# EPA RESPONSE

TO EXTERNAL PEER REVIEW COMMENTS

on the

DRAFT AQ UA TIC LIFE AMBIENT ESTUARINE/MARINE WATER QUALITY CRITERIA FOR C OPPER

July 201 6

Office of Water U.S. Environmental Protection Agency

Washington, DCii



### T ABLE OF 

### C ONTENTS

1 INTRODUCTION

................................ ................................ ................................ ................................ ... 1

1.1 Background

................................ ................................ ................................ ................................ ...... 1

1.2 Peer Reviewers

................................ ................................ ................................ ................................ 1

1.3 Review Materials Provided

................................ ................................ ................................ .............. 1

1.4 Charge Questions

................................ ................................ ................................ ............................. 1

2 EXTERNAL PEER REVIEW ER COMMENTS AND EPA RESPONSES, ORGANIZED BY CHARGE QUESTION

................................ ................................ ................................ ................................ ..... 2

2.1 Charge Question 1

................................ ................................ ................................ ........................ 3

2.2 Charge Question 2

................................ ................................ ................................ ........................ 9

2.3 Char ge Question 3

................................ ................................ ................................ ...................... 16

2.4 Charge Question 4

................................ ................................ ................................ ...................... 20

2.5 Other Comments Provided

................................ ................................ ................................ ......... 22

3 REFERENCES CITED BY REVIEWERS

................................ ................................ ......................... 241



## 1 I NTRODUCTION

EPA submitted its Draft Aquatic Life Ambient Estuarine/Marine Water Quality Criteria (AWQC) for C opper for contractor

- led independent, external peer review from November 24, 2015 to December 11

, 2015 . The external peer reviewers provided their independent responses to EPA’s charge questions. This report

documents the EPA’s response to the comments provided to EPA

.

T his report present s the four peer review charge questions and individual reviewer comments ( verbatim ) in Sections 2.1 through 2. 5

. Section 2. 6 presents additional minor comments provided by two reviewer s

. New
information (e.g., references) prov ided by reviewers is presented in Section 3. EPA separated each reviewer ’ s comments by charge question into distinct topics and responded to each topic individually, and also indicat ed

how the estuarine/marine copper criteria document was revised in response to peer reviewer comments

.



### 1.1 B ACKGROUND

EPA ’s Office of Water is developing the recommended ambient WQC for copper in estuarine/marine waters through its authority under §304(a) of the Clean Water Act (CWA). The Agency is developing the water

q uality criteria to protect aquatic life and aquatic

- dependent wildlife from the presence of c opper in estuarine/marine environments in order to reflect the latest scientific knowledge.

EPA’s Draft Aquatic Life Ambient Estuarine/Marine Water Quality Criteria for Copper presen ted acute and chronic criteria expressed as concentrations of copper in estuarine/marine waters (dissolved). The 2015 draft copper criteria update utilize d the recently developed marine BLM to provide updated acute and chronic water quality criteria for copper in estuarine/marine waters. The BLM is based on the premise that toxicity is related to the amount of metal bound to a biochemical site (the biotic ligand) and that binding is related to total dissolved metal and complexing ligands concentrations in the water. The draft criteria also included updated toxicity test information for copper effects on estuarine/marine aquatic species. This draft differ ed from previous estuarine/m arine copper criteria which were based on empirical relationships between toxicity

and water hardness.



### 1.2 P EER 

### R EVIEWERS

An EPA contractor identified and selected five reviewers who met the technical selection criteria provided by

EPA and who had no conflict of interest in performing th is review

.

The EPA contractor provided reviewers with instructions, the review document (including appendices), the charge to reviewers) prepared by EPA, and supporting reference materials as described in the charge.

R eviewers worked individually to develop written comments in response to the charge questions.



### 1.3 R EVIEW 

### M ATERIALS 

### P ROVIDED

 Draft Saltwater BLM Cu (11

- 23

- 15 draft ).docx

 Marine BLM ver 0043.zip



### 1.4 C HARGE 

### Q UESTIONS

1. Please comment on the overall clarity of the d ocument and construction as it relates to the derivation

of each criterion

.

2. Please comment on the technical approach used to derive the draft copper criteria; is it logical, does the science support the conclusion, and is it consistent with the protection of estuarine/marine aquatic life from acute, chronic, and bioaccumulative effects?2

3. (a) Please comment on the data used to derive the revised criteria, including data adequacy/ comprehensiveness, and the appropriateness of the data selected and/or exclude d from the derivation

of the draft criteria

.

(b) Are there other relevant data that you are aware of that should be included? If so, please provide

the criteria.

4. Are the derived criteria appropriately protective of listed species and commercially and recreationally important species ?



## 2 E XTERNAL 

## P EER 

## R EVIEWER 

## C OMMENTS AND 

## EPA R ESPONSES 

## , O RGANIZED BY 

## C HARGE 

## Q UESTION

The following tables list the charge questions submitted to the external peer reviewers, the external peer reviewers’ comments regarding those questions (broken into distinct topics ), and EPA’s responses to the peer

reviewer s’ comments. EPA revised the 201 6 draft considering the external peer review comments, and noted

in the t able where the draft criteria document was edited.3



### 2.1 C HARGE 

### Q UESTION 

### 1

1. Please comment on the overall clarity of the document and construction as it relates to the derivation of each criterion.

Reviewer External Peer Reviewer Comments Regarding Charge

Question 1 EPA Response Revision
Location in

Document

Reviewer 1 The document is reasonably clear, albeit a bit redundant in that

some of the same language is recycled several times in describing the Biotic Ligand Model (BLM). Thank you for your comment

. The document was revi sed to eliminate unnecessary redund ancies. H owever, some repetition was intentionally written into the document to tie sections together and facilitate use by readers who may o nly access specific document sections. Various

sections

Reviewer 1 The language regarding the derivation of the final Acute to

Chronic Ratio (ACR) is a bit convoluted in the use of freshwater

values. The language used to describe the derivation of the Final Acute to Chronic Ratio (FACR) was clarified

. Section 3.6.2

Reviewer 2 I believe this is a very good work product and should be quite

useful for those entities charged with regulating copper in marine

and estuarine waters. Thank you for your comment

. No edits

needed.

Reviewer 2 Problem formulation. Well done, nicely laid out and exposure

scenarios described well. Thank you for your comment

. No edits

needed.

Reviewer 2 Case Study. Nice illustration and should serve as educational tool.

