Environmental and Water Quality Operational Studies. Water Quality, Macroinvertebrates, Larval Fishes, and Fishes of the Lower Mississippi River - A Synthesis.

摘要

This is a synoptic report describing water quality and composition and distribution of benthic macroinvertebrates, larval fishes, and fishes within a 62-mile reach of the lower Mississippi River. Major water quality differences among habitates were related to the presence or absence of current. Continual flow and high turbulence in lotic habitats such as the main channel and permanent secondary channel resulted in high suspended solids concentrations, high turbidites, low water transparencies, and low light penetration. Such physical characteristics resulted in low algal biomass, more stable pH and dissolved oxygen levels, and the constant availability of algal nutrients. In contrast, lentic areas, such as the abandoned channel at most river stages, and the dike fields at low flows, had relatively lower suspended solids and increased water clarity. This resulted in high algal biomass, higher pH readings, frequent dissolved oxygen supersaturation in surface waters, and nutrient depletion in slack-water areas.