Copper toxicity to larval stages of three marine invertebrates and copper complexation capacity in San Diego Bay, California.
Temporal and spatial measurements of the toxicity (EC50), chemical speciation, and complexation capacity (Cu-CC) of copper in waters from San Diego Bay suggest control of the Cu-CC over copper bioavailability. While spatial distributions of total copper (CuT) indicate an increase in concentration from the mouth toward the head of San Diego Bay, the distribution of aqueous free copper ion (Cu(II)aq) shows the opposite trend. This suggests that the bioavailability of copper to organisms decreases toward the head of the bay, and is corroborated by the increase in the amount of copper needed to reach an EC50, observed for larval stages of three marine invertebrates (Mediterranean mussel, Mytilus galloprovincialis, sand dollar, Dendraster excentricus, and purple sea urchin, Strongylocentrotus purpuratus), and by the increase in Cu-CC heading into the head of the bay. The amount of Cu(II)aq required to produce a 50% reduction in normal larval development (referred to here as pCuTox,) of the mussel, the most sensitive of the three marine invertebrates, was generally at or above approximately 1 x 10(-11) mol L(-1) equivalents of Cu (i.e., pCuTox approximately 11 = -(log [Cu(II)aq])). These results suggest that the copper complexation capacity in San Diego Bay controls copper toxicity by keeping the concentration of Cu(II)aq at nontoxic levels.
Rivera-Duarte
Ignacio
I
SSC-San Diego, Code 2375, San Diego, California 92152-6325, USA. ignacio.rivera@navy.mil
Rosen
Gunther
G
Lapota
David
D
Chadwick
David B
DB
Kear-Padilla
Lora
L
Zirino
Alberto
A
D000818:Animals; D001682:Biological Availability; D049872:Bivalvia; D002140:California; D003300:Copper / Q000737:chemistry* / Q000633:toxicity*; D004784:Environmental Monitoring; D007814:Larva; D012617:Sea Urchins; D014873:Water Pollutants / Q000633:toxicity*
D014873:Water Pollutants; D003300:Copper