The comparison between freshwater and marine scenarios is also

useful and should benefit the reader. Thank you for your comment

. No edits

needed.

Reviewer 2 Figure 5 was particularly useful and leads the reader to figure 6.

Major drawback: It is an equi librium model and does not allow for consideration of pulsed or episodic exposure with organism recovery. This is not necessarily a criticism of the document. Rather, it should be a consideration for future research. The reviewer is correct in that pulsed exposures are not
considered , consistent with standard ecological assessment practices in the U.S. and many international jurisdictions. EPA agrees that consideration of pulsed or episodic exposure s with organism recovery would be a useful area of future r esearch by the scientific community

. No edits

needed.

Reviewer 2 How does the varying salinity in estuaries pose special

challenges? Section 2.4 provides a detailed discussion of the BLM’s function in environments with varying salinities

. Section 2.4

Reviewer 2 Given the obvious mechanism of phytotoxicity for copper, it is

surprising that little data exists for estuarine plants. However, it is likely that the same mechanisms that make estuarine plants tolerant to salinity likely make them less sensitiv e to metals such

as copper. Thank you for your comment . T here are limited data for estuarine plants , as noted

. However, a n additional analysis was performed to BLM normalize plant effect concentrations to further characterize the protectiveness of the chro nic criterion

to estuarine/marine plants. Section 4.44 Reviewer External Peer Reviewer Comments Regarding Charge

Question 1 EPA Response Revision

Location in

Document

Reviewer 3 The text is clearly written. There are some repetitions but they are

probably useful to remind the reader about limits and scope of the

work. It is however difficult for the reader to appreciate the rigor of the approach without reading some of the cited references such as Chadwick et al (2008) which may not be easily accessible. Perhaps an appendix could be added. Thank you for your comment. The document was revi sed to
eliminate unnece ssary redundancies. As the reviewer noted, however, some repetition was intentionally written into the document to tie sections together and facilitate use by readers who may only access specific document sections. A direct

clickable link to the Chadwick d ocument was added in the

reference section to facilitate document access by the end user. Various

sections.

Reviewer 3 The use of the term “bioavailable” is, in my opinion, not always

correct. Because of the dynamic nature of metal binding, one cannot say that a particular metal species is not bioavailable. This was clearly laid out in the original Morel book [1] as well as in Campbell [2] . Here is part of page 55 of the latter reference:

I have noted many statements with such a bioavailability misconcept being conveyed: p. 1, l. 15; p. 14 (4 times); p. 47 penultimate line. The reviewer is not correct in the implication that the BLM uses one chemical species as the definition of “bioavailable”.

The BLM , for example, does not simply predict free metal ion and equate that with bioavailability. The free metal ion

concentration a t the BLM

- predicted effect concentration will change with changing chemical conditions. The interpretation of bioavailability used by the BLM is consistent with the text cited by the reviewer. No edits

needed.

Reviewer 3 Figures 4, 5, 6 and 7 are lacking information for the reader to

understand them. The meaning of the inserted legends is unknown. The legend of figure 4 says “Values collapse into a single dose response when compared with measured copper
accumulation” but it is not clear what this refers to . In figure 5

dotted lines are not described. The phrase “collapse into a single dose response” was referring to a comparison of the same toxicity data plotted versus dissolved copper, which showed different dose response relationships, or versus copper ac cumulation (as in Figure 4) which were now similar. Since the version of the figure based on dissolved copper was deleted, the comparison is no longer relevant and the text w as revised accordingly. Section 2.45 Reviewer External Peer Reviewer Comments Regarding Charge

Question 1 EPA Response Revision

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Document

Reviewer 3 Section 2.5 (pp. 22

- 24) seems supe rfluous. Consider removing. Thank you for your comment

. T he inclusion of a conceptual

mode l is informative and consistent with relating the copper

criteria to a broader risk assessment framework , and is consistent with EPA’s Ecological Risk Assessment Guidelines (1998) No edits

needed.

Reviewer 3 P. 40, middle: “Application of the BLM may reduce, if not

eliminate, the need for site

- specific modifications to account for

site

- specific chemistry influences on metal toxicity.” I would argue that the use of the BLM is another way to account for site specific differences. Consider rephrasing. The referenced text was revised to clarify that the BLM provides a model that can be used to account for the influence of important site

- specific parameters, in this cas e temperature, pH, DOC, and salinity , on copper toxicity.

Reviewer 3 P. 11. Last paragraph is incomplete and incoherent but I was

instructed to ignore this paragraph. The text was revised to be complete and to describe the primary form of copper in estuarine and marine environments.

Reviewer 3 P. 46, Figure 11: I am not convinced this figure is useful with

only two values. Note also that the y

- axis label should read copper and not cadmium. The text was revised as suggested and Figure 11 was retaine d. Figure 11

Reviewer 4 Overall the document is well written and clear as to how the

criteria are derived. I do have a few minor comments, however,

on areas that could be clarified. Thank you for your comment

. No edits

needed.

Reviewer 4 Pgs. 17

- 18: The discussion about Figs 4 and 5 is a little confusing

the way it’s presented. T he t ext w as modified to clarify. Section 2.4

Reviewer 4 Fig. 4: Define “(N)” and “(S)”. N and S are sample names. The figure and text w as revised to clarify. Figure 4 and 5

Reviewer 4 Fig. 5: Where is the “convergence”? Please clarify the “single

model representation”. See response to reviewer 3 ’s comment above

. Section 2.4

Reviewer 5 Overall the draft document content is comprehensive, accurate,

and persuasive. It is well w ritten and well organized. The cited references represent major works in the related fields and these are overall supportive of the Draft Update of Aquatic Life Ambient/Marine Water Quality Criteria for Copper (herein referred to as MWQC

- Cu ). The Chadwick et al. (2008) citation requires review and update (see detail below). The overall report

is well

- written in a clear and communicative style. The report heading and subheadings are helpful to reader and present an organized development of the supporting work for the draft acute Thank you for your comment

. The Chadwick reference was updated to the final report and a hyperlink was added to

facilitate access to this document. The fonts were reviewed, though some of the differences in the fonts are by design to

differenti ate between the different header levels. No edits

needed.6 Reviewer External Peer Reviewer Comments Regarding Charge

Question 1 EPA Response Revision

Location in

Document

and chronic criterion . The Table of Contents ha s font mismatches

. The List of Figures, List of Tables, List of Appendices and Acronyms list are complete. In my reading of the report text, the balance of number of figures and number of table to support the development and explanation of the criterion de velopment was satisfyingly complete. The document is well edited for correct grammar and spelling, clear sentence structure, and informative paragraph development. Paragraph transitions are present and logical, and maintain the flow of thought throughout t he report.

