TECHNICAL MEMORANDUM, UPDATED TREND ANALYSIS …technical memorandum, updated trend analysis for housatonic river fish including 2012 and 2014 collections, young of year fish (10/05/2015

AVATA-t • - - 111 ~ 11'' ENVIRONMENTAL

A Service-Disabled Veteran-Owned Small Business

Depa1tment of the Army Corps of Engineers New England Division 696 Virginia Road Concord, MA 01742-751

Attn: Mr. Peter Hugh

Re: Contract W912WJ-14-D-0003 DCN: AE-100515-ABAZ

5 October 2015

Updated Trend Analysis for Housatonic River Young of Year Fish

Dear Mr. Hugh :

Avatar Environmental LLC (Avatar) herewith encloses the final technical memorandum from Gary Lawrence (Golder Associates) to Scott Campbell (Avatar Environmental) titled Updated Trend Analysis for Housatonic River Fish Including 2012 and 2014 Collections.

Please feel free to contact me at ( 413) 442-4224 if you have any questions regarding this enclosure.

Very truly yours,

Senior Project Manager

Avatar Environmental

Enclosures

Cc: DCN Files (Avatar)

Robe1t Leitch, USACE

Dean Tagliaferro, EPA

Golder Associates Ltd.

Suite 200 - 2920 Virtual Way, Vancouver, BC, V5M 0C4 Tel: +1 (604) 296 4200 Fax: +1 (604) 298 5253 www.golder.com

Golder Associates: Operations in Africa, Asia, Australasia, Europe, North America and South America

Golder, Golder Associates and the GA globe design are trademarks of Golder Associates Corporation.

1.0 INTRODUCTION

Golder Associates Ltd. (Golder) was retained by Avatar Environmental LLC (Avatar) to provide technical support

related to statistical assessment of Housatonic River fish tissue chemistry. The scope is summarized in the

document “Golder Associates Limited. Task Order 0001” submitted to Golder on April 28, 2015 under

Subcontractor Agreement 7900-10.

This memorandum summarizes the findings of an updated trend analysis for tissue PCB concentrations in

young-of-year (YOY) Housatonic River fish. The updated trend analysis is based on inclusion of 2012 and 2014

fish tissue data for whole body juvenile composite samples that were collected as part of General Electric’s

(GE’s) biennial YOY sampling program. No adult fish were collected as part of the 2012 and 2014 programs;

therefore, the assessment of trends in adult fish PCB concentrations remains as previously communicated to the

project team.

2.0 METHODS

The sampling design for the 2012 and 2014 programs was consistent with previous years, targeting seven

composite samples for each of three species (largemouth bass [LB], yellow perch [YP], and bluegill sunfish [BG])

from four sampling locations within the Housatonic River Rest-of-River area. The sampling locations were

consistent with previous monitoring events and included:

Reach 5B (GE Sampling ID of HR2) – located in Primary Study Area (PSA);

Reach 6 (Woods Pond; GE Sampling ID of WP) – located in PSA;

Reach 7G (Glendale Impoundment; GE Sampling ID of GD) – located downstream of PSA in

Massachusetts north of Rising Pond; and

Reach 9 (GE Sampling ID of HR6) – located downstream of PSA in Massachusetts south of Rising Pond.

DATE September 14, 2015 REFERENCE No. 1530443-001-TM-Rev2

TO Scott Campbell Avatar Environmental LLC

FROM Gary Lawrence EMAIL [email protected]

UPDATED TREND ANALYSIS FOR HOUSATONIC RIVER FISH INCLUDING 2012 AND 2014 COLLECTIONS

Scott Campbell 1530443-001-TM-Rev2

Avatar Environmental LLC September 14, 2015

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Although pumpkinseed sunfish (PK; Lepomis gibbosus) have been collected in previous biennial sampling programs, all centrarchid sunfish specimens collected in 2014 (as in all years since 2006) were bluegills (Lepomis macrochirus). Data for these two species have been kept distinct rather than pooled into an analysis for members of this genus. Although sunfish species from the genus Lepomis have generally similar anatomy and feeding ecology, the distinction among species prevents confounding from minor dietary differences and variable sample sizes among species.

With the exception of perch in 2012, all seven composite samples were collected for each target species and sampling location in 2012 and 2014. Each composite sample contained between 4 and 20 individual whole body YOY specimens. In 2012, there was difficulty collecting the target number of yellow perch. Therefore perch were only collected at Reach 5B (one composite sample) and Reach 6 (seven composite samples) in 2012, with none collected in downstream reaches.

