HUDSON GENERATING STATION

316(b) STUDY REPORT

2009-2011

Prepared for:

PSEG Fossil LLC

80 Park Plaza

Newark, New Jersey 07102

Prepared by:

ASA Analysis & Communication, Inc.

5 Fairlawn Drive, Suite 205

PO Box 57

Washingtonville, New York 10992

June 2011
HUDSON GENERATING STATION 316(b) STUDY REPORT

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TABLE OF CONTENTS

LIST OF FIGURES

LIST OF TABLES

1. INTRODUCTION.............................................................................................................. 1-1

2. STATION DESCRIPTION AND OPERATION............................................................ 2-1

2.1 INTAKE STRUCTURE............................................................................................ 2-1

2.2 STATION OPERATION .......................................................................................... 2-2

3. WATERBODY DESCRIPTION ...................................................................................... 3-1

3.1 PHYSICAL FEATURES .......................................................................................... 3-1

3.2 AQUATIC HABITAT............................................................................................... 3-2

3.3 WATER AND SEDIMENT QUALITY................................................................... 3-3

3.3.1 Water Quality........................................................................................................... 3-3

3.3.2 Sediment Quality ..................................................................................................... 3-5

4. FISH COMMUNITY......................................................................................................... 4-1

4.1 HISTORICAL COMMUNITY................................................................................. 4-1

4.2 RECENT CHANGES ................................................................................................ 4-1

4.3 2009-2010 TRAWL AND ICHTHYOPLANKTON SURVEYS............................ 4-4

4.3.1 Bottom Trawling Methods....................................................................................... 4-4

4.3.2 Bottom Trawling Results......................................................................................... 4-5

4.3.3 Ichthyoplankton Sampling Methods........................................................................ 4-5

4.3.4 Ichthyoplankton Sampling Results.......................................................................... 4-6

5. ENTRAINMENT............................................................................................................... 5-1

5.1 METHODS................................................................................................................. 5-1

5.1.1 Sampling Schedule................................................................................................... 5-1

5.1.2 Sampling Gear and Methods.................................................................................... 5-1

5.1.3 Sample Processing ................................................................................................... 5-2

5.1.4 QA/QC..................................................................................................................... 5-3

5.2 RESULTS ................................................................................................................... 5-3

5.2.1 Species and Life Stage Composition ....................................................................... 5-3

5.2.2 Temporal Patterns.................................................................................................... 5-4

5.2.3 Comparison to 1996-1997 Entrainment Study ........................................................ 5-5

6. IMPINGEMENT................................................................................................................ 6-1

6.1 METHODS................................................................................................................. 6-1

6.1.1 Sampling Schedule................................................................................................... 6-1

6.1.2 Sampling Gear and Methods.................................................................................... 6-1

6.1.3 Sample Processing ................................................................................................... 6-2
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6.1.4 QA/QC..................................................................................................................... 6-3

6.2 RESULTS ................................................................................................................... 6-3

6.2.1 Species Composition................................................................................................ 6-3

6.2.2 Seasonal Patterns ..................................................................................................... 6-4

6.2.3 Comparison to 1996-1997 Impingement Study....................................................... 6-5

7. IMPINGEMENT SURVIVAL.......................................................................................... 7-1

7.1 METHODS................................................................................................................. 7-1

7.2 OVERALL IMPINGEMENT SURVIVAL............................................................. 7-2

7.3 FACTORS AFFECTING SURVIVAL.................................................................... 7-2

8. ANNUAL DIRECT LOSSES............................................................................................ 8-1

8.1 METHODS................................................................................................................. 8-1

8.2 RESULTS ................................................................................................................... 8-3

8.2.1 Entrainment.............................................................................................................. 8-3

8.2.2 Impingement ............................................................................................................ 8-3

8.3 COMPARISON OF 1996-1997 AND 2009-2011 RESULTS.................................. 8-4

9. HUDSON UNIT 1 .............................................................................................................. 9-1

9.1 LONG-TERM VIABILITY OF UNIT 1 ................................................................. 9-1

9.2 PROPOSED 316(b) RULE........................................................................................ 9-1

9.3 CONCLUSION .......................................................................................................... 9-2

10. LITERATURE CITED ............................................................................................... 10-1

APPENDIX A............................................................................................................................ A-1

APPENDIX B ............................................................................................................................ B-1

APPENDIX C............................................................................................................................ C-1
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LIST OF FIGURES

Figure 2-1. Location Map for Hudson Generating Station ........................................................ 2-4

Figure 2-2. Aerial View of Hudson Generating Station ............................................................. 2-5

Figure 2-3. Intake Structure of Hudson Generating Station ....................................................... 2-6

Figure 2-4. Intake and Discharge Water Temperatures and Total Daily Cooling Water Flow for 

Unit 1, January 2009 – January 2011........................................................................................... 2-7

Figure 2-5. Intake and Discharge Water Temperatures and Total Daily Cooling Water Flow for 

Unit 2, January 2009 – January 2011........................................................................................... 2-8

Figure 4-1. Bottom Trawl and Ichthyoplankton Sampling Stations........................................... 4-7

Figure 4-2. Total Annual Bottom Trawl Catch by Sampling Station, 2010 and 2011 ............... 4-8

Figure 4-3. Total Monthly Bottom Trawl Catch by Sampling Station, 2009 and 2010 ............. 4-9

Figure 4-4. Average Monthly Ichthyoplankton Density, 2009 and 2010 ................................. 4-10

Figure 4-5. Average Seasonal Ichthyoplankton Density at Five Sampling Stations, 2009 and 

2010............................................................................................................................................ 4-11

Figure 5-1. Temporal Distribution of Entrainment by Life Stage for All Species Combined, 

2009-2010 .................................................................................................................................... 5-6

Figure 5-2. Temporal Distribution of Entrainment by Life Stage for All Species Combined, 

2010-2011 .................................................................................................................................... 5-7

Figure 5-3. Temporal Distribution of Entrainment by Life Stage for Bay Anchovy, 2009-2010 5-

8

Figure 5-4. Temporal Distribution of Entrainment by Life Stage for Bay Anchovy, 2010-2011 5-

9

Figure 5-5. Temporal Distribution of Entrainment by Life Stage for Atlantic Croaker, 2009-

2010............................................................................................................................................ 5-10

Figure 5-6. Temporal Distribution of Entrainment by Life Stage for Atlantic Croaker, 2010-

2011............................................................................................................................................ 5-11

Figure 5-7. Temporal Distribution of Entrainment by Life Stage for Tautog, 2009-2010....... 5-12

Figure 5-8. Temporal Distribution of Entrainment by Life Stage for Tautog, 2010-2011....... 5-13

Figure 5-9. Temporal Distribution of Entrainment by Life Stage for Atlantic Menhaden, 2009-

2010............................................................................................................................................ 5-14

Figure 5-10. Temporal Distribution of Entrainment by Life Stage for Atlantic Menhaden, 2010-

2011............................................................................................................................................ 5-15

Figure 5-11. Temporal Distribution of Entrainment by Life Stage for Naked Goby, 2009-2010 5-

16

Figure 5-12. Temporal Distribution of Entrainment by Life Stage for Naked Goby, 2010-2011 5-

17

Figure 6-1. Weekly Impingement Rate for All Fish Species Combined by Age Group, 2009-

2010 (Year 1) and 2010-2011 (Year 2)........................................................................................ 6-6

Figure 6-2 Weekly Impingement Rate for White Perch by Age Group, 2009-2010 (Year 1) and 

2010-2011 (Year 2)...................................................................................................................... 6-7

Figure 6-3. Length Frequency of Impinged White Perch, 2009-2010 (Year 1) and 2010-2011 

(Year 2)........................................................................................................................................ 6-8

Figure 6-4. Weekly Impingement Rate for Bay Anchovy by Age Group, 2009-2010 (Year 1) 

and 2010-2011 (Year 2)............................................................................................................... 6-9
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Figure 6-5. Length Frequency of Impinged Bay Anchovy, 2009-2010 (Year 1) and 2010-2011 

(Year 2)...................................................................................................................................... 6-10

Figure 6-6. Weekly Impingement Rate for Spotted Hake by Age Group, 2009-2010 (Year 1) and 

2010-2011 (Year 2).................................................................................................................... 6-11

Figure 6-7. Length Frequency of Impinged Spotted Hake, 2009-2010 (Year 1) and 2010-2011 

(Year 2)...................................................................................................................................... 6-12

Figure 6-8. Weekly Impingement Rate for Atlantic Silverside by Age Group, 2009-2010 (Year 

1) and 2010-2011 (Year 2)......................................................................................................... 6-13

Figure 6-9. Length Frequency of Impinged Atlantic Silverside, 2009-2010 (Year 1) and 2010-

2011 (Year 2)............................................................................................................................. 6-14

Figure 6-10. Weekly Impingement Rate for Blue Crab, 2009-2010 (Year 1) and 2010-2011 

(Year 2)...................................................................................................................................... 6-15

Figure 6-11. Size Frequency (Carapace Width) of Impinged Blue Crab, 2009-2010 (Year 1) and 

2010-2011 (Year 2).................................................................................................................... 6-16

Figure 6-12. Mean Density of Impinged White Perch by 6-Hour Collection Period, 2009 and 

2010............................................................................................................................................ 6-17

Figure 6-13. Mean Density of Impinged Bay Anchovy by 6-Hour Collection Period, 2009 and 

2010............................................................................................................................................ 6-18

Figure 6-14. Mean Density of Impinged Spotted Hake by 6-Hour Collection Period, 2009 and 

2010............................................................................................................................................ 6-19

Figure 6-15. Mean Density of Impinged Atlantic Silverside by 6-Hour Collection Period, 2009 

and 2010..................................................................................................................................... 6-20

Figure 6-16. Mean Density of Impinged Blue Crab by 6-Hour Collection Period, 2009 and 2010

.................................................................................................................................................... 6-21
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LIST OF TABLES

Table 2-1. Monthly Mean Cooling Water Flow Rate (MGD) and Percentage of Maximum 

Design Generation and Flow Rate for Unit 1, 2007-2010........................................................... 2-9

Table 2-2. Monthly Mean Cooling Water Flow Rate (MGD) and Percentage of Maximum 

Design Generation and Flow Rate for Unit 2, 2007-2010......................................................... 2-10

Table 4-1. Fish Species Collected From the Hackensack River (Sources: PSE&G 1998, Bragin 

et al. 2005, and Present Study)................................................................................................... 4-12

Table 4-2. Percent Composition of Bottom Trawl Catches in 1971-1973, 1986-1987, 1996-1997, 

and 2009-2010 ........................................................................................................................... 4-15

Table 4-3 Annual Presence of Ichthyoplankton by Life Stage in the Hackensack River Study 

Area for 1972-1973, 1986-1987, 1996-1997, and 2009-2010................................................... 4-17

Table 4-4. Species Composition of Impingement Collections during 1972-1973, 1978, 1987-

1988, and 1996-1997 ................................................................................................................. 4-19

Table 4-5. Presence of Species by Life Stage in Entrainment Collections in 1987-1988 and 

1996-1997 .................................................................................................................................. 4-22

Table 4-6. Gear Specifications for the Bottom Trawl and Ichthyoplankton Net...................... 4-23

Table 4-7. Monthly Total Bottom Trawl Catch by Species, 2009............................................ 4-24

Table 4-8. Monthly Total Bottom Trawl Catch by Species, 2010............................................ 4-25

Table 4-9. Average Monthly Ichthyoplankton Density (#/1,000 m3) at Five Sampling Stations in 

2009............................................................................................................................................ 4-26

Table 4-10. Average Monthly Ichthyoplankton Density (#/1,000 m3) at Five Sampling Stations 

in 2010 ....................................................................................................................................... 4-26

Table 5-1. Number of Samples Collected in Entrainment Monitoring at Hudson Generating 

Station, January 2009 – January 2011 ....................................................................................... 5-18

Table 5-2. Overall Numerical Composition of Ichthyoplankton Collected in Entrainment 

Monitoring at Hudson Generating Station, 26 January 2009 – 18 January 2010...................... 5-19

Table 5-3. Overall Numerical Composition of Ichthyoplankton Collected in Entrainment 

Monitoring at Hudson Generating Station, 25 January 2010 – 17 January 2011...................... 5-20

Table 5-4. Average Diel Density (#/1,000 m3) of Selected Species Collected in Entrainment 

Monitoring, 26 January 2009 – 18 January 2010 ...................................................................... 5-21

Table 5-5. Average Diel Density (#/1,000 m3) of Selected Species Collected in Entrainment 

Monitoring, 25 January 2010 – 17 January 2011 ...................................................................... 5-22

Table 6-1. Number of Samples Collected in Impingement Monitoring at Hudson Generating 

Station, January 2009 – January 2011 ....................................................................................... 6-22

Table 6-2. Overall Numerical Composition of Fish Species Collected in Impingement 

Monitoring at Hudson Generating Station, 26 January 2009 – 18 January 2010...................... 6-23

Table 6-3. Overall Numerical Composition of Fish Species Collected in Impingement 

Monitoring at Hudson Generating Station, 25 January 2010 – 17 January 2011...................... 6-25

Table 7-1 Overall Catch and Condition of Fish by Species in the Impingement Survival Study at 

the Hudson Generating Station, 2010 - 2011............................................................................... 7-5

Table 7-2 Estimates of Impingement Survival Through 48 hours for Selected Fish Species Based 

on Sampling at the Hudson Generating Station, 2009 - 2010...................................................... 7-7

Table 7-3 Model Parameters and Standard Errors to Predict Impingement Survival for Selected 

Fish Species Based on Sampling at the Hudson Generating Station, 2009 - 2010...................... 7-8
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Table 8-1 Estimates of Percent Mortality from Mechanical Effects of Entrainment at the Hudson 

Generating Station ....................................................................................................................... 8-5

Table 8-2 Estimates of the Annual Loss by Fish Species Through Entrainment at the Hudson 

Generating Station under Various Operating Modes, January 2009 - January 2010................... 8-6

Table 8-3 Estimates of the Annual Loss by Fish Species Through Entrainment at the Hudson 

Generating Station under Various Operating Modes, January 2010 - January 2011................... 8-7

Table 8-4 Estimates of the Annual Loss by Fish species Through Impingement at the Hudson 

Generating Station under Various Operating Modes, January 2009 - January 2010................... 8-8

Table 8-5 Estimates of the Annual Loss by Fish Species Through Impingement at the Hudson 

Generating Station under Various Operating Modes, January 2010 - January 2011................. 8-10

Table 8-6 Estimates of Annual Entrainment Loss at Hudson for Selected Species Under Actual 

Operations With Entrainment Survival Based on Entrainment Monitoring in 1996-1997 and in 

2009-2010. ................................................................................................................................. 8-12

Table 8-7 Estimates of Annual Impingement Loss at Hudson for Selected Species Using Actual 

Operations Based on Impingement Monitoring in 1996-1997 and in 2009-2010..................... 8-13
HUDSON GENERATING STATION 316(b) STUDY REPORT

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1. INTRODUCTION

The Hudson Generating Station (Hudson or the Station) presently has a New Jersey Pollution 

Discharge Elimination System (NJPDES) Permit (Number NJ0000647) that authorizes the intake 

of water from the Hackensack River and discharge of several wastestreams, including noncontact cooling water and process wastewater to the same waterbody. The majority of water 

withdrawn through the facility’s intake is non-contact water used for once-through cooling of its 

steam condensers. On 12 January 2011, the New Jersey Department of Environmental 

Protection (NJDEP) issued the draft Surface Water Renewal Permit Action for renewal of the 

existing NJPDES permit (Permit) in accordance with N.J.A.C. 7:14A-1 et seq. by authority of 

the Water Pollution Control Act at N.J.S.A. 58:10A-11 et seq. To date, NJDEP has not finalized 

the Renewal Permit Action. The current permit was first issued on 18 June 2003 and went into 

effect on 1 August 2003. This permit was subsequently modified several times with last 

modification issued on 29 May 2008.

The renewal permit will incorporate NJDEP’s determination pursuant to §316(b) of the Federal 

Clean Water Act (CWA) regarding the best technology available for cooling water structures in 

accordance with best professional judgment (BPJ). §316(b) requires that the location, design, 

construction, and capacity of cooling water intake structures reflect the best technology available 

(BTA) for minimizing adverse environmental impact. The primary impacts of concern under 

§316(b) are entrainment of smaller aquatic organisms into the cooling water system and 

impingement of larger organisms onto traveling screens in the cooling water intake. 

The Station’s June 2003 NJPDES Permit noted an improvement in water quality and marine 

diversity and abundance in the Hackensack River and other regions of the New York/New Jersey 

Harbor Estuary, of which it is a part, largely observed from the results of studies conducted by 

the Station in 1996-1997 and earlier. After review of alternative technologies, the NJDEP 

selected new coarse-mesh Ristroph-type traveling screens as BTA for the Station. The screens 

would have a dual nozzle wash system with high and low spray pressures, as well as separate 

fish and debris collection troughs that would merge into a return trough leading to the river and 

common to the facility’s two generating units. The traveling screen panels would have fish 

lifting buckets to hold fish in water until washed from the screens by the low pressure spraywash 

system. 

The permit modification issued 18 May 2007 and effective on 1 June 2007 directed the Station

to: (1) install the specified Ristroph traveling screens and other intake modifications on Unit 2 no 

later than 31 December 2008; (2) submit a 316(b) work plan for NJDEP approval at least 60 days 

prior to commencement of the 316(b) study; and (3) submit the completed 361(b) study to 

NJDEP within three years of completion of the installation and operation of the modified intake 

structure. As required, (1) the Ristroph traveling screen installation and other intake 

modifications on Unit 2 were completed on 10 June 2008; (2) the 316(b) work plan consisting of 

impingement monitoring was submitted for NJDEP approval on 25 September 2008; and (3) this 

316(b) Study Report is being submitted on 10 June 2011, within three years of completion of the 

installation and operation of the modified intake structure.
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Unit 2 is the principle generating unit for the Station, and Unit 1 is only used for rare peaking 

operations1. This report presents the results of two years of entrainment and impingement 

monitoring (January 2009 to January 2011) following installation of the permit-required intake 

modifications for Unit 2. This monitoring also included an evaluation of the survival of fish and 

blue crabs impinged on the new Ristroph screens and sampled from the new fish return system. 

With two years of additional monitoring data, interannual variability can be addressed and 

comparisons can be made between impingement survival observed from the new Ristroph screen 

and fish return system versus expected survival of fish impinged on the unmodified Unit 1 

screens. 

This report provides a brief description of the Station and its cooling water intake structure and 

operation in Chapter 2. Chapter 3 describes the source of cooling water, the Hackensack River 

estuary, in terms of its physical features, the biological habitat it provides, and the characteristics 

of water quality and sediment quality as they presently occur in the estuary. Chapter 4 describes 

the fish community of the Hackensack River from both a current and historical perspective. The 

fish community has experienced a renaissance in the past few decades as pollution sources have 

been mitigated and water quality has improved, all of which can influence the characteristics of 

entrainment and impingement observed at the Station. Contributing to information on the fish 

community are the results of ichthyoplankton sampling and bottom trawling conducted in the 

vicinity of the Station during the present (2009-2010) study. 

Chapters 5 and 6 address the results of the current years of entrainment and impingement 

monitoring, respectively, in terms of species and life stage or age composition, temporal patterns, 

and general comparisons to the results from the previous studies conducted in 1996-1997. 

Chapter 7 fully describes the methodology and results of impingement survival testing conducted 

at Unit 2 during the two-year study, and their application for estimating impingement losses. 

Chapter 8 combines the results reported in Chapters 5 through 7 to derive annual estimates of 

entrainment and impingement losses based on actual and full (design) cooling water flows. 

These estimates are then compared to estimates that had been derived from the 1996-1997 

studies at the Station. 

 

1

Operation history for the two generating units is presented in Chapter 2 of this report.
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2. STATION DESCRIPTION AND OPERATION

The Hudson Generating Station (Hudson or “the Station”) is an electric generating facility 

owned by PSEG Power LLC and operated by PSEG Fossil LLC (PSEG). The Station is located 

in Hudson County upriver of Newark Bay at River Mile (RM) 3.2 of the Hackensack River (the 

River) in Jersey City, New Jersey (Figure 2-1). The Station consists of three fossil-fired electric 

generating units. Units 1 and 2 are steam electric generators that became operational in 

December 1964 and December 1968, respectively. Unit 3, a combustion turbine that began 

operation in December 1967, was retired in 2004. The net summer ratings are 383 megawatts 

(MWe) for Unit 1 and 600 MWe for Unit 2. This chapter further describes the Station’s cooling 

water intake structure and operation since 2007.

2.1 INTAKE STRUCTURE

Units 1 and 2 utilize a once-through condenser cooling water system (CWS). The shoreline 

intake structure (Figure 2-2) is located directly in front of the Station, where the Hackensack 

River is approximately 550 ft wide. Units 1 and 2 each have two intake bays (Figure 2-3), and 

each unit is equipped with two circulating water pumps and two service water pumps. The 

circulating water pumps withdraw cooling water from the River through the common intake 

structure and provide non-contact cooling water to the turbine generator steam surface 

condensers and condensate cooler heat exchangers. The rated capacity for each Unit 1circulating

pump is 135,000 gallons per minute (gpm) and the rated capacity for each Unit 2 circulating 

pump is 175,000 gpm. When all four circulating water pumps operate at their rated capacities, 

the total flow rate of the CWS is 620,000 gpm. The heated water is returned to the river through 

a common discharge canal, designated as Discharge Serial Number (DSN) 361 in the NJPDES 

Permit.

Each unit also has two service water pumps located in the Station’s common intake structure 

next to the circulating water pumps, with which they share intake bays for water withdrawal. 

The service water pumps provide auxiliary cooling water for other components. The rated 

capacity for each of Unit 1’s service water pumps is approximately 4,600 gpm, and the rated 

capacity for each of Unit 2’s service water pumps is approximately 5,000 gpm. Unit 1’s service 

water discharge is returned directly to the River via DSN 365A and Unit 2’s service water flow 

is returned via DSN 366A. DSN 365A and DSN 366 are located just downriver of the intake 

structure.

Water entering each intake bay is first strained by a steel bar trash rack that is approximately 

even with the shoreline. The trash rack consists of fixed 3.0-inch by 0.5-inch by 24-ft vertical 

bars spaced at 3.5-inch centers with resultant 3.0-inch openings. Behind the trash bars are two 

concrete skimmer walls that hang down below the water surface. The first ends about 7 inches

below lower low water (LLW) and about 23 ft above the bottom of the structure. The second 

skimmer wall extends about 4 ft below LLW and about 20 ft off the bottom.

Each of the intake bays is fitted with a vertical traveling screen, recessed approximately 10 ft 

behind the trash rack. The screens measure approximately 11 ft wide by 44 ft long. Unit 1 

utilizes two conventional traveling screens of 0.080-in diameter stainless steel mesh with 1⁄4 inch 

by 1⁄2 inch openings. Two new modified Ristroph-type traveling screens were installed on Unit 2 
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in 2008 by placing them in the screen guides for the existing screens2. The new Unit 2 screens 

are equipped with 0.080-in diameter stainless steel wire mesh with 1⁄4 inch by 1⁄2 inch openings. 

The screens have fish baskets with a Fletcher-design flow spoiler at the bottom of each screen 

panel. Impinged fish are carried in the fish baskets until dropped into a trough on the top, 

backside (descending side) of the screen, with the assistance of two low-pressure (7 psi and 15 

psi) water jets to wash them off the screen. Below the fish trough and after the fish have been 

removed, there is a debris trough that carries debris washed from the screen by one high-pressure 

(80 psi) water jet. Flow rate for the low-pressure wash system is 256 gpm and 238 gpm for the 

debris wash system. 

The fish trough is extended both upstream and downstream at the edge of the intake structure. 

The direction of the flow is controlled by motor-controlled stainless steel slide gates at either end 

of the two-screen array. The trough extensions slope down to the river upstream and 

downstream at a point beneath the catwalks connecting the mooring caissons. The trough 

extensions are inclined less than a 45° angle to approximately mean high tide level, with 

sufficient water depth in the sloped trough to assure the fish are transported in water for the 

entire distance. 

The traveling screens typically are rotated and washed on a continuous basis whenever the 

associated circulating pump is operating. Screen rotation speed is 10 feet per minute (fpm) for 

normal, constant operation for fish removal. This results in a maximum screen retention time of 

approximately 4.5 minutes. When the water level differential across the screens is 2 ft or greater, 

the screen rotation speed is increased to 15 fpm.

Average through-screen velocities range from 1.31 to 2.90 feet per second (fps), depending on 

tide height. The average peak approach velocity to the screens is 1.67 fps. At Unit 1, the suction 

bellmouth inlet of the pumps has a vertical alignment, whereas the Unit 2 pumps have a 90°

concrete suction elbow resulting in horizontal alignment (Figure 2-3). Velocity through the 

screens varies depending on location relative to the pump inlet. Generally, the highest velocities 

occur near the bottom, with an eddy backflow near the surface.

2.2 STATION OPERATION

Units 1 and 2 originally were operated to meet base-load demand, but now operate in response to 

seasonal and daily changes in electrical demand, i.e., they are load-following. Tables 2-1 and 2-

2 present monthly data on the MWh generation and cooling water flows for the period 2007-

2010 for Units 1 and 2, respectively. Since 2007, the average annual generation capacity factor 

for Unit 1 has been very low, ranging from 0.46 percent in 2009 to 3.01 percent in 2010 (Table 

2-1). Unit 2 generation has been greater, but average annual capacity factors were relatively low 

(from 28 percent in 2009 to 43 percent in 2008), reflecting the load-following operation of this 

unit (Table 2-2). 

The average annual cooling water flow rates at Unit 1 since 2007 have averaged 20 percent and

ranged from 17 percent to 25 percent of pumping rate capacity (Table 2-1), reflecting the limited 

generation of this unit. Unit 2 withdraws cooling water at an annual average rate of 70 percent 

 

2

The Unit 1 screens have not been replaced.
HUDSON GENERATING STATION 316(b) STUDY REPORT

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of pumping capacity, with values for individual years ranging from 68 percent in 2007 to 74

percent in 2008 (Table 2-2). Cooling flow rates at Unit 1 generally are highest during summer 

months, June – August (Table 2-1). At Unit 2 (Table 2-2), cooling flow rates generally are 

highest during both summer (June – August) and mid-winter (December – January).