Reviewer 5 The Introduction provides overall sufficient background for

copper and previews major points in aquatic ecosystem concerns and concomitant regulatory science development. Section 2.1, Overview of Copper Sources and Occur, page 5 paragraph 1

could be broade ned to also include copper sulfate use in dairy cattle foot baths, an emerging source of problematic copper release to the environment because of animal hygiene and manure management practices associated with large animal agriculture operations. For exampl e in the Agricultural Extension publication:
http://articles.extension.org/pages/22177/copper

- sulfate

- foot

baths

- on

- dairies

- and

- crop

- toxicities

and in Jokela, WE, et al. (2010) Manure Nutrient Content on Vermont Dairy Farms: Long

- Term Trends and

Relation ships

COMMUNICATIONS IN SOIL SCIENCE AND

PLANT ANALYSIS Volume: 41 Issue: 5 Pages: 623

- 637
DOI: 10.1080/00103620903531193 Text was added to include dairy cattle foot baths as a potential source of copper to the environment. Section 2.1

Reviewer 5 Directly germane and important in the development of the EFT of

marine copper, yet absent in the citations to this report, is a significant review by Turner (2010): Turner, A (2010) Marine pollution from antifouling paint particles Antifouling paint particles were added as a potential source of copper to the environment and the two summary/review

articles were cited and added to the references. Section 2.17 Reviewer External Peer Reviewer Comments Regarding Charge

Question 1 EPA Response Revision

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Document

MARINE POLLUTION BULLET IN Volume: 60 Issue: 2 Pages: 159

- 171 DOI: 10.1016/j.marpolbul.2009.12.004

Thomas, KV and Brooks, S (2010) The environmental fate and effects of antifouling paint biocides

BIOFOULING Volume: 26 Issue: 1 Pages: 73

- 88

DOI: 10.1080/08927010903216564

The sam e could be said of the review by Kiaune and Singhasemanon (2011): Kiaune, L and Singhasemanon, N (2011) Pesticidal Copper (I) Oxide: Environmental Fate and Aquatic Toxicity. Edited by: Whitacre, DM

REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, VOL 213.

Book Series: REVIEWS OF ENVIRONMENTAL

CONTAMINATION AND TOXICOLOGY Volume: 213 Pages: 1

- 26

DOI: 10.1007/978

- 1

- 4419

- 9860

- 6_1

Reviewer 5 Copper flux from sediments is an important EFT dynamic in

marine ecosystems and a source of exposure for benthic organisms and may be a significant driver of Cu speciation and

concentration in the overlaying waters. Section 2.2 of the Introduction would be strengthened by a short comment about marine sediment Cu geochemistry such as could be developed by

references such as: Skrabal, SA et al. (2000) Pore water distributions of dissolved copper and copper

- complexing ligands in

estuarine and coastal marine sediments

GEOCHIMICA ET COSMOCHIMICA ACTA Volume: 64 Issue: 11 Pages: 1843

- 1857

DOI: 10.1016/S0016

- 7037(99)00387

- 7
Published: JUN 2000 An additional discussion was added to the document to disc uss the Cu geochemistry from marine sediments using the reference you provided. Section 2.28 Reviewer External Peer Reviewer Comments Regarding Charge

Question 1 EPA Response Revision

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Document

Reviewer 5 Section 2.4, Overview of Historic and BLM Criteria

Development Methods, would be improved with the citation and short distillation of Erickson (2013), a significant review reference describing BLM strengths and cautionary weaknesses: The biotic ligand model approach for addressing effects of exposure water chemistry on aquatic toxicity of metals: Genesis and challenges

ENVIRONMENTAL TOXICOLOGY AND

CHEMIST RY Volume: 32 Issue: 6 Pages: 1212

- 1214

DOI: 10.1002/etc.2222 Erickson (2013) would also provide significant support for the discussion of MWQC

- Cu Section 3.8.3, BLM

Uncertainties and Performance. Modifications to the text and referenc e to Erickson w ere added , as suggested

. Section 2.49



### 2.2 C HARGE 

### Q UESTION 

### 2

2. Please comment on the technical approach used to derive the draft copper criteria; is it logical, does the science support th e conclusion, and is it consistent with the protection of estuarine/marine aquatic life from acute, chronic, and bioaccumulative effects? ?

Reviewer External Peer Reviewer Comments Regarding Charge

Question 2 EPA Response Revision

Location in

Document

Reviewer 1 I have a lot of respect for the scientific merit a ssociated with the

BLM. If toxicity of Cu was exclusively based on surficial binding and associated osmoregulatory effects, the approach used in this WQC would be fine. Unfortunately, a lot of credible science is ignored, and a WQC is being proposed that o nly uses a portion of our scientific understanding. The criteria is based on a narrow literature evaluation of copper toxicity. It ignores literature that shows dietary Cu bioaccumulation and effects (e.g. Bielmeyer paper that was not considered because th e exposure route was via diet). It only acknowledges a segment of what is known about Cu toxicity in general (all biota) and in aquatic organisms specifically. The oxidative toxicity of Cu is ignored completely despite dozens of papers that describe it in aquatic organisms. I've attached a new book chapter that may be helpful. (Bielmeyer and Grosell, Chapter 5: Emerging issue in marine metal toxicity.) EPA concurs with the reviewer about the difficulty in characterizing dietary exposure and establishing c ritical tissue

effects thresholds for bioaccumulated metals.

Text has been added to discuss these points and incorporate the work of other researchers who discuss copper bioaccumulation and dietary exposure in detail and the uncertainties currently associ ated with its evaluation. In particular, text was added to detail how cop p er can bioaccumulate in aquatic organisms through multiple exposure routes including ingestion and direct exposure, and how total uptake depends on the copper concentration, exposure route and the duration of exposure.

