title: Variations in macrobenthic community structures in relation to environmental variables in the Seto Inland Sea, Japan.
abstract: A data set of 425 sites investigated by the Ministry of the Environment in 2001-2005 was used to evaluate the current sediment situation and its effect on macrobenthic community structure in the Seto Inland Sea, Japan. Cluster analysis and principle component analysis of sediments using physico-chemical parameters revealed that total organic carbon, mud, sulfide contents, and oxidation-reduction potential were important parameters influencing macrobenthic population size and biodiversity. A total organic carbon of 1 mg g(-1) interval was highly negatively correlated with two biodiversity indices in the range of 1-20 mg g(-1). Overall, 42% of total sites were organically enriched with much lower macrobenthic population sizes and biodiversity, while 26% were characterized by sandy sediment with a high population size and high proportion of Arthropoda. Nemertea sp., Glycera sp., Notomastus sp. and Ophiophragmus japonicus were common macrobenthos, while Theora fragilis and Ptychoderidae were typical macrobenthos in organically enriched sediments.
authors.affiliation: Environmental Research and Management Center, Hiroshima University, 1-5-3, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8513, Japan. Electronic address: wataru@hiroshima-u.ac.jp.
authors.forename: Wataru
authors.initials: W
authors.lastname: Nishijima
authors.affiliation: Environmental Research and Management Center, Hiroshima University, 1-5-3, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8513, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Umehara
authors.affiliation: Environmental Research and Management Center, Hiroshima University, 1-5-3, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8513, Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Okuda
authors.affiliation: Graduate School of Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakai
mesh_terms: D000818:Animals; D001181:Arthropods / Q000502:physiology; D044822:Biodiversity; D016000:Cluster Analysis; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D007564:Japan; D011077:Polychaeta / Q000502:physiology; D011157:Population Dynamics; D025341:Principal Component Analysis
keywords: Biodiversity; Macrobenthos; Mud content; Sediment; TOC content; The Seto Inland Sea