# Effects of copper on marine invertebrate larvae in surface water from San Diego Bay, CA Gunther Rosen 1 

# , Ignacio Rivera-Duarte 1 

# , Lora Kear-Padilla2

# ,

and Bart Chadwick 1 1 

# SPAWAR Systems Center San Diego 53475 Strothe Rd., San Diego, CA 92152
- 6325 2

# Computer Sciences Corporation, San Diego, CA 92110

# Background Copper sources in San Diego Bay  Industrial discharges  Storm water 

##  Non
-point source runoff  Ship discharges (e.g. cooling water)  Flux from sediment  Antifouling hull coatings (67% of total load)  Navy, commercial, and civilian hull leaching 

###  Navy and civilian hull cleaning 

# Effect in the bay  Copper concentrations approach or exceed chronic water quality criterion (WQC) in some parts of the bay

# Background  Exceedance of current national chronic Cu WQC (3.1 μg/L dissolved) not necessarily indicative of bioavailability or toxicity to biota  WQC derived from toxicity studies with laboratory water (e.g. Narragansett Bay, RI) with lower ability to complex Cu 

#  EPA acknowledges that site
- specific water quality characteristics can dramatically affect metal speciation and exposure  WER procedure current acceptable method for deriving site


# specific criteria (U.S. EPA 1994)

# Study Site: San Diego Bay
 Six surveys over two -year period  Samples collected from 27 

### “boxes” along the axis of the bay.  Samples were composites of research vessel’s track within each box (~ 1 km)  Clean sampling techniques  Boxes 1 - 17 = North Bay Boxes 18 -27 = South Bay 

# N Coronado Bridge

# Experimental Design
 Standard EPA methods for short-term tests using west coast marine organisms (USEPA 1995)  Spike surface water samples with at least 8 copper concentrations 

## (range = 3
–50 μg/L)  Negative Control = site water with no added copper  Positive Control = copper reference toxicant test in lab water  Endpoint = normal larval development  EC 50 

## (concentration affecting 50% of test population) calculated with 

## Probit method (ToxCalc)

# Mytilus galloprovincialis Mediterranean mussel Strongylocentrotus purpuratus Purple sea urchin Dendraster excentricus Sand dollar 

# Species testedPolychaete worm Florida pompano Common rangia Mummichog Green crab Copepod Sheep head Spot Top smelt Copepod Polychaete worm Mysid Polychaete worm Tidewater silverside Copepod Mysid Atlantic silverside Inland silverside Winter flounder Red abalone American lobster Copepod Black abalone Dungeness crab Soft - shell clam Copepod Eastern oyster Sea urchin Pacific oyster Coot clam Summer flounder Blue mussel 0 10 20 30 40 50 60 70 80 90 100

1 10 100 1,000



## Dissolved copper concentration (μg L - 1 

## ) Cumulative probability (%)

Acute toxicity data Cumulative probability fit Lower 95% confidence limit Upper 95% confidence limit

3.1 4.8 EPA

dissolved copper acute WQC EPA dissolved copper chronic WQC 

# Appropriate Test Species

• Test species sensitivity should be close to criterion concentration

# Water Effect Ratio Procedure

Lab Water (SIO) Site Water Simultaneous Toxicity Tests with Copper

WER = EC 50 

# in Site Water  EC 50 

# in Lab Water 

# Site
- specific Criterion = WER X WQC Purpose : Account for differences in bioavailability between site and laboratory water for site
- specific criterion development

# Control Development  20 sites in the bay tested 1
-4 times 

#  93 ± 5% normal larval development in controls across all test sites and sampling events  Indicative of no 

# ambient toxicity in the bay Box # Lab 1 2 3 4 5 6 7 9 11 12 13 14 15 16 18 21 23 25 26 27 Normal Control Development (%)

0 20 40 60 80 100 120

# Copper Additions

 Selected mussel data from survey on February 27, 

### 2002  Higher Cu concentrations required for samples towards head of bay 

### before toxicity observed  Indicates less bioavailability of Cu towards South bay Copper Concentration ( μ g/L) 0 5 10 15 20 25 30 Normal Larval Development (%)

0 20 40 60 80 100 120 

### Box 1 Box 18



### February 27, 2002 Box 27

#  EC 50

# s increased with increasing distance towards 

# back of bay  EC 50 

# range:

- mussel: 7

–24 μg/L



## -urchin: 13

–44 μg/L 

#  Mussel approximately 

# twice as sensitive to copper as urchin 

# Spatial Trend in Toxicity

Feb. 27, 2002

Box # Lab 1 2 3 4 5 9 11 12 15 18 21 23 25 26 27 0 10 20 30 40 EC50 ( μg/L) 