Information regarding the oxidative toxicity of copper has

been added to Section 2.3

. Section 4.3.1 (a new section)

Reviewer 1 The treatment of bioaccumulative effects is terribly inadequate,

particularly in light of the lack of chronic data. It is well

established that invertebrates receive considerable tissue

concentrations of metals from their diets. It is also well

established that Cu that is not detoxified can be a potent pro

oxidant. This is acknowledged as only occurring in mammals in this document despite abundant literature describing this phenomenon in aquatic organisms. It seems that EPA is only acknowledging the potenti al for toxicity via dissolved exposures. This is incomplete. It seems as though EPA discounts metal bioaccumulation as potentially problematic because a single tissue effects threshold does not exist. If toxicity can result from dietary exposures (shown in the literature), there should be no problem in using the dissolved concentrations that the diet was exposed to as a descriptor of exposure. Text has been added to discuss these points and incorporate the work of other researchers who discuss copper

bioac cumulation and dietary exposure in detail and the uncertainties currently associated with its evaluation. In particular, text was added to detail how copper can bioaccumulate in aquatic organisms through multiple exposure routes including ingestion and dir ect exposure, and how total uptake depends on the copper concentration, exposure route and the duration of exposure.

In addition, it should be noted that the larval life stage of the

invertebrate M

ytilus edulis (blue mussel) is the most acutely

sensitive species in the copper database, and that this life stage does not feed during development. Section 4.3.1 (a new section)10 Reviewer External Peer Reviewer Comments Regarding Charge

Question 2 EPA Response Revision

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Document

Reviewer 1 P. 1: “The biotic ligand is the gill surface and the site of toxicity

on the organism”. This statement is only partially t rue. Gill binding is associated with toxicity, most likely via interactions with ion transport systems and carbonic anhydrase. However this is not the only way copper causes toxicity (see comment above). Bioaccumulated Cu (from all exposure routes) has the potential to

be toxic as well. T he text was modified to refer to biological membranes rather

than only the “gill” as th e biotic ligand

. Section 1.0

Section 2.4

Reviewer 1 P. 12: Figure 2 is not particularly informative. Figure 2 has been revised to provide a clearer depiction of

copper characteristics in estuarine/marine waters

. Figure 2

Reviewer 1 P. 12: The overview of toxicity is woefully inadequate. This is an

exceptionally well

- studied metal. There is no reason for this section to not provi de a comprehensive overview of what is known about Cu toxicity. Section 2.3 has been revised to provide a more detailed and

comp rehensive summary of copper toxicity to estuarine/marine organisms. Section 2.3

Reviewer 1 P. 13: With all of the work that has examined the bioavailability

of Cu from sediments, the only thing mentioned is AVS? (AVS is not universally recognized and is highly controversial among knowledgeable scientists )

. A discussion of the bioavailability of copper from marine

sediments was added to the document. Section 2.2

Reviewer 1 P. 16 Figure 3: Shouldn’t the anions and their importance in

complexation reactions be portrayed here? Figure 3 w as revised to include this detail. Figure 3

Reviewer 1 P. 16: Again, the overly simplistic and incomplete view of

toxicity is expressed here. T h e document i n cludes discussions of copper toxicity mediated via water and dietary exposures, a nd illustrates the primary toxicity modifying factors that can alter

bio availability. Section 2.3 has been revised to provide a more detailed and comp rehensive summary of copper toxicity to estuarine/marine organisms. Section 2.3

Reviewer 1 P. 17: It is interesting that whole body accumulation values are

used here. It is inte resting that the interpretation is that whole body accumulation is related to surficial binding, with surficial binding being the cause of toxicity where it could very well be that toxicity results from whole body accumulation. Along those lines, it opens up the idea that bioaccumulated Cu is potentially important, and the simple BLM

- only view of the world is not complete. The accumulation data in question were from short exposures designed to only allow surficial binding in experiments with embryo larval forms of the organisms. Therefore it is by design, and not by assumption, that accumulation in this study is equated with surficial binding. No edits

needed.11 Reviewer External Peer Reviewer Comments Regarding Charge

Question 2 EPA Response Revision

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Document

Reviewer 1 P. 24: The conceptual model includes ingestion but none of the

acceptable data inclu de ingestion as an exposure route. This is a huge source of uncertainty. Importantly, the BLM could be used to better understand both direct exposure via water, and ingestion pathways because it is well known that water chemistry affects Cu uptake in phyto plankton (which is typically accumulative). Discussion has been added regarding the uncertainty of diet as
an exposure route. Section 4.3.1 (a new section)

Reviewer 1 P. 31: section 2.8.2 check grammar of first sentence. T he t ext was revised to correct

. Section 2.8.2

Reviewer 1 P. 33: These criteria apply to marine and estuarine waters......I’m

very uncomfortable with the language about the stability of marine waters and its application to estuarine waters as well (which are less stable). Text was added to c larify the statement about stability was in reference to full salinity marine waters. Text was also added to discuss the variability of ionic composition in estuarine waters, and how this is addressed by the salinity parameter in

the BLM. Section 2.8 .3

Reviewer 1 P. 34: I’m not sure about the use of the term “threshold” to

describe an LC50. The term is not used to describe the LC 50 . Rather

, the text reads, “The LA 50 s represent the critical threshold concentrations at the biotic ligand that result in acut e toxicity

...” . The term threshold is appropriate since it refers to the concentration that results in toxicity. No edits

needed.

Reviewer 1 P. 38: What is a 96 hour static multi

- generational test? T he t ext was edited to clarify the type of test conducted with

the rotifer Brachionus plicatilis

. Section 3.2

Reviewer 1 P. 39: What if rotifers were fed a diet that was equilibrated to the

same copper concentrations? Would the toxicity values be expected to change? This is an interesting question. Unfortunately, the only way to determine if the toxicity values would change is to conduct the

test and these data are not currently available

. No edits

Reviewer 1 P. 41 Table 8: I assume the 2°C is a typo? T he t ext was revised to correct

. Table 8

Reviewer 1 P. 46 Figure 11: check Y axis label. This is a copper criterion not

a cadmium criterion. T he t ext was revised to correct

. Figure 11

Reviewer 1 It is interesting that copper is used as an aquatic herbicide, yet

several times in the text it is noted that toxicity to plants is comparable to toxicity in animals. Shouldn’t this raise concerns? The plant data with low effect concentrations were BLM
normalized to the test conditions to allow comparison to the

FCV . The results of this analysis w ere added to the document

, and suggested (based on available data) that the criteria would in most cases also be protective of aquatic plants

. Section 4.4

Reviewer 2 The technical approach is sound and consistent with both

previous BLM e fforts as well as the established methodology for developing water quality criteria. Table 3 lays out the data, summary statistics and metrics and should be easily understood Thank you for your comment

. No edits

needed.12 Reviewer External Peer Reviewer Comments Regarding Charge

Question 2 EPA Response Revision

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Document by the reader. While a little short on chronic data, the results are

sound and sc ientifically defensible.

