<p>Izembek Lagoon, located on the north side of the Alaska Peninsula in the Bering Sea, is designated as critical molting and wintering habitat for the Alaska-breeding population of Steller’s eiders (<i>Polysticta stelleri</i>), listed Threatened under the United States Endangered Species Act. During the nonbreeding season, the lagoon also hosts a large proportion of the population of Steller’s eiders that breed along the coast of north-eastern Russia. Since the early 1980s, numbers of Steller’s eiders have declined in their known nonbreeding range in the southern Bering Sea, especially in Izembek Lagoon during their remigial molt in the fall. We replicated a 1998 benthic sampling effort in fall of 2019 to understand if prey availability has become less favorable to Steller’s eiders during their molt in Izembek Lagoon. We compared forage conditions based on overall biomass (g/m²) and size (mm) of organisms belonging to the marine benthic groups: Bivalvia, Gastropoda, Crustacea, and Polychaeta between the two time points. The results are compatible with a community shift in these taxa with an associated change in their biomass and size. There was a significant reduction in bivalve and crustacean biomass in 2019 as compared to 1998, and bivalves and gastropods were significantly smaller. Contemporary foraging conditions at Izembek Lagoon may be less favorable for supporting historical numbers of Steller’s eiders during an energetically taxing time in their annual cycle. Understanding habitat needs of molting Steller’s eiders will be increasingly important for their recovery if previously significant locations become unsuitable in the future.</p>