Water and sediment quality at mussel (Unionidae) habitats in the Ochlockonee River of Florida and Georgia

Abstract

Water chemical analyses, porewater and whole sediment chemical analyses, and pore- water and whole sediment toxicity testing were performed as part of a combined effort between the US Fish and Wildlife Service and the US Geological Survey. These analyses were used to predict impaired stream sites that may impede a healthy natural riverine community. The analyses also revealed differences between sites that currently support and those that have ceased to support mus- sel populations. We estimated risk scores for the riverine community based on water and sediment characteristics. To identify and rank habitat in need of restoration, the risk estimation was derived by comparing collected data to water quality standards, sediment quality guidelines and toxicity test controls. High-risk scores often coincided with areas that no longer support historical freshwater mussel populations. Based on the data collected, factors thought to impede the existence of a natural riverine community included: sediment toxicity (porewater and whole sediment), sediment lead, sediment manganese, sediment ammonia, and low dissolved oxygen. KEY