Figures 2-4 and 2-5 present temperatures measured at the Station’s intake and discharge for the 

period of study, January 2009 – January 2011 for Units 1 and 2, respectively. Since the two 

units share the same intake and discharge canal, the temperature records are identical for the two 

units. Also on these figures is the record of the hourly cooling water flow for the two units 

during the study period. The stepped nature of the flow records shows the difference between 

single pump and two pump operation. Unit 1 flows are limited primarily to March through 

October (Figure 2-4), whereas Unit 2 cooling water flows are more continuous except during 

outages (Figure 2-5).
HUDSON GENERATING STATION 316(b) STUDY REPORT

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Figure 2-1. Location Map for Hudson Generating Station

2 mi

2km

HUDSON POWER STATION
HUDSON GENERATING STATION 316(b) STUDY REPORT

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Figure 2-2. Aerial View of Hudson Generating Station

 

 

 
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Figure 2-3. Intake Structure of 

Hudson Generating Station
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Figure 2-4. Intake and Discharge Water Temperatures and Total Daily Cooling Water 

Flow for Unit 1, January 2009 – January 2011
HUDSON GENERATING STATION 316(b) STUDY REPORT

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Figure 2-5. Intake and Discharge Water Temperatures and Total Daily Cooling Water 

Flow for Unit 2, January 2009 – January 2011
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Table 2-1. Monthly Mean Cooling Water Flow Rate (MGD) and Percentage of Maximum Design Generation and Flow Rate 

for Unit 1, 2007-2010

Unit 1

Percentage of Maximum Generation (383 MW)

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

2007 0.06% 0.38% 1.77% 0.06% 0.06% 0.11% 8.18% 1.18% 0.07% 1.60% 0.07% 0.06% 1.13%

2008 0.06% 0.07% 0.06% 0.07% 0.07% 7.23% 1.82% 0.73% 0.08% 0.07% 0.07% 0.07% 0.87%

2009 0.07% 0.06% 1.71% 0.08% 0.08% 1.05% 0.08% 2.11% 0.08% 0.07% 0.08% 0.07% 0.46%

2010 0.07% 0.07% 0.07% 0.07% 0.07% 0.06% 23.75% 3.57% 8.09% 0.10% 0.11% 0.09% 3.01%

Average 0.07% 0.14% 0.91% 0.07% 0.07% 2.11% 8.46% 1.90% 2.08% 0.46% 0.08% 0.07% 1.37%

Actual Plant Flow Rate (MGD)

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

2007 19 109 154 125 0 76 120 141 3 134 4 15 75

2008 23 9 4 0 0 177 181 234 114 0 11 36 66

2009 0 8 172 151 46 213 96 333 47 81 14 0 97

2010 0 0 116 58 0 13 245 146 198 170 20 0 80

Average 11 31 112 84 12 120 161 213 90 96 12 13 80

Percentage of Maximum Flow Rate (389 MGD)

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

2007 5% 28% 40% 32% 0% 19% 31% 36% 1% 35% 1% 4% 19%

2008 6% 2% 1% 0% 0% 45% 47% 60% 29% 0% 3% 9% 17%

2009 0% 2% 44% 39% 12% 55% 25% 86% 12% 21% 4% 0% 25%

2010 0% 0% 30% 15% 0% 3% 63% 38% 51% 44% 5% 0% 21%

Average 3% 8% 29% 21% 3% 31% 41% 55% 23% 25% 3% 3% 20%
HUDSON GENERATING STATION 316(b) STUDY REPORT

2-10

Table 2-2. Monthly Mean Cooling Water Flow Rate (MGD) and Percentage of Maximum Design Generation and Flow Rate 

for Unit 2, 2007-2010

Unit 2

Percentage of Maximum Generation (600 MW)

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

2007 41% 49% 27% 0% 14% 58% 45% 56% 34% 52% 41% 63% 40%

2008 73% 44% 48% 0% 0% 33% 24% 75% 72% 67% 22% 57% 43%

2009 36% 9% 55% 6% 2% 35% 23% 57% 16% 21% 13% 64% 28%

2010 51% 46% 33% 69% 33% 63% 75% 51% 32% 1% 0% 41% 41%

Average 50% 37% 41% 19% 12% 47% 42% 60% 38% 35% 19% 56% 38%

Actual Plant Flow Rate (MGD)

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

2007 382 356 164 0 218 465 423 445 393 421 400 431 342

2008 448 442 405 0 51 465 311 476 475 428 478 499 373

2009 436 319 491 56 374 375 348 424 299 302 309 465 350

2010 394 446 253 436 402 428 459 452 91 0 287 508 346

Average 415 391 328 123 261 433 385 450 314 288 368 476 353

Percentage of Maximum Flow Rate (504 MGD)

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

2007 76% 71% 33% 0% 43% 92% 84% 88% 78% 84% 79% 86% 68%

2008 89% 88% 80% 0% 10% 92% 62% 95% 94% 85% 95% 99% 74%

2009 87% 63% 97% 11% 74% 74% 69% 84% 59% 60% 61% 92% 69%

2010 78% 88% 50% 87% 80% 85% 91% 90% 18% 0% 57% 101% 69%

Average 82% 77% 65% 24% 52% 86% 76% 89% 62% 57% 73% 94% 70%
HUDSON GENERATING STATION 316(b) STUDY REPORT

3-1

3. WATERBODY DESCRIPTION

This chapter describes the source waterbody for the Station’s cooling water, i.e., the Hackensack 

River and its associated tidal estuary; the aquatic habitat it provides for fish and shellfish; and the 

water quality and sediment quality features that influence the fish and shellfish community of the 

river estuary.

3.1 PHYSICAL FEATURES

The Hackensack River (the River) originates in the Palisades near Haverstraw, New York and 

flows southward over a distance of 50 miles to Newark Bay. The River drains a 197-mi2

watershed that is bounded on the east by the crest of the Palisades ridge and on the west and 

northwest by the crest of the Watchung and Ramapo mountains. The River is separated by 

Oradell Dam into a non-tidal freshwater reach and a tidal brackish reach. Oradell Dam was 

constructed in 1922 to supply potable water to various communities in northern New Jersey and 

is located just above New Milford, New Jersey at RM 22.5. The dam restricts the saline and 

brackish waters to the lower one-third of the River. 

The tidal segment of the River is part of the Newark Bay Complex, which includes Newark Bay, 

Kill Van Kull, Elizabethport Reach of the Arthur Kill, Passaic River, and associated tributaries. 

The Newark Bay Complex is part of the New York-New Jersey Harbor Estuary (Harbor 

Estuary), which also includes the lower Hudson River, Raritan Bay, Upper and Lower New York 

bays, East River, and Jamaica Bay. The Hackensack and Passaic rivers discharge to the northern 

region of Newark Bay. Newark Bay is connected to the remainder of the estuary by the Arthur 

Kill and the Kill Van Kull. The Kill Van Kull connects Newark Bay to the Upper and Lower 

New York Bays, and the Arthur Kill connects Newark Bay to Raritan Bay. The Upper New 

York Bay joins the Hudson River. Raritan Bay and the Lower Bay are directly connected to the 

Atlantic Ocean.

The hydrodynamics of the River are normally dominated by the tides, which propagate into 

Newark Bay through the Arthur Kill and Kill Van Kull. The hydrodynamics of the Arthur Kill, 

the Kill Van Kull, and Newark Bay are very complex and have a pronounced effect on these 

water bodies. Tides in the Newark Bay Complex are semi-diurnal, with two high waters and two 

low waters per day. The mean tidal range of Newark Bay is 2.8 ft, with flood and ebb tidal 

currents averaging 1.2 ft/sec (PSE&G 1988). Under normal conditions, the volume of water 

entering and leaving Newark Bay over a tidal cycle (the tidal prism) is estimated to be 13,800 

million gallons of water (Clinton Bogart Associates 1992). At the mouth of the Hackensack

River, the flood currents average about 1.5 ft/sec and the ebb currents average 1.3 ft/sec. At 

times of spring tides, both the ebb and flood velocities are approximately 1.8 ft/sec (Kassner 

1971, in Jack McCormick & Associates 1977).

Freshwater inflows to the River include releases from Oradell Dam, flows from tributaries below 

Oradell Dam and anthropogenic sources. During dry weather, these inflows have a relatively 

minor effect on the hydrodynamics of the River in the vicinity of the Station. At its confluence 

with Newark Bay, the River has an annual mean discharge of 95.8 cfs. Daily mean discharges 

range from 0.4 cfs to 263 cfs (Bauersfeld et al. 1994).
HUDSON GENERATING STATION 316(b) STUDY REPORT

3-2

3.2 AQUATIC HABITAT 

The River has a dredged channel approximately 30 ft deep that begins in Newark Bay and ends 

in a turning basin at RM 3.5, which is just offshore of the Station’s discharge canal. The River 

becomes shallower (i.e., an average depth of approximately 20 ft) between RM 4 and RM 13, 

although this segment is full of deep holes. The river depth decreases from approximately 20 ft 

to approximately 10 ft between RM 13 and RM 16.6, and is very shallow (<6 ft) between RM 

16.6 and RM 22, just below Oradell Dam (PSE&G 1988).

Longitudinally, the lower River can be thought of as a continuum divided into several zones: 

freshwater streams, the freshwater portion of the tidal estuary, and a brackish zone, where tidal 

fresh water mixes with the salt water. The seasonal salinity regime depends primarily on the 

amount of freshwater inflow to the system.

Tidal marshes are located primarily between RM 3.2 and RM 8.0. They provide significant 

storage during times of high water. For example, approximately 40 percent of the tidal flow 

entering the River is diverted to extensive tidal flats along the Sawmill Creek at about RM 5 

(Clinton Bogart Associates 1992). The area around Sawmill Creek includes a large, open water 

wetland that is inundated at high tide. The periodic flooding and draining of these marshes 

affects the magnitudes and phases of the flood and ebb currents in the main stem of the River. 

Extensive low salt marsh areas support stands of salt marsh cordgrass, with common reed 

growing at slightly higher elevations bordering most of the creek edges (HMDC 1984). Two 

dominant plant species that occur in the high salt marsh are salt hay (Spartina patens) and salt 

grass (Distichlis spicata). Interspersed among the vegetated portions of the high salt marsh are 

pannes, which are shallow pools devoid of vegetation. Flood-tide water becomes trapped in 

these depressions and then evaporates, resulting in very high salt concentrations. Glasswort 

(Salicornia europaea) occasionally grows along the edges of the pannes (HMDC 1984).

Freshwater marsh occurs primarily in Kearny Marsh, the Penhorn Creek Basin, and North 

Bergen where roads, railroads, dikes, tide gates and other barriers have isolated wetlands from 

tidal flooding. These areas support a series of large freshwater wetlands that are inundated by 

various depths of freshwater, depending on the origin, volume, and regularity of flow of the 

freshwater source. The freshwater wetlands are interspersed by stands of common reed. Duck 

weed (Lemna minor) is often associated with common reed, and marsh mallow (Althaea 

officinalis) grows along some of the creek channels. Kearny Marsh contributes substantially to 

the biological diversity of the River, although the best quality freshwater marshes in the River 

system have been at the headwaters of Penhorn Creek (HMDC 1984).

Shallow tidal bays and mudflats occur predominantly as part of the 1,186-ac Sawmill Creek 

Wildlife Management Area (WMA) located in the southwestern section of the River. This area 

consists of exposed mudflats during low tide, which are transformed into shallow tidal bays as 

the mudflats are inundated during high tide. The primary plants in this community are horned 

pondweed (Zannichellia palustris) and algae. In some areas, salt marsh cordgrass is revegetating the mudflats (HMDC 1984).
HUDSON GENERATING STATION 316(b) STUDY REPORT

3-3

3.3 WATER AND SEDIMENT QUALITY

Water quality and sediment quality in the Hackensack River have been influenced by urban and 

industrial activities that have occurred over the past two centuries and by tidal exchange with 

adjacent waters (Mattson and Vallario 1976). The River has limited freshwater inflow and only 

indirect interaction with the Atlantic Ocean and, therefore, is not as well mixed longitudinally as 

many estuaries (Clinton Bogart Associates 1992). These two factors affect the water quality of 

the River.

3.3.1 Water Quality

The water quality of the River and distribution of aquatic organisms are often determined by the 

levels of several parameters such as salinity, dissolved oxygen (DO), temperature and toxics. 

The following summarizes the current knowledge about these factors in the Hackensack River.

Higher salinity water from Newark Bay is transported into the River at depth by tidal action, at 

times undercutting the lower salinity water from upriver. This process results in a longitudinal 

salinity gradient. Based on a 1986 survey, the River was generally mesohaline at 5-18 parts per 

thousand (ppt) salinity from RM 0 to about RM 10, oligohaline (0.5-5.0 ppt salinity) from RM 

10 to about RM 16, and tidal-fresh water (0-0.5 ppt salinity) from RM 16 to the Oradell Dam 

(PSE&G 1988). However, the longitudinal salinity gradient changes with the seasons as the 

amount of freshwater runoff from rainfall or snow melt changes. The freshwater segment is

longest (RMs 13-22) during winter and spring when freshwater flow is greatest, and shortest 

(RMs 18-22) through the drier summer and fall seasons. As the size of the freshwater 

compartment shrinks, the mesohaline and the oligohaline compartments expand upriver. During 

dry periods of no freshwater flow over the dam, brackish tidal water extends almost to Oradell 

Dam (RM 22.5). 

With regard to DO concentration and toxics, the NewYork/New Jersey Harbor Estuary Program

(HEP), a partnership of state, federal, and local agencies and other cooperating entities begun in 

1987, is in the process of implementing a comprehensive harbor-wide program to assess and 

improve water quality in the Harbor Estuary (Steinberg et al. 2004). The HEP presently is 

developing total maximum daily loads (TMDLs) intended to meet surface water quality 

standards for pathogens, DO demands (nutrients and organics), and toxics

(HEP/NJHDG/NYCDEP 2008, Pecchioli et al. 2007, HydroQual 2010a). 

According to New Jersey surface water quality standards, portions of the Hackensack River are 

classified as SE3 Fishing/Fish Migration3(mouth to Routes 1&9 overpass, approximately RM 3), 

SE2 Fishing/Fish Migration4(Routes 1&9 overpass upstream to Overpeck Creek confluence 

 

3

Designated best uses are secondary contact recreation; maintenance and migration of fish populations; migration 

of diadromous fish; maintenance of wildlife; and other reasonable uses.

4

Designated best uses are maintenance, migration and propagation of natural and established biota; migration of 

diadromous fish; maintenance of wildlife; secondary contact recreation; and other reasonable uses.
HUDSON GENERATING STATION 316(b) STUDY REPORT

3-4

with mainstem river), and SE1 Shellfish/Bathing5(confluence with Overpeck Creek upstream to

Oradell Dam). For DO, the water quality criteria are as follows:

 SE3: >3 mg/L at any time

 SE2: >4 mg/L at any time

 SE1: >4 mg/L at any time and 24-hour average >5 mg/L

As of 2006, the Hackensack River was identified as one of the areas in the Harbor Estuary with 

the lowest DO concentrations (HEP-NJHDG-NYCDEP 2008). However, the harbor-wide trend 

is one of improving DO concentrations, with summer (June-September) seasonal averages for 

2004-2006 ranging from 6.43 mg/L to 6.77 mg/L at the surface and 5.50 mg/L to 5.88 mg/L at 

the bottom. In the Hackensack River, the summer seasonal average for 2006 for surface and 

bottom was in the range of 4.00-4.79 mg/L at RM 3 and 3.00-3.99 mg/L at RM 7. 

The New Jersey Meadowlands Commission (NJMC) monitors five sites seasonally (fall, winter, 

spring, and summer) in the mainstem Hackensack River and nine sites in tributaries to the river. 

From the data collected, a trend of increasing DO was observed from 1993 through 2005, with a 

predicted increase in the average DO concentration over the 12 years of 2.3 mg/L (HydroQual 

2010b). However, the trend was not as obvious at individual sites with the exception of the most 

downstream site (RM 3), where an increasing trend has been observed from 1998 to 2010. 

Minimum site-specific values ranged from 0.9 mg/L to 2.4 mg/L.

Water quality measurements were taken during monthly fishery surveys performed by the NJMC 

from August 2001 through July 2002

6

at 15 sampling sites in the Hackensack River, from 

approximately RMs 3.0 to 12.5, and at six sites in its tributaries (Bragin et al. 2005). A total of 

330 surface measurements of DO were made during the study, of which 50 (15 percent) were 

below the 4 mg/L criterion. DO concentrations at the surface ranged from 2.1 mg/L in 

November at RM 7.4 to 13.6 mg/L in March at RM 12.5. The DO criterion of 4 mg/L was not 

met at 23 percent of the bottom measurements (43 of 186), which ranged from 1.3 mg/L in 

August at RM 12.2 to 10.5 mg/L in April at RM 7.5. Monthly average bottom DO 

concentrations across all sites fell below the 4.0 mg/l criterion from June through August (3.66 

mg/L in July to 3.94 mg/L in June), but not so for monthly surface averages (4.80-5.30 mg/L).

However, as many as 57 percent of the individual surface measurements and 75 percent of the 

individual bottom measurement in August were < 4 mg/L.

Surface temperatures during the NJMC fishery surveys of 2001-2002 (Bragen et al. 2005) ranged 

from 1.8°C in January at RM 7.4 to 30.8°C in July at RM 3.5. Bottom temperatures were similar 

at each site and date (range of 1.7°C in January to 30.4°C in August, both at RM 6.8), indicating 

thermal mixing and the absence of strong thermal stratification.

 

5

Designated best uses are shellfish harvesting; maintenance, migration and propagation of natural and established 

biota; primary and secondary contact recreation; and other reasonable uses.

6

Sampling continued seasonally thereafter, rather than monthly, from fall 2002 to summer 2003.
HUDSON GENERATING STATION 316(b) STUDY REPORT

3-5

The Hackensack River and Newark Bay Complex are contaminated with toxic chemicals that 

reduce water quality, resulting in fish and shellfish consumption advisories, potential 

reproductive impairments, and adverse impacts to the ecosystems. In response, a New Jersey 

Toxics Reduction Workplan was developed by the NJDEP to identify sources of toxic chemicals 

of concern and to prioritize the sources for appropriate action (Pecchioli et al. 2007). 

A water quality monitoring program conducted from June 2000 to May 2002 collected water 

samples from the Hackensack, Passaic, Elizabeth, Rahway, and Raritan rivers as well as Newark 

Bay, Arthur Kill, and Kill van Kull (Stevens Institute of Technology 2007). The samples were 

analyzed to determine concentrations of metals (cadmium, lead, mercury, and methyl-mercury), 

polychlorinated biphenyls (PCBs), dioxins/furans, pesticides, and polycyclic aromatic 

hydrocarbons (PAHs). Contaminants that were found to exceed either New Jersey Saline 

Aquatic Chronic Water Quality Criteria or Human Health criteria included mercury, PCBs, 

dioxins/furans, PAHs [benzo(a)pyrene], DDT and metabolites, total chlordane, and total dieldrin

(Pecchioli et al. 2007, Stevens Institute of Technology 2007). While Hackensack River samples 

exceeded criteria for all of these contaminants but DDT/metabolites, it was identified as the most 

contaminated area in the NY/NJ Harbor Estuary for mercury.

Laboratory experiments have shown that young-of-year bluefish fed prey from the Hackensack 

River accumulate very high levels of PCBs, mercury, and chlorinated pesticides, resulting in 

reduction in the fish’s appetite, swimming activity, and growth (Weis 2009). The study authors 

hypothesized that these alterations could have detrimental effects on body condition, migratory 

competence and overwintering, and ultimately recruitment of young fish to the fishery.

Blue crabs from the Hackensack River were found to have reduced ability to capture active prey 

such as juvenile blue crabs and adult mummichogs (Reichmuth et al. 2009). The result might be 

lower growth rates and reduced fitness. Nevertheless, the abundance of blue crabs in the river 

appears to be increasing, possibly because of a ban on harvesting and improved environmental 

conditions (Bragin et al. 2005, Reichmuth et al. 2009). Other species for which there is a 

specific consumption advisory are striped bass, American eel, white perch, and white catfish.

A recent study on contaminant levels in the tissues of white perch from the Hackensack River 

found that 32 percent of the sampled fish had concentrations exceeding the one meal per month 

action level of 0.47 μg/g wet weight for mercury and 2 percent exceeded the no consumption at 

all level of 1 μg/g (Weis 2005). Also, 40 percent of the sampled white perch exceeded the Food 

and Drug Administration (FDA) action level (2,000 ng/g) for PCBs. All sampled white perch

exceeded the U.S. Environmental Protection Agency (USEPA) guideline of no more than one 

meal per month for fish with a total PCB concentration of 52 ng/g or higher, with nearly all of 

the sample concentrations exceeding this guideline level by a factor of 10.

3.3.2 Sediment Quality

The texture and chemical composition of the Hackensack River sediments were investigated by 

the NJMC in 2003 (NJMC 2007, Konsevick and Bragin 2010). Sediment samples were collected 

at 21 sites in the mainstem river from RM 3 to RM 12.5, and at five sites in tributaries to the 

river. The samples were analyzed for grain size distribution; total organic carbon (TOC) content; 
HUDSON GENERATING STATION 316(b) STUDY REPORT

3-6

the metals arsenic, cadmium, chromium, copper, iron, lead, mercury, nickel, and zinc; pesticides; 

and PCBs. 

Sediments at the sampling sites consisted primarily (69 percent) of fine particles (silt and clay). 

As would be expected based on hydrodynamics, the percentage of fines is greater in the 

tributaries than in the mainstem river, but the percentage in tributaries has declined 12 percent 

since last surveyed in 1988 (NJMC 2007). Likewise, silt and clay sediments are greater in the 

upper and middle segments of the river (approximately 70-80 percent) than in the lower segment

(approximately 40 percent), indicating greater deposition than in the lower river. Fine sediments 

with higher TOC and an anoxic environment have a higher affinity for metals.

Based on USEPA’s sediment assessment criteria for metals, the ecological condition of the 

Hackensack River estuary sediments would be considered poor (NJMC 2007), since the Effects 

Range Median (ERM) concentration7 was exceeded for mercury by its average concentration. 

However, this indicated improvement in sediment quality in that cadmium, copper, and nickel 

also exceeded their ERM values when tested in 1988. Effects Range Low values(ERL)8 were 

exceeded at some individual sites for arsenic, cadmium, chromium, copper, mercury, lead, 

nickel, and zinc; 60 percent of the sites exceeded ERL criteria for more than five of these metals 

(NJMC 2007). Potential contamination sources include Newark Bay, Passaic River, historic 

industrial sites, hazardous waste site, landfills, power plant emissions, and combined sewer 

outfalls (CSOs). 

Organic contaminants were analyzed only for a limited number of samples (NJMC 2007). 

Nevertheless, the results showed organic pollution was present, but chlorinated hydrocarbon 

pesticides such as endosulfan, aldrin, and dieldrin had low concentrations.

 

7

The ERM is the median concentration of a contaminant observed to have adverse biological effects in prior studies 

(Long et al. 1995).

8

The ERL is the 10th percentile concentration represented by studies demonstrating adverse biological effect (Long 

et al. 1995)
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-1

4. FISH COMMUNITY

The Hackensack River estuary has a diverse fish community consisting of marine, estuarine, and 

freshwater species. Species composition changes spatially with the salinity levels. The species 

can be grouped into use categories based on estuarine habitat utilization. Permanent residents, 

such as killifish and white perch, are euryhaline species that inhabit the estuary all year. 

Diadromous species utilize the Hackensack River only during specific life stages or periods.

This group includes anadromous species that spawn in freshwater or brackish water, such as 

Atlantic tomcod, American shad, alewife, striped bass and blueback herring; and the 

catadromous species American eel, which spawns in the Sargasso Sea but matures in freshwater. 

Additionally, estuarine species such as weakfish, winter flounder, bay anchovy, bluefish, and 

Atlantic menhaden utilize the estuary as a juvenile nursery area. The estuarine species often 

dominate fish biomass and production, particularly during the summer. Many species are 

transient and found only occasionally in the lower River, including both marine and freshwater 

species. While these transient species have been collected, they do not play a large role in the 

functioning of the food web. In all, at least 96 fish species have been identified in recent years in 

the Hackensack River estuary (Table 4-1).

4.1 HISTORICAL COMMUNITY

The fish community in the Hackensack River and the Newark Bay Complex (defined as 

including the Hackensack River, Newark Bay, Passaic River, Kill Van Kull, Elizabethport Reach 

of the Arthur Kill, and associated tributaries) has been subjected to decades of negative human 

impact. The Newark Bay Complex is located in one of the most heavily industrialized and 

densely populated metropolitan areas of the world (Crawford et al. 1994). This massive human 

influence has not gone without impact on the associated environment. Since 1855, the size of 

Newark Bay has been reduced by more than a third, and three quarters of the associated 

marshland has been destroyed (Crawford et al. 1994). 

The Hackensack River and Newark Bay ecosystem historically supported commercially and 

recreationally important species, but lost most of these species due to pollution, dam 

construction, and overfishing. Historic commercial and recreational fisheries existed for 

American eel, white suckers, Atlantic tomcod, common carp, rainbow smelt, striped bass, white 

perch, various herring species, bullhead, blue crab, and American shad (Zeisel 1989). There was 

an extensive commercial fishery in the early and mid-1800s for American shad which 

disappeared by 1914 (Berg and Levinton 1985, Zeisel 1989, Crawford et al. 1994). Rainbow 

smelt also contributed to the commercial fishery, but the runs ceased by 1920 (Zeisel 1989). In 

1926, the U.S. War Department surveyed the area and declared that “the fish life was destroyed” 

(Crawford et al. 1994).

4.2 RECENT CHANGES

While the fish community historically has been severely impoverished, there are indications that 

it is improving. Past surveys conducted by Public Service Electric and Gas Company (PSE&G) 

as part of §316 Demonstrations for its stations on the river, provide the opportunity to trace 

changes in the fish community since 1971 (IA 1974, 1978, 1979; PSE&G 1988, 1998). Data are 
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-2

available from bottom trawl and ichthyoplankton surveys in the river and adjoining water bodies 

and from impingement and entrainment collections from the Station.

In 1971-1973, river surveys were characterized by relatively few species. There were 11 fish 

species collected in the bottom trawl (Table 4-2) and 12 fish species (unique taxa) collected in 

the ichthyoplankton surveys (Table 4-3). Bottom trawl catches were dominated by mummichog, 

which accounted for 78 percent of the catch. Impingement collections at the Station during 1972 

and 1973 contained more species (a total of 20 species and 25 species, respectively; Table 4-4) 

than were found in the bottom trawl or ichthyoplankton samples. However, like the bottom trawl 

samples, the 1973 impingement collections were dominated by mummichog, which constituted 

80 percent of the total. 

In 1978, PSE&G conducted impingement collections (IA 1979), but no river surveys. By 1978 

there already was a marked increase in the number of species (to 41) appearing in the 

impingement collections (Table 4-4). Mummichogs were still dominant (58.4 percent), but 

somewhat less so. River herring (blueback herring and alewife) continued to be secondarily 

dominant, comprising 12.2 and 10.7 percent of the 1978 collections, respectively.

The apparent addition of fish species to the river community continued into the 1980s. There 

was an increase in the number of species in both the bottom trawl and ichthyoplankton surveys, 

roughly doubling the totals from the 1971-1973 surveys (Tables 4-2 and 4-3). Twenty-seven 

species were caught in bottom trawls during 1986-1987 compared to 11 in 1971-1973, and 21 

species (or unique taxa) of ichthyoplankton were identified compared to 12 species in 1972-

1973. The percent composition changed substantially as well. The percentage of the bottom 

trawl catch made up of mummichogs declined to 49.6 percent in 1986-1987, compared to 1971-

1973 (Table 4-2). The numbers of Atlantic tomcod, striped killifish, bay anchovy and spotted 

hake also increased. The increasing diversity of the fish community by 1987-1988 was evident 

in impingement collections. The number of species had increased by 10 since 1978 to a total of 

51 (Table 4-4). All of the additional species were relatively uncommon visitors to the River.

In 1996-1997, the number of species in the bottom trawl catch declined from 27 to 21(Table 4-

2), probably due to the decreased number of bottom trawl tows made in 1996-1997 between RM 

0 and RM 10 (60 tows) compared to 1986-1987 (209 tows). Fewer tows in 1996-1997 resulted 

in less chance to capture uncommon species; each of the species missing in the 1996-1997 

bottom trawl collections comprised a relatively small percentage of the 1986-1987 catch (i.e., 

<0.42 percent). There also was a notable reduction in the mummichog catch since 1971-1973; 

mummichogs were 78 percent of the total bottom trawl catch in 1971-1973 and nearly zero (0.23

percent) in the 1996-1997 study. 

From 1986-1987 to 1996-1997, the ichthyoplankton survey had a near doubling of the number of 

species from 21 to 38 (Table 4-3). In addition to the increase in number of species present, there 

was also a progressive increase in the number of ichthyoplankton life stages from 1972-1973 to 

1996-1997 (Table 4-3).

Impingement collections in 1996-1997 yielded 54 species (unique taxa), which was three more 

than occurred in the 1986-1987 impingement collections (Table 4-4). In particular, the relative 

abundance of impinged bay anchovy and weakfish increased while Atlantic menhaden, blueback 
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-3

herring, and mummichog decreased. Entrainment collections in 1996-1997 showed an increase 

in the number of unique taxa and number of life stages compared to entrainment collections from 

1986-1987 (Table 4-5), similar to the ichthyoplankton samples from the river discussed above.

The NJMC similarly has been tracking changes in the Hackensack River fish community over 

the past few decades. In 1987, the NJMC initiated a two-year inventory of the fish community in 

the lower Hackensack River (Bragin et al 2005). This inventory was repeated in 2001-2003 

using the same sampling gear and the same 21 sampling locations from RM 3 to RM 12.5. The 

sampling gear consisted of a 16-ft otter trawl, a 60-ft x 6-ft seine, 200-ft experimental sinking 

gill nets, and 3-ft x 6-ft Indiana trap nets. Each sampling location was sampled monthly from 

August 2001 through July 2002, and seasonally (four times) in the fall of 2002 through the 

summer of 2003.