Lipid-normalized concentrations of PCBs in fish tissues were calculated using sample-specific lipid content data. The wet weight concentration was divided by the fraction lipid (expressed on a decimal basis) to yield a PCB concentration in the units of mg/kg lipid.

Statistical analyses consisted of the following:

Descriptive Statistics – The raw PCB data were summarized (minimum, mean, median, maximum, interquartile range) for each species and sampling location, consistent with previous sampling events.

Halving Time Calculations – A simple exponential decay model was fit to each species, using combined data from the PSA.

General Linear Modeling (GLM) – For each species and for each of the two broad geographical areas (i.e., PSA samples and downstream samples), a GLM model was fit to the data. A GLM is a generalized model that incorporates combined elements of linear regression analysis and analysis of variance (ANOVA).

Prior to running the GLM model, the dependent variables (i.e., lipid-normalized or wet-weight

PCB concentrations) were natural logarithm (ln) transformed to stabilize variances and linearize exponential

decay trends. The initial model was fit using river reach as a categorical factor and sampling year as a

continuous variable, and the interaction effect (reach × year) was also assessed. In a stepwise manner, the

model was simplified to exclude non-significant terms. When the reach effect was determined to be statistically

significant, the year effect was tested for each reach individually.

An example of the initial analysis of variance from this recent updated trend analysis is provided below. In this

example, the reach and interaction terms were found to be non-significant (i.e., p-Value above 0.05).

Analysis of Variance – Lipid Normalized PCBs in PSA Largemouth Bass

Source Type III SS Degrees of Freedom

Mean Square F-Ratio p-Value

Year 10.158 1 10.158 89.051 <0.00001

Reach (Category) 0.039 1 0.039 0.343 Non-significant

(0.56)

Reach × Year (Interaction Term)

0.041 1 0.041 0.358 Non-significant

(0.55)

Model Error 17.682 155 0.114



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The incorporation of an interaction term is a formal test for similarity of regression slopes across sampled reaches. The non-significant interaction term in the above example meant that the slopes of the regressions among reaches were not statistically different, such that the GLM could be simplified to an ANOVA of main effects (reach, year).

Analysis of Variance – Lipid Normalized PCBs in PSA Largemouth Bass

Source Type III SS Degrees of Freedom

Mean Square F-Ratio p-Value

Year 10.131 1 10.131 89.18 <0.00001

Reach (Category) 1.802 1 1.802 15.864 <0.00001

Model Error 17.723 156 0.114

In this example, the significant reach term means that the magnitudes of PCB concentrations were significantly different between Reach 5BC and Reach 6. Note that the reach term was significant in the simplified model, despite having non-significance in the fully specified initial model. The removal of the extraneous interaction term resulted in the reallocation of the model variance to the remaining model terms, such that the p-value for the reach term changed. The significant reach term means that the model should be simplified into two linear regression models for each reach, as follows.

Regression Coefficient Matrix – Lipid Normalized PCBs in Reach 5B Largemouth Bass

Effect Coefficient Standard

Error Standard

Coefficient Tolerance t Statistic p-Value

Model Constant 91.916 9.101 0 . 10.1 <0.00001

Year -0.043 0.005 -0.735 1 -9.385 <0.00001

Regression Coefficient Matrix – Lipid Normalized PCBs in Reach 6 Largemouth Bass

Effect Coefficient Standard

Error Standard

Coefficient Tolerance t Statistic p-Value

Model Constant 81.942 14.125 0 . 5.801 <0.00001

Year -0.038 0.007 -0.512 1 -5.324 <0.00001

The low p-value (<0.00001) for the main effect of year in both reaches indicates a highly significant temporal trend, with a coefficient of -0.043 per year in Reach 5B and -0.038 per year in Reach 6 (indicative of decreasing PCB concentrations over time). Where a rate constant is calculated from linear regression on ln-transformed data, the halving time (i.e., average time for concentrations to decrease by factor of 2) can be calculated as (where λ is the absolute value of the regression coefficient [decay constant]):

The halving time calculated above does not refer to a reduction in the concentrations of individual fish (which tend to increase over time as fish grow, age, and increase lipid content), but rather references the yearly reduction of the average PCB concentration in YOY fish. By definition, each sampling event monitors a new cohort of YOY fish, with interannual changes attributable to the changes in the environmental exposures to PCBs.



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Using the regression coefficient for Reach 5B as example (λ = 0.043) therefore yielded a halving time of

approximately 16 years for PCBs (mg/kg lipid) in largemouth bass from Reach 5B. A similar procedure was

applied to other combinations of concentration type (wet weight or lipid normalized), location, and fish species.

