A laboratory assessment of the toxicity of urban runoff oh the fathead minnow (pimephales promelas)

Abstract

The early life stage effects of urban runoff (rain and snowmelt) on hatching, growth and survival of the fathead minnow (Pimephales promelas) was assessed in static and flow‐through systems. The data indicate a Maximum Allowable Toxicant Concentration (MATC) and a reduction of growth to 50% of controls at 28% and 60% runoff, respectively. Hatchability and average lengths were not as sensitive indicators of stress as millimeters produced per treatment. The data indicate a maximum toxicity in the fall which coincided with the reported drop in macroinvertebrate diversity during the same period, when untreated runoff events can contribute up to 1/4 of the river flow.

Key words:

• urban runoff
• bioassay
• early stage toxicity
• fathead minnow