Estuaries

, Volume 19, Issue 2, pp 488–499

A sediment chronology of the eutrophication of Chesapeake Bay

  • Jeffrey C. Cornwell
  • Daniel J. Conley
  • Michael Owens
  • J. Court Stevenson
Article

DOI: 10.2307/1352465

Cite this article as:
Cornwell, J.C., Conley, D.J., Owens, M. et al. Estuaries (1996) 19: 488. doi:10.2307/1352465

Abstract

Chesapeake Bay sediments were examined for biogeochemical evidence of eutrophication trends using two mesohaline sediment cores. Measurements of 210Pb geochronology and sediment profiles of organic carbon, nitrogen, organic phosphorus, inorganic phosphorus, and biogenis silica (BSi) were used used to develop temporal concentration trends. Recent sediments have 2–3 times as much organic carbon and nitrogen as sediments from 80 to 100 yr ago, but the increases result from both changes in organic matter deposition and time-dependent changes in organic matter decomposition rates. Despite increases in phosphorus loading, no major changes in phosphorus concentration were noted throughout most of the century; anthropogenic phosphorus deposition, though not evident in sulfidic mid-bay sediments, must occur in more oxidizing sediment environments in both the northern and southern bays. Temporal trends in BSi concentrations are much less evident and the lack of substantial increases in this century suggest that BSi inputs may be capped by late spring-summer Si limitation.

Copyright information

© Estuarine Research Federation 1996

Authors and Affiliations

  • Jeffrey C. Cornwell
    • 1
  • Daniel J. Conley
    • 1
  • Michael Owens
    • 1
  • J. Court Stevenson
    • 1
  1. 1.Horn Point Environmental Laboratory University of Maryland SystemCenter for Environmental and Estuarine StudiesCambridge