Hudsonia (2007), in reviewing the NJMC study results, suggested that it might be difficult to sort 

out changes in the fish community due to environmental improvements in the Hackensack River 

(e.g., water quality and wetland restoration) from those due to changes in habitat quality and 

species abundances in the overall NY/NJ Harbor Estuary system outside the river. Of the three 

species that increased in abundance by two orders of magnitude (gizzard shad, striped bass, and 

white perch), gizzard shad and striped bass also dramatically increased in abundance in the 

Hudson River during this time period. Another species, Atlantic silverside, while not increasing 

as dramatically in the Hackensack River, has also increased in the overall Harbor Estuary (Hurst 

et al. 2004). Of the three species that decreased in abundance in the NJMC survey by two orders 

of magnitude (Atlantic tomcod, bay anchovy, and pumpkinseed), Atlantic tomcod has reached its 

lowest levels of abundance in 27 years within the Hudson River estuary (Daniels et al. 2005). 

NJMC collected 36 fish species during the 1987-1988 survey and 39 species during the 2001-

2003 survey and concluded that the community structure had changed during the intervening 15 

years (Bragin et al. 2005). In their 1987-1988 samples, mummichog was overwhelming 

dominant (85 percent of the total catch), somewhat similar to the results of PSE&G’s earliest 

studies (1971-1973 and 1986-1987). Mummichogs likely were more abundant in the NJMC 

samples than in PSE&G samples because NJMC sampled intertidal and shallow subtidal areas 

with seines and trapnets while PSE&G did not. Mummichog remained the dominant species in 

the 2001-2003 NJMC survey, but had decreased in relative abundance to approximately 40 

percent of the total catch. Another important observation was the great increase in relative 

abundance of white perch (from 1 percent to 28 percent of the total catch), Atlantic silverside 

(from 3 to 16 percent), and striped bass (0.1 to 3 percent). NJMC concluded that the species 

composition in the community became more balanced, with a decrease in the pollution tolerant 

mummichog and an increase in more desirable game species.

In summary, there has been a progressive diversification in the fish community in the River since 

the early 1970s, probably as the result of improving water quality. The results of river sampling 

and entrainment and impingement sampling at the Station during the present study (2009-2011) 

further shed light on the possible transitions occurring in the Hackensack River fish community. 

River sampling is discussed in the following section (Section 4.3). Entrainment monitoring is 

discussed in Section 5, and impingement monitoring is discussed in Section 6. 
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-4

4.3 2009-2010 TRAWL AND ICHTHYOPLANKTON SURVEYS 

The fish community was sampled during the present study to determine the species and their age 

and size structure of the community potentially vulnerable to entrainment and impingement at 

the Station. The two components of the community that were sampled were demersal fish and 

blue crabs and early pelagic life stages (ichthyoplankton). Demersal fish and blue crabs were 

sampled by bottom trawling, and early life stages of fish were sampled by towing a plankton net. 

Both types of sampling were conducted once per month during March-November 20099and 

February-November, weather permitting, at five fixed sampling locations (Figure 4-1). The 

sampling locations were as follows:

 Hackensack River near RM 2

 Hackensack River near RM 3.2

 Hackensack River near RM 4

 Middle of Newark Bay

 Arthur Kill in vicinity of the Sewaren Generating Station

All gear tows were made in the center of the navigation channel at each location. 

The following sections describe the sampling gear and methods, and present and interpret the 

results by survey type.

4.3.1 Bottom Trawling Methods 

A 30-ft bottom trawl (specifications in Table 4-6) was towed for 5 minutes against the prevailing

current during daylight at each sampling location at a speed of 4.9 ft/sec (150 cm/sec). Tow 

speed was monitored using a GO flowmeter Model 2031 and deck readout Model 2035. A 

minimum ratio of 3:1 tow cable length to maximum station water depth was maintained to 

ensure the trawl was in contact with the bottom. With each sample, the following parameters 

were recorded: weather condition, surface salinity, bottom salinity, surface temperature, bottom 

temperature, air temperature, surface dissolved oxygen (DO), bottom DO, Secchi depth, and tide 

stage.

All fish and blue crabs were removed from the retrieved sample. The fish were identified to 

species, enumerated, and measured to the nearest millimeter for total length. In cases of large 

sample size, a sub-sample of up to 50 fish per species was processed. Evidence of disease, 

tumors, fin damage, and/or skeletal anomalies was recorded. Fish age groups were determined

based on species-specific growth data (length ranges for various age classes) presented in the 

scientific literature or previous PSEG filings. Representative specimens for each species were

retained in a voucher fish collection. Fish that could not be identified in the field were returned 

to the laboratory for identification. Live organisms were returned to the river. 

 

9

Ice cover and inclement weather prevented sampling in February 2009.
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-5

4.3.2 Bottom Trawling Results

A total of 2,014 fish were caught by bottom trawling from March through November 2009, and 

1,879 fish were caught from February through November 2010. In 2009, the total catch at each 

sampling station increased in a downstream direction from Station 1, which is 0.8 miles upstream 

from the Station, to Station 4 in the midsection of Newark Bay, then declined at Station 5 in the 

Arthur Kill (Figures 4-1 and 4-2). However, this pattern was not repeated in 2010, when 

Stations 1 and 5 had the highest catch, followed closely by Station 3 (Figure 4-2). 

The monthly breakdown by sampling station is shown in Figure 4-3. In 2009, the greater catches 

at Station 4 occurred sporadically (March, May, and September); white perch and striped bass 

dominated the March catch , spotted hake dominated the May catch, and bay anchovy dominated 

the September catch (Appendix Table A-1). The peak catch at Station 5 in June (Figure 4-3) also 

consisted primarily of bay anchovy. 

In 2010, elevated catches at Station 5 (Figure 4-3) consisted primarily of white perch in February 

and blue crab and spotted hake in June. The peak catch at Station 1 in April was dominated by 

blue crab, spotted hake, American eel, and Atlantic tomcod. Peak total catches at Station 3 in 

April and May 2010 were dominated by spotted hake and Atlantic tomcod in April and by 

spotted hake in May. Appendix Table A-2 presents the monthly catch totals by station and 

species.

For all five sampling stations combined, the most frequently caught species in 2009 (in declining 

order) were bay anchovy, spotted hake, white perch, Atlantic tomcod ,and blue crab (Table 4-7), 

which together accounted for 86 percent of the total annual catch. Bay anchovy were caught 

from May through November. Spotted hake were caught during March-June and November. 

White perch and blue crab were caught in most months, reflecting their year-round residency 

(Table 4-7). Atlantic tomcod were most abundant during May-July, but were caught in limited 

numbers in October-November. In 2010, the same five species dominated the trawl catch, 

comprising 82 percent of the total annual catch. In declining order they were spotted hake, blue 

crab, white perch, Atlantic tomcod, and bay anchovy, in declining order (Table 4-8). The 

seasonal occurrence of these species was similar to that in 2009 except that Atlantic tomcod 

appeared earlier (April-June rather than May-July) and spotted hake first appeared in April rather 

than March.

4.3.3 Ichthyoplankton Sampling Methods

Ichthyoplankton samples were collected at night, defined as 1 hour after sunset to 1 hour before 

sunrise, with a 1.0-m

2

Tucker trawl and a 333-μm mesh net (specifications in Table 4-6). Tows 

were made in depths of water greater than 20 ft. Each sample was taken as an oblique tow

stepwise at approximately 1-minute intervals from near the bottom to near the surface at five

equal depth intervals. In depths of water less than 20 ft, each sample was taken as a mid-depth 

tow. Tow duration was 5 minutes unless adjusted to account for obstructions, limited transect 

distances, commercial traffic, etc. Tows were against the prevailing current at a through-water 

speed of 90 to 110 cm/sec (2.95- to 3.6 ft/sec). Tow velocities were monitored using a General 

Oceanics flowmeter Model 2031 and General Oceanics deck readout Model 2035. 
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-6

The Tucker trawl was equipped with a double-trip release mechanism (DTRM) to permit 

opening and closing the net during sampling. A calibrated digital flowmeter (General Oceanics 

Model 2030) was mounted in the net mouth and was used in the calculation of sample volume. 

Target net depth was set and monitored using a tow cable length-to-wire angle relationship.

Following retrieval of the gear, the contents of the net were washed into a labeled container, and 

the sample was preserved with a 10 percent formalin solution. With each sample, the following 

parameters were recorded: weather condition, surface salinity, bottom salinity, surface 

temperature, bottom temperature, air temperature, surface and bottom DO, Secchi depth, and tide 

stage. Upon completion of sampling, a Chain of Custody sheet was filled out identifying all

samples to be transported to a laboratory for processing. Lab processing methods were identical 

to those used for entrainment samples, as described in Sections 5.1.3 and 5.1.4.

4.3.4 Ichthyoplankton Sampling Results

The ichthyoplankton sampling effort captured planktonic life stages of 24 species in 2009 and 26 

species in 2010 (Table 4-3). While the species count was relatively high, ichthyoplankton in the 

study area consisted almost entirely of a single species, bay anchovy, which had monthly 

densities up to approximately 50,000-125,000/1,000 m

3

and several orders of magnitude greater 

than other species (Appendix Tables B-1 and B-2). The only other species of note in terms of 

relative abundance were naked goby (post yolk-sac larvae) and fourbeard rockling (eggs), the 

former only in 2009. 

The average monthly density of ichthyoplankton in both sampling years (Figure 4-4) reflected 

the abundance of bay anchovies. Peak densities occurred in June and July when bay anchovy 

eggs were most abundant. Eggs first appeared in abundance in June and by July bay anchovy

larvae densities were highest in both years. Outside of June and July, the monthly density of all 

species combined averaged across the five sampling stations was 1,565 individuals/1,000 m

3

or 

less. 

Average seasonal ichthyoplankton densities at the three Hackensack River sampling stations (1, 

2 and 3) for all species and life stages combined were several orders of magnitude less than at the 

sampling stations in Newark Bay and the Arthur Kill (Tables 4-9 and 4-10). In both 2009 and 

2010, the highest densities occurred at station 5 in the Arthur Kill (Figure 4-5), but in 2009 

densities at station 4 in Newark Bay also were high in comparison to the Hackensack River 

stations (Table 4-9 and Figure 4-5) when collections consisted primarily of bay anchovy eggs .
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-7

Figure 4-1. Bottom Trawl and Ichthyoplankton Sampling Stations
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-8

Figure 4-2. Total Annual Bottom Trawl Catch by Sampling Station, 2010 and 2011

0

100

200

300

400

500

600

700

800

Station 1 Station 2 Station 3 Station 4 Station 5

Total Catch

Bottom Trawl Total Catch 2009

0

100

200

300

400

500

600

Station 1 Station 2 Station 3 Station 4 Station 5

Total Catch

Bottom Trawl Total Catch 2010
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-9

Figure 4-3. Total Monthly Bottom Trawl Catch by Sampling Station, 2009 and 2010

0

50

100

150

200

250

Mar Apr May Jun Jul Aug Sep Oct Nov

Catch per tow

Month

Bottom Trawl Catch 2009

Station 1

Station 2

Station 3

Station 4

Station 5

0

50

100

150

200

250

300

Feb Mar Apr May Jun Jul Aug Sep Oct Nov

Catch per tow

Month

Bottom Trawl Catch 2010

Station 1

Station 2

Station 3

Station 4

Station 5
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-10

Figure 4-4. Average Monthly Ichthyoplankton Density, 2009 and 2010

-

10,000 

20,000 

30,000 

40,000 

50,000 

60,000 

70,000 

Mar Apr May Jun Jul Aug Sep Oct Nov

#/1,000 cubic meters

Month

Ichthyoplankton Density 2009

-

20,000 

40,000 

60,000 

80,000 

100,000 

120,000 

140,000 

Feb Mar Apr May Jun Jul Aug Sep Oct Nov

#/1,000 cubic meters

Month

Ichthyoplankton Density 2010
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-11

Figure 4-5. Average Seasonal Ichthyoplankton Density at Five Sampling Stations, 2009 

and 2010

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

Station 1 Station 2 Station 3 Station 4 Station 5

#/1,000 cubic meters

Average Ichthyoplankton Density 2009

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

Station 1 Station 2 Station 3 Station 4 Station 5

#/1,000 cubic meters

Average Ichthyoplankton Density 2010
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-12

Table 4-1. Fish Species Collected From the Hackensack River (Sources: PSE&G 1998, 

Bragin et al. 2005, and Present Study)

Family Species Common name

Petromyzontidae Petromyzon marinus sea lamprey

Rajidae Raja erinacea little skate 

Lepisostidae Atractosteus spatula alligator gar

Anguillidae Anguilla rostrata American eel

Congridae Conger oceanicus conger eel 

Engraulidae Anchoa hepsetus striped anchovy 

Anchoa mitchilli bay anchovy

Clupeidae Alosa aestivalis blueback herring 

Alosa mediocris hickory shad 

Alosa pseudoharengus alewife

Alosa sapidissima American shad

Brevoortia tyrannus Atlantic menhaden

Clupea harengus Atlantic herring

Dorosoma cepedianum gizzard shad

Cyprinidae Carassuis auratus goldfish

Cyprinus carpio common carp

Notemigonus crysoleucas golden shiner

Notropis hudsonius spottail shiner

Ictaluridae Ameirus nebulosus brown bullhead 

Ictalurus catus white catfish

Umbridae Umbra pygmaea eastern mudminnow

Osmeridae Osmerus mordax rainbow smelt

Synodontidae Synodus foetens inshore lizardfish

Ophidiidae Ophidion marginatum striped cuskeel 

Phycidae Urophycis chuss red hake

Urophycis regia spotted hake

Merluccuius bilinearis silver hake 

Enchelyopus cimbrius fourbeard rockling

Gadidae Microgadus tomcod Atlantic tomcod 

Pollachius virens pollock

Batrachoididae Opsanus tau oyster toadfish

Mugilidae Mugil cephalus striped mullet

Mugil curema white mullet 
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-13

Table 4-1 Continued

Family Species Common name

Atherinopsidae Membras martinica rough silverside 

Menidia beryllina inland silverside

Menidia menidia Atlantic silverside

Menidia peninsulae tidewater silverside

Fundulidae Fundulus diaphanus banded killifish

Fundulus heteroclitus mummichog

Fundulus majalis striped killifish 

Gasterosteidae Apeltes quadracus fourspine stickleback

Gasterosteus aculeatus threespine stickleback 

Syngnathidae Hippocampus erectus lined seahorse

Syngnathus fuscus northern pipefish 

Fistulariidae Fistularia tabacaria bluespotted cornetfish

Triglidae Prionotus carolinus northern searobin 

Prionotus evolans striped searobin

Cottidae Myoxocephalus aenaeus grubby

Myoxocephalus octodecemspinosus longhorn sculpin

Moronidae Morone americana white perch 

Morone saxatilis striped bass 

Serranidae Centropristis striata black sea bass 

Centrarchidae Lepomis auritus redbreast sunfish

Lepomis gibbosus pumpkinseed 

Lepomis gulosus warmouth

Lepomis macrochirus bluegill 

Lepomis cyanellus green sunfish

Micropterus salmoides largemouth bass

Pomoxis nigromaculatus black crappie

Percidae Perca flavescens yellow perch 

Priacanthidae Pristigenys alta short bigeye

Pomatomidae Pomatomus saltatrix bluefish

Carangidae Catanx hippos crevalle jack 

Selene setapinnis Atlantic moonfish

Selene vomer lookdown 
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-14

Table 4-1 Continued

Family Species Common name

Lutjanidae Lutjanus grieseus gray snapper

Sparidae Archosargus probatocephalus sheepshead 

Stenotomus chrysops scup

Sciaenidae Aplodinotus grunniens freshwater drum

Bairdiella chrysoura silver perch 

Cynoscion regalis weakfish 

Leiostomus xanthurus spot

Menticirrhus saxitilis northern kingfish

Micropogonias undulatus Atlantic croaker 

Labridae Tautoga onitis tautog 

Tautogolabrus adspersus cunner

Pholidae Pholis gunnellus rock gunnel 

Ammodytidae Ammodytes americanus American sand lance

Uranoscopidae Astroscopus guttatus northern stargazer 

Blennidae Hypsoblennius hentz feather blenny

Gobiesocidae Gobiesox strumosus skilletfish

Gobiidae Gobionellus oceanicus highfin goby

Gobiosoma bosc naked goby

Gobiosoma ginsburgi seaboard goby

Scombridae Scomber scombrus Atlantic mackerel

Stromateidae Peprilus triacanthus butterfish

Scopthalmidae Scophthalmus aquosus windowpane

Paralichthyidae Citharichthys articfrons Gulf Stream flounder

Etropus microstomus smallmouth flounder

Paralichthys dentatus summer flounder 

Paralichthys oblongus fourspot flounder 

Pleuronectidae Pseudopleuronectes americanus winter flounder

Achiridae Trinectes maculatus hogchoker 

Ostraciidae Lactophrys triqueter smooth trunkfish 

Tetradontidae Chilomycterus schoepfi striped burrfish

Sphoeroides maculatus northern puffer
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-15

Table 4-2. Percent Composition of Bottom Trawl Catches in 1971-1973, 1986-1987, 1996-

1997, and 2009-2010

Percent Composition

Species

1971-

1973

1986-

1987

1996-

1997 2009 2010

Alewife 4.86 0.23 1.44 0.09

American eel 1.34 0.48 0.89 2.96 9.36

American shad 1.78 0.56 0.08 0.61 0.09

Atlantic croaker 0.30 0.09

Atlantic menhaden 0.42 0.15 0.62

Atlantic moonfish 0.23 1.94

Atlantic silverside 0.04

Atlantic tomcod 7.27 21.78 1.87 10.77 14.84

Bay anchovy 0.67 3.85 0.10 30.27 10.51

Black seabass 0.08

Blueback herring 2.28 0.08 0.15

Bluefish 0.24 0.08 0.08

Brown bullhead 0.23

Butterfish 0.68 0.71

Conger eel 0.19

Cunner 0.23

Gizzard shad 6.74 0.08 0.18

Grubby 0.09 0.08

Hogchoker 0.38 0.23 1.75 6.01

Inland silverside 0.21

Mummichog 77.89 49.63 0.23

Naked goby 0.15 0.27

Northern pipefish 0.71 0.12 <0.01

Northern puffer 0.09

Northern searobin 0.18

Oyster toadfish 0.38 2.74

Red hake 0.10 0.23 1.33

Scup 0.08

Seaboard goby 0.08

Sheepshead 0.08

Silver hake 0.44

Smallmouth flounder 0.24

Spot 0.44 0.15 56.86

Spotted hake 1.87 10.43 0.08 18.06 28.53

Striped bass 0.13 5.85 5.69 1.68
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-16

Table 4-2 Continued

Species

1971-

1973

1986-

1987

1996-

1997 2009 2010

Striped cusk-eel 0.23

Striped killifish 6.43 0.08

Striped searobin 0.38

Summer flounder 0.17 0.08 0.83 0.71

Tautog 0.15

Threespine stickleback 0.30 0.08 0.09

Weakfish 1.26 0.65 1.06 1.59

White perch 0.89 0.66 24.57 19.88 16.87

Windowpane 0.12 0.38 0.27

Winter flounder 1.70 0.87 2.96 0.8

Number of species 11 27 21 28 25

Sources: IA 1974, PSE&G 1988 and 1998, present study
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-17

Table 4-3 Annual Presence of Ichthyoplankton by Life Stage in the Hackensack River 

Study Area for 1972-1973, 1986-1987, 1996-1997, and 2009-2010

Species 1972-1973a1986-1987b1996-1997 2009 2010

Alewife J,A J

American eel J J,A A P P

American sandlance L P

Atherinid unidentified U

Atlantic croaker P,J P,J P,J

Atlantic herring P P,J P,J

Atlantic menhaden L P,J P,J E,P,J

Atlantic moonfish J

Atlantic silverside P Y,P,J,A,U Y,P

Atlantic tomcod L,J J Y,P,U P P,J

Banded killifish P

Bay anchovy E,L,J E,Y,P,P,J,A E,Y,P,J,A,U E,Y,P,J,A E,P,J,A

Blueback herring A E,J J

Bluefish J J

Butterfish J J J

Carp L

Centrarchid unidentified P

Conger eel P J

Cottidae family P

Cunner E,Y E

Cyprinid unidentified Y

Fourbeard rockling E E E

Fundulus sp. (killfish) L P Y,P,U P

Gizzard shad Y,P,A

Gobiid unid. L P,J P,J

Grubby L E,Y,P,U Y,P,J Y,P

Highfin goby P,J,A

Hogchoker E E P

Inland silverside E

Labridae E

Menidia sp. E,Y,P P P

Mummichog E,J J,A P,J

Naked goby J J P,J P,J,A

Northern pipefish Y,P,L,J,A Y,P,J,A P,J,A P,J

Northern puffer P P
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-18

Table 4-3 Continued

Species 1972-1973a1986-1987b1996-1997 2009 2010

Prionotus sp. (searobin) E

River herring E E,P P

Rock gunnel Y,P P P

Rough silverside Y

Sand lances P

Sciaenidae family P

Spot P

Spotted hake J

Striped anchovy A

Striped bass Y,P,A

Striped killifish Y

Summer flounder P,J P,J P,J

Tautog E,P E E

Threespine stickleback J,A J E

Weakfish P,L P,J,A P,J

White perch L P Y,P P,J J

Windowpane E,Y,P E,J P,J

Winter flounder L P,J E,Y,P,U P,J P,J

Yellow perch Y,P P

Unidentified E,P E,P,U E

Number of unique taxa 12 21 38 24 26

Key: 

E = egg, Y = Yolk-sac larvae, P = Post-yolk-sac larvae, L = Larvae, J= Juvenile, A = Adult, U = Unidentified

Sources: IA 1974, PSE&G 1988 and 1998, present study
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-19

Table 4-4. Species Composition of Impingement Collections during 1972-1973, 1978, 1987-

1988, and 1996-1997

Species 1972 1973 1978 1987-1988 1996-1997

Alewife 30.6 1.7 10.7 2.0 0.2

American eel 0.1 0.5 0.1 0.6 0.2

American shad 0.3 1.0 0.3 1.7 0.1

Atlantic croaker <0.1

Atlantic herring 1.7 2.9

Atlantic mackerel <0.1

Atlantic menhaden 0.1 0.1 <0.1 16.3 2.2

Atlantic moonfish <0.1 <0.1

Atlantic silverside <0.1 0.5 0.1 6.0 0.6

Atlantic tomcod 0.2 0.4 0.2 6.4 1.6

Banded killifish <0.1

Bay anchovy <0.1 0.7 0.3 2.2 27.2

Black crappie 0.1 0.1 0.1

Black sea bass 0.1 <0.1 <0.1

Blueback herring 36.5 9.6 12.2 17.0 1.7

Bluefish 0.1 0.3 7.0 3.1

Bluegill 0.2 0.1 0.1 0.2 0.1

Brown bullhead <0.1 0.1

Butterfish 0.1 <0.1 0.1 <0.1

Common carp <0.1

Conger eel <0.1

Crevalle jack 0.1 <0.1 1.3 0.1

Cunner <0.1 0.1 0.1

Cyprinodontidae ** <0.1

Fourspot flounder 0.0

Fundulus sp.** <0.1

Gizzard shad 0.3 1.8 3.3

Golden shiner <0.1

Goldfish 0.1 0.1 <0.1 <0.1

Grubby <0.1 <0.1 0.3

Hickory shad <0.1 <0.1

Hogchoker <0.1 <0.1 <0.1 0.2

Inland silverside 0.4

Lined seahorse <0.1 0.1

Little skate <0.1

Longhorn sculpin <0.1
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-20

Table 4-4 Continued

Species 1972 1973 1978 1987-1988 1996-1997

Lookdown <0.1

Menidia spp.** 0.1

Morone sp.** <0.1

Mummichog 27.7 80.0 58.4 11.7 0.2

Naked goby 0.1

Northern pipefish <0.1 0.2

Northern puffer <0.1

Northern searobin <0.1 <0.1 0.2

Pumpkinseed 0.1 0.1 <0.1 0.3 0.1

Rainbow smelt 0.2 0.3 <0.1

Red hake <0.1 0.1 0.4 1.6 1.5

Scup <0.1

Seaboard goby <0.1

Silver hake 0.2 0.4 0.3 <0.1 0.1

Silver perch 0.1

Smallmouth flounder <0.1 0.2 0.2

Smooth trunkfish <0.1

Spot 1.6 <0.1 0.1 2.6

Spotted hake 0.1 2.0

Striped anchovy <0.1

Striped bass 0.8 0.5 5.1 1.7 2.1

Striped burrfish <0.1

Striped cuskeel <0.1

Striped killifish 2.8 0.4

Striped mullet <0.1

Striped searobin 0.1 <0.1 0.3 0.1

Summer flounder <0.1 0.2 0.2

Tautog <0.1 <0.1 <0.1

Threespine stickleback <0.1 0.2 0.5 1.0 9.6

Warmouth <0.1

Weakfish 0.2 5.7 7.2 21.2

White catfish <0.1 <0.1
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-21

Table 4-4 Continued

Species 1972 1973 1978 1987-1988 1996-1997

White mullet 2.8 2.3 0.2 <0.1

White perch 4.5 3.8 7.8

Windowpane 0.2 0.2

Winter flounder 0.2 0.1 3.7 6.6

Yellow perch <0.1

Total Taxa Count 54 20 25 42 51

** not counted as unique taxa 

Sources: IA 1974, 1979; PSEG 1988, 1998
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-22

Table 4-5. Presence of Species by Life Stage in Entrainment Collections in 1987-1988 and 

1996-1997

Species Collected in 1987-1988 Collected in 1996-1997

American eel JUV JUV AD

American sand lance EGG YSL PYSL

Atlantic croaker EGG PYSL JUV

Atlantic herring PYSL JUV PYSL

Atlantic menhaden EGG PYSL PYSL JUV

Atlantic silverside EGG PYSL YSL PYSL JUV

Atlantic tomcod EGG YSL PYSL JUV EGG YSL PYSL JUV

Bay anchovy EGG PYSL JUV EGG PYSL JUV AD

Blueback herring PYSL** EGG PYSL JUV

Bluefish JUV JUV

Centrarchidae family. YSL PYSL

Conger eel PYSL

Cunner EGG YSL

Cyprinidae spp. EGG

Fourbeard rockling EGG

Gobiidae unid. PYSL JUV YSL PYSL JUV

Grubby YSL PYSL YSL PYSL JUV

Hogchoker EGG EGG

Inland silverside EGG PYSL

Labridae spp. EGG

Mummichog JUV YSL PYSL

Naked goby AD

Northern pipefish PYSL JUV PYSL JUV AD

Pollock JUV

Rock gunnel YSL PYSL YSL PYSL

Scianidae family. PYSL

Seaboard goby AD

Smallmouth flounder JUV

Spot JUV

Summer flounder PYSL JUV

Tautog

Threespine stickleback PYSL

Tidewater silverside JUV

Weakfish PYSL PYSL JUV

White perch YSL PYSL

Windowpane PYSL EGG PYSL JUV

Winter flounder YSL PYSL JUV YSL PYSL JUV

Yellow perch PYSL

YSL = Yolk-sac larvae; PYSL = post-yolk-sac larvae; JUV = Juvenile; AD= adult

Source: PSEG 1998
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-23

Table 4-6. Gear Specifications for the Bottom Trawl and Ichthyoplankton Net

30-Ft Semi-balloon Bottom trawl

 Headrope 25.9 ft (7.9-m)

 Footrope 27.9 ft (8.5-m)

 Wing height 3.6 ft (1.1-m)

 Total length 35.1 ft (10.7-m)

 Wing mesh (square) 2.0-in (5.1-cm)

 Body mesh (square) 2.0-in (5.1-cm)

 Cod end mesh (square) 0.75-in (1.9-cm)

 Cod end liner mesh (square) 0.25-in (0.6-cm)

 Trawl doors (oak) 32.0 x 17.0 x 1.0-in (81.3 x 43.2 x 2.5-cm)

 Tow Bridle 100-ft (30.5-m) Galvanized wire rope

 Tow line length Min 3 times maximum station water depth

1.0-m

2 Tucker Trawl with 333-μm Mesh Net

 Vertical Dimension (open) 1.4-m (1.0-m when under tow)

 Horizontal Dimension (open) 1.0-m

 Total length 8.0-m

 Net Mesh 333-μ (micron)