3.0 RESULTS – PRIMARY STUDY AREA

Figures 1 through 6 depict the temporal trends in PSA composite fish samples between 1994 and 2014,

including trends in wet-weight and lipid-normalized PCB concentrations for each species. The plots indicate

substantial interannual variability but also convey overall long-term trends of decline in fish tissue PCB

concentrations. The rates of decrease in some of the plots do not appear to be consistent across the entire

period of record. For some species, steep reductions were observed between 2000 and 2002 relative to previous

sampling years, but only modest changes in PCB concentrations since that event. The steeper reductions

between 2000 and 2002 were most apparent in the lipid normalized concentration data for largemouth bass and

bluegill sunfish. The timing of the steepest reductions coincides with the timing of significant remediation

activities in the Upper 1/2-Mile Reach in the East Branch of the Housatonic River (i.e., the 2002 fish collections

are the first monitoring data following non-aqueous phase [NAPL] source control activities such as the

installation of impermeable sheet-pile walls along the riverbank, and removal of heavily contaminated sediment

and NAPL from the approximate 1/2-Mile stretch of the river adjacent to the GE facility). Because this steep

reduction occurred relatively early in the period of record, the rate of change predicted from the ln-linear model of

PCBs over the full period of record will overstate the actual rate of change under current conditions.

Following 2002, continued reductions of PCBs in YOY fish tissues are observed, although at a lower rate of

decline relative to the 2000-2002 period. The recent declines reflect a combination of natural recovery and the

continued influence of additional and ongoing remediation that affects boundary conditions (water and sediment

PCB sources to the Rest of River area). Upstream remediation efforts in other parts of the East Branch have

continued from 2002 to present day. These actions include the remediation of the sediment and bank soil in the

1.5 Mile Reach (2002-2006, entailing the removal of 91,700 cubic yards of PCB-contaminated sediment and

riverbank soil), remediation of former oxbows (2003-2007), actions in the GE Plant area (2008-2011),

remediation of Silver Lake (2012-2013), and remediation of Unkamet Brook (2015-present). All of these actions

continue to reduce the PCB loading to the Rest of River area; however, their effect may be less than the

reductions achieved from the initial source control and Upper 1/2-Mile reach remediation activities.

Figure 7 (wet weight) and Figure 8 (lipid normalized) display the descriptive statistics (median, interquartile

range, minimum, and maximum) derived from the individual concentration data described above.

A summary of the GLM analyses for PSA samples is provided in Table 1. The following subsections summarize

the statistical results for each species.

3.1 Largemouth Bass

The reach effect was statistically significant (p < 0.05) for both lipid-normalized and wet weight analyses (and

with a significant interaction term for wet weight analysis), meaning that the relationship with time varied

depending on the subreach investigated. Therefore, separate analyses were conducted for Reach 5B and

Reach 6.



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For both wet-weight and lipid-normalized analyses, samples from both Reach 5B and Reach 6 exhibited the

same general temporal pattern, including statistically significant decreases in PCBs over time (Figures 11 and 12).

The estimated halving times for PCB concentrations in PSA largemouth bass were:

Reach 5B (wet weight) – 19 years.

Reach 5B (lipid normalized) – 16 years.

Reach 6 (wet weight) – 36 years.

Reach 6 (lipid normalized) – 18 years.

The estimated halving times indicate that wet weight and lipid normalized PCB concentrations in Woods Pond

(Reach 6) fish are declining at a lower rate than in Reach 5B.

3.2 Bluegill Sunfish

The reach and interaction effect were statistically significant for lipid-normalized analysis, but not significant for

the wet weight analysis. As shown in Figure 3, the wet weight PCB concentrations in bluegill in 2000 were

elevated relative to other sampling years; this is partly attributable to the higher lipid concentrations observed in

that sampling year. Lipid-normalized PCB data were analyzed separately for Reach 5B and Reach 6, whereas

the wet weight PCB data form both reaches were pooled. The lipid-normalized PCB data in both reaches had the

same general temporal pattern (Figure 13).

The estimated halving times for PCB concentrations in PSA bluegill were:

Reach 5B (lipid normalized) – 11 years.


Reach 5B and 6 (pooled wet weight) – 12 years.

For the lipid-normalized analysis, the results were similar to YOY bass in that the decrease was more

pronounced (i.e., steeper rate of decline) in Reach 5B relative to Woods Pond. However, the decreasing trends

were statistically significant in both reaches.