Reviewer 3 I think the use of the BLM is an improvement over the use of

empirical hardness relationships. The BLM approach is based on sound premises and previous successful applications. Thank you for your comment

. No edits

needed.

Reviewer 3 P. 17: “An advantage of the BLM is that most of the parameters

are invariant for different organisms, despite the complexity of the modeling framework. All of the thermodynamic constants used to simulate inorganic and organic chemical equilibrium reactions are determined by ch aracteristics of the metal and the available ligands. As such, the constants do not change for simulations involving different organisms.” That is true for all reactions between metals and ligands in solution but there should

be a different set of biotic l igand constants with copper for each organism. The way this paragraph is written may mislead the

reader. The reviewer is correct in that thermodynamic constants are properties of the metal and do not change in simulations with different organisms. While c onstants for reactions involving the biotic ligand may be different for different organisms, in the implementation of the BLM for development of the marine criteria for copper, they also do not change in the analysis used to prepare this document and the d escription is accurate as currently provided in the quoted text

. No e dits

needed.

Reviewer 3 A missing piece of information is related to the calculation of

copper speciation. In saltwater, the ionic strength is 0.7 M. At such a high ionic strength, adjustment of binding constants is not straightforward. The commonly used empirical relations of Davies or Debye

- Hückel cannot be used. How does the BLM account for ionic strength? The text w as modified to describe the ionic strength

correction

. Section 2. 4

Reviewer 4 The technical approach used to derive the draft copper criteria is

logical and scientifically sound. The premise of the BLM and the input parameters are adequately explained. A limitation is that the criteria may not be adequately protective in tropical environments. The BLM uses a temperature of 22 0 C and higher temperatures may increase copper bioaccumulation and toxicity to aquatic organisms. The BLM was developed to protective of species representative of those present in North American waters. Because temperature is one of the variables in the BLM, the model can be run with a temperature that is applicable to site conditions. The temperature of 22 0 C was only used as a representati ve value. Text was added to clarify that the model allows input parameters , including temperature, to be adjusted to be applicable to site conditions.

Reviewer 5 The MWQC

- Cu relies heavily on the Environmental Security

Technology Certification Program U .S. Department of Defense (ESTCP

- DoD) study cited as: The reference was updated to the final report

. A hyperlink was added to facilitate access to this document

. Section 5.013 Reviewer External Peer Reviewer Comments Regarding Charge

Question 2 EPA Response Revision

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Document Chadwick, D.B., I. Rivera

- Duarte, P.F. Wang, G. Rosen, R. Santore, P. Paquin and A. Ryan. 2008. Demonstration of an integrated compliance model for predicting copper fate and effects in DoD Harbors, En vironmental Security Technology Certification Program (ESTCP). Project ER

- 0523, Draft Final Technical Report, June 16, 2008

.

This citation should be updated to the “ Final Report November 1,

2008 ” as found at http://www.dtic.mil/dtic/tr/fulltext/u2/a499564.pdf if the authors view the modifications from the draft to the final report for Project ER

- 0523 to be not significant or substantial with regards to the application of this report and i ts seawater BLM parameters to the development of the MWQC

- Cu. I could not locate the Draft Final Technical Report, June 16, 2008.

The Chadwick et al. (2008) project report does not appear to have made it into the peer

- reviewed literature using my Web of Science searches for “Chadwick, D.B/author”, “copper biotic ligand model/topic” or “marine biotic ligand model/topic” or
“seawater b iotic ligand model/topic.” While this is unfortunate in the development of the MWQC

- Cu, exemplified by descriptors in the report referring to “emerging” seawater BLM, I explored this reference in sufficient detail to support it as a primary and well

- execut ed scientific resource in the development of the MWQC

- Cu. The role and expertise of some of the Project ER

- 0523 report authors as the primary scientists responsible for the well

- established freshwater BLM science

– which is a significant

advancement in wat er quality risk management

– lends significant support for application of the Project ER

- 0523 report as a key resource in support of the MWQC

- Cu. In particular, the laboratory validation approaches cited as SERDP Projects ER

- 1156 and ER

- 1157 in Chadwick et al. (2008) appear as significant bench validation of seawater Cu behavior in application the BLM.14 Reviewer External Peer Reviewer Comments Regarding Charge

Question 2 EPA Response Revision

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Document As reported in Chadwick et al. (2008), the seawater BLM tested well against a rigorous set of model validation performance metrics. This effort coupled wit h the knowledge of an almost constant competing cation load and inorganic ligand load of seawater relative to freshwater, as illustrated in Figure 3, secures the high stability and adaptability of the BLM in a seawater application and thus in the developme nt of the MWQC

- Cu. Thus I conclude that the overall technical model approach of the

seawater BLM

– if there is concordance between the Draft Final Technical Report, June 16, 2008 as cited with the Final Report November 1, 2008

– is scientifically sound and supported.

Reviewer 5 There are two recent papers by Deruytter, et al. that are not cited

in the present draft report. The work: Deruytter, D, et al. (2014) The Combined Effect of Dissolved Organic Carbon and Salinity on the Bioaccumulation of Copper in Marine Mussel Larvae

ENVIRONMENTAL SCIENCE & TECHNOLOGY Volume: 48 Issue: 1 Pages: 698

- 705

DOI: 10.1021/es4024699

and Deruytter, D , et al. (2015) Salinity and dissolved organic carbon both affect copper toxicity in mussel larvae: Copper speciation or competition cannot explain everything

ENVIRONMENTAL TOXICOLOGY AND

CHEMISTRY Volume: 34 Issue: 6 Pages: 1330

- 1336

DOI: 10.1002/etc.2924 Deruytter, D, et al. (2015) appears to expand on the concerns of work published by de Polo and Scrimshaw (2012) that suggests incorporation of an osmotic gradient into the seawater BLM since the intestine can also be a biotic ligand. de Polo, A and Scrim shaw, MD (2012) Challenges for the development of a biotic ligand model predicting copper toxicity in estuaries and seas Th e referenced papers were not cited because they were not available when the draft document was prepared. The

c itations have been added to the documen t

. Various

locations

.15 Reviewer External Peer Reviewer Comments Regarding Charge

Question 2 EPA Response Revision

Location in

Document

ENVIRONMENTAL TOXICOLOGY AND

CHEMISTRY Volume: 31 Issue: 2 Pages: 230

- 238

DOI: 10.1002/etc.1705

The primary driver of the MWQC

- Cu is t he work of Chadwick et al (2008), but because it never appeared in the primary peer

reviewed literature, it is uncited in de Polo and Scrimshaw (2012) or Deruytter, D, et al. (2015). Figure 8 of the MWQC