 Cod-End Bucket 4-in dia. x 12-in (10.5-cm x 30.5-cm)

 Cod-End Bucket Mesh 333-μ (micron)

 Weight (nominal) 250-lbs (113.4-kg)

 Tow line length Based on wire length & angle charts
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-24

Table 4-7. Monthly Total Bottom Trawl Catch by Species, 2009

Species Mar Apr May Jun Jul Aug Sep Oct Nov Total

Alewife 13 5 1 19

American eel 1 35 2 1 39

American shad 8 8

Atlantic menhaden 1 1 2

Atlantic moonfish 2 1 3

Atlantic tomcod 30 67 53 2 2 154

Bay anchovy 21 208 99 86 303 29 2 748

Black seabass 1 1

Blue crab 1 17 26 14 4 26 32 120

Blueback herring 2 2

Bluefish 1 1

Butterfish 8 1 9

Cunner 1 1 1 3

Gizzard shad 1 1

Grubby 1 1

Hogchoker 7 13 2 1 23

Naked goby 2 2

Oyster toadfish 2 1 1 1 5

Red hake 2 1 3

Scup 1 1

Spotted hake 12 19 326 52 7 416

Striped bass 47 16 4 8 75

Striped cusk-eel 3 3

Striped searobin 3 2 5

Summer flounder 1 2 8 11

Tautog 2 2

Weakfish 2 2 10 14

White perch 132 51 17 6 6 13 74 299

Windowpane 3 2 5

Winter flounder 6 1 1 13 7 2 9 39

Total 221 102 471 419 177 87 330 75 132 2014
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-25

Table 4-8. Monthly Total Bottom Trawl Catch by Species, 2010

Species Feb Mar Apr May Jun Jul Aug Sep Oct Nov Total

Alewife 1 1

American eel 2 65 5 20 2 7 4 1 106

American shad 1 1

Atlantic croaker 1 1

Atlantic menhaden 7 7

Atlantic moonfish 1 21 22

Atlantic tomcod 130 9 33 1 1 174

Bay anchovy 9 17 36 2 31 17 7 119

Blue crab 4 185 29 135 27 44 31 5 9 469

Butterfish 1 5 1 1 8

Gizzard shad 2 2

Hogchoker 1 15 41 2 8 1 68

Naked goby 1 1 1 3

Northern puffer 1 1

Northern searobin 1 1 2

Oyster toadfish 1 3 9 1 9 7 1 31

Red hake 1 12 1 1 15

Silver hake 5 5

Spotted hake 265 127 86 4 482

Striped bass 3 1 1 7 4 3 19

Summer flounder 2 3 3 8

Threespine stickleback 1 1

Weakfish 4 7 3 4 18

White perch 182 29 12 1 2 12 30 21 16 305

Windowpane 1 2 3

Winter flounder 1 1 1 1 1 3 8

Total 168 37 681 193 326 124 83 122 83 42 1879
HUDSON GENERATING STATION 316(b) STUDY REPORT

4-26

Table 4-9. Average Monthly Ichthyoplankton Density (#/1,000 m3) at Five Sampling 

Stations in 2009

Month

Station 

1

Station 

2

Station 

3

Station 

4

Station 

5 All Station Avg

Mar 131 112 153 443 75 183

Apr 95 102 239 327 177 188

May 170 29 75 1,971 581 565

Jun 376 693 9,724 138,514 1,455 30,153

Jul 1,853 4,212 5,944 9,902 327,809 69,944

Aug 2,830 467 1,254 656 1,022 1,246

Sep 90 230 502 348 180 270

Oct 3,070 326 748 401 459 1,001

Nov 131 34 352 346 134 199

Average 972 689 2,110 16,990 36,877 11,528

Table 4-10. Average Monthly Ichthyoplankton Density (#/1,000 m3) at Five Sampling 

Stations in 2010

Month

Station 

1

Station 

2

Station 

3

Station 

4

Station 

5 All Station Avg

Feb 0 17 14 4 18 11

Mar 24 35 39 175 70 69

Apr 56 103 340 181 260 188

May 81 74 71 52 39 63

Jun 16,615 7,795 7,117 21,204 184,055 47,357

Jul 1,513 1,455 1,267 2,224 632,236 127,739

Aug 400 604 718 2,499 3,607 1,565

Sep 299 223 37 86 47 139

Oct 55 64 53 252 676 220

Nov 7 49 34 118 50 51

Average 1,905 1,042 969 2,679 82,106 17,740
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-1

5. ENTRAINMENT

This chapter presents the 2009-2011 sampling program for entrainment at Hudson Generating 

Station. Entrainment is the passage of small organisms through the Station’s cooling water 

system resulting from withdrawing water for cooling purposes. Passage through the cooling 

water system can subject entrained organisms to mechanical, thermal, and chemical stresses. 

The ability of entrained organisms to withstand these stresses varies widely among taxa. 

Entrained organisms typically are weak swimming or younger planktonic or semi-planktonic life 

stages of fish and invertebrates that are small enough to pass through the 3/8-inch mesh vertical 

traveling screens that are used at the Station. Fish life stages entrained at the Station included

eggs, yolk-sac larvae (YSL), post-yolk-sac larvae (PYSL), juveniles, and smaller adults. 

Chapter 5.1 describes the entrainment sampling schedule, sampling gear, sampling methods, and 

sample processing including Quality Assurance and Quality Control (QA/QC) procedures. 

Chapter 5.2 presents the collection results of the two-year sampling program, including species 

composition, temporal patterns, and comparisons to previous years. Estimates of annual direct 

losses of fish to entrainment are presented in Chapter 8, along with a comparison with results 

from a similar program conducted at the Station in 1996-1997.

5.1 METHODS

Entrainment sampling involved the collection and preservation of samples at the intake;

recording of water quality variables at the time of sampling; and laboratory processing of 

samples for taxonomic and life stage identification, counts, and measurements.

5.1.1 Sampling Schedule

Entrainment sampling was conducted once per week starting on 26 January 2009 and continuing 

through 17 January 2011 for a total of 104 weeks. A sample of at least 100 m3volume was taken 

during each 6-hour interval on each sampling day for a total of four samples per sampling event. 

The sampling intervals were 0001-0600, 0601-1200, 1201-1800, and 1801-2400 hours.

5.1.2 Sampling Gear and Methods

Sampling was conducted using a pumped entrainment sampler consisting of a 4-inch gasolinepowered trash pump attached to a 4-inch flexible intake line that could be raised and lowered to 

specified depths, and a circular tank equipped with a 75-cm diameter plankton net with 333-μm 

mesh netting. Samples were collected from the center of the common intake for both Units 1 and 

2 at a location immediately in front of or behind the skimmer wall. Each sample consisted of a 

composite of approximately equal samples drawn from near surface, mid-depth, and near 

bottom. Samples were collected regardless of whether cooling water pumps were operating at 

the time of sampling. 

At the completion of each collection, the tank was drained and the net was carefully washed to 

concentrate all materials collected into the collection cup. After a thorough wash-down, the 

collected materials (plankton and detritus) were removed from the cup, placed in a glass jar and 

preserved with 10 percent formalin containing rose bengal dye. Each jar was then labeled and 

transported to the laboratory for subsequent processing.
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-2

Water quality and environmental parameters were recorded every 6 hours during a sampling 

event at mid-depth in the intake using an in-situ multi-parameter water quality meter and 

turbidity meter. The parameters were consisted of:

 Water temperature (to 0.1°C)

 Dissolved oxygen (DO) concentration (to 0.1 mg/l)

 Turbidity (NTU units)

 Tidal stage and height (ft)

 Salinity (ppt)

 Conductivity (μS/cm)

 Air temperature (to 0.1°C)

 Weather conditions

The water quality and turbidity meters were calibrated according to the manufacturer’s 

specifications for the meters prior to and after each sampling event.

5.1.3 Sample Processing

In the laboratory, all fish eggs, larvae, and juveniles were carefully sorted from sample detritus 

and invertebrates. When numbers of ichthyoplankters was high, samples were randomly split 

using a Motoda plankton-splitter and a sufficient number of splits were analyzed such that a 

minimum of 200 fish eggs or larvae/juveniles had been sorted. All specimens removed from 

each sample were identified to the lowest practical taxon and separated into the following life 

stages:

Egg – The embryonic developmental stages from spawning to hatching.

Yolk-sac larvae (YSL) – The transition stage from hatching through the development of 

a complete, functional digestive system (regardless of the degree of yolk and/or oil 

globule retention).

Post yolk-sac larvae (PYSL) – The transition stage from the yolk-sac larval stage to 

transformation to the juvenile stage, including the leptocephalus stage of eels.

Juvenile – The stage following completion of a full complement of fin rays up to 12 

months of age.

Adult – Determined as 1 year old or older based on literature values.

Specimens up to 15 mm in length were measured to the nearest 0.1 mm (TL) and to the nearest 1 

mm for specimens over 15 mm. 
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-3

5.1.4 QA/QC

The results of laboratory processing, including counts and lengths, were recorded on projectspecific data sheets. All laboratory processing was subject to a statistically-based quality control 

process based on a continuous sampling plan (derived from military-standard MIL-STD 1235B), 

which guarantees an Average Outgoing Quality Level (AOQL) of 95 percent or more. That is, 

samples selected based on the continuous sampling plan are re-inspected to assure that more than 

95 percent of organisms have been removed during sorting and that an accuracy of at least 95 

percent is achieved in identifying, assigning a life stage, or counting any species. Samples not 

achieving these acceptance limits are rejected and reprocessed.

5.2 RESULTS

A total 192 entrainment samples were collected from 26 January 2009 through 18 January 2010 

(Year 1), and 207 samples from 25 January 2010 through 17 January 2011 (Year 2) (Table 5-1). 

Occasionally samples were unavoidably missed due to cold weather-related problems like a 

frozen pump sampler or to a broken pump or blocked access to the sampling equipment. A total 

of 16 samples corresponding to four sampling dates were not collected in Year 1, and one sample 

was not collected in Year 2 because of blocked access to the sampling equipment.

5.2.1 Species and Life Stage Composition

In Year 1, a total of 3,779 organisms comprising 24 unique taxa were found in entrainment 

collections (Table 5-2). In Year 2, the total collection consisted of 13,394 organisms and 28 

unique taxa (Table 5-3). Bay anchovy was the most abundant species during both years, 

comprising 64.1 percent of the collections in Year 1 and 91.8 percent in Year 2. Bay anchovy 

life stages included eggs, PYSL, juveniles, and adults. 

Atlantic croaker was the only other species that made up more than 10 percent of an annual 

entrainment collection, and that happened only in Year 1 (470 individuals or 12.4 percent, Table 

5-2). In Year 2, Atlantic croaker had decreased in abundance to 36 individuals, representing 

only 0.3 percent of the collections. Atlantic croaker life stages entrained included PSYL and 

juvenile. Atlantic croaker in the Middle Atlantic Bight is almost totally restricted to continental 

shelf waters (Able and Fahay 2010), so it is likely that the larvae and juveniles found in the study 

area moved from offshore to use the estuary as a nursery area rather than spawning there. 

Two species, tautog and naked goby, ranked among the most frequently collected species (>2 

percent of total collected) in both sampling years. Tautog eggs ranked third in abundance in both 

years with 4.4 percent of the Year 1 collections and 2.7 percent of the Year 2 collections (Table 

5-2 and 5-3). Naked goby was the second-most frequently entrained species in Year 2 with 2.8 

percent of the total collection, and was seventh-most frequently entrained in Year 1 with 2.7 

percent of the total collection.

One other species, Atlantic menhaden, was notable in terms of the consistency that it appeared in 

the two years of entrainment collections (Tables 5-2 and 5-3). It ranked among the seven most 

frequently collected species and included eggs, PYSL, and juveniles.
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-4

Together, these five species comprised 87 percent of the Year 1 collections and 98 percent of the 

Year 2 collections. In addition to all species combined, these five species were selected as 

individual species to examine temporal patterns of entrainment collections by life stage in the 

following section. 

Larval and juvenile length frequency data for each species and sampling year are provided in 

Appendix C.

5.2.2 Temporal Patterns

Overall, while entrainment at the Station occurred in nearly every month, there was variation 

between the two sampling years in the seasonal occurrence and abundance of life stages for all 

species combined (Figures 5-1 and 5-2). In both years, eggs were entrained in greatest densities 

from May to early July, reflecting the relative abundance of bay anchovy and tautog eggs, two 

species that are late spring and early summer spawners. YSL were never abundant in 

entrainment (<20 larvae/1,000 m

3

); in Year 1 they occurred from mid-February to early April 

(Figure 5-1) but in Year 2 they were most abundant in late May (Figure 5-2). In Year 1, most 

YSL were grubby (Table 5-2), a late winter-early spring spawner, and in Year 2 most YSL were 

identified as genus Menidia, silversides (Table 5-3), which are spring or summer spawners (Able 

and Fahay 2010). PYSL was the most frequently entrained life stage collected and was entrained 

throughout the year, but in greatest densities in both sampling years from June through August 

due to the dominance of bay anchovies. Juveniles were entrained only at reduced densities, but 

there were differences between Years 1 and 2. In Year 1, peak entrainment occurred in late 

November and early December (Figure 5-1), dominated by Atlantic croaker and Atlantic 

menhaden juveniles (Table 5-2). In Year 2, entrainment of juveniles was reduced, and peak rates 

occurred in March and April, reflecting the relative abundance of juvenile Atlantic herring, 

which at northern latitudes spawns in the fall (Able and Fahay 2010).

Bay anchovy entrainment almost exclusively involved eggs and PYSL. In both sampling years, 

eggs were entrained during May and July, and PYSL were entrained primarily during June 

through August (Figures 5-3 and 5-4). As larval bay anchovies transformed to juveniles, 

entrainment of the juvenile stage was delayed until August in Year 1 and July in Year 2 and 

continued at low levels into late fall and early winter (November and December).

Entrainment of Atlantic croaker was restricted of fall and early winter months, SeptemberDecember (Figure 5-5 and 5-6), reflecting available literature information that spawning for this 

species in this region begins in September, peaks in October, and ends in December (Able and 

Fahay 2010). The occurrence of PYSL in September, particularly in Year 2, may indicate that 

spawning along the coastline in this region begins earlier in some years. No eggs or YSL were 

entrained.

Tautog eggs were entrained during May and June of both sampling years (Figures 5-7 and 5-8). 

With the exception of a single juvenile tautog collected in early November 2009, no other life 

stages were entrained.

Entrainment levels for Atlantic menhaden were relatively low; densities for each life stage were 

<25 individuals/1,000 m3except for juveniles in Year 2 (Figures 5-9 and 5-10). Eggs were
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-5

collected in May of both years, but most PYSL were not entrained until October-December. 

Able and Fahay (2010) state that Atlantic menhaden in the Middle Atlantic Bight spawn mostly 

in the fall and early winter over the inner continental shelf, but there may be limited spawning in 

coastal waters in the spring. This observation may explain why some eggs were entrained during 

May and a very limited number of PYSL were entrained in April or July (Figures 5-9 and 5-10).

The only life stages of naked goby that were entrained at the Station were PYSL and juveniles. 

PYSL were entrained from mid-May until early October, and juvenile entrainment was very 

limited (<2.5 individuals/1,000 m3) and only occurred in Year 2 during September (Figures 5-11 

and 5-12). Naked gobies can spawn from April or May through August or September (Able and 

Fahay 2010), coinciding with the months of entrainment for PYSL at the Station. Eggs or YSL 

would not be expected to be entrained since the eggs are deposited and guarded in nests by the 

parent fish.

The average density of entrained fish that occurred in each of the four 6-hour collections was 

examined for the five species and their life stages to determine whether there was a diel 

periodicity to their entrainment, i.e., what time of day were they most likely to be entrained. The 

results are presented in Tables 5-4 and 5-5. There were no strong or consistent diel entrainment

patterns apparent for any of the five species or their life stages across both years of sampling.

5.2.3 Comparison to 1996-1997 Entrainment Study

When entrainment was monitored at the Station during 1996-1997, bay anchovy dominated 

entrainment collections, constituting 64.3 percent of the total entrained fish collected (PSE&G 

1998). This value is nearly identical to the Year 1 value in the present study (64.5 percent, Table 

5-2), but less than the Year 2 value (91.7 percent). Nevertheless, it is apparent that bay anchovy 

is and has been the predominantly entrained species in recent years at the Station, and likely will 

continue to be in the near future.

In 1996-1997, Atlantic tomcod was the second-most abundant species in entrainment collections, 

comprising 29.9 percent of all entrained fishes (PSE&G 1998). In Year 1 of the present study, 

only four entrained Atlantic tomcod were collected, and Atlantic tomcod did not appear at all in 

the Year 2 collections (Tables 5-2 and 5-3). As discussed in Chapter 4-2, Atlantic tomcod has 

reached its lowest levels of abundance in 27 or more years within the Hudson River estuary 

(Daniels et al. 2005), which may account for the near elimination of the species from 

entrainment at the Station since the 1996-1997 study was conducted.

Since no other species have been dominant, or even relatively abundant, in entrainment 

collections, species-specific trends would be difficult to detect for entrainment. Seasonal 

entrainment in the prior study (1996-1997) for all species and life stages combined was similar to 

the present study, in that peak entrainment was during summer, June-August (PSE&G 1998). 

Bay anchovy eggs and PYSL had dominated the June-October collections, like in the present 

study. Unlike the present study, entrainment levels were elevated in December 1996-January 

1997 by collections of Atlantic tomcod eggs, thought to have been extruded by impinged ripe 

females.
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-6

Figure 5-1. Temporal Distribution of Entrainment by Life Stage for All Species Combined, 

2009-2010
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-7

Figure 5-2. Temporal Distribution of Entrainment by Life Stage for All Species Combined, 

2010-2011
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-8

Figure 5-3. Temporal Distribution of Entrainment by Life Stage for Bay Anchovy, 2009-

2010
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-9

Figure 5-4. Temporal Distribution of Entrainment by Life Stage for Bay Anchovy, 2010-

2011
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-10

Figure 5-5. Temporal Distribution of Entrainment by Life Stage for Atlantic Croaker, 

2009-2010
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-11

Figure 5-6. Temporal Distribution of Entrainment by Life Stage for Atlantic Croaker, 

2010-2011
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-12

Figure 5-7. Temporal Distribution of Entrainment by Life Stage for Tautog, 2009-2010
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-13

Figure 5-8. Temporal Distribution of Entrainment by Life Stage for Tautog, 2010-2011
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-14

Figure 5-9. Temporal Distribution of Entrainment by Life Stage for Atlantic Menhaden, 

2009-2010
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-15

Figure 5-10. Temporal Distribution of Entrainment by Life Stage for Atlantic Menhaden, 

2010-2011
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-16

Figure 5-11. Temporal Distribution of Entrainment by Life Stage for Naked Goby, 2009-

2010
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-17

Figure 5-12. Temporal Distribution of Entrainment by Life Stage for Naked Goby, 2010-

2011
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-18

Table 5-1. Number of Samples Collected in Entrainment Monitoring at Hudson 

Generating Station, January 2009 – January 2011

Study Year 2009 Study Year 2010

Sample 

Date

No. of

Samples

Sample

Date

No. of

Samples

Sample 

Date

No. of

Samples

Sample

Date

No. of

Samples

26-Jan-09 4 27-Jul-09 4 25-Jan-10 4 26-Jul-10 4

2-Feb-09 4 3-Aug-09 NS21-Feb-10 4 2-Aug-10 4

9-Feb-09 4 10-Aug-09 4 8-Feb-10 4 10-Aug-10 4

16-Feb-09 NS117-Aug-09 4 15-Feb-10 4 17-Aug-10 4

23-Feb-09 4 24-Aug-09 4 22-Feb-10 3

4

23-Aug-10 4

2-Mar-09 4 31-Aug-09 4 1-Mar-10 4 30-Aug-10 4

9-Mar-09 4 7-Sep-09 4 8-Mar-10 4 6-Sep-10 4

16-Mar-09 4 14-Sep-09 4 15-Mar-10 4 13-Sep-10 4

23-Mar-09 4 21-Sep-09 NS222-Mar-10 4 20-Sep-10 4

30-Mar-09 4 28-Sep-09 4 29-Mar-10 4 27-Sep-10 4

6-Apr-09 4 5-Oct-09 4 5-Apr-10 4 5-Oct-10 4

13-Apr-09 4 12-Oct-09 4 12-Apr-10 4 12-Oct-10 4

20-Apr-09 4 19-Oct-09 4 19-Apr-10 4 18-Oct-10 4

27-Apr-09 4 26-Oct-09 4 26-Apr-10 4 28-Oct-10 4

4-May-09 4 2-Nov-09 4 3-May-10 4 1-Nov-10 4

11-May-09 4 9-Nov-09 4 10-May-10 4 8-Nov-10 4

18-May-09 4 16-Nov-09 4 17-May-10 4 15-Nov-10 4

25-May-09 4 23-Nov-09 4 24-May-10 4 22-Nov-10 4

1-Jun-09 4 30-Nov-09 4 31-May-10 4 29-Nov-10 4

8-Jun-09 4 7-Dec-09 4 7-Jun-10 4 6-Dec-10 4

15-Jun-09 4 14-Dec-09 4 14-Jun-10 4 13-Dec-10 4

22-Jun-09 4 21-Dec-09 NS321-Jun-10 4 20-Dec-10 4

29-Jun-09 4 28-Dec-09 4 28-Jun-10 4 27-Dec-10 4

6-Jul-09 4 4-Jan-10 4 5-Jul-10 4 3-Jan-11 4

13-Jul-09 4 11-Jan-10 4 12-Jul-10 4 10-Jan-11 4

20-Jul-09 418-Jan-10 4 19-Jul-10 4 17-Jan-11 4

Total 192 Total 207

1

Sampling canceled due to plant maintenance of screen and unable to access sampling device.

2

 Sampling pump broken.

3 Hoses and pipes were frozen on entrainment sampler.

4

 One sample was not collected due to blocked access to sampling equipment.
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-19

Table 5-2. Overall Numerical Composition of Ichthyoplankton Collected in Entrainment 

Monitoring at Hudson Generating Station, 26 January 2009 – 18 January 2010

Taxon

Total Count1

Egg YSL PYSL Juvenile Adult Total Percent

Bay anchovy 873 1516 26 9 2424 64.14

Atlantic croaker 201 269 470 12.44

Tautog 165 1 166 4.39

Cunner 154 154 4.08

Grubby 14 135 5 154 4.08

Atlantic menhaden 2 27 105 134 3.55

Naked goby 103 103 2.73

Northern pipefish 2 36 1 39 1.03

Summer flounder 9 23 32 0.85

Winter flounder 22 22 0.58

American eel 20 20 0.53

Atlantic herring 4 8 12 0.32

Rock gunnel 11 1 12 0.32

Unidentifiable fish 2 5 2 2 11 0.29

Atlantic silverside 6 6 0.16

Highfin goby 4 4 0.11

Threespine stickleback 3 3 0.08

Weakfish 3 3 0.08

White perch 2 2 0.05

Butterfish 1 1 0.03

Crevalle jack 1 1 0.03

Fundulus sp. 1 1 0.03

Northern puffer 1 1 0.03

Red hake 1 1 0.03

Spotted hake 1 1 0.03

Striped killifish 1 1 0.03

Urophycis sp. 1 1 0.03

Total 1196 14 2069 486 13 3779 100.00
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-20

Table 5-3. Overall Numerical Composition of Ichthyoplankton Collected in Entrainment 

Monitoring at Hudson Generating Station, 25 January 2010 – 17 January 2011

Taxon

Total Count1

Egg YSL PYSL Juvenile Adult Total Percent

Bay Anchovy 9569 2712 6 5 12292 91.77

Naked goby 1 358 1 8 368 2.75

Tautog 364 364 2.72

Atlantic herring 12 95 107 0.80

Grubby 3 37 40 0.30

Atlantic croaker 21 15 36 0.27

Atlantic menhaden 6 23 1 30 0.22

American eel 23 23 0.17

Menidia sp. 15 6 21 0.16

Northern pipefish 2 15 17 0.13

Winter flounder 10 6 16 0.12

Unidentifiable fish 12 1 13 0.10

Cunner 10 10 0.07

Threespine stickleback 8 1 9 0.07

Fundulus sp. 8 8 0.06

Striped bass 8 8 0.06

Summer flounder 8 8 0.06

Atlantic silverside 5 5 0.04

Atlantic tomcod 3 1 4 0.03

Conger eel 2 2 0.01

Highfin goby 2 2 0.01

White perch 2 2 0.01

Blueback herring 1 1 0.01

Bluegill 1 1 0.01

Butterfish 1 1 0.01

Feather blenny 1 1 0.01

Inshore lizardfish 1 1 0.01

Oyster toadfish 1 1 0.01

Rock gunnel 1 1 0.01

Skilletfish 1 1 0.01

Smallmouth flounder 1 1 0.01

Total 9978 20 3220 157 19 13394 100.00
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-21

Table 5-4. Average Diel Density (#/1,000 m3) of Selected Species Collected in Entrainment 

Monitoring, 26 January 2009 – 18 January 2010

Taxa

Life 

Stage

Beginning of 6-Hour Sampling Period

0:00 6:00 12:00 18:00 

Atlantic croaker PYSL 4.53 2.54 12.73 18.08

JUV 5.62 13.46 15.40 17.61

Atlantic herring PYSL 0.38 0.00 0.20 0.20

JUV 0.19 0.39 0.00 1.01

Atlantic menhaden PYSL 0.80 0.20 1.02 3.13

JUV 20.96 0.00 0.21 0.20

Bay anchovy Eggs 19.83 46.88 70.45 39.32

PYSL 49.81 68.80 110.23 74.22

JUV 1.22 1.41 1.04 1.20

Adult 0.20 0.40 0.21 1.01

Naked goby PYSL 2.18 2.40 12.24 3.82

Tautog Eggs 12.18 6.62 7.20 7.47

JUV 0.00 0.00 0.20 0.00

YSL = Yolk-sac larvae

PYSL = Post yolk-sac larvae

JUV = Juvenile
HUDSON GENERATING STATION 316(b) STUDY REPORT

5-22

Table 5-5. Average Diel Density (#/1,000 m3) of Selected Species Collected in Entrainment 

Monitoring, 25 January 2010 – 17 January 2011

Taxa

Life 

Stage

Beginning of 6-Hour Sampling Period

0:00 6:00 12:00 18:00 

Atlantic croaker PYSL 0.94 1.13 0.74 0.94

JUV 0.93 0.76 0.37 1.72

Atlantic herring PYSL 0.18 0.18 0.36 1.37

JUV 4.63 2.33 0.00 9.73

Atlantic menhaden Eggs 0.00 0.76 0.00 0.36

PYSL 0.54 0.96 0.93 1.12

JUV 0.00 0.00 0.38 0.00

Bay anchovy Eggs 556.54 292.41 186.86 581.57

PYSL 54.42 40.91 69.45 179.45

JUV 0.00 0.57 0.37 0.19

Adult 0.00 0.56 0.00 0.00

Naked goby PYSL 18.71 9.37 9.59 16.73

JUV 0.19 0.00 0.00 0.00

Adult 0.19 0.17 0.54 0.50

Tautog Eggs 7.49 8.88 31.33 19.87

YSL = Yolk-sac larvae

PYSL = Post yolk-sac larvae

JUV = Juvenile
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-1

6. IMPINGEMENT

This chapter presents the 2009-2011 sampling program for impingement at Hudson Generating 

Station. Impingement is the entrapment of organisms too large to pass through the mesh of the 

traveling screens. Chapter 6.1 describes the impingement sampling schedule, sampling gear, 

sampling methods, and sample processing including Quality Assurance and Quality Control 

(QA/QC) procedures. Chapter 6.2 presents the collection results of the two-year sampling 

program, including species composition, temporal patterns, and comparisons to previous years. 

The results of impingement survival testing on the recently installed Ristroph traveling screens in 

Unit 2 are presented in Chapter 7. Estimates of annual direct losses of fish to impingement are

presented in Chapter 8, along with a comparison with results from a similar program conducted 

at the Station in 1996-1997.

6.1 METHODS

Impingement sampling involved the collection of samples of impinged fish and blue crabs at the 

intake; identification to species, counting, and recording lengths for age group determination and 

size frequency determination; and recording of water quality variables at the time of sampling.

