Title

COMPARISON OF NUTRIENT AND TRACE-ELEMENT DISTRIBUTIONS IN THE DELTA AND SHELF OUTFLOW REGIONS OF THE MISSISSIPPI AND ATCHAFALAYA RIVERS

Authors

AM SHILLER

Document Type

Article

Publication Date

9-1-1993

Department

Marine Science

Abstract

Nutrient and trace element distributions were determined in the outflow region of the Mississippi and Atchafalaya rivers during high river discharge. This outflow region can be divided into two physiographic areas: the broad, shallow Louisiana Shelf off the Atchafalaya River and the narrow shelf off the Mississippi Delta. The physiographic differences between these two areas lead to observable differences in the chemical distributions. During high discharge conditions, nutrient depletion occurs at lower salinities on the Louisiana Shelf, relative to the delta outflow plume, and significant uptake of nickel and cadmium is apparent in these shelf waters, too. Important factors that appear to connect the physiographic to the chemical include the fate of the fluvial suspended load, rates of mixing, and the extent of productivity supported by recycled nutrients. The results suggest that the Mississippi-Atchafalaya outflow region may provide a natural laboratory for examining the possible effects of sea-level change on the biogeochemistry of estuarine and coastal environments.

Publication Title

ESTUARIES

Volume

16

Issue

3A

First Page

541

Last Page

546