Biogeochemistry

, Volume 10, Issue 3, pp 177–197

Transport of groundwater-borne nutrients from watersheds and their effects on coastal waters

  • Ivan Valiela
  • Joseph Costa
  • Kenneth Foreman
  • John M. Teal
  • Brian Howes
  • David Aubrey
Article

DOI: 10.1007/BF00003143

Cite this article as:
Valiela, I., Costa, J., Foreman, K. et al. Biogeochemistry (1990) 10: 177. doi:10.1007/BF00003143
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Abstract

Anthropogenic activities on coastal watersheds increase nutrient concentrations of groundwater. As groundwater travels downslope it transports these nutrients toward the adjoining coastal water. The resulting nutrient loading rates can be significant because nutrient concentrations in coastal groundwaters may be several orders of magnitude greater than those of receiving coastal waters. Groundwater-borne nutrients are most subject to active biogeochemical transformations as they course through the upper 1 m or so of bottom sediments. There conditions favor anaerobic processes such as denitrification, as well as other mechanisms that either sequester or release nutrients. The relative importance of advective vs. regenerative pathways of nutrient supply may result in widely different rates of release of nutrients from sediments. The relative activity of denitrifiers also may alter the ratio of N to P released to overlying waters, and hence affect which nutrient limits growth of producers. The consequences of nutrient (particularly nitrate) loading include somewhat elevated nutrient concentrations in the watercolumn, increased growth of macroalgae and phytoplankton, reduction of seagrass beds, and reductions of the associated fauna. The decline in animals occurs because of habitat changes and because of the increased frequency of anoxic events prompted by the characteristically high respiration rates found in enriched waters.

Key words

groundwater-borne nutrients shallow coastal ecosystem 

Copyright information

© Kluwer Academic Publishers 1990

Authors and Affiliations

  • Ivan Valiela
    • 1
  • Joseph Costa
    • 1
  • Kenneth Foreman
    • 1
  • John M. Teal
    • 2
  • Brian Howes
    • 2
  • David Aubrey
    • 2
  1. 1.Boston University Marine ProgramMarine Biological LaboratoryWoods HoleUSA
  2. 2.Woods Hole Oceanographic InstitutionWoods HoleUSA
  3. 3.Buzzards Bay Project, Coastal Zone ManagementMarion

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