PARENT SESSION

HA10 Environmental Toxicology, Environmental Assessment
D135-136
8:00 AM - 12:00 PM, Thursday

() Preliminary results of a copper Water-Effect Ratio (WER) using Mytilus galloprovincialis in Shelter Island Yacht Basin, San Diego Bay.

Stransky, B.¹, Rudolph, J.¹, Bailey, Dr. H.¹, Boothe, Dr. P.², Moore, T. ³, ¹ Nautilus Environmental, San Diego, California, USA² Albion Environmental, College Station, Texas, USA³ Risk Sciences, Brentwood, Tennessee, USA

ABSTRACT- Levels of copper and its potential to cause toxicity in the Shelter Island Yacht Basin (SIYB), located in northern San Diego Bay, were investigated in January 2004. The study was conducted in response to a Total Maximum Daily Load (TMDL) requirement issued for copper in SIYB due to consistent levels exceeding the current EPA water quality criterion of 3.1 g/L. Total and dissolved copper concentrations were measured on surface and near-bottom water samples collected at five locations during high and low tides within the basin. All samples were collected using clean metals techniques including real-time filtration for dissolved copper. Copper analyses were performed by preconcentration ICP-MS (EPA Method 1640, ML 0.1 ppb). Water-effect ratios (WER) were determined for one centrally located station to develop a protective site-specific water quality criterion for copper. Total copper values ranged from 0.41 g/L outside the entrance of SIYB to 11.4 g/L in the inner portion of the harbor. Dissolved concentrations were similar, ranging from 0.23 to 9.1 g/L. In general, copper concentrations were the highest near the surface and at low tide. A total copper WER value of 2.3 was obtained for both high tide and low tide samples, resulting in a site-specific water quality criterion of 7.1 g/L. Further investigation is suggested to evaluate seasonal changes in copper levels and bioavailability.

Key words: water-effect ratio, copper, site-specific water quality criterion