Seasonal changes in infaunal community structure in a hypertrophic brackish canal: Effects of hypoxia, sulfide, and predator–prey interaction. (July 2015)

• Record Type: Journal Article
• Authors: Kanaya, Gen; Nakamura, Yasuo; Koizumi, Tomoyoshi; Yamada, Katsumasa
• Is Part Of: Marine environmental research. Volume 108(2015:Jul.)
• Page Start: 14
• Page End: 23
• Publication Date: 2015-07
• Subjects: Eutrophication -- Oxygen depletion -- Macrozoobenthos -- Trophic interaction -- Stable isotopes -- Succession -- Sulphide; Marine pollution -- Environmental aspects -- Periodicals; Marine ecology -- Periodicals; Mer -- Pollution -- Aspect de l'environnement -- Périodiques; Écologie marine -- Périodiques; Electronic journals; 577.705
• DOI: 10.1016/j.marenvres.2015.04.006
• Languages: English
• ISSNs: 0141-1136

Abstract

Abstract: We conducted a one-year survey of macrozoobenthic community structure at 5 stations in a eutrophic canal in inner Tokyo Bay, focusing on the impacts of hypoxia, sediment H2 S, and species interaction in the littoral soft-bottom habitats. Complete defaunation or decreasing density of less-tolerant taxa occurred under hypoxia during warmer months, especially at subtidal or sulfidic stations; this was followed by rapid recolonization by opportunistic polychaetes in fall–winter. Sedimentary H2 S increased the mortality of macroinvertebrates under hypoxia or delayed population recovery during recolonization. The density of several polychaetes (e.g., Pseudopolydora reticulata ) declined in winter, coincident with immigration of the predator Armandia lanceolata . This suggests that absence of A. lanceolata under moderate hypoxia enabled the proliferation of prey taxa. We conclude that oxygen concentration, sediment H2 S, and hypoxia-induced changes in species interactions are potential drivers for spatiotemporal changes in macrozoobenthic assemblage structure in hypoxia-prone soft-bottom communities. Highlights: Seasonal changes in infaunal assemblage were analyzed in a eutrophic brackish canal. Hypoxia, sediment H2 S level, and species interaction were major determinant factors. H2 S accelerated mortality under hypoxia and/or delayed population recovery. Drastic changes in dominant taxa occurred in winter as DO condition recovered. Absence of infaunal predator under hypoxia may allow the proliferation of prey taxa.