- Cu describing the Conceptual Model for Copper Effect s on Aquatic Organisms shows gills and integument and thus appears to address some of the concerns of de Polo and Scrimshaw (2012). Coupled with the practical description of the well

- supported salinity sensitivity of some Cu sensitive juvenile test species (e.g. Mytilus ) discussed on page 21 there appears to be solid data to directly and briefly address the observations of de Polo and Scrimshaw (2012) and Deruytter, D, et al. (2015) within the MWQC

- Cu draft report. In addition, the follow

- up toxicodynamic

w ork of de Polo, A, et al. (2014) may be very useful the MWQC

Cu Section 2.3, Overview of Copper Toxicity: de Polo, A, et al. (2014) A New Role for Carbonic Anhydrase 2 in the Response of Fish to Copper and Osmotic Stress: Implications for Multi

- Stressor St udies

PLOS ONE
Volume: 9 Issue: 10 Article Number: e107707 DOI: 10.1371/journal.pone.0107707

With the minor adjustments outlined above, the technical approach used to derive the draft copper criteria is logical, scientifically supported, and is consistent with the protection of estuarine/marine aquatic life from acute, chronic, and

bioaccumulative effects.16



### 2.3 C HARGE 

### Q UESTION 

### 3 ( A 

### )

3. (a) Please comment on the data used to derive the revised criteria, including data adequacy/ comprehensiveness, and the appro priateness of

the data selected and/or excluded from the derivation of the draft criteria.

Reviewer External Peer Reviewer Comments Regarding Charge

Question 3(a) EPA Response Revision

Location in

Document

Reviewer 1 The exclusion of dietary studies is unfortunate and does not

reflect the current scientific understanding of metal toxicology. The exclusion of the Bielmyer papers is particularly without scientific justification. I understand the need to relate WQC to

dis solved concentrations here, but the exposure concentration that the food is exposed to can be used as a descriptor of exposure.

EPA’s failure to consider all exposure routes is very troubling. This would be analogous to setting a tolerance for a chemical residue on a food but not considering drinking water as important

in a human health hazard assessment. EPA concurs with the reviewer about the difficulty in characterizing dietary exposure and establishing critical tissue

effects thresholds for bioaccum ulated metals.

Text has been added to discuss these points and incorporate the work of other researchers who discuss copper bioaccumulation and dietary exposure in detail and the uncertainties currently associated with its evaluation. In particular, text was added to detail how copper can bioaccumulate in aquatic organisms through multiple exposure routes including ingestion and direct exposure, and how total uptake depends on the copper concentration, exposure route and the duration of exposure. Section 4.3.1 (a new section)

Reviewer 2 The additional data used to generate the new criteria are sound

and the approach transparent. Results are in line with what would be expected by simply examining the current data set. Thank you for your comment

. No edits

needed.

Reviewer 3 Here the rationale for accepting /rejecting data is not provided. It

might be useful to include an appendix to summarize how these decisions are made without having to dig up the report on this

method. Data selection is consistent with the procedures presented in
the 1985 Guidelines , as indicated in the criteria document, and key components of the data selection process are discussed

. The 1985 Guidelines is generally available and EPA does not think it would be necessary to include the f ull document as part of the appendix. No edits

needed.

Reviewer 3 One of the key parameters of the proposed copper BLM that

influence the resulting values is the amount of dissolved organic

carbon. I could not find a rationale for the use of the value o f 1.3 mg/L. There is only a reference to a footnote in appendix A. A sensitivity analysis would be useful for the reader to appreciate the influence of this parameter on the aquatic life criteria. New reference conditions were selected and all toxicity data

were re

- normalized.

The reference condition corresponds to values for pH, DOC, and salinity that are representative of some natural waters.

These selected values are analogous to selecting a hardness of

50 as a reference condition for freshwater metal criteria based on a hardness equ ation. The BLM is designed to allow users to Various

locations.17 Reviewer External Peer Reviewer Comments Regarding Charge

Question 3(a) EPA Response Revision

Location in

Document input and account for site

- specific conditions, including a various dissolved orga nic carbon values, instead of adhering to a fixed set of site conditions. Text was added to clarify these points.

Reviewer 3 It would be useful for the reader to get an idea of the uncertainty

on the values given throughout the report . This could be done through several changes: i) provide uncertainty on data when available (for every mean values, a standard error can be computed); ii) perform error propagation calculations when possible, if not warn reader about the potential error; a nd iii) reduce the number of significant figures to two (I have seen many values with five significant figures; these mislead the reader to think that these values are very accurate). T here document describes several factors which serve to

reduce and/or ch aracterize uncertainty in the data. First, all studies are individually reviewed and evaluated to ensure they conform to standards of QA/QC and acceptability consistent
with the 1985 Guidelines. Studies that were eliminated based on this analysis are summa rized in Appendix F, along with the

reason for their removal. Further, acceptable acute data were

available for 84 species representing 58 taxonomic families, representing a robust database , helping to reduce uncertainty. Limited chronic data were available, so the more robust acute
database was used with an acute

- to

- chronic ratio to derive the chronic value. Finally, Figure 15 provides a chara cterization of the variability of data used to derive the acute criteria with the depiction of 25 th to 75 th percentile ranges of these data.

Text was added that indicated intermediate calculations were performed to four significant figures to prevent rounding errors in subsequent revisions and that the number of digits does not reflect precision . Values were edited that had five significant figures. Final values are presented to two significant figures. Section 2.8.3

Reviewer 4 The acute data used to derive the CMC are both adequate and

comprehensive; however the chronic data are severely lacking, with data provided from only two animal species and no plant species. I do agree that criteria protective of animals should also theoretically be protective of plants, given that plants are generally more tolerant. Th at is a logical assumption. Even with the limited number of species in the chronic toxicity data set, the approach used to derive the CCC was logical and the CCC should be protective of most aquatic organisms. Thank you for your comment

. Based on limitatio ns in the

chronic data a robust acute

- to

- chronic ratio was derived using available data for two estuarine/marine species and data for five representative freshwater species, as described in Section

3.6.2. No edits

needed.18 Reviewer External Peer Reviewer Comments Regarding Charge

Question 3(a) EPA Response Revision

Location in

Document

Reviewer 4 Tables are provided in appendices listing the unused data and the

reasons for not using them. However, adding a list of the criteria necessary for data/studies to be included would be helpful (i.e., minimum number of animals, etc.). I do not think that I saw that

in this docume nt. Data selection is consistent with the procedures presented in
the 1985 Guidelines and k ey components of the data selection process are discussed in the criteria document. The 1985 Guidelines is generally available and it is beyond the scope of the document to provide additional discussion of the criteria necessary for data to be included/excluded from the analysis. No edits

needed.