6.1.1 Sampling Schedule

Impingement sampling was conducted on the same days as entrainment sampling, i.e., once per 

week starting on 26 January 2009 and continuing through 17 January 2011 for a total of 104

weeks. The sampling intervals were 0001-0600, 0601-1200, 1201-1800, and 1801-2400 hours. 

Altogether, there were six collections made during each sampling event. One sample was taken 

over approximately 1 hour during each 6-hour interval on each sampling day. In addition to the 

regular 1-hour samples, a second 1-hour sample was taken during the first two sampling 

intervals, 0001-0600 and 0601-1200 hours. The second collection during these two sampling 

intervals was intended to increase the number of fish available for impingement survival testing, 

described in Chapter 7. Data on fish collected during the extra 1-hour collections in the first two 

sampling intervals were combined with data from the first collections, and estimates of total 

impingement during each sampling interval were derived by extrapolating from 1 or 2 hour 

collections to the full 6-hour interval.

6.1.2 Sampling Gear and Methods

Sampling was conducted from the fish collection pool attached to the washwater sluice for Unit 

2.

10

 The collection pool was located behind and between the traveling screens of Units 1 and 2. 

The traveling screen housings and sluice were cleaned prior to initiation of sampling. Water was 

directed to the collection pool using the south tide gate, a board in the middle of the sluice, and 

the gate on the collection pool. To begin the collection, the start time was recorded, the 

collection pool gate was opened, and the gates at both ends of the washwater sluice were closed. 

Thereafter, the collection pool was checked regularly to ensure that the contents did not 

overflow. 

 

10 All sampling was conducted at Unit 2. Unit 1 was not sampled due to the lack of access to its washwater sluice 

because of the modified screenhouse configuration after installation of the modified Ristroph-type screens and 

screen washwater system for Unit 2.
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-2

At the conclusion of the sample collection, the gate to the fish collection pool was closed and the 

gates in the fish return sluice were opened. A screen was used to concentrate the impingement 

sample, and all fish and blue crabs were removed from the pool. If present, any threatened or 

endangered species were collected, identified, and measured with as little handling stress as 

possible, before being released alive. Any encounter with threatened or endangered species was 

reported to the onsite PSEG supervisor.

Water quality and environmental parameters were recorded every 6 hours during a sampling 

event at mid-depth in the intake using an in-situ multi-parameter water quality meter and 

turbidity meter. The parameters were consisted of:

 Water temperature (to 0.1°C)

 Dissolved oxygen (DO) concentration (to 0.1 mg/L)

 Turbidity (NTU units)

 Tidal stage and height (ft)

 Salinity (ppt)

 Conductivity (μS/cm)

 Air temperature (to 0.1°C)

 Weather conditions

The water quality and turbidity meters were calibrated according to the manufacturer’s 

specifications for the meters prior to and after each sampling event.

6.1.3 Sample Processing

Collected fish and blue crabs specimens were identified to species, and their condition was 

classified as being alive, stunned, or dead. Based on available regional size at age information, 

each specimen was assigned to one of three age/length groups: age-0 (young-of-year), age-1 or 

older (yearling and older), and unknown. Counts were made on the basis of species, age/length 

group, and condition, defined as follows:

 Live: Actively swimming and oriented in upright position, with no visible external 

physical damage.

 Stunned: Swimming abnormally, struggling, swimming on side, or upside down, or 

nonmotile except when gently probed; with visible external physical damage such as 

missing scales, torn fins, hemorrhaging, or gouges.

 Dead: No vital life signs, no body or opercular movement, no response to gentle probing; 

or severely damaged or mutilated with slight opercular movement.
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-3

If counts were particularly high, total counts were derived using a subsampling procedure based 

on the weight of 100 individuals. 

Up to 50 intact individuals from each sample, taxon, and age/length group were measured to the 

nearest millimeter and weighed to the nearest gram. Fish were measured for total length (TL)

and blue crabs were measured for carapace width.

6.1.4 QA/QC

References and taxonomic keys were maintained in the fish processing lab for use in the 

identification process. The field crew supervisor checked all identifications before the sample is 

released or discarded. Any discrepancies were resolved before being recorded; any fish 

unidentified were preserved for further study. All length/weight measurements were checked by 

the data recorder before being recorded, any discrepancies were resolved before being recorded.

6.2 RESULTS

A total 242 impingement samples were collected from 26 January 2009 through 18 January 2010 

(Year 1), and 239 samples from 25 January 2010 through 17 January 2011 (Year 2) (Table 6-1). 

Impingement sampling could not occur on 10 dates during Year 1 and on 12 dates during Year 2, 

usually because of Unit 2 outage and inoperative circulating pumps (explanations are provided 

by date in Table 6-1). On occasion, one or two of the four daily samples could not be collected 

on other dates because of temporary inaccessibility of the sampling gear due to screen or pump 

maintenance, gear malfunction, or lack of washwater flow.

6.2.1 Species Composition

In Year 1, a total of 7,966 organisms comprising 51 fish species plus blue crab were found in 

impingement collections (Table 6-2). In Year 2, the total collection consisted of 22,958 

individuals and 50 unique fish species plus blue crab (Table 6-3). Blue crab was the most 

abundant species during both years, comprising 60.9 percent of the collections in Year 1 and 

80.2 percent in Year 2. The four most frequently collected fish species were consistent for both 

sampling years: white perch followed in order by bay anchovy, spotted hake, and Atlantic 

silverside (Tables 6-2 and 6-3). 

White perch comprised 13.8 percent of the total collections in Year 1 and 5.5 percent in Year 2. 

Over one half (61.1 and 65.8 percent, respectively) of the white perch were yearling or older fish 

(Tables 6-2 and 6-3). Bay anchovy comprised 7.3 percent of the total collections in Year 1 and 

4.0 percent in Year 2, and over 90 percent were adult fish of age 1 or older. Spotted hake and 

Atlantic silverside were nearly as abundant as bay anchovy, but nearly all spotted hake were 

yearling or older fish while approximately 60 percent of the impinged Atlantic silversides were 

age 0 (young-of-year or YOY) fish (Tables 6-2 and 6-3). 

Although the total number of impinged fish species was relatively high, the only species with 

total collections greater than 100 fish, other than those discussed above, were threespine 

stickleback in Year 1 and red hake and oyster toadfish in Year 2 (Tables 6-2 and 6-3). Thus, 90 

percent of the fish species impinged in Year 1 and 88 percent of the fish species in Year 2 were 

represented by relatively few (<100) total fish in the annual impingement collections, and 
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-4

approximately 50 to 60 percent of all the species were represented by fewer than 10 fish 

collected.

6.2.2 Seasonal Patterns

With all fish species combined, impingement rates were less variable seasonally during Year 1 

than Year 2 (Figure 6-1). In Year 2, there were distinct peaks in impingement rates (>6,000 

fish/million m3) in late April - early May and in late June. In Year 1, peak rates remained below 

6,000 fish/million m3and occurred in early May, early November, and December. In both years, 

young-of-year fish did not appear in impingement collections until late May or June, and usually 

were dominant after August in Year 1 and after June in Year 2 (Figure 6-1).

White perch were impinged nearly year-round, reflecting the fact that they are a resident species 

in the Hackensack River system. However, impingement rates generally were higher from 

November through early May (Figure 6-2). Young-of-year first appeared in impingement 

collections from late June to July and thereafter typically were the dominant age group. The 

length frequency distribution for impinged white perch was bimodal, with modes occurring at 

80-100 mm TL and 160-200 mm TL (Figure 6-3). 

The majority of bay anchovies were impinged from May through August (Figure 6-4). The 

length frequency distribution (Figure 6-5) was unimodal (mode of 60-80 mm TL), reflecting the 

relatively short life span and lack of multiple age groups for this species. 

Impingement of spotted hake was restricted primarily to November through July, with peak rates 

in May (Figure 6-6). Total lengths ranged from approximately 50 to 300 mm, but most fish were 

<200 mm TL (Figure 6-7). Able and Fahay (2010) found that in the Middle Atlantic Bight there 

were two modes of spawning activity: August-October and February-April. The predominance 

of spotted hake impingement in the spring, given the observed length range, could have 

originated from a fall spawning and subsequent migration of young fish from coastal waters to 

the estuary in the spring.

Most impingement of Atlantic silversides occurred in the fall and involved YOY fish. In Year 1, 

impingement rates began to increase in September and peaked in early November (Figure 6-8, 

Year 1). Impingement of this 2009 year class carried over through early April of Year 2 as 

yearling and older fish (Figure 6-8, Year 2). In Year 2, most impingement again occurred in the 

fall but appeared to begin later, in November, although there was a reduced level of impingement 

in the summer, June-August. The length frequency distributions for impinged Atlantic

silversides in both sampling years were similar and unimodal, with lengths ranging from 

approximately 60 to 130 mm TL (Figure 6-9).

Blue crabs were impinged during warmer months when they are most active. In Year 1, 

impingement occurred primarily from May through early November (Figure 6-10). In Year 2, 

impingement began earlier (late March) and nearly ceased altogether in mid to late August, but 

peak impingement rates were over four times greater than in Year 1 (Figure 6-10). The size 

frequency distributions for the two sampling years also differed greatly. In Year 1, small crabs 

(<60 mm carapace width) dominated impingement collections (Figure 6-11). In Year 2, size

frequency was more normally distributed with peak widths of 100-120 mm.
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-5

Figures 6-12 through 6-16 depict the diel impingement rates for the five dominant species, 

presented as monthly mean density (#/million m3of water withdrawn) during the four collection 

periods within a sampling day. There did not appear to be any consistency in the diel 

impingement rates on a monthly basis for white perch (Figure 6-12) or Atlantic silverside (Figure 

6-15). Impingement rates for bay anchovy appeared to be somewhat greater during darkness 

(1800-0600 hours) than daylight (0600-1800 hours) from June or July into August, and were

especially elevated during evening hours (1800-0000 hours) in June 2010 (Figure 6-13). 

Impingement of spotted hake also appeared to be greater during darkness, as shown by Figure 6-

14, particularly during May peak impingement rates. During some months, impingement of blue 

crabs was greater during darkness (1800-0600 hours), particularly in 2010, but this pattern was 

not consistent (Figure 6-16). 

6.2.3 Comparison to 1996-1997 Impingement Study

Blue crab was the most frequently impinged species in both the 1996-1997 study and the present 

study at the Station. In the 1996-1997 study, estimated impingement totals for blue crab were 

nearly 20 times the total for the second-most frequently impinged species, bay anchovy (PSE&G 

1998). In the 1996-1997 study, white perch were not as abundant in impingement collections as 

they are now relative to other species, reflecting the recent population increase for this species

(Chapter 4.2). Weakfish and winter flounder were relatively more abundant in the 1996-1997 

impingement study at the Station than they are now. Further comparisons of study results are 

made in Chapter 8.
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-6

Figure 6-1. Weekly Impingement Rate for All Fish Species Combined by Age Group, 2009-

2010 (Year 1) and 2010-2011 (Year 2)
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-7

Figure 6-2 Weekly Impingement Rate for White Perch by Age Group, 2009-2010 (Year 1) 

and 2010-2011 (Year 2)
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-8

Figure 6-3. Length Frequency of Impinged White Perch, 2009-2010 (Year 1) and 2010-

2011 (Year 2)
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-9

Figure 6-4. Weekly Impingement Rate for Bay Anchovy by Age Group, 2009-2010 (Year 1) 

and 2010-2011 (Year 2)
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-10

Figure 6-5. Length Frequency of Impinged Bay Anchovy, 2009-2010 (Year 1) and 2010-

2011 (Year 2)
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-11

Figure 6-6. Weekly Impingement Rate for Spotted Hake by Age Group, 2009-2010 (Year 

1) and 2010-2011 (Year 2)
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-12

Figure 6-7. Length Frequency of Impinged Spotted Hake, 2009-2010 (Year 1) and 2010-

2011 (Year 2)
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-13

Figure 6-8. Weekly Impingement Rate for Atlantic Silverside by Age Group, 2009-2010 

(Year 1) and 2010-2011 (Year 2)
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-14

Figure 6-9. Length Frequency of Impinged Atlantic Silverside, 2009-2010 (Year 1) and 

2010-2011 (Year 2)
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-15

Figure 6-10. Weekly Impingement Rate for Blue Crab, 2009-2010 (Year 1) and 2010-2011 

(Year 2)
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-16

Figure 6-11. Size Frequency (Carapace Width) of Impinged Blue Crab, 2009-2010 (Year 1) 

and 2010-2011 (Year 2)
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-17

Figure 6-12. Mean Density of Impinged White Perch by 6-Hour Collection Period, 2009 

and 2010

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

100

200

300

400

500

NS

2010

2009

Impingement Diel Distribution for White Perch Mean Density (number/10

6 m

3

)

18:00-00:00

00:00-06:00

06:00-12:00

12:00-18:00

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

100

200

300

400

500

NS NS
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-18

Figure 6-13. Mean Density of Impinged Bay Anchovy by 6-Hour Collection Period, 2009 

and 2010

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

100

200

300

400

500

600

700

800

NS

2010

2009

Impingement Diel Distribution for Bay Anchovy Mean Density (number/10

6 m

3

)

18:00-00:00

00:00-06:00

06:00-12:00

12:00-18:00

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

100

200

300

400

500

600

700

800

NS NS
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-19

Figure 6-14. Mean Density of Impinged Spotted Hake by 6-Hour Collection Period, 2009 

and 2010

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

200

400

600

800

1000

NS

2010

2009

Impingement Diel Distribution for Spotted Hake Mean Density (number/10

6 m

3

)

18:00-00:00

00:00-06:00

06:00-12:00

12:00-18:00

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

200

400

600

800

1000

NS NS
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-20

Figure 6-15. Mean Density of Impinged Atlantic Silverside by 6-Hour Collection Period, 

2009 and 2010

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

20

40

60

80

100

120

140

160

180

200

NS

2010

2009

Impingement Diel Distribution for Atlantic Silverside Mean Density (number/10

6 m

3

)

18:00-00:00

00:00-06:00

06:00-12:00

12:00-18:00

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

20

40

60

80

100

120

140

160

180

200

NS NS
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-21

Figure 6-16. Mean Density of Impinged Blue Crab by 6-Hour Collection Period, 2009 and 

2010

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

1000

2000

3000

4000

5000

NS NS

2010

2009

Impingement Diel Distribution for Blue Crab Mean Density (number/10

6 m

3

)

18:00-00:00

00:00-06:00

06:00-12:00

12:00-18:00

NS

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

1000

2000

3000

4000

5000
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-22

Table 6-1. Number of Samples Collected in Impingement Monitoring at Hudson 

Generating Station, January 2009 – January 2011

Study Year 2009 Study Year 2010

Sample 

Date

No. of

Samples

Sample

Date

No. of

Samples

Sample 

Date

No. of

Samples

Sample

Date

No. of

Samples

26-Jan-09 6 27-Jul-09 6 25-Jan-10 6 26-Jul-10 6

2-Feb-09 6 3-Aug-09 6 1-Feb-10 6 2-Aug-10 6

9-Feb-09 6 10-Aug-09 5

5

8-Feb-10 6 10-Aug-10 6

16-Feb-09 NS117-Aug-09 6 15-Feb-10 6 17-Aug-10 6

23-Feb-09 6 24-Aug-09 NS522-Feb-10 6 23-Aug-10 6

2-Mar-09 6 31-Aug-09 6 1-Mar-10 6 30-Aug-10 6

9-Mar-09 6 7-Sep-09 NS58-Mar-10 6 6-Sep-10 NS3

16-Mar-09 6 14-Sep-09 NS515-Mar-10 6 13-Sep-10 NS3

23-Mar-09 6 21-Sep-09 6 22-Mar-10 NS320-Sep-10 NS3

30-Mar-09 NS228-Sep-09 1

5

29-Mar-10 NS327-Sep-10 NS3

6-Apr-09 NS35-Oct-09 6 5-Apr-10 6 5-Oct-10 NS3

13-Apr-09 NS312-Oct-09 6 12-Apr-10 6 12-Oct-10 NS3

20-Apr-09 NS319-Oct-09 6 19-Apr-10 6 18-Oct-10 NS3

27-Apr-09 NS326-Oct-09 6 26-Apr-10 NS728-Oct-10 NS3

4-May-09 6 2-Nov-09 6 3-May-10 6 1-Nov-10 NS3

11-May-09 6 9-Nov-09 5

5

10-May-10 6 8-Nov-10 6

18-May-09 6 16-Nov-09 6 17-May-10 6 15-Nov-10 6

25-May-09 4

4

23-Nov-09 5

6

24-May-10 6 22-Nov-10 6

1-Jun-09 6 30-Nov-09 6 31-May-10 6 29-Nov-10 6

8-Jun-09 6 7-Dec-09 6 7-Jun-10 6 6-Dec-10 6

15-Jun-09 6 14-Dec-09 6 14-Jun-10 6 13-Dec-10 6

22-Jun-09 6 21-Dec-09 6 21-Jun-10 6 20-Dec-10 6

29-Jun-09 6 28-Dec-09 6 28-Jun-10 6 27-Dec-10 5

5

6-Jul-09 NS34-Jan-10 6 5-Jul-10 6 3-Jan-11 6

13-Jul-09 6 11-Jan-10 6 12-Jul-10 6 10-Jan-11 6

20-Jul-09 6 18-Jan-10 6 19-Jul-10 6 17-Jan-11 6

Total 242 Total 239

1 Sampling canceled due to screen maintenance.

2

 Tide gate stuck open and unable to use impingement sampler.

3 Outage at Unit 2.

4

 Two samples not collected due to pump and screen maintenance.

5

 Samples not collected due to lack of water in screenwash sluice.

6

 One sample not collected because circulating pumps not operating.

7

 Sampling canceled because south gate unable to close.
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-23

Table 6-2. Overall Numerical Composition of Fish Species Collected in Impingement 

Monitoring at Hudson Generating Station, 26 January 2009 – 18 January 2010

Species

Young of Year Yearling and Older Total 

Count Percent of Total Count Percent of Total Count

Blue crab14,854

White perch 429 38.93 673 61.07 1,102

Bay anchovy 10 1.72 571 98.28 581

Spotted hake 2 1.01 196 98.99 198

Atlantic silverside 117 60.00 78 40.00 195

Threespine stickleback 0 0.00 163 100.00 163

Gizzard shad 78 82.11 17 17.89 95

Winter flounder 53 59.55 36 40.45 89

Blueback herring 0 0.00 81 100.00 81

Oyster toadfish 0 0.00 71 100.00 71

Alewife 40 61.54 25 38.46 65

Red hake 0 0.00 64 100.00 64

Atlantic tomcod 26 50.98 25 49.02 51

Silver hake 25 50.00 25 50.00 50

Bluefish 40 95.24 2 4.76 42

Atlantic menhaden 29 70.73 12 29.27 41

Striped searobin 22 95.65 1 4.35 23

Striped bass 0 0.00 22 100.00 22

American eel 0 0.00 20 100.00 20

Hogchoker 7 38.89 11 61.11 18

Windowpane 0 0.00 18 100.00 18

Northern pipefish 1 7.14 13 92.86 14

Weakfish 6 42.86 8 57.14 14

Black sea bass 8 66.67 4 33.33 12

Mummichog 0 0.00 10 100.00 10

Butterfish 6 66.67 3 33.33 9

Bluegill 2 25.00 6 75.00 8

Atlantic croaker 0 0.00 5 100.00 5

Lined seahorse 0 0.00 5 100.00 5

Striped cusk eel 0 0.00 4 100.00 4

Striped killifish 0 0.00 4 100.00 4

Tautog 0 0.00 4 100.00 4

Conger eel 0 0.00 3 100.00 3

Gulf Stream flounder 0 0.00 3 100.00 3

Lookdown 0 0.00 3 100.00 3

Naked goby 0 0.00 3 100.00 3

Black crappie 0 0.00 2 100.00 2

Cunner 0 0.00 2 100.00 2

Grubby 0 0.00 2 100.00 2

Northern searobin 2 100.00 0 0.00 2

Sea lamprey 0 0.00 2 100.00 2

Summer flounder 0 0.00 2 100.00 2

American shad 0 0.00 1 100.00 1
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-24

Table 6-2 Continued

Species

Young of Year Yearling and Older Total 

Count Percent of Total Count Percent of Total Count

Bluespotted cometfish 0 0.00 1 100.00 1

Crevalle jack 1 100.00 0 0.00 1

Golden shiner 0 0.00 1 100.00 1

Goldfish 1 100.00 0 0.00 1

Hickory shad 0 0.00 1 100.00 1

Moonfish 0 0.00 1 100.00 1

Northern stargazer 1 100.00 0 0.00 1

Pumpkinseed 1 100.00 0 0.00 1

Seaboard goby 0 0.00 1 100.00 1

Total 907 11.39 7,059 88.61 7,966

1

 Blue crab age classifications not made.
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-25

Table 6-3. Overall Numerical Composition of Fish Species Collected in Impingement 

Monitoring at Hudson Generating Station, 25 January 2010 – 17 January 2011

Species

Young of Year Yearling and Older Total 

Count Percent of Total Count Percent of Total Count

Blue crab118,405

White perch 428 34.19 824 65.81 1,252

Bay anchovy 75 8.07 854 91.93 929

Spotted hake 2 0.23 878 99.77 880

Atlantic silverside 281 59.28 193 40.72 474

Red hake 0 0.00 154 100.00 154

Oyster toadfish 15 13.27 98 86.73 113

Silver hake 50 66.67 25 33.33 75

Alewife 46 63.01 27 36.99 73

Lookdown 73 100.00 0 0.00 73

Threespine stickleback 0 0.00 65 100.00 65

Winter flounder 35 55.56 28 44.44 63

Blueback herring 21 43.75 27 56.25 48

American eel 0 0.00 38 100.00 38

Striped bass 11 30.56 25 69.44 36

Hochoker 0 0.00 34 100.00 34

Bluefish 19 63.33 11 36.67 30

Gizzard shad 9 30.00 21 70.00 30

Butterfish 21 75.00 7 25.00 28

Atlantic tomcod 2 9.52 19 90.48 21

Bluegill 3 18.75 13 81.25 16

Weakfish 13 86.67 2 13.33 15

Striped killifish 1 7.69 12 92.31 13

Mummichog 0 0.00 9 100.00 9

Windowpane 0 0.00 9 100.00 9

Gray snapper 0 0.00 8 100.00 8

Atlantic menhaden 3 42.86 4 57.14 7

Northern searobin 1 14.29 6 85.71 7

Striped searobin 5 71.43 2 28.57 7

Northern pipefish 0 0.00 5 100.00 5

Pumpkinseed 1 20.00 4 80.00 5

Seaboard goby 0 0.00 5 100.00 5

Summer flounder 2 40.00 3 60.00 5

American shad 3 100.00 0 0.00 3

Spottail shiner 3 100.00 0 0.00 3

Atlantic croaker 1 50.00 1 50.00 2

Northern kingfish 2 100.00 0 0.00 2

Striped cusk eel 0 0.00 2 100.00 2

Banded killifish 1 100.00 0 0.00 1

Black crappie 0 0.00 1 100.00 1

Brown bullhead 0 0.00 1 100.00 1

Conger eel 0 0.00 1 100.00 1

Crevalle jack 1 100.00 0 0.00 1
HUDSON GENERATING STATION 316(b) STUDY REPORT

6-26

Table 6-3 Continued

Species

Young of Year Yearling and Older Total 

Count Percent of Total Count Percent of Total Count

Eastern mudminnow 0 0.00 1 100.00 1

Fourspine stickleback 0 0.00 1 100.00 1

Freshwater drum 0 0.00 1 100.00 1

Inshore lizardfish 0 0.00 1 100.00 1

Lined seahorse 0 0.00 1 100.00 1

Northern puffer 1 100.00 0 0.00 1

Short bigeye 1 100.00 0 0.00 1

Tautog 0 0.00 1 100.00 1

Unidentified Morone 1 100.00 0 0.00 1

Total 1,131 4.93 21,827 95.07 22,958

1

 Blue crab age classifications not made.
HUDSON GENERATING STATION 316(b) STUDY REPORT

7-1

7. IMPINGEMENT SURVIVAL

In addition to the impingement monitoring study described above, a special impingement 

survival study was conducted at Hudson Unit 2. The purpose of this special study was to 

estimate the survival of fish impinged on the modified-Ristroph screens newly installed at the 

Unit 2 cooling water intake structure for up to 48 hours after impingement. In addition, the 

factors potentially affecting these survival rates were evaluated.

7.1 METHODS

Fish for this study were obtained from the routine impingement monitoring study conducted 

during the first two 6-hour sampling periods on each sample date. A total of two 1-hour

collections (one regular and one additional) were made during each of the first two sampling 

periods as described for impingement monitoring above. At the completion of each 1-hour

collection, all fish were removed from the sampling tank and categorized as to condition using to 

the following criteria:

Live: Actively swimming and oriented in upright position, with no visible external 

physical damage.

Stunned: Swimming abnormally, struggling, swimming on side, or upside down, or 

nonmotile except when gently probed; with visible external physical damage such as 

missing scales, torn fins, hemorrhaging, or gouges.

Dead: No vital life signs, no body or opercular movement, no response to gentle probing; 

or severely damaged or mutilated with slight opercular movement.

When sufficient numbers warranted, all live and stunned fish were in 5-gal holding containers, 

separately by collection interval and in a manner to minimize predation. A maximum of 100 fish 

per species were held on each sampling date. These holding containers were placed in a latenteffects holding facility. This holding facility was located next to the Hudson cooling water 

intake and it was provided ambient water on a flow-through basis. Each holding container was 

labeled with a unique number identifying the day, month, year and collection period. All dead 

fish from each collection were identified to species, measured and weighed. All data were 

recorded on study-specific data sheets.

The fish retained in the latent-effects holding facility were checked again approximately 24

hours after collection and all dead fish were removed, identified to species, measured and 

weighed. At 48 hours after collection, all remaining fish were classified as to condition 

according to the criteria described above, identified to species, measured and weighed. At this 

time, the holding was terminated and all live or stunned fish were released to the Hackensack 

River. In addition to the fish checks, water temperature, dissolved oxygen, conductivity, and 

ammonia in the water trough were measured and recorded to ensure adequate water conditions 

for long-term holding at the time of each check. All sampling was conducted according to 

Standard Operating Procedures and all data collected as part of this study were recorded on 

study-specific data sheets.

Using these data, three measures of percent survival were calculated for each species:
HUDSON GENERATING STATION 316(b) STUDY REPORT

7-2

Initial survival = (Number alive at collection/Total number collected)*100;

Extended survival = (Number alive at 48 hours/ Number alive at collection*100; and,

Total 48-hr survival = (Number alive at 48 hours/Total number collected)*100.

For all analysis, any fish categorized as stunned were considered to be non-viable and treated as 

dead.

7.2 OVERALL IMPINGEMENT SURVIVAL

A total of 5,079 individuals from 56 species and one genus (Morone) were collected in this study 

and held for latent effects evaluation. Overall initial survival was just over 92 percent and 

extended (0 to 48 hours) survival was almost 62 percent yielding an overall impingement 

survival rate through 48 hours of more than 56 percent across all species combined (Table 7-1). 

All of the species collected are common inhabitants of brackish water areas in the Northeast.

Sufficient data to warrant calculation of impingement survival (> 20 fish collected) existed for 22 

of the 56 species collected (39 percent). These 22 species accounted for more than 97 percent of 

the fish evaluated in this survival study. Estimates of survival for each of these species and for 

the remaining individuals combined are provided in Table 7-2. Initial survival was relatively 

high (>90 percent) for most of the individual species. However, extended (0 to 48 hour) survival 

was highly variable depending on species. Overall impingement survival at 48 hours post 

impingement ranged from more 98 percent for threespine stickleback to only 5 percent for 

butterfish. Half of the individual species addressed in this analysis had impingement survival 

rates greater than 70 percent.

7.3 FACTORS AFFECTING SURVIVAL 

Several factors, independent of the design and operation of the intake screens, have the potential 

to affect the survival of impinged fish (EPRI 2003). These include the size and age of the 

individuals affected as well as the temperature and salinity of the source waterbody. To evaluate 

the potential effects of these factors on estimates of impingement survival at Hudson, data 

collected in this study were subject to detailed statistical analysis. 