3.3 Yellow Perch

The reach effect was not significant and was dropped from the model, leaving a simple model of PCBs versus

time. The results indicate a significant decrease over time for both lipid-normalized and wet weight PCB

concentrations (p < 0.0001). The 2012 and 2014 data confirm the broad finding that reductions in PCB

concentrations have occurred during the monitoring period (Figures 5 and 6).

Reach 5B and 6 (pooled wet weight) – 17 years.

Reach 5B and 6 (pooled lipid normalized) – 17 years.



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4.0 RESULTS – DOWNSTREAM

Figure 9 (wet weight concentrations) and Figure 10 (lipid normalized concentrations) display the descriptive

statistics (median, interquartile range, minimum, and maximum) derived from the individual values described

above.

A summary of the GLM analyses for downstream samples is provided in Table 2. The following subsections

summarize the statistical results for each species.

4.1 Largemouth Bass

The initial GLM indicated a significant reach effect for both wet weight and lipid-normalized PCBs. The locational

differences may be attributable to the reduced sediment PCB exposures between these sampling locations, as

related to the Rising Pond Dam and impoundment in Reach 8. Figures 9 and 10 indicate that there is a

systematic difference of approximately a factor of three for all fish species between Reach 7G and Reach 9 (note

the difference in the axis range between the reaches on these plots).

The models for both wet weight PCBs and lipid-normalized PCBs indicate a statistically significant decrease in

PCB concentrations over time. The general patterns of PCB concentrations over time were qualitatively similar in

the two reaches (Figures 14 and 15). PCB concentrations in Reach 9 largemouth bass increased in 2014 relative

to both 2010 and 2012 monitoring events; this caused a dampening of the overall rate of decline relative to the

previous trend analysis (which included data up to 2010 only). In contrast, the lipid-normalized PCB

concentrations in Reach 7G largemouth bass were among the lowest observed over the period of record, such

that the trend in Reach 7G has steepened relative to the previous trend analysis. These changes emphasize the

sensitivity of the trend analyses to inter-annual variability in PCB concentrations.

The estimated halving times for PCB concentrations in downstream largemouth bass were:

Reach 7G (wet weight) – 20 years.

Reach 7G (lipid normalized) – 22 years.



4.2 Bluegill Sunfish

The bluegills in both reaches exhibited a statistically significant declining trend for both wet weight and lipid-

normalized PCB data. The bluegill data indicate differences in the magnitudes of PCB concentrations between

the two reaches (Figures 16 and 17).

The estimated halving times for PCB concentrations in downstream bluegill sunfish were:







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Based on estimated halving times, wet weight and lipid normalized PCB concentrations in Reach 9 fish appear

to be declining more slowly than in Reach 7G.

4.3 Yellow Perch

The 2014 perch YOY PCB concentrations were similar or higher than concentrations observed in 2010

(Figures 9 and 10). Similar to the other fish species in downstream reaches, the initial GLM indicated a

significant reach effect for both wet weight and lipid-normalized PCBs. For both wet-weight and lipid-normalized

analyses, we observed the same general temporal pattern (Figures 11 and 12). The perch in both reaches

exhibited a statistically significant declining trend for both wet weight and lipid-normalized PCB data.

The estimated halving times for PCB concentrations in downstream yellow perch were:





Similar to the trend observed for bluegills, PCB concentrations in Reach 9 fish appear to be declining more

slowly than in Reach 7G.

5.0 CONCLUSIONS

In PSA reaches, PCB concentrations in bass, bluegill sunfish, and perch samples collected in 2012 and 2014

remain elevated but are among the lowest observed over the period of record, suggesting that PCB

concentrations are continuing to decline. Statistically significant decreases were observed for all species and

sampling locations over the period of record, and qualitatively similar trends were observed for both wet weight

and lipid-normalized concentrations. However, some species appeared to exhibit a “step function”, in which the

trends in concentrations are less steep both before and after the 2000-2002 period of decline. The differences

between the slopes across the period of record may be related to changes attributable to upstream remediation

efforts in the East Branch. The rate of decline was greatest immediately following non-aqueous phase [NAPL]

source control activities in the East Branch, with continued reductions since 2002 concurrent with ongoing

remediation elsewhere in the East Branch. The significant reductions observed between 2000 and 2002

influence the overall model fit, such that the rate of decline over the last 15 years may be significantly less than

suggested by the regression models fit to the entire period of record.