Reviewer 5 My review of MWQC

- Cu Section 3 and Section 4 and the related

report citations suggests a complete and comprehensive inclusion of the available peer

- reviewed and published data validated for application to this purpose. For this review I did not access the individual papers to validate that the data was correctly used and transcribed in the context of the original citation. Thank you for your comment

. No edits

needed.19



### 2.4 C HARGE 

### Q UESTION 

### 3( B 

### )

3. ( b ) Are there other relevant data that you are aware of that should be included? If so, please provide the criteria.

Reviewer External Peer Reviewer Comments Regarding Charge

Question 3(b) EPA Response Revision
Location in

Document

Reviewer 1 Industr y should support the generation of chronic tests that

include the use of food that has been equilibrated with the identical aqueous test solutions used as the exposure water to the test animals. Only then will uncertainties about toxicity be

alleviated. EPA agrees that generation of additional estuarine/marine chronic toxicity data for copper by the scientific community

would be desirable. No edits

needed.

Reviewer 2 No. Thank you for your comment

. No edits

needed.

Reviewer 4 (See the answer to question #4). Thank you for your comment

. No edits

needed.

Reviewer 5 My search of the marine/seawater Cu toxicity literature found

only one marine aquatic toxicity reference uncited in the MWQC

Cu draft document, Oliveira, et al. (2014). My brief assessment of

t he findings of this work suggest it would not change the criterion developed in the MWQC

- Cu, however the authors may wish to confirm this and add this reference for completeness. Oliveira, BL (2014) Acute copper toxicity in juvenile fat snook Centropomus parallelus (Teleostei: Centropomidae) in sea water

NEOTROPICAL ICHTHYOLOGY Volume: 12 Issue: 4 Pages: 845

- 852
DOI: 10.1590/1982

- 0224

- 20140040 Thank you for the additional study. The data for the species met acceptability criteria and was added to the acute dataset. Various

locations20



### 2.5 C HARGE 

### Q UESTION 

### 4

4. Are the derived criteria appropriately protective of listed species and commercially and recreationally important species ?

Reviewer External Peer Reviewer Comments Regarding Charge

Question 4) EPA Response Revision
Location in

Document

Reviewer 1 I think ignoring all exposure routes leads to uncertainty here. EPA concurs with the reviewer about the difficulty in characterizing dietary exposure and establishing critical tissue

effects thresholds for bioaccumulated metals.

Text has been added to discuss these points and incorporate

the work of other researchers who discuss copper bioaccumulation and dietary exposure in detail and the uncertainties currently associated with its evaluation. In particular, text was added to detail how copper can bioaccumulate in aquatic organisms through multiple exposure

routes in cluding ingestion and direct exposure, and how total uptake depends on the copper concentration, exposure route and the duration of exposure. Section 4.3.1 (a new section)

Reviewer 2 In my opinion the derived criteria are appropriate, protective and

scientifically defensible. Thank you for your comment

. No edits

needed.

Reviewer 3 This question falls out of my area of expertise. However, the few

commercially and recreationally important species are well identified in the report. Thank you for your co mment

. No edits

needed.

Reviewer 4 I think that the Bielmyer et al., 2010 paper (listed in the unused

data table) should have been included because it presented chronic data about a sensitive tropical coral species that had been

listed as threatened under the ESA. It was not included because the coral are symbiotic and contained algae housed in their coral exoskeleton. If the algae were separated from the coral, then the coral would be stressed, and toxicity data from those organisms

would be skewed. Becau se symbiotic organisms are not included, they may not be protected by the copper CCC, particularly in tropical environments. This is another limitation of the chronic

data set. The Bielmyer et al. (2010) paper was reviewed and since the study methodology e mployed only three exposure

concentrations per test , each would be classified as unused. However, the data are discussed as other data in support of the

derived chronic criterion. Section 4.221 Reviewer External Peer Reviewer Comments Regarding Charge

Question 4) EPA Response Revision

Location in

Document

Reviewer 5 In my review of the draft report the MWQC

- Cu, the derived

criteria are appropriately protective of listed species and commercially and recreationally important species, by direct inclusion or extrapolation from published work. The authors have

followed acc epted pathways of aquatic ecosystem risk analysis and risk management, using best available knowledge and practices accepted in the major disciplinary areas overlapped in this complex challenge. In my view, the BLM has been satisfactorily adapted to seawat er/marine environments within the generally accepted limitations of all modeling approaches. The MWQC

- Cu draft report is honest about these limitations and the major MWQC

- Cu citation of Chadwick et al. (2008) explicitly and exhaustively explores the practi cal and economic limitations of quantitative risk assessment/management and the advantages of using well vetted models in a complex scenario of dynamic variables, multiple stressors, and multiple receptors. In this regard

the acute and chronic criteria dev eloped are a major step forward in marine/estuarine management of copper. Thank you for your comment

. No edits

needed.22



### 2.6 O THER 

### C OMMENTS 

### P ROVIDED

Reviewer Other Comments EPA Response Revision

Location in

Document

Reviewer 3 Other comments:

 Foreword, 1 st paragraph: “copper” rather than
“cadmium”. T he t ext was corrected as suggested. Foreword

Reviewer 3  Throughout the text there is an inconsistent use of:

spacing before and after equal (=) signs; spacing between parentheses; e.g. “)(“ or “)_(“; “fresh water” and “freshwater”; “salt water” and “saltwater”. Freshwater and/or fresh water use is grammatically correct.

Parentheses were edited to be consistent. Various

locations

Reviewer 3  Acronyms missing on page xii: MDR; GMCV. MDR, GMCV and SMCV were adde d to the Acronym List Acronyms

Reviewer 3  P. 4: Not clear to me why “registration” and

“reregistration” are both used. Th ese terms are consistent with the language FIFRA uses. No edits

needed.