In this analysis, survival was estimated by fitting the general logistic equation:

S(t) =1-1/[1+ exp{-[M0 + ML(e

t

-1)/ + MLen(Length) + Mtemp(T) + Msal(Sal) + Mage(Age) + 

Mseason]}]

where:

S(t) = fraction surviving at time t (days) from collection;

M0 = intercept term;

ML = latent instantaneous mortality rate (reflect deaths occurring over 48-hr monitoring 

period);

 = parameter describing change in latent mortality rate through time;
HUDSON GENERATING STATION 316(b) STUDY REPORT

7-3

MLen = mortality coefficient for length (mm);

Mtemp = mortality coefficient for temperature (C);

Msal = mortality coefficient for salinity (ppt);

Mage = mortality coefficient for age (years); and,

Mseason = mortality coefficient for season (spring, summer, fall, winter).

This statistical model has the advantage of being able to utilize information from the entire time

course of mortality over this study to predict impingement survival.

Species for which at least 100 fish were collected were modeled as separate taxa. Species that 

had less than 100 fish collected were combined into "All other species". This model was fitted in 

sequence by maximum likelihood methods using the NLIN procedure in SAS, with some terms 

being set to zero for particular models: 

Model Parameters Estimated

Number of 

Parameters

Combined 

Loglikelihood(x -2)1Improvement

1 M0, ML 24 8,877 0

2a M0, ML, MLen 36 8,772 105

2b M0, ML,  36 8,616 261

2c M0, ML, Mtemp 36 8,741 135

2d M0, ML, Msal 36 8,811 66

2e M0, ML, Mage 36 8,777 100

2f M0, ML, Mseason 60 8,688 189

3a M0, ML, , Mtemp 48 8,485 392

3b M0, ML, , MLen 48 8,551 325

3c M0, ML, , Msal 48 8,512 365

4a M0, ML, , Mtemp, MLen 60 8,424 452

4b M0, ML, , Mtemp, MLen, Msal 72 8,374 503

All models that added one additional factor to the estimates of impingement survival (Model 2a 

through Model 2f) reduced the combined loglikelihood11 an amount ranging from 66 (Model 2d: 

Msal) to 261 (Model 2b: ). However these improvements in fit by inclusion of additional 

parameters need to be compared to the appropriate Chi-squared statistic 

α,ndf) to determine if 

improvement are greater than those expected due to random chance alone. For Models 2a 

through 2e, one additional parameter was added for each of the 12 taxonomic groups. Therefore, 

the improvements in these models need be compared to 



 df = 21. The seasonal model 

(Model 2f) contained 36 additional parameters (three for each taxon). Hence, the appropriate 

value for this comparison is 



 df = 51. Based on these comparisons, all of the stage 2 models 

were significantly better than Model 1. 

In the next step, parameters for temperature, length, and salinity were added individually to 

Model 2b which include the  parameter for temporal change in the latent mortality rate. This 

model was selected as the base as it yielded the greatest improvement among the stage 2 models. 

 

11 The combined loglikelihood is analogous to combined error SS in the more traditional least 

squares analysis.
HUDSON GENERATING STATION 316(b) STUDY REPORT

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In this step, while each of the models also provided a significant improvement over the base 

model (Model 2b), the inclusion of temperature (Model 3a) exhibited the most improvement, 

followed by the models with salinity, then length. 

In final step, length (Model 4a) and length and salinity (Model 4b) were separately added to 

Model 3a, the model exhibiting the greatest improvement in the prior step. Significant 

improvement over Model 3a occurred both with both Model 4a and Model 4b. Although further 

improvement in fit to the data set could have been achieved by adding more independent 

variables or interactions among the variables, additional terms in the model increase the variance 

of the predicted survival and the risk of tailoring the model too closely to the current data set at 

the expense of poor prediction ability for other data sets to which the model could be applied. 

Therefore, Model 4b was selected as the appropriate model for predicting impingement survival 

at Hudson. This model includes effects of length, temperature and salinity on impingement 

survival. Parameter estimates and associated standard errors for each of the individual species 

included in this analysis are provided in Table 7-3. These parameter estimates can then be used 

to determine the impingement mortality for each species based on the length of the individual 

and the water temperature and salinity at the time of impingement.
HUDSON GENERATING STATION 316(b) STUDY REPORT

7-5

Table 7-1 Overall Catch and Condition of Fish by Species in the Impingement Survival 

Study at the Hudson Generating Station, 2010 - 2011

Common

Name

Initial

Dead

24 Hr

Dead

48 Hr Total

Dead Stunned Live Number

White perch 57 90 82 13 1,046 1,288

Bay anchovy 163 764 156 1 142 1,226

Spotted hake 103 52 87 1 415 658

Atlantic silverside 3 25 52 2 324 406

Red hake 2 8 10 0 168 188

Threespine stickleback 1 0 1 0 147 149

Oyster toadfish 2 7 6 1 112 128

Winter flounder 7 12 16 0 90 125

Alewife 11 26 23 7 50 117

Silver hake 5 19 42 5 36 107

Blueback herring 2 45 17 7 29 100

Lookdown 5 31 12 0 22 70

Gizzard shad 3 19 17 2 23 64

Bluefish 15 25 3 1 12 56

Atlantic tomcod 0 7 5 0 41 53

American eel 1 5 7 0 39 52

Hogchoker 3 1 3 0 30 37

Atlantic menhaden 4 10 9 0 9 32

Striped bass 0 1 3 0 20 24

Weakfish 1 4 5 0 13 23

Bluegill 2 0 1 0 17 20

Butterfish 1 9 8 1 1 20

Windowpane 1 0 6 0 9 16

Striped searobin 1 2 2 0 10 15

Northern pipefish 1 1 2 0 9 13

Mummichog 0 1 1 0 10 12

Striped killifish 0 0 0 0 12 12

Black sea bass 2 0 0 0 8 10

Striped cusk-eel 0 1 2 0 3 6

Tautog 0 1 0 0 4 5

Summer flounder 0 0 2 0 2 4

Northern searobin 0 0 0 0 4 4

American shad 0 1 0 1 1 3

Pumpkinseed 0 0 0 0 3 3

Spottail shiner 0 2 0 0 1 3

Lined seahorse 0 0 2 0 1 3
HUDSON GENERATING STATION 316(b) STUDY REPORT

7-6

Common

Name

Initial

Dead

24 Hr

Dead

48 Hr Total

Dead Stunned Live Number

Atlantic croaker 2 1 0 0 0 3

Northern kingfish 0 0 0 0 2 2

Conger eel 0 0 0 0 2 2

Seaboard goby 0 0 1 0 1 2

Gulf Stream flounder 0 0 0 0 2 2

Black crappie 0 0 1 0 0 1

Golden shiner 0 1 0 0 0 1

Banded killifish 0 0 0 0 1 1

Fourspine stickleback 0 0 0 0 1 1

Crevalle jack 0 0 1 0 0 1

Unid. Morone 0 0 1 0 0 1

Sea lamprey 0 0 1 0 0 1

Northern puffer 0 0 0 0 1 1

Grubby 0 0 1 0 0 1

Eastern mudminnow 0 0 0 0 1 1

Naked goby 0 0 0 0 1 1

Northern stargazer 0 0 0 0 1 1

Inshore lizardfish 0 0 0 0 1 1

Cunner 0 0 0 0 1 1

Bluespotted cornetfish 1 0 0 0 0 1

Freshwater drum 0 0 0 0 1 1

Total 399 1,171 588 42 2,879 5,079
HUDSON GENERATING STATION 316(b) STUDY REPORT

7-7

Table 7-2 Estimates of Impingement Survival Through 48 hours for Selected Fish Species 

Based on Sampling at the Hudson Generating Station, 2009 - 2010

Common

Name

Total

Number

Collected

Percent Survival

Initial Extended

Total

48 hr

Total 48 hr

Confidence 

Interval12

Threespine stickleback 149 99.3 99.3 98.7 95.2 - 99.8

Red hake 188 98.9 90.3 89.4 84.1 - 93.4

Oyster toadfish 128 98.4 88.9 87.5 80.5 - 92.7

Bluegill 20 90.0 94.4 85.0 62.1 - 96.8

Striped bass 24 100.0 83.3 83.3 62.6 - 95.3

White perch 1,288 95.6 85.0 81.2 79.0 - 83.3

Hogchoker 37 91.9 88.2 81.1 64.9 - 92.0

Atlantic silverside 406 99.3 80.4 79.8 75.6 - 83.6

Atlantic tomcod 53 100.0 77.4 77.4 63.8 - 87.7

American eel 52 98.1 76.5 75.0 61.1 - 86.0

Winter flounder 125 94.4 76.3 72.0 63.3 - 79.7

Spotted hake 658 84.3 74.8 63.1 59.3 - 66.8

Weakfish 23 95.7 59.1 56.5 34.5 - 76.8

Alewife 117 90.6 47.2 42.7 33.6 - 52.2

Gizzard shad 64 95.3 37.7 35.9 24.3 - 48.9

Silver hake 107 95.3 35.3 33.6 24.8 - 43.4

Lookdown 70 92.9 33.8 31.4 20.9 - 43.6

Blueback herring 100 98.0 29.6 29.0 20.4 - 38.9

Atlantic menhaden 32 87.5 32.1 28.1 13.8 - 46.8

Bluefish 56 73.2 29.3 21.4 11.6 - 34.4

Bay anchovy 1,226 86.7 13.4 11.6 9.8 - 13.5

Butterfish 20 95.0 5.3 5.0 0.1 - 24.5

All other species 136 94.1 72.7 68.4 59.9 - 76.1

All fish combined 5,079 92.1 61.5 56.7 55.3 - 58.1

 

12 95 percent exact binomial confidence intervals. Source: http://statpages.org/confint.html (5/5/2011).
HUDSON GENERATING STATION 316(b) STUDY REPORT

7-8

Table 7-3 Model Parameters and Standard Errors to Predict Impingement Survival for Selected Fish Species Based on 

Sampling at the Hudson Generating Station, 2009 - 2010 

 

Species N

Likeli

hood M0 se(M0) ML se(ML)  se() MLen se(MLen) MTemp se(MTemp) MSal se(MSal)

Alewife 117 288 1.822 1.633 1.886 0.510 -0.491 0.270 -0.052 0.015 0.040 0.027 -0.011 0.062

Atlantic silverside 406 546 -4.913 1.267 2.632 0.832 -0.620 0.257 0.009 0.011 -0.008 0.025 -0.016 0.042

Bay anchovy 1,11013 2515 -3.329 0.517 4.387 0.263 -1.022 0.085 0.004 0.003 0.027 0.017 0.051 0.014

Blueback herring 100 237 -5.751 1.373 4.611 1.041 -1.223 0.276 0.024 0.009 -0.028 0.025 0.111 0.045

Oyster toadfish 128 122 -5.297 2.218 2.351 1.392 -0.746 0.533 -0.008 0.007 0.143 0.085 -0.124 0.059

Red hake 188 137 -7.420 1.401 1.717 1.122 -0.354 0.529 0.021 0.007 0.119 0.040 -0.110 0.065

Silver hake 107 262 -0.023 1.942 1.244 0.429 0.256 0.264 -0.012 0.014 0.024 0.033 -0.118 0.072

Spotted hake 622

13 1114 -4.436 0.612 2.262 0.488 -0.091 0.161 0.000 0.002 -0.032 0.022 0.063 0.029

Threespine stickleback 149 20 18.711 17.703 0.008 0.000 2.768 0.592 -0.453 0.277 -0.444 1.005 0.246 0.692

White perch 1,288 1633 -2.329 0.372 1.382 0.221 -0.746 0.159 -0.008 0.002 0.048 0.011 -0.025 0.020

Winter flounder 125 186 -5.699 1.843 1.457 0.629 -0.227 0.376 -0.007 0.007 0.216 0.066 -0.109 0.040

All other species 587 1314 -3.868 0.361 2.047 0.282 -0.620 0.133 -0.002 0.001 0.054 0.013 0.045 0.018

 

 

13 Number included in analysis less than that listed in Table 7-2 since not all individuals were measured.
HUDSON GENERATING STATION 316(b) STUDY REPORT

8-1

8. ANNUAL DIRECT LOSSES

The results of the entrainment and impingement monitoring program described in Chapters 5 and 

6 were used to calculate the total annual loss of fish and shellfish at the Hudson Generating 

Station for each of the two study years. These estimates were calculated under two operating 

conditions; using full design cooling water flow all year (Design Operation) and using actual 

cooling water flows along with actual intake and discharge temperatures observed at the station

(Actual Operation). In addition, estimates of direct loss under the Actual Operation case were 

calculated both with and without survival.

8.1 METHODS

Estimates of annual direct loss for both entrainment and impingement were calculated for each 

species and each unit at Hudson as follows:

 

 

 

where:

Di = Mean density of species entrained or impinged during week (i);

Vi = Total cooling water flow at the unit during week (i); and,

Si = Mean survival rate of species entrained or impinged during week (i).

Mean densities were calculated using data collected during the entrainment and impingement 

monitoring programs described in Chapters 5 and 6. The mean density of each species was 

assumed to be the same at both Unit 1 and Unit 2. For the Design Operation case and for the 

Actual Operation with no survival case, all organisms entrained or impinged were assumed to die 

(i.e., 100 percent mortality). For the Actual Operation with survival case, entrainment and 

impingement survival at Hudson was determined as described below.

As a result of passage through a cooling water system, entrained organisms are exposed to both 

mechanical (physical) and thermal stresses. Each of these sources of stress can contribute to 

mortality. Overall, the probability of an organism surviving entrainment (Pe) is equivalent to the 

joint probability of surviving mechanical stresses (Pm) and thermal stress (Pt):

 .

Estimates of the probability of surviving mechanical stresses were made using Best Professional 

Judgment (BPJ) and the results of entrainment survival studies conducted at other facilities. In 

some cases, data from surrogate species were used. BPJ estimates of the probability of surviving 

mechanical stresses at Hudson are provided in Table 8-1.

The probability of surviving thermal stresses during entrainment is a function of the water 

temperature to which the organisms are acclimated and the temperature that they are exposed to 

during cooling water system passage. To estimate the probability of surviving thermal stresses, 
HUDSON GENERATING STATION 316(b) STUDY REPORT

8-2

thermal effects data collected in other studies to develop linear regressions that predict median 

mortality rates (TL50) from acclimation and discharge temperatures was used. The thermal 

effects data used were collected for two groups of species, those that spawn in the winter and 

very early spring (e.g., winter flounder and Atlantic tomcod) and those that spawn in the later 

spring and summer (i.e., all other species). Next, we assumed that the probability of thermal 

mortality ranged from 0 percent at 3.6°F less than the TL50 temperature to 100 percent at 3.6°F 

greater than the TL50 temperature.14 The resulting functions that predict probability of 

entrainment survival from thermal stresses are listed below.

Winter Spawning Species:

 

 

 

 

Spring-Summer Spawning Species:

 

 

 

 .

In this assessment, acclimation temperature was assumed to be represented by the intake 

temperature (IT) at Hudson while the discharge temperature (DT) was obtained from Hudson 

hourly operating records for the period January 2009 to January 2011.

Impingement survival was calculated based on the results of studies conducted at Hudson and 

described in Chapter 7 and only applied to Unit 2. At Unit 1, no impingement survival was 

assumed. For this study, survival after a 48-hour holding period was judged to be the best 

measure of impingement survival at Hudson Unit 2. For the 11 individual species subject to 

detailed statistical analysis (Section 7.3), impingement survival was estimated using the logistic 

equations based on length, water temperature, and salinity at the time of impingement with the 

species-specific parameters listed on Table 7-3. For the remaining 11 individual species for 

which there was sufficient catch to estimate overall survival (Table 7-2), values from Table 7-2 

were used. For any other species, the average survival for all other species reported on Table 7-2 

was used. 

No data on the impingement survival of blue crabs were available for Hudson. However, this 

species is known to be very hardy and studies conducted elsewhere demonstrate very high 

impingement survival. For this assessment, survival of blue crabs following impingement at 

Hudson was assumed to be 95 percent at Hudson Unit 2 based on the high impingement survival 

reported in EPRI (2003).

 

14 It has been shown that a 3.6F safety factor is sufficient to adjust TL50 temperatures to temperatures at which 

essentially no mortality would occur (NAS/NAE 1973).
HUDSON GENERATING STATION 316(b) STUDY REPORT

8-3

8.2 RESULTS

8.2.1 Entrainment

Estimates of the annual direct losses from entrainment at Hudson for each study year are 

provided for three cases: Design Operation, Actual Operation with no survival and Actual 

Operation with Survival in Table 8-2 and Table 8-3. In both years, entrainment at Hudson was 

dominated by bay anchovy which accounted for almost 80 percent of the overall entrainment 

under actual operations with survival in Year 1 and more than 90 percent in Year 2. At Unit 1, 

overall entrainment based on actual operations with survival was 76 percent lower in Year 1 and 

92 percent lower in Year 2 than it was under design operations in each year, respectively. At 

Unit 2, the reductions were 58 percent in Years 1 and 2, respectively. When both units are 

combined together, the reductions from design operations were 65 percent and 73 percent for the 

two years.

8.2.2 Impingement

Estimates of the annual direct losses from impingement at Hudson for each study year are 

provided for both Design and Actual operations. in Tables 8-4 and Table 8-5. In addition, 

estimates for Unit 2 are provided assuming 100 percent mortality as well as using the estimate 

impingement mortality for the new intake screens. In both years, impingement at Hudson was 

dominated by blue crabs which accounted for more than 46 percent of the overall impingement 

under actual operations with survival in Year 1 and more than 75 percent in Year 2. Actual 

impingement mortality of fish was dominated by four species, bay anchovy, white perch, spotted 

hake, and Atlantic silverside. These four species accounted for more than 68 percent of actual 

fish impingement mortality in Year 1 and almost 79 percent in Year 2. 

At Unit 1, overall impingement mortality based on actual operations was 76 percent lower in 

Year 1 and 55 percent lower in Year 2 than it was under design operations in each year, 

respectively. At Unit 2, the reductions in impingement were 87 percent in Year 1 and 90 percent 

in Year 2, respectively. When both units are combined together, the reductions from design 

operations were 82 percent and more than 74 percent for the two years. For fish alone, 

impingement at Unit 1 under actual operations was 82 percent lower in Year 1 and in Year 2 

than it was under design operations in each year, respectively. At Unit 2, the reductions in fish

impingement with survival were 72 percent under design operations in both years. When both 

units are combined together, the reductions in fish impingement from design operations were 

more than 76 percent in both years. 

Finally, installation of the new screens at Hudson Unit 2 under actual operations reduced fish 

impingement mortality at Unit 2 62 percent in Year 1 and 60 percent in Year 2 while total 

impingement mortality at Unit 2 was reduced by 81 percent and 87 percent in Years 1 and 2, 

respectively. These reductions in impingement mortality at Unit 2 translate to an overall 

reduction in impingement mortality of fish for Hudson of 52 percent in Year 1 and 49 percent in 

Year 2 and in total impingement mortality of 64 percent and 61 percent in Years 1 and 2, 

respectively.
HUDSON GENERATING STATION 316(b) STUDY REPORT

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8.3 COMPARISON OF 1996-1997 AND 2009-2011 RESULTS

Estimates of direct loss to impingement were available for the following 11 selected species 

based on entrainment monitoring conducted at Hudson in 1996 and 1997 (PSEG 1998):

 Atlantic menhaden  Bluefish

 Atlantic silverside  Striped bass

 Bay anchovy  Weakfish

 Blueback herring  White perch

 Mummichog  Winter flounder

 Atlantic tomcod.

These estimates can then be compared to those generated for this report based on the most recent 

sampling. In addition to the species listed above, impingement estimates for three other species, 

gizzard shad, American shad, and blue crab, were available for comparison.

Total entrainment across all 11 species was lower in both 2009 and in 2010 than reported for 

1996-1997 (Table 8-6). Significant reductions in entrainment were evident in Atlantic tomcod, 

weakfish and winter flounder. As previously noted, entrainment levels of Atlantic tomcod were 

elevated in December 1996-January 1997 by collections of Atlantic tomcod eggs, thought to 

have been extruded by impinged ripe females and, hence, non-viable. Increases in entrainment 

were evident in both Atlantic menhaden and striped bass.

Total impingement across all 14 species was substantially lower in both 2009 and in 2010 than 

reported for 1996-1997 (Table 8-7). Similar levels of reduction were evident across most (nine) 

of the species included. Greater impingement was in the current study evident for only one 

species, Atlantic silverside. 

Reasons for these differences in entrainment and impingement between the two study years is 

unclear. However, these differences are well within the range expected based on natural 

fluctuations in overall population sizes as well as to potential seasonal salinity patterns in the 

lower Hackensack River. These differences are also well within the range of year-to-year 

variation in entrainment and impingement observed at other facilities.
HUDSON GENERATING STATION 316(b) STUDY REPORT

8-5

Table 8-1 Estimates of Percent Mortality from Mechanical Effects of Entrainment at the

Hudson Generating Station

Species

Life Stage

Egg

Yolk-sac 

larvae

Post yolksac larvaeEarly 

Juveniles

Bay anchovy 39 86 86

American eel 0

Atlantic menhaden 90 90 80 80

Northern pipefish 49 49

Weakfish 42 37

Tautog 42 22 15

Winter flounder 42 26

Gobies 7 7

Cunner 42 22 15

All Other Taxa 48 63 45 40
HUDSON GENERATING STATION 316(b) STUDY REPORT

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Table 8-2 Estimates of the Annual Loss by Fish Species Through Entrainment at the 

Hudson Generating Station under Various Operating Modes, January 2009 - January 2010

Species

Unit 1 Unit 2 Total

Design

Operation

Actual

Operation

No Survival

Actual 

Operation 

With 

Survival

Design

Operation

Actual

Operation

No 

Survival

Actual 

Operation 

With 

Survival

Design

Operation

Actual

Operation

No 

Survival

Actual 

Operation 

With 

Survival

American Eel 480,281 211,441 0 622,586 514,872 0 1,102,867 726,313 0

Atlantic Croaker 13,046,099 460,073 170,227 16,911,610 14,130,292 5,228,208 29,957,709 14,590,365 5,398,435

Atlantic Herring 293,039 47,868 38,295 379,866 277,167 221,733 672,905 325,035 260,028

Atlantic Menhaden 4,721,159 97,032 77,915 6,120,021 5,277,881 4,225,864 10,841,180 5,374,913 4,303,779

Atlantic Silverside 148,821 67,558 30,401 192,917 139,604 62,844 341,738 207,162 93,245

Atlantic Tomcod 0 0 0 0 0 0 0 0 0

Bay Anchovy 63,623,099 31,044,244 22,367,337 82,474,388 56,418,892 40,892,992 146,097,487 87,463,136 63,260,329

Blueback Herring 0 0 0 0 0 0 0 0 0

Cunner 3,832,280 1,126,441 473,105 4,967,771 2,497,686 1,049,081 8,800,051 3,624,127 1,522,186

Grubby 3,775,045 1,031,233 267,480 4,893,577 3,304,968 861,666 8,668,622 4,336,201 1,129,146

Naked Goby 2,578,886 866,954 65,900 3,343,001 1,891,940 144,238 5,921,887 2,758,894 210,138

Northern Pipefish 947,868 461,148 227,220 1,228,718 868,135 428,248 2,176,586 1,329,283 655,468

Striped bass 0 0 0 0 0 0 0 0 0

Summer Flounder 916,624 195,649 50,869 1,188,216 945,453 245,818 2,104,840 1,141,102 296,687

Tautog 4,139,750 1,041,868 437,402 5,366,343 2,472,550 1,035,524 9,506,093 3,514,418 1,472,926

Weakfish 87,260 38,867 17,782 113,115 97,375 45,151 200,375 136,242 62,933

White Perch 49,539 0 0 64,218 58,552 23,421 113,757 58,552 23,421

Winter Flounder 543,491 189,501 49,270 704,525 165,660 43,072 1,248,016 355,161 92,342

Other Taxa 840,788 256,371 109,726 1,089,911 553,537 242,490 1,930,699 809,908 352,216

Total 100,024,029 37,136,248 24,382,929 129,660,783 89,614,564 54,750,350 229,684,812 126,750,812 79,133,279
HUDSON GENERATING STATION 316(b) STUDY REPORT

8-7

Table 8-3 Estimates of the Annual Loss by Fish Species Through Entrainment at the 

Hudson Generating Station under Various Operating Modes, January 2010 - January 2011

Species

Unit 1 Unit 2 Total

Design

Operation

Actual

Operation

No 

Survival

Actual 

Operation 

With 

Survival

Design

Operation

Actual

Operation

No 

Survival

Actual 

Operation 

With 

Survival

Design

Operation

Actual

Operation

No 

Survival

Actual 

Operation 

With 

Survival

American Eel 536,224 55,794 0 695,105 512,316 0 1,231,329 568,110 0

Atlantic Croaker 1,015,658 316,784 117,210 1,316,593 558,571 206,671 2,332,251 875,355 323,881

Atlantic Herring 2,510,231 415,805 332,644 3,254,003 2,227,464 1,781,972 5,764,234 2,643,269 2,114,616

Atlantic Menhaden 675,612 67,501 55,353 875,793 730,097 601,842 1,551,405 797,598 657,195

Atlantic Silverside 0 0 0 0 0 0 0 0 0

Atlantic Tomcod 89,308 27,308 12,289 115,769 51,390 21,941 205,077 78,698 34,230

Bay Anchovy 281,594,495 38,972,886 22,686,093 365,029,901 317,934,259 156,179,437 646,624,396 356,907,145 178,865,530

Blueback Herring 24,159 2,420 1,162 31,317 27,703 15,065 55,476 30,123 16,227

Cunner 246,544 10,885 4,572 319,594 285,923 127,682 566,138 296,808 132,254

Grubby 921,552 100,097 25,114 1,194,605 964,562 243,783 2,116,157 1,064,659 268,897

Naked Goby 7,259,899 1,991,909 342,107 9,410,980 8,158,011 1,343,386 16,670,879 10,149,920 1,685,493

Northern Pipefish 339,755 82,904 42,622 440,423 340,745 177,645 780,178 423,649 220,267

Striped bass 201,120 0 0 260,711 202,931 97,437 461,831 202,931 97,437

Summer Flounder 193,741 2,504 651 251,145 245,084 63,722 444,886 247,588 64,373

Tautog 9,025,654 419,531 176,473 11,699,922 10,225,961 4,450,881 20,725,576 10,645,492 4,627,354

Weakfish 0 0 0 0 0 0 0 0 0

White Perch 48,809 0 0 63,271 56,015 22,406 112,080 56,015 22,406

Winter Flounder 356,921 19,338 5,047 462,675 376,583 126,945 819,596 395,921 131,992

Other Taxa 1,516,160 288,836 163,313 1,965,393 1,563,255 839,376 3,481,553 1,852,091 1,002,689

Total 306,555,842 42,774,502 23,964,650 397,387,200 344,460,870 166,300,191 703,943,042 387,235,372 190,264,841
HUDSON GENERATING STATION 316(b) STUDY REPORT

8-8

Table 8-4 Estimates of the Annual Loss by Fish species Through Impingement at the 

Hudson Generating Station under Various Operating Modes, January 2009 - January 2010

Species

Unit 1 Unit 2 Total

Design

Operation

Actual

Operation

Design

Operation

Actual

Operation

No 

Survival

Actual 

Operation 

With 

Survival

Design

Operation

Actual 

Operation15

Alewife 2,367 319 3,069 1,909 1,058 5,436 1,377

American eel 485 134 628 439 110 1,113 244

American shad 16 15 21 21 7 37 22

Atlantic croaker 97 0 125 110 35 222 35

Atlantic menhaden 1,451 308 1,880 1,434 1,031 3,331 1,339

Atlantic moonfish 50 6 65 53 17 115 23

Atlantic silverside 7,538 862 9,772 6,572 1,343 17,310 2,205

Atlantic tomcod 1,095 189 1,419 1,236 279 2,514 468

Banded killifish 0 0 0 0 0 0

0

Bay anchovy 15,796 7,612 20,476 16,087 14,115 36,272 21,727

Black crappie 39 0 51 43 13 90 13

Black sea bass 289 9 374 250 79 663 88

Blueback herring 2,865 777 3,714 2,340 1,663 6,579 2,440

Bluefish 1,128 621 1,462 1,280 1,006 2,590 1,627

Bluegill 185 20 240 192 29 425 49

Bluespotted cornetfish 15 2 19 16 5 34 7

Brown bullhead 0 0 0 0 0 0

0

Butterfish 819 45 1,062 725 363 1,881 408

Conger eel 42 0 55 42 13 97 13

Crevalle jack 15 2 20 17 5 35 7

Cunner 37 7 48 38 12 85 19

Eastern mudminnow 0 0 0 0 0 0

0

Fourspine stickleback 0 0 0 0 0 0

0

Freshwater drum 0 0 0 0 0 0

0

Gizzard shad 3,631 109 4,707 3,913 2,508 8,338 2,617

Golden shiner 16 1 21 21 7 37 8

Goldfish 35 0 45 42 13 80 13

Gray snapper 0 0 0 0 0 0

0

Grubby 35 0 45 40 13 80 13

Gulf Stream flounder 118 18 154 110 35 272 53

Hickory shad 54 12 70 28 9 124 21

Hogchoker 603 88 782 567 107 1,385 195

Inshore lizardfish 0 0 0 0 0 0

0

 

