hempel studied biology and geology at the universities of mainz and heidelberg. in 1952 he gained his ph.d. with a study on the energetics of grasshopper jumps from heidelberg university. he then went on to work as a scientific assistant at various research institutes in wilhelmshaven, helgoland, and hamburg, where he habilitated with a thesis on the ecology of fry in 1963. four years later, he became a professor at the university of kiel at the institute of marine sciences (institut für meereskunde kiel), where he remained director of the department of fisheries biology for the next 14 years and served as acting director of the institute from 1972 to 1976. in 1981, he helped found the alfred wegener institute for polar and marine research in bremerhaven whereupon he became the institution's first director. in the same year, he also became director of the institute for polar ecology at the university of kiel. in bremerhaven, he initiated the construction of the polar research vessel pfs polarstern. in 1992, he became the first director of the then newly founded center for marine tropical ecology at the university of bremen. hempel retired in 1994.