Nutrient Biogeochemistry of the Coastal Zone
T. D. Jickells
REVIEW
The coastal seas are one of the most valuable and vulnerable of
Earth's habitats. Significant inputs of nutrients to the coastal zone
arrive via rivers, groundwater, and the atmosphere. Nutrient fluxes
through these routes have been increased by human activity. In
addition, the N:P:Si ratios of these inputs have been perturbed, and
many coastal management practices exacerbate these perturbations. There
is evidence of impacts arising from these changes (in phytoplankton numbers and relative species abundance, and deep-water oxygen declines)
in areas of restricted water exchange. Elsewhere, the nutrient fluxes
through the coastal zone appear to be still dominated by large
inputs from the open ocean, and there is little evidence of
anthropogenic perturbations.
The author is in School of Environmental Sciences, University of
East Anglia, Norwich, NR4 7TJ, UK. E-mail: t.jickells{at}uea.ac.uk