In downstream reaches, PCB concentrations in fish samples collected in 2012 and 2014 are generally similar

to concentrations previously observed during the period of monitoring. For some species and locations

(e.g., Reach 9 bass), average concentrations were higher than other recent monitoring events, although this is

likely due to variance (interannual variability) that is not associated with the longer-term trend of gradual decline.

Statistically significant decreases were observed for all species and sampling locations over the period of record.

The rate of decline of PCB concentrations in fish collected from Reach 9 appears to be considerably lower than

fish from Reach 7G, and also lower than observed in PSA fish.



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In terms of the rate of change (halving times of PCBs in fish tissues), estimates calculated from slope coefficients range from approximately a decade to up to four decades. This wide variation results from pronounced variability in fish tissue concentrations, with individual sampling events often yielding mean values that deviate from the long term trends, resulting in imprecise slope estimates for some species that fluctuate as new data are added to the analysis. These fluctuations will have reduced influence as more years of monitoring data are conducted. Overall, the PSA data indicate halving times of approximately 20 years, which is similar to the approximate halving times of Reach 7G. The halving times in downstream reaches have increased relative to estimates previously reported in 2011.

There are important limitations to this analysis, including the following:

The ln-linear model assumes a continuous, exponential rate of change (decline) during the entire record of monitoring. As indicated previously, changes to upstream boundary conditions due to remediation activities may affect the validity of this assumption because remediation efforts, although ongoing from 2000-2015, would not have an equal effect on boundary conditions over the entire period of record. Segmented regression modeling (i.e., hockey-stick or other regression models) would be required to compare slopes across different portions of the monitoring period.

Some structure to model residuals was observed, which is indicative of potential violation of underlying regression model assumptions. Although the structure was not considered to warrant discarding the model output, it adds uncertainty to the estimates of model parameters (including slopes).

The variability of the underlying dataset prevents the development of precise estimates of slopes (rates of decline).

Given the above referenced changes to upstream boundary conditions, it is possible that the rate of decline in fish tissue concentrations is best represented by multiple slopes, with the steeper slopes representing change following the most significant upstream removal actions, and the shallower slope representing the slower rate of change under conditions of less intensive remediation and/or natural recovery. In previous statistical assessments, there were insufficient rounds of tissue monitoring to distinguish multiple slopes within the period of record, particularly given the degree of interannual variability observed for all monitored species. However, as the monitoring program continues, the power to detect significant slope changes steadily improves. At present, there are seven biennial monitoring events post-2000, and with future collections the data will support a quantitative evaluation that is restricted to post-remediation monitoring events. Therefore, in subsequent analyses, we recommend that halving times be calculated using two approaches:

Full record – Repeat the approach applied in this memorandum, acknowledging that the derived slopes reflect both short and long-term trends over the entire period of record.

Post-1/2 mile remediation – Constrain the data to results from 2002 and more recent, to provide an estimate of changes expected under more recent boundary conditions.

Both approaches above have limitations given that boundary conditions are changing as a result of both remediation actions and natural processes, such that no single or consistent rate of decline can be assumed. The concentrations in YOY reflect the exposures in both water and sediment, both of which are influenced by fate and transport processes that are time-variable. The degree to which reductions reflect changing exposure conditions from upstream boundary conditions versus natural recovery processes is uncertain, and such complexities are beyond the scope of this study.

Scott Campbell

Avatar Environmental LLC

1530443-001-TM-Rev2

September 14, 2015

Given the constraints to formal statistical trend assessment, the importance of graphical (visual) assessment of the PCB concentration data is emphasized. The figures included with this memorandum provide important context for the statistical output provided in Tables 1 and 2.

In summary, the analysis of long-term YOY monitoring data, including the addition of data from the 2012 and 2014 sampling years, indicates a continuation of the previously identified trend of slowly decreasing PCB concentrations in all monitored fish species. However, elevated concentrations of PCBs continue to be observed

in YOY collected in 2012 and 2014. The rates of decline are generally similar to those observed in the previous trend assessment, although some combinations of location and species indicate strengthening or weakening of slopes. For example, the rates of decline in Reach 9 largemouth bass and perch have decreased relative to previous trend analyses. The calculations of slopes are influenced by interannual variations in PCB tissue chemistry and to the strong influence of some individual sampling years (e.g., 2000 sampling event in Reach 7G). However, when viewed in aggregate, the findings from the most recent two years of monitoring do not fundamentally change our understanding of the long-term trends in PCB concentrations.

6.0 CLOSURE

We trust that the enclosed information is sufficient to meet your current needs. If you have any questions, feel free to contact Gary Lawrence at 604-297-2003.

GOLDER ASSOCIATES LTD.

