Abstract
Long‐term changes in the demersal assemblage, including both fishes and invertebrates, in Tokyo Bay, Japan, were examined between 1977 and 1995. A total of 255 species were collected, of which 113 were regarded as representative in terms of occurrence. Multivariate analyses of the representative species showed that fluctuations in the catch were related to three periods that reflected changes in relative abundance and species composition. In particular, mantis shrimp, Oratosquilla oratoria (de Haan), whipfin dragonet, Repomucenus valenciennei (Temminck & Schlegel), and marbled sole, Pleuronectes yokohamae Günther, showed high dominance in the mid‐1980s. Discriminant analysis suggested that the demersal assemblage changed synchronously with environmental conditions. Causes of the temporal changes in the demersal assemblage in relation to variations in environmental factors are discussed.