Ted Pietsch is Professor Emeritus in the School of Aquatic and Fishery Sciences, and Curator Emeritus of Fishes at the Burke Museum of Natural History and Culture, University of Washington. He is a Fellow of the California Academy of Sciences, the Linnean Society of London, the American Association for the Advancement of Science, the University of Washington Teaching Academy, and an Honorary Member of the Ichthyological Society of Japan.

He is interested primarily in marine ichthyology, especially the biosystematics, zoogeography, reproductive biology, and behavior of deep-sea fishes. As former curator of the Fish Collection of the University of Washington Burke Museum of Natural History (UWFishCollection.org), he is also interested in natural history collections and collection building, and in biotic survey and inventory, the latter best exemplified by a decade-long series of expeditions to collect plants and animals on the islands of the Kuril Archipelago in the Russian Far East. He also led a two-year floral and faunal survey of the Elwha River Valley on the Olympic Peninsula in Western Washington State. A book on the Fishes of the Salish Sea: Puget Sound and the Straits of Georgia and Juan de Fuca will soon be published by the UW Press.

He has also published extensively on the history of science, especially the history of ichthyology. Among the latter are works on the French comparative anatomist Georges Cuvier (1769-1832) and his 22-volume Histoire Naturelle des Poissons (1828-1849); bookdealer, publisher, and secret agent Louis Renard (1678/79-1746) and his Fishes, Crayfishes, and Crabs; the unpublished manuscripts of the seventeenth-century explorer-naturalist Charles Plumier (1646-1704); and on the history of natural history collection-building. His current efforts are directed toward an annotated, illustrated, English translation of Cuvier's five-volume  Histoire des Sciences Naturelles, depuis leur Origine jusqu'a nos Jours (1841-1845), the first three volumes of which have already been published.