MP13 Aquatic Ecotoxicology
Monday, 14 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(RUD-1117-867855) Stormwater Toxicity Evaluation of Major Rivers Entering the Southern California Bight.

Rudolph, J¹, Stransky, B¹, Bailey, H¹, Bay, S², Greenstein, D², ¹ Nautilus Environmental, San Diego, CA, USA² Southern California Coastal Water Research Project, Westminster, CA, USA

ABSTRACT- In an effort to assess the overall ecological condition of the Southern California Bight, this project was designed to address the magnitude and persistence of toxicity in nine river discharges into Southern California coastal waters using gametes of the purple urchin Strongylocentrotus purpuratus. Magnitude of runoff toxicity was determined by collecting and testing samples from each river near its ocean discharge point. Samples were collected during three storm events (≥0.25 in.), which occurred on February 23, 2004 (eight rivers), February 12, 2005 (two rivers), and March 24, 2005 (seven rivers). Persistence of toxicity following a storm event was evaluated by testing samples collected one, three, and five days following each storm. Sample holding time effects were evaluated by re-testing selected samples on multiple occasions after collection. Test results and data analyses (e.g., among rivers and between years) are presented. Toxicity was observed in several rivers, but the degree of toxicity, when present, often varied substantially between samples collected immediately following each storm, between storm events, and during sample holding.

Key words: stormwater, urchins, river, temporal