Risk assessment of water quality in three North Carolina, USA, streams supporting federally endangered freshwater mussels (Unionidae)

Environmental Toxicology and Chemistry
By: , and 



Water quality data were collected from three drainages supporting the endangered Carolina heelsplitter (Lasmigona decorata) and dwarf wedgemussel (Alasmidonta heterodon) to determine the potential for impaired water quality to limit the recovery of these freshwater mussels in North Carolina, USA. Total recoverable copper, total residual chlorine, and total ammonia nitrogen were measured every two months for approximately a year at sites bracketing wastewater sources and mussel habitat. These data and state monitoring datasets were compared with ecological screening values, including estimates of chemical concentrations likely to be protective of mussels, and federal ambient water quality criteria to assess site risks following a hazard quotient approach. In one drainage, the site-specific ammonia ecological screening value for acute exposures was exceeded in 6% of the samples, and 15% of samples exceeded the chronic ecological screening value; however, ammonia concentrations were generally below levels of concern in other drainages. In all drainages, copper concentrations were higher than ecological screening values most frequently (exceeding the ecological screening values for acute exposures in 65-94% of the samples). Chlorine concentrations exceeding the acute water quality criterion were observed in 14 and 35% of samples in two of three drainages. The ecological screening values were exceeded most frequently in Goose Creek and the Upper Tar River drainages; concentrations rarely exceeded ecological screening values in the Swift Creek drainage except for copper. The site-specific risk assessment approach provides valuable information (including site-specific risk estimates and ecological screening values for protection) that can be applied through regulatory and nonregulatory means to improve water quality for mussels where risks are indicated and pollutant threats persist. ?? 2007 SETAC.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Risk assessment of water quality in three North Carolina, USA, streams supporting federally endangered freshwater mussels (Unionidae)
Series title Environmental Toxicology and Chemistry
DOI 10.1897/06-561R.1
Volume 26
Issue 10
Year Published 2007
Language English
Publisher Wiley
Contributing office(s) Columbia Environmental Research Center
Description 11 p.
First page 2075
Last page 2085
Country United States
State North Carolina
Other Geospatial Goose Creek, Swift Creek, Tar River basin
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
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