Reviewer 3  P. 11: “...which form of Cu +1 or Cu +2 is found...” OR

“...which form s of Cu +1 or Cu +2 are found...” The text was edited as, “... which forms of Cu +1 or Cu +2 are found.” Section 2.2

Reviewer 3  P. 11: “...the free cupric (Cu 2+ ) ion may be present”:

the use of the word “may” suggests that this species

may be absent which is physically impossible. All species are always present but these concentrations may be very low. The text was edited as, “In oxic natural waters with neutral pH and above, the free cupric (Cu 2+ ) ion is generally a minor species (Stumm and Morgan 1981).” Section 2.2

Reviewer 3  P. 12, Figure 2: “forms” or “chemical species” instead

of “strategy”? T he t ext was edited as, “chemical species.” Figure 2

Reviewer 3  P. 21: Check font size for “μ”. T he t ext was revised as suggested. Section 2.4

Reviewer 3  P. 22, last line: Delete extra period. T he t ext was revised as suggested. Section 2.5

Reviewer 3  P. 33: HCO 3. T he t ext was revised as suggested. Section 2.8.323 Reviewer Other Comments EPA Response Revision

Location in

Document

Reviewer 3  P. 40, penultimate line: while alkalinity.

References cited: [1] Morel FMM ed. 1983. Principles of Aquatic Chemistry. John Wiley & Sons, New York, NY, USA.

[2] Campbell PGC. 1995. Interactions between trace metals and aquatic organisms: A critique of the free

- ion activity model. In Tessier A, Turner DR, eds, Metal Speciation and Bioavailability in Aquatic Systems. John Wiley & Sons, New York, NY, USA, pp 45

- 102. T he t ext was edited as, “...while salinity.” Section 3.3

Reviewer 4 Minor Comments:

Pg. 16 and Fig. 6: Delete blue outline around figures. T he t ext was revised as suggested. Figure 3 Figure 6

Reviewer 4 Pg. 22, last line: Delete the double period. T he t ext was revised as suggested. Section 2.5

Reviewer 4 Pg. 26, Table 2: Change “cadmium” to “copper” T he t ext was revised as suggested. Table 2

Reviewer 4 Pg. 32, 1st sentence: Delete “to” T he t ext was revised as suggested. Section 2.8.2

Reviewer 4 Pg. 40, second to last line: Change “whilealinity” to “while

salinity” T he t ext was revised as suggested. Section 3.3

Reviewer 4 Pg. 41, Table 8: Change the temperature to “22” instead of “2” T he t ext was revised as suggested. Table 8

Reviewer 4 Table 9, 1st line: Delete the space after “FAV” before “:” T he t ext was revised as suggested. Table 9

Reviewer 4 Fig. 11: Change “cadmium” to “copper” T he t ext was revised as suggested. Figure 11

Reviewer 4 Appendix F: Delete “Unused” as it is redundant. T he t ext was revised as suggested. Appendix F24



## 3 R EFERENCES 

## C ITED BY 

## R EVIEWERS

Bielmyer, G. K. and M. Grosell. 2011. Emerging issues in marine metal toxicity. Surface Chemistry, Bioavailability and Metal Homeostasis in Aquatic Organisms: An Integrated Approach. N. Bury and R. Handy. London (England), Kings College: 129

- 158.

Chadwick, D.B., I. Rivera

- Duarte, P.F. Wang, G . Rosen, R. Santore, P. Paquin and A. Ryan. 2008. Demonstration of an integrated compliance model for predicting copper fate and effects in DoD Harbors, Environmental Security Technology Certification Program (ESTCP). Project ER

- 0523, Final Report

November 1, 2008. Available online at: www.dtic.mil/dtic/tr/fulltext/u2/a499564.pdf

.

de Polo, A. and M.D. Scrimshaw. 2012. Challenges for the development of a biotic ligand model predicting copper toxicity in estuaries and seas. Environ. Toxicol. Chem. 31(2): 230

- 238.

de Polo, A., L. Margiotta

- Casaluci, A.E. Lockyer and M.D. Scrimshaw. 2014. A new role for carbonic anhydrase 2 in the response of fish to copper and osmotic stress: Implications for multi

- stressor studies. PLOS ONE 9(10) Article Number: e107707.

Deruytter, D., J. Garrevo et, M.B. Vandegehuchte, E. Vergucht, B. De Samber, B. Vekemans, K. Appel, G. Falkenberg, K. Delbeke, R. Blust, K.A.C. De Schamphelaere, L. Vincze and C.R. Janssen. 2014. The combined effect of dissolved organic carbon and salinity on the bioaccumulation of copper in marine mussel larvae. Environ. Sci. Tech. 48(1): 698

- 705.

Deruytter, D., M.B. Vandegehuchte, J. Garrevoet, F. De Laender, E. Vergucht, K. Delbeke, R. Blust, K.A.C. De Schamphelaere, L. Vincze and C.R. Janssen. 2015. Salinity and dissolved organ ic carbon both affect copper toxicity in mussel larvae: Copper speciation or competition cannot explain everything. Environ. Toxicol. Chem. 34(6): 1330

- 1336.

Erickson, R.J. 2013. The biotic ligand model approach for addressing effects of exposure water ch emistry on aquatic toxicity of metals: Genesis and challenges. Environ. Toxicol. Chem. 32(6): 1212

- 1214.

Jokela, W.E., J.P. Tilley and D.S. Ross. 2010. Manure nutrient content on Vermont dairy farms: Long

- term trends and relationships. Comm. Soil Sci. Pla nt Anal. 41(5): 623

- 637.

Kiaune, L. and N. Singhasemanon. 2011. Pesticidal copper (I) oxide: Environmental fate and aquatic toxicity. D.M. Whitacre ( Ed .). Rev. Environ. Contam. Toxicol. 213: 1

- 26.

Oliveira, B.L. 2014 Acute copper toxicity in juvenile fat snook Centropomus parallelus (Teleostei: Centropomidae) in sea water. Neotrop. Ichthyol. 12(4): 845

- 852.

Skrabal, S.A. J.R. Donat and D.J. Burdige. 2000. Pore water distributions of dissolved copper and copper

complexing ligands in estuarine and coastal marine sediments. Geochimica Et Cosmochimica Acta. 64(11):

1843

- 1857.

Thomas, K.V. and S. Brooks. 2010. The environmental fate and effects of antifouling paint biocides. Biofoul. 26(1): 73

- 88.

Turner, A. 2010. Marine pollution from antifouling paint part icles. Mar. Pollut. Bull. 60(2): 159

- 171.25



### U.S. EPA. 1998. Guidelines for ecological risk assessment. United States Environmental Protection Agency. Risk Assessment Forum. Office of Research and Development, Washington, D.C.

EPA/630/R

- 95/002F.