James Dwyer, M.Sc. Environmental Scientist

JCD/GSL/lih

Gary Lawrence, M.R.M, R.P. Bio. Associate, Senior Environmental Scientist

o:\final\201513 proj\1530443 avatar confidential\ 1530443-001-tm-rev2\1530443-001-tm-rev2-trend analysis for fish pcb 14sep_ 15.docx

9/30 (ft Golder

Associates



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Table 1: Summary of GLM Analysis for Primary Study Area

Fish Type Parameter

Reach Effect Year Effect

Comments p (main effect)

p (interaction)

Reach p Slope

YOY Largemouth Bass

tPCB mg/kg lipid <0.0001 ns Reach 5BReach 6

<0.0001 <0.0001

-0.043 -0.038

No concerns with pattern of residuals

tPCB mg/kg ww 0.01 0.01 Reach 5BReach 6

<0.0001 0.001

-0.037 -0.019

Two outliers excluded from statistical analysis of Reach 5B (low values in 2006);slight structure in residuals

YOY Bluegill Sunfish

tPCB mg/kg lipid 0.04 0.04 Reach 5BReach 6

<0.0001 <0.0001

-0.065 -0.048

Slight to moderate structure in residuals

tPCB mg/kg ww ns ns na <0.0001 -0.056 Slight structure in residuals; one outlier removed from statistical analysis of Reach 6 (low value in 1994)

YOY Yellow Perch

tPCB mg/kg lipid ns ns na <0.0001 -0.04

Slight structure in residuals (possible step function); two outliers removed from statistical analysis of Reach 6 (high value in 1994 and low value in 2012)

tPCB mg/kg ww ns ns na <0.0001 -0.042

Slight structure in residuals (possible step function); one outlier removed from statistical analysis of Reach 6 (low value in 2012)

Note: Dependent variable ln-transformed

When Reach effect significant, year effect was tested for each reach individually

ns = non-significant at α=0.05; na = not applicable (factor was ns)



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Table 2: Summary of GLM Analysis for Downstream Reaches

Fish Type Parameter

Reach Effect Year Effect

Comments p (main effect)

p (interaction)

Reach p Slope

YOY Largemouth Bass

tPCB mg/kg lipid <0.0001 ns Reach 7GReach 9

<0.0001 <0.0001

-0.032 -0.035

No concerns with pattern of residuals

tPCB mg/kg ww <0.0001 ns Reach 7GReach 9

<0.0001 <0.0001

-0.035 -0.043

Slight to moderate structure in residuals; one outlier removed from Reach 9 (low value in 2006)

YOY Bluegill Sunfish

tPCB mg/kg lipid 0.007 0.008 Reach 7GReach 9

<0.0001 0.003

-0.049 -0.021

Moderate to strong structure in residuals

tPCB mg/kg ww <0.0001 ns Reach 7GReach 9

<0.0001 <0.0001

-0.05 -0.026

Moderate to strong structure in residuals

YOY Yellow Perch

tPCB mg/kg lipid 0.012 0.014 Reach 7GReach 9

<0.0001 <0.0001

-0.033 -0.016

Moderate to strong structure in residuals; one outlier removed from statistical analysis of Reach 9 (low value in 2006)

tPCB mg/kg ww <0.0001 <0.0001 Reach 7GReach 9

<0.0001 <0.0001

-0.054 -0.023

Moderate structure in residuals; one outlier removed from statistical analysis of Reach 9 (low value in 2006)

Note: Dependent variable ln-transformed

When Reach effect significant, year effect was tested for each reach individually

ns = non-significant at α=0.05; na = not applicable (factor was ns)



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Figure 1: Temporal trend of PCB concentrations (wet weight) in young of year largemouth bass (PSA)



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Figure 2: Temporal trend of PCB concentrations (lipid normalized) in young of year largemouth bass (PSA)



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Figure 3: Temporal trend of PCB concentrations (wet weight) in young of year bluegill sunfish (PSA)



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Figure 4: Temporal trend of PCB concentrations (lipid normalized) in young of year bluegill sunfish (PSA)



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Figure 5: Temporal trend of PCB concentrations (wet weight) in young of year yellow perch (PSA)



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Figure 6: Temporal trend of PCB concentrations (lipid normalized) in young of year yellow perch (PSA)



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Figure 7: Wet Weight PCB Concentrations over Time in YOY Fish from Biennial Sampling (PSA Reaches)

