Tracing anthropogenic inputs to production in the Seto Inland Sea, Japan – A stable isotope approach

• Published in: Marine pollution bulletin Vol. 60; no. 10; pp. 1803 - 1809
• Main Authors: Miller, Todd W., Omori, Koji, Hamaoka, Hideki, Shibata, Jun-ya, Hidejiro, Onishi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2010; Elsevier
• Subjects: Acetal resins; Applied sciences; Carbon; Carbon - chemistry; Carbon Isotopes - chemistry; Commerce; Copepoda; Environmental Monitoring - methods; Eutrophication; Exact sciences and technology; Foods; Human Activities; Isotopes; Japan; Marine; Natural water pollution; Nitrogen - chemistry; Nitrogen Isotopes - chemistry; Pollution; Principal component analysis; Seawaters, estuaries; Seto Inland Sea; Stable isotopes; Surface water; Trophic; Waste Disposal, Fluid; Water Pollutants, Chemical - chemistry; Water pollution; Water Pollution, Chemical; Water treatment and pollution; Zooplankton; Asia; Inland Sea; Japan Sea; Japan; INW, Japan, Seto Naikai Sea; Seto Inland Sea; Trophic; Environmental factor; Particulate organic matter; Urban area; Runoff water; Nitrogen; Seto Inland Sea, Eutrophication; Eutrophication; Salinity; Trophic chain; Pollution; Marine; Food industry; Stable isotopes; Trend analysis; Surface water; Stream; Water pollution; Isotopes; Zooplankton; Principal component analysis; Anthropogenic factor
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2010.06.002

The Seto Inland Sea (SIS) receives waste runoff from ∼24% of Japan’s total population, yet it is also important in regional fisheries, recreation and commerce. During August 2006 we measured carbon and nitrogen stable isotopes of particulate organic matter (POM) and zooplankton across urban population gradients of the SIS. Results showed a consistent trend of increasing δ15N in POM and zooplankton from the western to eastern subsystems of the SIS, corresponding to increasing population load. Principal components analysis of environmental variables indicated high positive loadings of δ15N and δ13C with high chlorophyll-a and surface water temperatures, and negative loadings of low salinities related to inputs from large rivers and high urban development in the eastern SIS. Anthropogenic nitrogen was therefore readily integrated into the SIS food web from primary production to copepods, which are a critical food source for many commercially important fishes.