Spatial and temporal variations in copper speciation in San Diego Bay

Copper in estuaries has been an issue of concern for its toxicity to marine organisms. The ability to understand the processes that control copper speciation is a key factor towards achieving an improved assessment of the ecological risk it poses in the marine environment. Field measurements were made in August 2000, January 2001, May 2001, and September 2001 to provide a comprehensive view of circulation and water quality both spatially and temporally for the entire San Diego Bay. Rapid, underway, analysis of copper provided a unique, high-resolution view of total and labile copper species. The data show that total copper concentrations in San Diego Bay have been close to or above water quality criteria, increasing gradually from the lowest values in the mouth region (8 nM) to the innermost region (approximately 55 nM) with elevated concentrations existing in the Shelter Island and Commercial Basins. This work indicates that free copper activity lies between 10−11 and 10−13, and declines from the entrance to the head of San Diego Bay, even though the total copper concentration increases, a likely result of complexation with organic and particulate matter. Free copper measurements also show a seasonal dependence with the highest concentrations occurring 2 wk after a winter rain event in January 2001, reaching close to or above toxic levels in some locations.

[1]  W. Sunda.  The relationship between cupric ion activity and the toxicity of copper to phytoplankton , 1975 .

[2]  Jacques Buffle,et al.  In situ voltammetric measurements in natural waters: Future prospects and challenges , 1993 .

[3]  Dynamics of Peel-Harvey Estuary, Southwest Australia , 1990 .

[4]  Khris B. Olsen,et al.  Remote stripping electrode for in situ monitoring of labile copper in the marine environment , 1995 .

[5]  Antifouling paints: Use on boats in San Diego Bay and a way to minimize adverse impacts , 1988 .

[6]  R. Altmann,et al.  Complexation by natural heterogeneous compounds: Site occupation distribution functions, a normalized description of metal complexation , 1990 .

[7]  Stephen H. Lieberman,et al.  Measurement of copper and zinc in San Diego Bay by automated anodic stripping voltammetry , 1978 .

[8]  D. J. Mackey,et al.  Copper speciation and toxicity in Macquarie Harbour, Tasmania: an investigation using a copper ion selective electrode , 2001 .

[9]  P. Campbel.  Interactions between trace metals and aquatic organisms : A critique of the Free-ion Activity Model , 1995 .

[10]  D. B. Chadwick,et al.  Integrated Measurement Technologies For Monitoring The Marine Environment , 1991, OCEANS 91 Proceedings.

[11]  A. Zirino,et al.  Chemistry, toxicity, and bioavailability of copper and its relationship to regulation in the marine environment. Final report , 1998 .

[12]  Bruce D. Honeyman,et al.  Heterogeneous processes affecting trace contaminant distribution in estuaries: The role of natural organic matter , 1997 .

[13]  Bradley K Esser,et al.  At-sea high-resolution trace element mapping: San Diego Bay and its plume in the adjacent coastal ocean. , 2002, Environmental science & technology.

[14]  F. Morel,et al.  Copper sensitivity of Gonyaulax tamarensis 1 , 1978 .

[15]  F. Kestner,et al.  Estuaries : a physical introduction , 1974 .

[16]  D. J. Mackey,et al.  Response of the Jalpaite Membrane Copper(II) Ion-Selective Electrode in Marine Waters , 1997 .

[17]  V. Rich.  Personal communication , 1989, Nature.

[18]  B. Pejcic,et al.  The Influence of Diffusion Fluxes on the Detection Limit of the Jalpaite Copper Ion-Selective Electrode , 2002 .

[19]  M. Gardner,et al.  An investigation of copper complexation in the severn estuary using differential pulse cathodic stripping voltammetry , 1990 .

[20]  A. Zirino,et al.  Copper Concentration and CuII Activity in San Diego Bay , 1998 .

[21]  E. Duursma,et al.  Organic complexation and its control of the dissolved concentrations of copper and zinc in the Scheldt estuary , 1987 .

[22]  A. Flegal,et al.  Comparable levels of trace metal contamination in two semi-enclosed embayments: San Diego Bay and South San Francisco Bay , 1993 .

[23]  A. Zirino,et al.  Direct measurement of Cu(II)(aq) in seawater at pH 8 with the jalpaite ion-selective electrode , 1998 .

[24]  A. Zirino,et al.  Behavior and calibration of the copper(II) ion-selective electrode in high chloride media and marine waters , 1993 .

[25]  A. Zirino,et al.  Environmental Effects from In-Water Hull Cleaning of Ablative Copper Antifouling Coatings , 1994 .

[26]  Ignacio Rivera-Duarte,et al.  Modeling the mass balance and fate of copper in San Diego Bay , 2004 .

[27]  Kenneth W. Bruland,et al.  ANALYSIS OF SEAWATER FOR DISSOLVED CADMIUM, COPPER AND LEAD: AN INTERCOMPARISON OF VOLTAMMETRIC AND ATOMIC ABSORPTION METHODS , 1985 .

[28]  A. Zirino,et al.  Determination of copper in seawater by anodic stripping voltammetry using ethylenediamine , 1990 .

[29]  P. Seligman,et al.  Measurement of copper release rates from antifouling paint under laboratory and in situ conditions: implications for loading estimation to marine water bodies. , 2003, Marine pollution bulletin.

[30]  J. Hollibaugh,et al.  Seasonally Hypersaline Estuaries in Mediterranean-climate Regions , 1997 .