0

10

20

30

40

50

60

BG BG BG BG BG BG BG BG BG BG BG LB LB LB LB LB LB LB LB LB LB LB PS PS PS PS PS PS PS PS PS PS PS YP YP YP YP YP YP YP YP YP YP YP

94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14

tPC

Bin

YO

YW

ho

le B

od

y (m

g/k

g w

w)

Species/Year

Reach 5BMedian (with maximum and minimum)75th percentile25th percentile

0

10

20

30

40

50

60

BG BG BG BG BG BG BG BG BG BG BG LB LB LB LB LB LB LB LB LB LB LB YP YP YP YP YP YP YP YP YP YP YP

94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14

tPC

Bin

YO

YW

ho

le B

od

y (m

g/k

g w

w)

Species/Year

Reach 6Median (with maximum and minimum)75th percentile25th percentile



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Figure 8: Lipid-Normalized PCB Concentrations over Time in YOY Fish from Biennial Sampling (PSA Reaches)

Median (with maximum and minimum)

75th percentile

25th percentile

0

500

1000

1500

2000

BG BG BG BG BG BG BG BG BG BG BG LB LB LB LB LB LB LB LB LB LB LB YP YP YP YP YP YP YP YP YP YP YP

94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14

Species/Year

Reach 6

0

500

1000

1500

2000

2500


94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14

tPC

Bin

YO

YW

ho

le B

od

y (m

g/k

g li

pid

)

Species/Year

Reach 5B

tPC

Bin

YO

YW

ho

le B

od

y (m

g/k

g li

pid

) 2500

Median (with maximum and minimum)75th percentile25th percentile

Median (with maximum and minimum)75th percentile25th percentile



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Figure 9: Wet Weight PCB Concentrations over Time in YOY Fish from Biennial Sampling (Downstream Reaches in Massachusetts)

0

5

10

15

20

25

30

BG BG BG BG BG BG BG BG BG BG LB LB LB LB LB LB LB LB LB LB PS PS PS PS PS PS PS PS PS PS YP YP YP YP YP YP YP YP YP YP

96 98 00 02 04 06 08 10 12 14 96 98 00 02 04 06 08 10 12 14 96 98 00 02 04 06 08 10 12 14 96 98 00 02 04 06 08 10 12 14

tPC

Bin

YO

YW

ho

le B

od

y (m

g/k

g w

w)

Species/Year

Reach 7G (Glendale Dam)Median (with maximum and minimum)75th percentile25th percentile

0

2

4

6

8

10


94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14

tPC

Bin

YO

YW

ho

le B

od

y (m

g/k

g w

w)

Species/Year

Reach 9 (Downstream of Rising Pond)Median (with maximum and minimum)75th percentile25th percentile



21/30

Figure 10: Lipid-Normalized PCB Concentrations over Time in YOY Fish from Biennial Sampling (Downstream Reaches in Massachusetts)

0

100

200

300

400

500

600

700

BG BG BG BG BG BG BG BG BG BG LB LB LB LB LB LB LB LB LB LB PS PS PS PS PS PS PS PS PS PS YP YP YP YP YP YP YP YP YP YP

96 98 00 02 04 06 08 10 12 14 96 98 00 02 04 06 08 10 12 14 96 98 00 02 04 06 08 10 12 14 96 98 00 02 04 06 08 10 12 14tPC

Bin

YO

YW

ho

le B

od

y (m

g/k

g li

pid

)

Species/Year

Reach 7G (Glendale Dam)Median (with maximum and minimum)75th percentile25th percentile

0

50

100

150

200

250


94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14 94 96 98 00 02 04 06 08 10 12 14tPC

Bin

YO

YW

ho

le B

od

y (m

g/k

g l

ipid

)

Species/Year

Reach 9 (Downstream of Rising Pond)Median (with maximum and minimum)75th percentile25th percentile



22/30

Figure 11: Wet Weight PCB Concentrations (mg/kg ww, natural logarithm) over Time in Largemouth Bass YOY from Primary Study Area (LCL = 95% Lower Confidence Limit; UCL = 95% Upper Confidence Limit; LPL = 95% Lower Prediction Limit; UPL = 95% Upper Prediction Limit)

Reach 5B

1990 2000 2010 2020

YEAR

2.2

2.8

3.3

3.8

LN_P

CB

_WW

UPLLPLUCLLCLESTIMATE

Reach 6

1990 2000 2010 2020

YEAR

1.8

2.7

3.6

4.5



23/30

Figure 12: Lipid Normalized PCB Concentrations (mg/kg lipid, natural logarithm) over Time in Largemouth Bass YOY from Primary Study Area (LCL = 95% Lower Confidence Limit; UCL = 95% Upper Confidence Limit; LPL = 95% Lower Prediction Limit; UPL = 95% Upper Prediction Limit)