## purple urchin mussel

# Spatial Trends in Toxicity
 Spatial trend consistent over course of four surveys 

###  EC 50 

### values within surveys differ by factors of 1.7 (May 2002) to 3.4 (Feb 2002)  On average, South Bay (Boxes >18) EC 50 

### values 65% higher than North Bay May 14, 2002

Box # Lab 1 3 12 15 18 21 23 25 26 27 4 6 8 10 12 14 16 18 Sept. 19, 2001

Box # Lab 1 3 4 5 7 9 11 12 13 15 16 21 23 25 26 27 10 15 20 25 30 35 40 Aug. 30, 2001

Box # Lab 1 5 6 13 26 EC50 ( μg/L)

5 10 15 20 25 30 35 

## sand dollar purple urchin mussel EC50 ( μg/L)

Feb. 27, 2002

Box # Lab 1 2 3 4 5 9 11 12 15 18 21 23 25 26 27 0 10 20 30 40 EC50 ( μg/L) EC50 ( μg/L)

# Dissolved Organic Carbon (DOC)

 DOC known to play large role in complexation of cationic metals  DOC ranged from <1 to about 4 mg/L  DOC concentration generally increased with increasing distance towards head of bay 

###  Upward trend in DOC not as clear for samples tested from May 2002 survey May 14, 2002

Box 0 5 10 15 20 25 30 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 Feb 27, 2002

Box 0 5 10 15 20 25 30 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Sep 19, 2001

Box 0 5 10 15 20 25 30 2.0 2.5 3.0 3.5 4.0 Aug 30, 2000

Box 0 5 10 15 20 25 30 DOC (mg/L)

1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 DOC (mg/L) DOC (mg/L) DOC (mg/L)

# Toxicity and DOC
 Significant relationship in all but May 2002 sampling 

## event.  Overall r2 

## = 0.71  DOC complexes free copper, limiting its bioavailability Feb. 27, 2002 mussel, r 2 = 0.686 urchin, r 2 = 0.825

DOC (mg/L) 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0 10 20 30 40 50 Sep. 19, 2001 sand dollar, r

2 = 0.360

DOC (mg/L) 1.5 2.0 2.5 3.0 3.5 4.0 15 20 25 30 35 40 Aug. 30, 2000

2 sand dollar, r = 0.954

DOC (mg/L) 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 5 10 15 20 25 30 35

May 14, 2002 mussel, r 2= not sig.

DOC (mg/L) 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 6 8 10 12 14 16 18 

## sand dollar purple urchin mussel EC50 ( μg/L) EC50 ( μg/L) EC50 ( μg/L) EC50 ( μg/L)

# WER Classification  North Bay 

#  Boxes 1
- 17  South Bay  Boxes 18
- 27  Bay
- wide N Coronado Bridge

# WER Estimates

Total Recoverable WER

All datasets 

# North Bay 1.80 South Bay 2.72 Bay- wide 2.20 Dissolved WER All datasets 

# North Bay 1.43 South Bay 2.15 

# Bay-wide 1.73 Sampling Date May 2002 Feb 2002 Feb 2002 Sept 2001 

### 0 1 

### 2 3 North Bay South Bay Bay-wide



##  Four datasets from three surveys used for final WER  All WERs greater than 1  Mussel WERs higher than echinoderm WERs WER 

### Mussels only 

# 2.09 3.09 2.57 Mussels only 

# 1.65 2.44 

# 2.03 Mussel Mussel Urchin Sand dollar

# Site- Specific Dissolved Criterion Calculation

Current 

# National Criterion Dissolved



# WER Site- specific



# Criterion 

# Acute: 4.8 μg/L ×



# Chronic : 3.1 μg/L × 1.73 = 8.3 μg/L



# 1.73 = 5.4 μg/L All datasets Mussels only



# 2.03 = 9.7 μg/L

2.03 = 6.3 μg/L

# TR = total recoverable D = dissolved 

# WER Studies From Other Estuaries

# Summary
 Ambient conditions in San Diego Bay do not appear to be toxic to bivalve or echinoderm embryos  Bioavailability of copper consistently decreases (up to 3.4 times) with increasing distance from mouth of the bay  Higher EC 50

# s (lower toxicity) generally strongly correlated with higher DOC concentrations.  Current national WQC for copper appears overprotective by a factor between 1.7 and 2 for San Diego Bay