How does benthic use and recycling of nutrients
and organic matter vary with changes in water fluxes and the quality
and quantity of organic matter inputs?
The role of sediments in an estuarine system
The benthos is a critical component of shallow water estuarine and coastal
marine ecosystems. On a global basis 30-50% of primary production occurs
in the continental margin and much settles to the bottom of coastal
systems. The coastal zone is a conduit for all organic matter washed
from land and benthic sediments are the site where most of this material
is deposited (Smith and Hollibaugh 1993). The extent to which organic
matter reaching the bottom is reoxidized, denitrified or buried affects
the productivity and quality of the overlying water.
Sediments play an important role in organic matter degradation and
nutrient recycling in aquatic ecosystems. During the decomposition of
organic matter, oxygen and other terminal electron acceptors are consumed
and inorganic nutrients are remineralized. With up to 75% of phytoplankton
nutrient requirements supplied from the benthos (Billen 1978, Nixon
1981), spatial and temporal patterns of benthic nutrient regeneration
may be important in regulating spatial and temporal patterns of productivity
in overlying water.
Rates of benthic metabolism and nutrient cycling in the Parker and Rowley Rivers of the Plum Island Sound estuary.
Sediment porewater nutrient, sulfide, pH, and alkalinity, sediment redox, and bulk sediment carbon, nitrogen, chlorophyll a and phaeopigments.
||Sediment organic carbon
content at four sites in the Parker River Plum Island Sound estuarine