Toxicity of Dry Weather Flow from the Santa Monica Bay Watershed

Abstract

A significant source of contaminants to Santa Monica Bay is the daily <br /><br />discharge of 10-25 million gallons of urban runoff from approximately 70 storm <br /><br />drains. Research conducted in 1990-93 examined the toxicity of dry weather flow <br /><br />from Ballona Creek and three other drains discharging into Santa Monica Bay. <br /><br />Toxicity tests were conducted using sensitive life stages of purple sea urchins, red <br /><br />abalone, and giant kelp. Spatial and temporal variations in toxicity were observed. <br /><br />Sea urchin sperm and abalone embryos were more sensitive than kelp spores, <br /><br />with toxic effects produced by >5.6% dry weather flow. Preliminary toxicity <br /><br />identification evaluations indicated that the constituents causing toxicity in dry <br /><br />weather flow are variable.