15 Actual operation results for Unit 1 plus actual operation with survival results for Unit 2.
HUDSON GENERATING STATION 316(b) STUDY REPORT

8-9

Species

Unit 1

Unit 2

Total

Design

Operation

Actual

Operation

Design

Operation

Actual

Operation

No 

Survival

Actual 

Operation 

With 

Survival

Design

Operation

Actual

Operation

Lined seahorse 317 115 410 142 45 727 160

Lookdown 57 24 74 60 41 131 65

Morone species 0 0 0 0 0 0

0

Mummichog 199 62 259 232 73 458 135

Naked goby 160 12 207 102 32 367 44

Northern kingfish 0 0 0 0 0 0

0

Northern pipefish 494 140 641 402 127 1,135 267

Northern puffer 0 0 0 0 0 0

0

Northern searobin 100 54 130 113 36 230 90

Northern stargazer 17 9 22 9 3 39 12

Oyster toadfish 2,123 559 2,752 1,823 213 4,875 772

Pumpkinseed 33 20 43 42 13 76 33

Red hake 909 0 1,179 1,024 112 2,088 112

Sea lamprey 126 23 163 94 30 289 53

Seaboard goby 115 46 149 40 13 264 59

Short bigeye 0 0 0 0 0 0

0

Silver hake 1,099 5 1,424 1,147 779 2,523 784

Spottail shiner 0 0 0 0 0 0

0

Spotted hake 6,282 1,355 8,143 4,743 2,307 14,425 3,662

Striped bass 682 150 884 749 125 1,566 275

Striped cusk-eel 145 51 188 91 29 333 80

Striped killifish 97 0 126 105 33 223 33

Striped searobin 1,238 109 1,605 946 299 2,843 408

Summer flounder 132 23 172 125 40 304 63

Tautog 82 6 106 88 28 188 34

Threespine stickleback 4,805 209 6,229 4,451 55 11,034 264

Weakfish 648 115 840 588 256 1,488 371

White perch 36,547 2,516 47,376 36,855 6,481 83,923 8,997

Windowpane 848 189 1,100 513 162 1,948 351

Winter flounder 2,829 630 3,667 2,754 765 6,496 1,395

Total fish 98,905 17,578 128,213 94,763 35,972 227,118 53,550

Blue crab 144,840 41,134 187,756 124,205 6,210 332,596 47,344

Total organisms 243,745 58,712 315,969 218,968 42,182 559,714 100,894
HUDSON GENERATING STATION 316(b) STUDY REPORT

8-10

Table 8-5 Estimates of the Annual Loss by Fish Species Through Impingement at the 

Hudson Generating Station under Various Operating Modes, January 2010 - January 2011

Species

Unit 1 Unit 2 Total

Design

Operation

Actual

Operation

Design

Operation

Actual

Operation

No 

Survival

Actual 

Operation 

With 

Survival

Design

Operation

Actual 

Operation16

Alewife 1,676 632 2,172 1,533 850 3,848 1,482

American eel 1,432 546 1,857 874 218 3,289 764

American shad 65 0 85 74 23 150 23

Atlantic croaker 139 0 180 137 43 319 43

Atlantic menhaden 204 88 265 215 154 469 242

Atlantic moonfish 0 0 0 0 0 0 0

Atlantic silverside 21,271 5,697 27,573 13,681 2,795 48,844 8,492

Atlantic tomcod 593 57 769 566 128 1,362 185

Banded killifish 16 0 21 21 7 37 7

Bay anchovy 23,401 2,371 30,334 26,271 23,051 53,735 25,422

Black crappie 33 0 43 38 12 76 12

Black sea bass 0 0 0 0 0 0 0

Blueback herring 1,785 508 2,314 1,223 869 4,099 1,377

Bluefish 690 337 895 719 565 1,585 902

Bluegill 489 74 634 417 63 1,123 137

Bluespotted cornetfish 0 0 0 0 0 0 0

Brown bullhead 35 0 46 42 13 81 13

Butterfish 664 263 861 771 386 1,525 649

Conger eel 25 1 32 29 9 57 10

Crevalle jack 96 48 125 27 9 221 57

Cunner 0 0 0 0 0 0 0

Eastern mudminnow 41 0 53 45 14 94 14

Fourspine stickleback 34 7 45 24 8 79 15

Freshwater drum 10 7 13 10 3 23 10

Gizzard shad 989 260 1,282 772 495 2,271 755

Golden shiner 0 0 0 0 0 0 0

Goldfish 0 0 0 0 0 0 0

Gray snapper 179 0 232 179 57 411 57

Grubby 0 0 0 0 0 0 0

Gulf Stream flounder 0 0 0 0 0 0 0

Hickory shad 0 0 0 0 0 0 0

Hogchoker 1,094 383 1,418 970 183 2,512 566

Inshore lizardfish 140 64 181 21 7 321 71

 

16 Actual operation results for Unit 1 plus actual operation with survival results for Unit 2.
HUDSON GENERATING STATION 316(b) STUDY REPORT

8-11

Species

Unit 1 Unit 2 Total

Design

Operation

Actual

Operation

Design

Operation

Actual

Operation

No

Survival

Actual

Operation

With

Survival

Design

Operation

Actual

Operation

Lined seahorse 19 0 25 21 7 44 7

Lookdown 2,409 987 3,123 1,415 971 5,532 1,958

Morone species 16 2 21 18 6 37 8

Mummichog 251 133 325 297 94 576 227

Naked goby 0 0 0 0 0 0 0

Northern kingfish 32 3 41 35 11 73 14

Northern pipefish 189 2 246 206 65 435 67

Northern puffer 27 13 35 30 10 62 23

Northern searobin 162 0 210 181 57 372 57

Northern stargazer 0 0 0 0 0 0 0

Oyster toadfish 4,157 1,050 5,388 3,012 352 9,545 1,402

Pumpkinseed 231 68 299 151 48 530 116

Red hake 4,615 629 5,983 3,933 430 10,598 1,059

Sea lamprey 0 0 0 0 0 0 0

Seaboard goby 141 6 183 148 47 324 53

Short bigeye 16 2 21 20 6 37 8

Silver hake 2,573 759 3,336 1,824 1,239 5,909 1,998

Spottail shiner 309 130 400 72 23 709 153

Spotted hake 21,800 1,173 28,259 22,453 10,920 50,059 12,093

Striped bass 1,461 398 1,894 1,318 220 3,355 618

Striped cusk-eel 44 2 57 48 15 101 17

Striped killifish 393 59 510 361 114 903 173

Striped searobin 305 73 396 217 69 701 142

Summer flounder 123 18 160 134 42 283 60

Tautog 12 0 15 15 5 27 5

Threespine stickleback 1,955 5 2,534 2,065 25 4,489 30

Weakfish 414 153 537 340 148 951 301

White perch 46,049 9,029 59,693 41,604 7,316 105,742 16,345

Windowpane 228 16 296 214 68 524 84

Winter flounder 2,292 644 2,971 1,429 397 5,263 1,041

Total fish 145,324 26,697 188,388 130,220 52,667 333,712 79,364

Blue crab 407,941 220,626 528,812 439,563 21,978 936,753 242,604

Total organisms 553,265 247,323 717,200 569,783 74,645 1,270,465 321,968
HUDSON GENERATING STATION 316(b) STUDY REPORT

8-12

Table 8-6 Estimates of Annual Entrainment Loss at Hudson for Selected Species Under 

Actual Operations With Entrainment Survival Based on Entrainment Monitoring in 1996-

1997 and in 2009-2010

Species 1996 - 1997 2009 2010

Atlantic menhaden 208,795 4,303,779 657,195

Atlantic silverside 811,932 92,245 0

Bay anchovy 385,422,807 63,260,329 178,865,530

Blueback herring 80,999 0 16,227

Mummichog 31,046 0 0

Atlantic tomcod 51,612,351 0 34,230

Bluefish 22,027 0 0

Striped bass 0 0 97,437

Weakfish 782,390 62,933 0

White perch 86,937 58,552 22,406

Winter flounder 614,815 92,342 131,992

Total of selected species 439,674,099 67,870,180 179,825,017
HUDSON GENERATING STATION 316(b) STUDY REPORT

8-13

Table 8-7 Estimates of Annual Impingement Loss at Hudson for Selected Species Using 

Actual Operations Based on Impingement Monitoring in 1996-1997 and in 2009-2010

Species 1996 - 1997 2009 2010

Atlantic menhaden 3,902 1,339 242

Atlantic silverside 2,390 2,205 8,792

Bay anchovy 86,094 20,794 25,132

Blueback herring 3,127 2,440 1,377

Gizzard shad 9,015 2,617 755

Mummichog 570 135 227

American shad 246 22 23

Atlantic tomcod 7,532 468 185

Bluefish 6,367 1,627 902

Striped bass 5,847 275 618

Weakfish 49,093 371 301

White perch 27,179 8,997 16,345

Winter flounder 15,574 1,395 1,041

Blue crab 1,695,019 47,344 242,604

Total of selected species 1,911,955 100,894 321,968
HUDSON GENERATING STATION 316(b) STUDY REPORT

9-1

9. HUDSON UNIT 1

Notwithstanding the result of this report, installation of the modified-Ristroph screens on Unit 1 

is premature and should be delayed for several reasons. First, PSEG is still evaluating the long 

term viability of Unit 1. A decision on the viability of Unit 1 is likely within the next one or two 

years. If PSEG decides to retire Unit 1, it does not make sense to install screens on this peaking 

unit. Second, but related, is that the USEPA is currently undergoing a rulemaking to implement 

§316(b). That rulemaking may have a significant impact on the type of technology that may be 

required at Unit 1. Thus, it would be premature to require the installation of screens at Hudson 

pending the final outcome of USEPA’s proposed 316(b) rule.

9.1 LONG-TERM VIABILITY OF UNIT 1

As stated in Section 2.2, Unit 1 has operated as a peaking unit, operating very infrequently. The 

generation capacity factor for Unit 1 has ranged from 0.46 percent in 2009 and 3.01 percent in 

2010. This unit recently was designated by the Federal Energy Regulatory Commission (FERC) 

as a Reliability, Must Run (RMR) unit. The RMR designation essentially means that a particular 

unit has been designated by FERC as being essential to meet certain system reliability 

requirements. Without such designation, and the appropriate payment made by the system 

operator, Unit 1 would be uneconomic and would be retired.

In addition to receiving approval for designating Unit 1 as RMR, PSEG has applied to FERC to 

approve costs associated with the operation of the unit. It is unknown at this time whether FERC 

will approve any request to include costs for intake structure upgrades as part of its approval. 

The RMR designation is not long-term. FERC’s designation of Unit 1 as a RMR unit expires 1 

September 2012. If Unit 1 is to continue to operate, FERC must continue the RMR designation 

and continue to make payments to make the unit economic. 

Even if FERC were to approve certain operation payments in the short term, PSEG also will 

have to make a decision whether to retire Unit 1 based upon the Reasonably Available Control 

Technology (RACT) rules for emissions of nitrogen oxides (NOx), including the High Electric 

Demand Day (HEDD) provisions of that rule. Pursuant to N.J.A.C. 7:27-19.4, electric 

generating units, including Unit 1, must begin to meet more stringent RACT requirements, which 

decline to a final emissions rate on 1 May 2015. Hudson Unit 1 cannot meet this rate without 

installing NOx control technologies, which may make the unit uneconomic. It would make no 

sense to install modified-Ristroph screens in 2011 or 2012 if it is decided that the unit cannot 

operate after 1 May 2015. 

9.2 PROPOSED 316(b) RULE

As NJDEP is aware, on 20 April 2011, USEPA proposed a rule that would implement §316(b) of 

the CWA entitled “National Pollutant Discharge Elimination System – Cooling Water Intake 

Structures at Existing Facilities and Phase I Facilities – Proposed Rule” (the Proposed 316(b) 

Rule). Pursuant to a Settlement Agreement between the USEPA and certain environmental 

groups, USEPA agreed to issue a final rule by 27 July 2012. Until that time, §316(b) continues 

to be implemented on a case-by-case basis. 
HUDSON GENERATING STATION 316(b) STUDY REPORT

9-2

The Proposed 316(b) Rule sets limits for the reduction of impingement mortality (IM) at electric 

generating stations such as Hudson, including Unit 1. Those standards are based upon the 

construction of modified traveling screens similar to the modified-Ristroph screens installed at 

Unit 2. However, the Proposed 316(b) Rule’s limits for IM reduction may lead to a result that 

the modified Ristroph screens will not meet the proposed IM standard. Thus, PSEG is concerned 

that Hudson’s NJPDES permit requires NJDEP to make a conclusion that the intake structure at 

Unit 2 meets §316(b) under today’s case-by-case best professional judgment analysis, and yet 

may not meet new standards imposed under a final 316(b) rule. Thus, it is premature. In order 

to analyze each electric generating unit’s ability to comply with the IM standards, USEPA has 

proposed that an owner or operator conduct certain studies that must be submitted within six

months after the effective date of the final rule. Those studies will include a proposed 

impingement mortality reduction plan. 

Until PSEG is able to determine the final requirements of the Proposed 316(b) Rule, it is 

premature to require any technologies at Unit 1. Although there is a proposed IM standard, that 

standard could be modified or changed by the time USEPA issues a final rule. Once the final 

rule is issued, USEPA will likely require studies submitted during the times established under the 

Proposed 316(b) Rule, or under another time period. In either case, PSEG will need to evaluate 

whether a technology, including the modified-Ristroph screens, can meet any standard issued 

under a final rule. 

9.3 CONCLUSION

Any upgrade to intake structure screens at Unit 1 is premature until USEPA takes final action on 

the Proposed 316(b) Rule. PSEG notes that the deadline for USEPA to take final action is very 

close in time to when the current RMR designation for Unit 1 expires. At that point PSEG, and 

consequently NJDEP, will have better facts as to whether the installation of the technology 

makes sense at Unit 1. Accordingly, the current condition in the NJPDES application to install 

modified-Ristroph screens at Unit 1 should be suspended until the Proposed 316(b) Rule is either 

adopted or modified, and only after all studies required pursuant to the final rule are completed 

and NJDEP issues a final NJPDES decision pursuant to that rule. In addition, installation of 

modified-Ristroph screens should not occur until PSEG makes a determination that Unit 1 will 

continue to operate for at least another RMR period. 
HUDSON GENERATING STATION 316(b) STUDY REPORT

10-1

10. LITERATURE CITED

Able, K.W. and M.P. Fahay. 2010. Ecology of Temperate Waters of the Western North Atlantic 

Estuarine Fishes. The Johns Hopkins University Press. Baltimore, Maryland. 566 pp.

Bauersfeld, W.R, E. Moshinsky, E. Pustay, and W. Jones. 1994. Water-Resources Data for New 

Jersey Water Year 1993, Volume 1. Surface Water Data. U.S. Geological Survey.

Berg, D. L. and J. S. Levinton. 1985. The Biology of the Hudson-Raritan Estuary, With 

Emphasis on Fishes. NOAA, Rockville, MD. 170 pp. 

Bragin, A.B., J. Musuik, C.A. Woolcott, K.R. Barrett, and R. Jusino-Atresino. 2005. A fishery 

resource inventory of the lower Hackensack River within the Hackensack Meadowlands 

District: a comparative study, 2001-2003 vs. 1987-1988. New Jersey Meadowlands 

Commission, Meadowlands Environmental Research Institute. May 2005.

Clinton Bogart Associates. 1992. Impact Analysis of Sewage Treatment Plant Discharges on the 

Water Quality of the Lower Hackensack River Volume I. Summary Report. Bergen County 

Utilities Authority.

Crawford, D.W., N.L. Bonnevie, C.A. Gillis, and R.J. Wenning. 1994. Historical changes in the 

ecological health of the Newark Bay Estuary, New Jersey. Ecotoxicity & Environmental 

Safety 29:276-303. 

Daniels, R.A. K.E. Limburg, R.E. Schmidt, D.L. Strayer, and R.C. Chambers. 2005. Changes in 

fish assemblages in the tidal Hudson River, New York. American Fisheries Society 

Symposium 45: 471-503.

Electric Power Research Institute (EPRI). 2003. Evaluating the Effects of Power Plant 

Operations on Aquatic Communities: Summary of Impingement Survival Studies. EPRI 

Report 1007821

Hackensack Meadowlands Development Commission (HMDC). 1984. Wetland Bio-Zones of the 

Hackensack Meadowlands. An Inventory. Hackensack Meadowlands Development 

Commission, Lyndhurst, NJ. 

Hudsonia. 2007. Monitoring biological diversity in the Hackensack Meadowlands: monitoring 

fishes in the Meadowlands. Report to the Meadowlands Environmental Research Institute of 

the New Jersey Meadownlands Commission. Revised 18 August 2007. Pages 50-55.

Hurst, T.P., K.A. McKown, and D.O. Conover. 2004. Interannual and long-term variation in the 

nearshore community of the mesohaline Hudson River estuary. Estuaries 27(4):659-669.

HydroQual. 2010a. Evaluation of ammonia toxicity in the NY/NJ Harbor within the context of 

nitrogen and carbon TMDL planning for attainment of dissolved oxygen standards. USEPA 

National Watershed Protection Program, NY/NJ Harbor Estuary Program, USEPA Region 2, 

New York, NY. USEPA Contract EP-C-08-003. September 20, 2010.
HUDSON GENERATING STATION 316(b) STUDY REPORT

10-2

HydroQual. 2010b. Narrative description of historical dissolved oxygen improvements in 

NY/NJ Harbor related to previous nutrient reduction activities. USEPA Region 2, NY/NJ 

Harbor Estuary Program. September 2010. HRFO.001.030, NEIW.006.

Ichthyological Associates, Inc. (IA). 1974. An ecological study of the Hackensack River in the 

vicinity of the Hudson Generating Station, Jersey City, New Jersey. In: Demonstration of 

Absence of Prior Appreciable Harm Respecting Application for Imposition of Alternative 

Thermal Effluent Limitations Hudson Steam Electric Generating Station Units No. 1 and No. 

2. Public Service Electric and Gas Company. 

Ichthyological Associates, Inc. (IA). 1978. Predictive Biological Information to Demonstrate the 

Passage and Maintenance of Representative Important Species. Demonstration Type III, 

Section 316(a) of FWPC Act Amendments of 1972, PL92500 for Hudson and Kearny 

Generating Stations. Public Service Electric and Gas Company. 

Ichthyological Associates, Inc. 1979. Effects of the cooling water intake structure-entrainment 

and impingement of fishes. In: Hudson Generating Station NPDES Permit No. NJ0000647. 

Demonstration for Section 316(b) of the Federal Water Pollution Control Act Amendments 

of 1972, PL 92-500. Public Service Electric and Gas Company. 49 pp. 

Jack McCormick & Associates, Inc. 1977. Draft Assessment of the Potential Impact of the 

Construction and Operation of a New Jersey Sports and Exposition Complex at a Site in East 

Rutherford, Bergen County, New Jersey. Prepared for the New Jersey Sports and Exposition 

Authority, Berwyn, PA. 

Konsevick E. and A.B. Bragin. 2010. Chemical characteristics of sediment of the lower 

Hackensack River, New Jersey. Proceedings of the Annual International Conference on 

Soils, Sediments, Water and Energy. Vol. 15, Article 25.

Long, E.R., D.D. Mac Donald, S.L. Smith, and F.D. Calder. 1995. Incidence of adverse 

biological effects within ranges of chemical concentrations in marine and estuarine 

sediments. Environmental Management 19(1):81-97.

Mattson, C.P. and N.C. Vallario. 1976. Water quality in a recovering ecosystem: A report on 

water quality research and monitoring in the Hackensack Meadowlands, 1971-1975. HMDC, 

Lyndhurst, NJ. 

NAS/NAE (1973) Water Quality Criteria 1972. In: A Report of the Committee on Water Quality 

of the Environmental Studies Board. Report EPA.R3.73.033. U. S. Environmental Protection 

Agency, Washington, DC.

New York/New Jersey Harbor Estuary Program, New Jersey Harbor Dischargers Group, and 

New York City Department of Environmental Protection (HEP/NJHDG/NYCDEP) 2008. 

Harbor-wide water quality monitoring report for the New York-New Jersey Harbor Estuary. 

39 pp.
HUDSON GENERATING STATION 316(b) STUDY REPORT

10-3

New Jersey Meadowlands Commission (NJMC). 2007. Chemical characteristics of sediment 

collected as part of the fishery resource inventory of the lower Hackensack River within the 

Hackensack Meadowlands District; a comparative study, 2001-2003 vs. 1987-1988. 

Meadowlands Environmental Research Institute. 35 pp.

Pecchioli, J.A., T. Wilson, K.N. Dimou, and J. Bonin. 2007. The New Jersey Toxics Reduction 

Workplan for New York – New Jersey Harbor: phase one ambient water quality studies. 

Research project summary. New Jersey Department of Environmental Protection, Division of 

Science, Research & Technology. Trenton, NJ. 11 pp.

Public Service Electric and Gas Company (PSE&G). 1988. Hudson Generating Station Units 1 

and 2 and Kearny Generating Station Units 7 and 8 Supplemental 316(b) Demonstration. 

Public Service Electric and Gas Company (PSE&G). 1998. Hudson Generating Station 316(b) 

Supplemental Demonstration. Newark, NJ.

Reichmuth, J.M., R. Roudez, T. Glover, and J.S. Weis. 2009. Differences in prey capture 

behavior in populations of blue crab (Callinectes sapidus Rathbun) form contaminated and 

clean estuaries in New Jersey. Estuaries and Coasts 32:298-308.

Steinberg, N., D.J. Suskowski, L. Clark, and J. Way. 2004. Health of the harbor: the first 

comprehensive look at the state of the NY/NJ Harbor Estuary. Report to the New York/New 

Jersey Harbor Estuary Program. Hudson River Foundation, New York, NY. 82 pp.

Stevens Institute of Technology. 2007. The New Jersey Toxics Reduction Workplan for NY-NJ 

Harbor. Ambient monitoring of water quality within major tributaries & the estuary. Studies 

I-D and I-E. Final report – April 2007. 197 pp. plus appendices.

Weis, J.S. 2005. White perch (Morone americana): diet and food web support in the 

Hackensack Meadowlands. Meadowlands Environmental Research Institute, New Jersey 

Meadowlands Commission. January 2005. 15 pp.

Weis, J.S. 2009. Trophic transfer of contaminants and mechanisms of behavioral effects on 

juvenile bluefish, Pomatomus saltatrix from the Hackensack River. New Jersey 

Meadowlands Commission. http://merilibrary.njmeadowlands.gov/dbtw-wpd/FullText/ML09-4.pdf

Zeisel, W. 1989. History of the tidal Hackensack River Fisheries. Fairleigh Dickinson 

University. Proceedings of the Third Annual Hackensack River Symposium. 24 pp. 
HUDSON GENERATING STATION 316(b) STUDY REPORT

A-1

APPENDIX A

2009-2010 BOTTOM TRAWL CATCH
HUDSON GENERATING STATION 316(b) STUDY REPORT

A-2

Appendix Table A-1 Monthly Total Catch by Species and Sampling Station in the Bottom 

Trawl, March – November 2009

Mar Apr May Jun Jul Aug Sep Oct Nov Total

Alewife 13 5 1 19

Station 1 1 1

Station 2 1 1

Station 4 4 5 9

Station 5 7 1 8

American Eel 1 35 2 1 39

Station 1 1 15 1 17

Station 2 14 14

Station 3 3 1 4

Station 4 3 1 4

American Shad 8 8

Station 2 1 1

Station 4 3 3

Station 5 4 4

Atlantic 

Menhaden 1 1 2

Station 2 1 1

Station 3 1 1

Atlantic 

Moonfish 2 1 3

Station 2 2 2

Station 5 1 1

Atlantic Tomcod 30 67 53 2 2 154

Station 1 1 1 1 3

Station 2 1 60 1 1 63

Station 3 22 5 52 2 81

Station 4 6 1 7

Bay Anchovy 21 208 99 86 303 29 2 748

Station 1 7 7 1 15

Station 2 4 2 1 17 3 27

Station 3 9 1 5 21 36

Station 4 4 2 24 6 199 26 261

Station 5 8 202 65 67 65 2 409

Black Seabass 1 1

Station 5 1 1

Blue Crab 1 17 26 14 4 26 32 120

Station 1 3 2 1 3 4 24 37

Station 2 7 9 1 6 2 25

Station 3 6 3 13 16 38

Station 4 1 1 7 4 13

Station 5 5 2 7
HUDSON GENERATING STATION 316(b) STUDY REPORT

A-3

Appendix Table A-1 continued

Mar Apr May Jun Jul Aug Sep Oct Nov Total

Blueback 

Herring 2 2

Station 4 2 2

Bluefish 1 1

Station 1 1 1

Butterfish 8 1 9

Station 4 1 1

Station 5 8 8

Cunner 1 1 1 3

Station 4 1 1 2

Station 5 1 1

Gizzard Shad 1 1

Station 3 1 1

Grubby 1 1

Station 4 1 1

Hogchoker 7 13 2 1 23

Station 2 2 12 14

Station 3 5 1 2 8

Station 4 1 1

Naked Goby 2 2

Station 1 2 2

Oyster Toadfish 2 1 1 1 5

Station 3 1 1

Station 4 2 1 1 4

Red Hake 2 1 3

Station 3 1 1

Station 4 1 1 2

Scup 1 1

Station 4 1 1

Spotted Hake 12 19 326 52 7 416

Station 1 1 2 1 4

Station 2 10 46 19 75

Station 3 3 73 14 90

Station 4 3 4 205 18 7 237

Station 5 9 1 10
HUDSON GENERATING STATION 316(b) STUDY REPORT

A-4

Appendix Table A-1 continued

Mar Apr May Jun Jul Aug Sep Oct Nov Total

Striped Bass 47 16 4 8 75

Station 2 1 3 4

Station 3 3 3 4 10

Station 4 44 16 1 61

Striped Cusk-eel 3 3

Station 3 3 3

Striped Searobin 3 2 5

Station 2 1 1

Station 4 3 1 4

Summer 

Flounder 1 2 8 11

Station 2 1 1

Station 3 1 1 2

Station 4 1 5 6

Station 5 2 2

Tautog 2 2

Station 4 2 2

Weakfish 2 2 10 14

Station 2 3 3

Station 3 2 1 3

Station 4 2 6 8

White Perch 132 51 17 6 6 13 74 299

Station 1 5 8 3 6 6 19 47

Station 2 5 6 1 12

Station 3 29 24 3 2 7 65

Station 4 87 16 53 156

Station 5 16 1 2 19

Windowpane 3 2 5

Station 2 1 1

Station 3 3 3

Station 4 1 1

Winter Flounder 6 1 1 13 7 2 9 39

Station 2 12 12

Station 3 1 1 7 2 11

Station 4 5 1 9 15

Station 5 1 1

Total 221 102 471 419 177 87 330 75 132 2014
HUDSON GENERATING STATION 316(b) STUDY REPORT

A-5

Appendix Table A-2 Monthly Total Catch by Species and Sampling Station in the Bottom 

