title: Temporal changes in carbon and nitrogen stable isotope ratios of macrozoobenthos on an artificial tidal flat facing a hypertrophic canal, inner Tokyo Bay.
abstract: Temporal changes in benthic food web structure were analyzed in an artificial tidal flat in inner Tokyo Bay, Japan, using carbon and nitrogen stable isotope ratios (δ(13)C and δ(15)N). Microphytobenthos were the most important food sources of macrozoobenthos, due to high microphytobenthic biomass on the tidal flat, while phytoplankton in canal water (canal POMPP), terrestrial materials from urban surface runoff (canal POMTM), and marsh plants were less important. Dietary contribution of microphytobenthos was highest in April to June, while decreased towards December owing to the supply of canal POMPP and canal POMTM following red tides and heavy rainfall events in summer to fall. Temporal changes in δ(15)N (Δδ(15)N) of consumer corresponded well to the (15)N-enrichment in canal POMPP in summer. A meta-analysis showed that the consumer-Δδ(15)N was considerably larger in inner Tokyo Bay than those in other estuaries, which may be a specific characteristic of benthic food web in highly urbanized estuaries.
authors.affiliation: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. gen@nies.go.jp
authors.forename: Gen
authors.initials: G
authors.lastname: Kanaya
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Koizumi
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Yamada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Koshikawa
authors.forename: Ayato
authors.initials: A
authors.lastname: Kohzu
authors.forename: Hideaki
authors.initials: H
authors.lastname: Maki
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000378:metabolism*; D002247:Carbon Isotopes; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D009587:Nitrogen Isotopes; D012623:Seawater / Q000737:chemistry*; D014041:Tokyo; D014873:Water Pollutants / Q000032:analysis / Q000378:metabolism*; D014876:Water Pollution / Q000706:statistics & numerical data*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D014873:Water Pollutants