Demographic differences in Bythotrephes longimanus populations are often used to infer the prevalence of different environmental conditions that regulate their population. We collected seasonal data on Bythotrephes abundance and life history at a nearshore (15 m), transitional (45 m) and offshore site (110 m) in Lake Michigan during 2007–2016. Due to higher fish predation requirements and the small size of zooplankton prey at the nearshore site, we expected life-history attributes of Bythotrephes would differ compared to the deeper sites, but body and spine length, percent of growth allocated to the spine, and brood size were similar among depths. Owing to higher abundances in the offshore, the ratio of consumption requirements: prey production (C:P) was relatively high throughout the growing season at the deepest site compared to the two shallower sites, where C:P was generally only high in the fall. However, reproductive characteristics of Bythotrephes at the offshore site did not reflect a food-limited population compared to the other two sites. Rather the proportion of barren females was higher at the nearshore site than those at the deeper sites, leading to much lower birth rates and abundance of Bythotrephes at the shallow site compared to the deeper sites.