Reach 5B

1990 2000 2010 2020

YEAR

5

6

7

8

LN_P

CB

_LIP


Reach 6

1990 2000 2010 2020

YEAR

4.5

6.0

7.5

9.0



24/30

Figure 13: Lipid Normalized PCB Concentrations (mg/kg lipid, natural logarithm) over Time in Bluegill YOY from Primary Study Area (LCL = 95% Lower Confidence Limit; UCL = 95% Upper Confidence Limit; LPL = 95% Lower Prediction Limit; UPL = 95% Upper Prediction Limit)

Reach 5B

1990 2000 2010 2020

YEAR

4.4

5.5

6.6

7.7

LN_P

CB

_LIP


Reach 6

1990 2000 2010 2020

YEAR

4.5

5.4

6.3

7.2



25/30

Figure 14: Wet Weight PCB Concentrations (mg/kg ww, natural logarithm) over Time in Largemouth Bass YOY from Downstream Reaches (LCL = 95% Lower Confidence Limit; UCL = 95% Upper Confidence Limit; LPL = 95% Lower Prediction Limit; UPL = 95% Upper Prediction Limit)

Reach 7G

1990 2000 2010 2020

YEAR

0

1

2

3

LN_P

CB

_WW


Reach 9

1990 2000 2010 2020

YEAR

-1

0

1

2



26/30

Figure 15: Lipid Normalized PCB Concentrations (mg/kg lipid, natural logarithm) over Time in Largemouth Bass YOY from Downstream Reaches (LCL = 95% Lower Confidence Limit; UCL = 95% Upper Confidence Limit; LPL = 95% Lower Prediction Limit; UPL = 95% Upper Prediction Limit)

Reach 7G

1990 2000 2010 2020

YEAR

3.6

4.5

5.4

6.3

LN_P

CB

_LIP


Reach 9

1990 2000 2010 2020

YEAR

3

4

5

6



27/30

Figure 16: Wet Weight PCB Concentrations (mg/kg ww, natural logarithm) over Time in Bluegill YOY from Downstream Reaches (LCL = 95% Lower Confidence Limit; UCL = 95% Upper Confidence Limit; LPL = 95% Lower Prediction Limit; UPL = 95% Upper Prediction Limit)

Reach 7G

1990 2000 2010 2020

YEAR

-2

0

2

4

LN_P

CB

_WW


Reach 9

1990 2000 2010 2020

YEAR

-1

0

1

2



28/30

Figure 17: Lipid Normalized PCB Concentrations (mg/kg lipid, natural logarithm) over Time in Bluegill YOY from Downstream Reaches (LCL = 95% Lower Confidence Limit; UCL = 95% Upper Confidence Limit; LPL = 95% Lower Prediction Limit; UPL = 95% Upper Prediction Limit)

Reach 7G

1990 2000 2010 2020

YEAR

3.6

4.5

5.4

6.3

LN_P

CB

_LIP


Reach 9

1990 2000 2010 2020

YEAR

2.7

3.6

4.5

5.4



29/30

Figure 18: Wet Weight PCB Concentrations (mg/kg ww, natural logarithm) over Time in Yellow Perch YOY from Downstream Reaches (LCL = 95% Lower Confidence Limit; UCL = 95% Upper Confidence Limit; LPL = 95% Lower Prediction Limit; UPL = 95% Upper Prediction Limit)

Reach 7G

1990 2000 2010 2020

YEAR

0.9

1.8

2.7

3.6

LN_P

CB

_WW


Reach 9

1990 2000 2010 2020

YEAR

0.9

1.8

2.7

3.6



30/30

Figure 19: Lipid Normalized PCB Concentrations (mg/kg lipid, natural logarithm) over Time in Yellow Perch YOY from Downstream Reaches (LCL = 95% Lower Confidence Limit; UCL = 95% Upper Confidence Limit; LPL = 95% Lower Prediction Limit; UPL = 95% Upper Prediction Limit)

Reach 7G

1990 2000 2010 2020

YEAR

4

5

6

7

LN_P

CB

_LIP


Reach 9

1990 2000 2010 2,020

YEAR

4.0

4.5

5.0

5.5

Documents

TECHNICAL MEMORANDUM, UPDATED TREND ANALYSIS …technical memorandum, updated trend analysis for housatonic river fish including 2012 and 2014 collections, young of year fish (10/05/2015