys for ichthyoplankton.