Trawl, February – November 2010

Feb Mar Apr May Jun Jul Aug Sep Oct Nov Total

Alewife 1 1

Station 4 1 1

American Eel 2 65 5 20 2 7 4 1 106

Station 1 2 50 5 20 6 3 1 87

Station 2 2 2 1 1 6

Station 3 13 13

American Shad 1 1

Station 5 1 1

Atlantic Croaker 1 1

Station 5 1 1

Atlantic 

Menhaden 7 7

Station 5 7 7

Atlantic Moonfish 1 21 22

Station 3 1 1

Station 4 18 18

Station 5 3 3

Atlantic Tomcod 130 9 33 1 1 174

Station 1 31 3 6 40

Station 2 8 16 1 1 26

Station 3 58 6 5 69

Station 4 33 1 34

Station 5 5 5

Bay Anchovy 9 17 36 2 31 17 7 119

Station 1 1 1

Station 2 15 1 1 17

Station 3 4 5 1 5 15

Station 4 2 3 1 10 1 17

Station 5 5 15 13 29 1 6 69

Blue Crab 4 185 29 135 27 44 31 5 9 469

Station 1 115 7 14 4 16 11 2 4 173

Station 2 1 41 1 3 16 4 17 1 2 86

Station 3 3 25 20 2 4 2 3 3 62

Station 4 4 1 2 2 9

Station 5 1 116 2 20 139

Butterfish 1 5 1 1 8

Station 3 1 1

Station 4 1 1

Station 5 1 4 1 6
HUDSON GENERATING STATION 316(b) STUDY REPORT

A-6

Appendix Table A-2 continued

Feb Mar Apr May Jun Jul Aug Sep Oct Nov Total

Gizzard Shad 2 2

Station 2 1 1

Station 4 1 1

Hogchoker 1 15 41 2 8 1 68

Station 1 2 1 3

Station 2 3 39 1 1 44

Station 3 5 7 12

Station 5 1 7 1 9

Naked Goby 1 1 1 3

Station 1 1 1

Station 2 1 1

Station 5 1 1

Northern Puffer 1 1

Station 2 1 1

Northern Searobin 1 1 2

Station 3 1 1 2

Oyster Toadfish 1 3 9 1 9 7 1 31

Station 1 1 1 2 5 9

Station 2 1 1 1 1 4

Station 3 2 1 3

Station 4 1 1 2

Station 5 8 5 13

Red Hake 1 12 1 1 15

Station 2 1 1

Station 4 12 1 13

Station 5 1 1

Silver Hake 5 5

Station 4 5 5

Spotted Hake 265 127 86 4 482

Station 1 59 19 2 80

Station 2 14 7 3 24

Station 3 114 79 1 194

Station 4 78 1 4 83

Station 5 22 79 101
HUDSON GENERATING STATION 316(b) STUDY REPORT

A-7

Appendix Table A-2 continued

Feb Mar Apr May Jun Jul Aug Sep Oct Nov Total

Striped Bass 3 1 1 7 4 3 19

Station 1 1 2 1 4

Station 2 1 4 5

Station 3 1 4 1 6

Station 4 1 1 2

Station 5 2 2

Summer Flounder 2 3 3 8

Station 3 2 2 4

Station 5 1 3 4

Threespine Stickleback 1 1

Station 2 1 1

Weakfish 4 7 3 4 18

Station 2 4 1 5

Station 3 1 1 2

Station 4 2 3 5

Station 5 5 1 6

White Perch 182 29 12 1 2 12 30 21 16 305

Station 1 17 19 11 2 9 18 14 7 97

Station 2 1 3 1 11 1 17

Station 3 5 1 3 1 7 8 25

Station 4 1 1

Station 5 164 1 165

Windowpane 1 2 3

Station 3 1 1

Station 5 2 2

Winter Flounder 1 1 1 1 1 3 8

Station 2 1 2 3

Station 3 1 1

Station 4 1 1

Station 5 1 1 1 3

Total 188 37 681 193 326 124 83 122 83 42 1879
HUDSON GENERATING STATION 316(b) STUDY REPORT

B-1

APPENDIX B

RIVER ICHTHYOPLANKTON DENSITY DATA
HUDSON GENERATING STATION 316(b) STUDY REPORT

B-2

Appendix Table B-1 Average Monthly Ichthyoplankton Densities (#/1,000m3) from Five 

Sampling Stations, 2009

Mar Apr May Jun Jul Aug Sep Oct Nov

American Eel 15.6 3.3 1.6 1.3 - - - - -

 PYSL 15.6 3.3 1.6 1.3 - - - - -

Atlantic Croaker - - - - - - - 561.2 153.9

 PYSL - - - - - - - 527.7 28.2

 Juv - - - - - - - 33.5 125.7

Atlantic Herring 66.4 57.5 - - - - - - -

 PYSL 5.9 1.3 - - - - - - -

 Juv 60.5 56.1 - - - - - - -

Atlantic Menhaden 2.3 - 55.2 - - 2.9 - 342.9 19.5

 PYSL 2.3 - 18.1 - - - - 342.9 19.5

 Juv - - 37.1 - - 2.9 - - -

Atlantic Silverside - - 19.8 - - - - - -

 YSL - - 9.5 - - - - - -

 PYSL - - 10.3 - - - - - -

Atlantic Tomcod 1.1 0.9 - - - - - - -

 PYSL 1.1 0.9 - - - - - - -

Bay Anchovy - - 16.7 29,224.7 66,712.3 1,197.7 239.8 90.3 13.3

 Eggs - - 1.2 29,207.9 59,895.6 - - - -

 PYSL - - - 4.3 6,779.0 1,066.3 200.5 2.1 7.1

 Juv - - - - 9.6 126.5 38.6 85.2 4.7

 Adult - - 15.5 12.5 28.1 4.9 0.7 3.0 1.5

Blueback Herring 0.6 0.7 - 6.5 7.9 - - - -

 Eggs - - - 6.5 7.9 - - - -

 Juv 0.6 0.7 - - - - - - -

Butterfish - - - - - 0.7 - - -

 Juv - - - - - 0.7 - - -

Cunner - - 291.3 1.5 - - - - -

 Eggs - - 291.3 1.5 - - - - -

Fourbeard Rockling - - 37.7 232.2 908.1 - - - -

 Eggs - - 37.7 232.2 908.1 - - - -

Grubby 72.2 99.9 - - - - - - -

 YSL 3.1 2.0 - - - - - - -

 PYSL 69.1 97.3 - - - - - - -

 Juv - 0.7 - - - - - - -

Naked Goby - - - 3.3 1,441.7 41.1 29.3 2.4 4.6

 PYSL - - - 3.3 1,437.7 39.7 29.3 0.7 4.6

 Juv - - - - 3.9 1.4 - 1.7 -

Northern Pipefish - 0.7 - 18.9 474.9 2.8 0.8 - 0.6

 PYSL - - - 3.0 2.6 - - - -

 Juv - - - 15.9 472.3 2.8 0.8 - 0.6

 Adult - 0.7 - - - - - - -

Rock Gunnel 10.8 8.0 - - - - - - -

 PYSL 10.8 8.0 - - - - - - -
HUDSON GENERATING STATION 316(b) STUDY REPORT

B-3

Appendix Table B-1 continued

Mar Apr May Jun Jul Aug Sep Oct Nov

Sand Lances 1.9 - - - - - - - -

 PYSL 1.9 - - - - - - - -

Spotted Hake - - 0.9 0.6 - - - - -

 Juv - - 0.9 0.6 - - - - -

Summer Flounder 4.6 0.7 - - - - - 3.8 7.4

 PYSL 1.7 - - - - - - 3.8 3.8

 Juv 2.9 0.7 - - - - - - 3.5

Tautog - - 123.2 662.3 391.0 - - - -

 Eggs - - 123.2 662.3 391.0 - - - -

Threespine Stickleback - - 0.6 - - - - - -

 Juv - - 0.6 - - - - - -

Weakfish - - - - 8.1 0.7 - - -

 PYSL - - - - 8.1 - - - -

 Juv - - - - - 0.7 - - -

White Perch 0.6 - 2.2 - - - - - -

 PYSL - - 2.2 - - - - - -

 Juv 0.6 - - - - - - - -

Windowpane 0.6 - 0.9 0.6 - - - - -

 PYSL - - - 0.6 - - - - -

 Juv 0.6 - 0.9 - - - - - -

Winter Flounder 6.0 16.6 14.8 0.7 - - - - -

 PYSL 6.0 13.1 7.5 - - - - - -

 Juv - 3.5 7.3 0.7 - - - - -

Total Density 182.8 188.2 565.2 30,152.5 69,943.9 1,245.8 269.9 1,000.7 199.2
HUDSON GENERATING STATION 316(b) STUDY REPORT

B-4

Appendix Table B-2 Average Monthly Ichthyoplankton Densities (#/1,000m3) from Five 

Sampling Stations , 2010

Feb Mar Apr May Jun Jul Aug Sep Oct Nov

Alewife - - - - - 0.9 - - - -

 Juv - - - - - 0.9 - - - -

American eel 2.1 10.6 1.7 0.7 - - - - - -

 PYSL 2.1 10.6 1.7 0.7 - - - - - -

Atlantic croaker - - - - - - - 20.1 94.0 24.0

 PYSL - - - - - - - 20.1 37.9 6.5

 Juv - - - - - - - - 56.2 17.5

Atlantic herring 3.0 20.3 84.1 10.4 - - - - - -

 PYSL - 6.0 - 1.7 - - - - - -

 Juv 3.0 14.3 84.1 8.8 - - - - - -

Atlantic menhaden - 0.7 28.1 3.1 163.4 - - - 0.8 9.0

 Eggs - - 27.4 - 163.4 - - - - -

 PYSL - - 0.7 3.1 - - - - 0.8 9.0

 Juv - 0.7 - - - - - - - -

Atlantic moonfish - - - - - - 0.7 - - -

 Juv - - - - - - 0.7 - - -

Atlantic tomcod - 4.6 20.8 0.7 - - - - - -

 PYSL - 4.6 0.7 - - - - - - -

 Juv - - 20.1 0.7 - - - - - -

Bay anchovy - - 6.5 24.6 45,406.2 125,568.3 1,195.8 68.4 106.9 10.2

 Eggs - - - - 45,203.0 120,378.0 622.8 - 39.7 -

 PYSL - - 0.9 - 201.6 5,153.4 467.6 55.2 10.4 -

 Juv - - 0.7 - - 25.9 103.9 13.3 53.8 9.5

 Adult - - 4.9 24.6 1.6 11.0 1.5 - 3.0 0.7

Blueback herring - - - - - - - - 3.2 -

 Juv - - - - - - - - 3.2 -

Butterfish - - - - - 0.9 0.8 - - -

 Juv - - - - - 0.9 0.8 - - -

Conger eel - - - 2.4 - - - - - -

 Juv - - - 2.4 - - - - - -

Fourbeard rockling - - - - - - - - 0.7 -

 Eggs - - - - - - - - 0.7 -

Fundulus sp. - - - - 0.8 - - - - -

 PYSL - - - - 0.8 - - - - -

Grubby 4.9 21.8 1.9 - - - - - - -

 YSL 1.4 - - - - - - - - -

 PYSL 3.5 21.8 1.9 - - - - - - -

Highfin goby - - - - - - - - - 2.2

 PYSL - - - - - - - - - 0.7

 Juv - - - - - - - - - 0.7

 Adult - - - - - - - - - 0.7

Hogchoker - - - - 0.9 - - - - -

 PYSL - - - - 0.9 - - - - -
HUDSON GENERATING STATION 316(b) STUDY REPORT

B-5

Appendix Table B-2 continued

Feb Mar Apr May Jun Jul Aug Sep Oct Nov

Menidia sp. - - - 1.5 2.5 - - - - -

 PYSL - - - 1.5 2.5 - - - - -

Naked goby - 0.7 - - 74.6 1,948.9 351.6 49.4 13.9 0.8

 PYSL - - - - 74.6 1,948.0 351.6 49.4 12.3 -

 Juv - - - - - 0.9 - - 0.8 0.8

 Adult - 0.7 - - - - - - 0.8 -

Northern pipefish - - - - 12.5 176.8 16.6 0.7 0.7 0.7

 PYSL - - - - - 28.7 5.9 - - -

 Juv - - - - 12.5 148.0 10.7 0.7 0.7 0.7

Rock gunnel - 0.7 - - - - - - - -

 PYSL - 0.7 - - - - - - - -

Summer flounder 0.7 7.5 - - - - - - - 3.8

 PYSL - 1.5 - - - - - - - 1.6

 Juv 0.7 6.1 - - - - - - - 2.2

Tautog - - - 3.1 1,075.0 - - - - -

 Eggs - - - 3.1 1,075.0 - - - - -

Threespine stickleback - - - - 614.4 28.7 - - - -

 Eggs - - - - 614.4 28.7 - - - -

Unidentifiable - - 0.9 - 6.7 14.5 - - - -

 Eggs - - 0.9 - 6.7 14.5 - - - -

White perch - - 0.7 - - - - - - 0.7

 Juv - - 0.7 - - - - - - 0.7

Winter flounder - 1.6 43.2 17.0 - - - - - -

 PYSL - 1.6 12.7 4.5 - - - - - -

 Juv - - 30.5 12.5 - - - - - -

Total Density 10.7 68.6 187.9 63.4 47,357.1 127,739.0 1,565.5 138.6 220.2 51.5
HUDSON GENERATING STATION 316(b) STUDY REPORT

C-1

APPENDIX C

ENTRAINMENT LENGTH FREQUENCY DATA
HUDSON GENERATING STATION 316(b) STUDY REPORT

C-2

Appendix Table C-1. Length Distribution of Ichthyoplankton Collected in Entrainment Monitoring at the Hudson Station, 26 

January 2009 – 18 January 2010

Midpoint of Length Interval (mm)

Taxa 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

American eel - - - - - - - - - - - - - - - - - - - - - - -

Atlantic croaker - - - - - - - - - - - - - - - - - - - - - - -

Atlantic herring - - - - 3 20 36 45 48 56 55 54 57 38 16 8 3 3 1 1 - - -

Atlantic 

menhaden

- - - - - - - - - - - - - - - - - - - - - - -

Atlantic 

silverside

- - - - - - - - -

4 13 22 28 21 9 4 4 1 2 3 3 4 2

Bay anchovy - - 2 1 3 - - - - - - - - - - - - - - - - - -

Butterfish 6 23 46 64 120 177 137 157 103 71 59 43 41 17 19 5 1 3 4 6 1 1

Crevalle jack - - - - - - - - - - 1 - - - - - - - - - - - -

Fundulus sp. - - - - - - - - - - - - - - - - - - - - - - -

Grubby - - - - - - 1 - - - - - - - - - - - - - - - -

Highfin goby - - - 4 33 45 30 22 8 6 3 - - - - - - - - - - - -

Naked goby - - - - - - - - - 1 1 1 - 1 - - - - - - - - -

Northern 

pipefish

-

28 26 17 7 2 4 7 5 5 1

- - - - - - - - - - - -

Northern puffer - - - - - - - - - - 1 - - - - - - - - - - - 1

Rock gunnel - - - - - - 1 - - - - - - - - - - - - - - - -

Spotted hake - - - - - - - - - - 1 - - - - - 2 1 1 1 - 2 -

Striped killifish - - - - - - - - - - - - - - - - - - - - - - -

Summer 

flounder

- - - - - - - - - - - - - - - - - - - - - - -

Tautog - - - - - - - - - - - 2 5 8 4 5 6 1 - - - - -

Threespine 

stickleback

- - - - - - - - - - - - - - - - - - - - - - -

Unidentifiable 

Fish

- - - - -

1

- - - - - - - - - - - - - - - - -

Urophycis sp. - - - - - - - - - - - - - - - - - - - - - - -

Weakfish - - - - 1 - 1 1 - - - - - - - - - - - - - - -

White perch - - - - - - - - - - - - - - - - - - - - - - -

Winter flounder - - - - 3 12 6 - - - - - - - - - - - - - - -
HUDSON GENERATING STATION 316(b) STUDY REPORT

C-3

Appendix Table C-1 continued

Midpoint of Length Interval (mm)

Taxa 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

American eel - - - - - - - - - - - - - - - - - - - - - - -

Atlantic croaker - - - - - - - - - - - - - - - - - - - - - - -

Atlantic herring - - - - - - - - - - - - - - - - 1 - - - - - -

Atlantic 

menhaden

- - - -

1

-

1 2

- -

1 1

-

2 1

- -

1

-

1

- - -

Atlantic 

silverside 3 1 1 1 1

- - -

1

- -

1

- -

1

- - - - - - - -

Bay anchovy - - - - - - - -

Butterfish 3 1 1 - - 1 - 1 - - - - - - 2 - - - - - - - -

Crevalle jack - - - - - - - - - - - - - - - - - - - - - - -

Fundulus sp. - - - - - - - - - - - - - - - - - - - - - - -

Grubby - - - - - - - - - - - - - - - - - - - - - - -

Highfin goby - - - - - - - - - - - - - - - - - - - - - - -

Naked goby - - - - - - - - - - - - - - - - - - - - - - -

Northern 

pipefish

- - - - - - - - - - - - - - - - - - - - - - -

Northern puffer - - - - 2 - 1 - - - 2 2 4 4 1 3 1 - 3 - 2 1 2

Rock gunnel - - - - - - - - - - - - - - - - - - - - - - -

Spotted hake - - - - - 2 - - - - - - - - - - - - - - - - -

Striped killifish - - - - - - - - - - - - - - - - - - - - - - -

Summer 

flounder

- - - - - - - - - - - - - - - - - - - - - - -

Tautog - - - - - - - - - - - - - - - - - - - - - - -

Threespine 

stickleback

- - - - - - - - - - - - - - - - - - - - - - -

Unidentifiable 

Fish

- - - - - - - - - - - - - - - - - - - - - - -

Urophycis sp. - - - - - - - - - - - - - - - - - - - - - - -

Weakfish - - - - - - - - - - - - - - - - - - - - - - -

White perch - - - - - - - - - - - - - - - - - - - - - - -

Winter flounder - - - - - - - - - - - - - - - - - - - - - - -
HUDSON GENERATING STATION 316(b) STUDY REPORT

C-4

Appendix Table C-1 continued

Midpoint of Length Interval (mm)

Taxa 48 49 52 53 54 55 56 57 58 59 60 61 62 63 66 67 68 71 72 76 77 78 81

American eel - - - - - - - - - - - - - - - - - - - - - - -

Atlantic 

croaker

- -

1 1 2 2 1

-

6 1

-

2

- - - - - - - - - - -

Atlantic 

herring

- - - - - - - - - - - - - - - - - - - - - - -

Atlantic 

menhaden

- - -

1

- - - - - - - - - - - - - - - - - - -

Atlantic 

silverside

- - - - - - - - - - - - - - - - - - - - - -

Bay anchovy - - - - - - - - - - - - - - - - - - - - - -

Butterfish - - - 2 - - - 1 - - - - 1 - 1 1 - 1 - - - - -

Crevalle jack - - - - - - - - - - - - - - - - - - - - - - -

Fundulus sp. - - - - - - - 1 - - - - - - - - - - - - - - -

Grubby - - - - - - - - - - - - - - - - - - - - - -

Highfin goby - - - - - - - - - - - - - - - - - - - - - -

Naked goby - - - - - - - - - - - - - - - - - - - - - -

Northern 

pipefish

- - - - - - - - - - - - - - - - - - - - - - -

Northern 

puffer 2

- -

1 1

- - - - - - - - - - - - - - - - - -

Rock gunnel - - - - - - - - - - - - - - - - - - - - - - -

Spotted hake - - - - - - - - - - - - - - - - - - - - - - -

Striped 

killifish

- - - - - - - - - - - - - - - - - - - - - -

1

Summer 

flounder

- - - - - - - - - - - - - - - - - - - - - - -

Tautog - - - - - - - - - - - - - - - - - - - - - - -

Threespine 

stickleback

- - - - - - - - - - - - - - - - - - -

1

- - -

Unidentifiable 

Fish

- - - - - - - - - - - - - - - - - - - - - - -

Urophycis sp. - - - - - - - - - - - - - - - - - - - - - - -

Weakfish - - - - - - - - - - - - - - - - - - - - - - -

White perch - - - - - - - - - - - - - - - 1 - - - - - 1 -

Winter 

flounder

- - - - - - - - - - - - - - - - - - - - - - -
HUDSON GENERATING STATION 316(b) STUDY REPORT

C-5

Appendix Table C-1 continued

Midpoint of Length Interval (mm)

Taxa 93 108 127

American eel - - -

Atlantic 

croaker

- - -

Atlantic 

herring

- - -

Atlantic 

menhaden

- - -

Atlantic 

silverside

- - -

Bay anchovy - - -

Butterfish - - -

Crevalle jack - - -

Fundulus sp. - - -

Grubby - - -

Highfin goby - - -

Naked goby - - -

Northern 

pipefish

- - -

Northern 

puffer

- - -

Rock gunnel - - -

Spotted hake - - -

Striped 

killifish

- - -

Summer 

flounder - 1 -

Tautog - - -

Threespine 

stickleback

- - -

Unidentifiable 

Fish

- - -

Urophycis sp. - - 1

Weakfish - - -

White perch - - -

Winter 

flounder

- - -
HUDSON GENERATING STATION 316(b) STUDY REPORT

C-6

Appendix Table C-2. Length Distribution of Ichthyoplankton Collected in Entrainment Monitoring at the Hudson Station, 25 

January 2010 – 17 January 2011

Midpoint of Length Interval (mm)

Taxa 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

American eel - - - - - - - - - - - - - - - - - - - - - - -

Atlantic croaker - - - - 2 3 5 5 5 4 2 2 3 1 2 1 1

Atlantic herring - - - - - - - - - - - - - - - - - - - - - - -

Atlantic menhaden - - - - - - - - 1 - - 1 1 - 2 3 - - 1 1 - 2 3

Atlantic silverside - - - - - - - - - - - - - - - - - - - - - - -

Atlantic tomcod - - - - - - - 1 1 - - 1 - - - - - - - - - - -

Bay anchovy 2 6 23 88 148 227 265 216 194 133 99 59 44 26 14 10 5 7 1 - 1 - -

Bluegill - - - - - - - - - - - - - - - - - - - - - - -

Butterfish - - - - - - - - - - - - - - - - - - - - - - -

Feather blenny - - - - - - - - - - - - - - - - - - - - - - -

Fundulus sp. - - - - 1 7 - - - - - - - - - - - - - - - - -

Grubby - - - 1 8 20 9 - - - - - - - - - - - - - - - -

Highfin goby - - - - - - - - - 1 1 - - - - - - - - - - -

Inshore lizardfish - - - - - - - - - - - - - - - - - - - - - - -

Menidia sp. - - 2 11 6 1 - - - - - - - - - - - - - - - - -

Naked goby 7 79 86 43 30 24 23 21 19 6 4 - - 1 - - - - - - - - -

Northern pipefish - - - - - - - - - - - - - - - 1 1 - - - - 1 -

Oyster toadfish - - - - - - - - - - - - - - - - - - 1 - - - -

Rock gunnel - - - - - - - - - - - - 1 - - - - - - - - - -

Skilletfish - - - - - - - - - - - - - - - - - - - - - -

Smallmouth 

flounder

- - - - - - - - - - - - - -

1

- - - - - - - -

Summer flounder - - - - - - - - - - - - - 3 - 3 - 1 - - - - -

Threespine 

stickleback

- - - - - - - - - - - - - - - - - - -

1

- - -

White perch - - - - - - - - - - - - - - - - - - - - - -

Winter flounder - - 1 1 - 2 9 3 - - - - - - - - - - - - - - -
HUDSON GENERATING STATION 316(b) STUDY REPORT

C-7

Appendix Table C-2 continued

Midpoint of Length Interval (mm)

Taxa 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

American eel - - - - - - - - - - - - - - - - - - - - - 1 -

Atlantic croaker - - - - - - - - - - - - - - - - - - - - - - -

Atlantic herring - - - - - 1 1 - 7 3 4 6 16 16 16 8 7 5 6 4 - - -

Atlantic 

menhaden 1 2 2 1 2

- - - - - - - - - - - - -

1

- - - -

Atlantic 

silverside

- - - - - - - - - - - - - - - - -

1

- - - - -

Atlantic tomcod - - - - - - - - 1 - - - - - - - - - - - - - -

Bay anchovy - - - - 1 - - - 1 - - - 1 - - - 1 - - - - - -

Bluegill - - - - - - - - - - - - - - - - - - - 1 - - -

Butterfish - - - - - - - - - 1 - - - - - - - - - - - - -

Feather blenny - - - - - - - - - - - - - - - - - - - - - - 1

Fundulus sp. - - - - - - - - -

Grubby - - - - - - - - - - - - - - - - - - - - - - -

Highfin goby - - - - - - - - - - - - - - - - - - - - - - -

Inshore 

lizardfish 1

- - - - - - - - - - - - - - - - - - - - - -

Menidia sp. - - - - - - - - - - - - - - - - - - - - - - -

Naked goby - - 1 - 2 - - 1 - - - - - 2 1 - - - - - 1 - -

Northern 

pipefish

- - - -

3

-

1

-

2 1 1 1

-

1

-

1

- -

1 1

- - -

Oyster toadfish - - - - - - - - - - - - - - - - - - - - - - -

Rock gunnel - - - - - - - - - - - - - - - - - - - - - - -

Skilletfish - - - - - - - - - - 1 - - - - - - - - - - - -

Smallmouth 

flounder

- - - - - - - - - - - - - - - - - - - - - - -

Summer 

flounder

- - - - - - - - - - - - - - - - - - - - - - -

Threespine 

stickleback

- - - - - - - - - - - - - - - - - - - - - - -

White perch - - - - - - - - - - - - - - - - - - - - - - -

Winter flounder - - - - - - - - - - - - - - - - - - - - - - -
HUDSON GENERATING STATION 316(b) STUDY REPORT

C-8

Appendix Table C-2 continued

Midpoint of Length Interval (mm)

Taxa 48 49 52 53 54 55 56 57 58 59 60 61 62 63 66 67 68 71 72 76 77 78 81

American eel - 1 1 1 2 2 2 2 4 1 1 1 1 - - - - - - - - -

Atlantic croaker - - - - - - - - - - - - - - - - - - - - - - -

Atlantic herring - - - - - - - - - - - - - - - - - - - - - - -

Atlantic menhaden - - - - - - - - - - - - - - - - - - - - - - -

Atlantic silverside

- - - - - - - - - - - - - - -

1

- -

1

- - - -

Atlantic tomcod - - - - - - - - - - - - - - - - - - - - - - -

Bay anchovy - - - - - - - - 1 - 1 - - - - 1 1 - - - 1 - -

Bluegill - - - - - - - - - - - - - - - - - - - - - - -

Butterfish - - - - - - - - - - - - - - - - - - - - - - -

Feather blenny - - - - - - - - - - - - - - - - - - - - - - -

Fundulus sp. - - - - - - - - - - - - - - - - - - - - - - -

Grubby - - - - - - - - - - - - - - - - - - - - - - -

Highfin goby - - - - - - - - - - - - - - - - - - - - - - -

Inshore lizardfish - - - - - - - - - - - - - - - - - - - - - - -

Menidia sp. - - - - - - - - - - - - - - - - - - - - - - -

Naked goby - - - - - - - - - - - - - - - - - - - - - - -

Northern pipefish - - - - - - - - - - - - - - - - - - - - - - 1

Oyster toadfish - - - - - - - - - - - - - - - - - - - - - - -

Rock gunnel - - - - - - - - - - - - - - - - - - - - - - -

Skilletfish - - - - - - - - - - - - - - - - - - - 1 - - -

Smallmouth flounder - - - - - - - - - - - - - - - - - - - - - - -

Summer flounder - - - - - - - - - - - - - - - - - - - - - - -

Threespine 

stickleback

- - - - - - - - - - - - - - - - - - - - - - -

White perch - - - - - - - - - - - - - - - - - - - - - - -

Winter flounder - - - - - - - - - - - - - - - - - - - - - - -
HUDSON GENERATING STATION 316(b) STUDY REPORT

C-9

Appendix Table C-2 continued

Midpoint of Length Interval (mm)

Taxa 93 108 127

American eel - - -

Atlantic croaker - - -

Atlantic herring - - -

Atlantic menhaden - - -

Atlantic silverside

- - -

Atlantic tomcod - - -

Bay anchovy - - -

Bluegill - - -

Butterfish - - -

Feather blenny - - -

Fundulus sp. - - -

Grubby - - -

Highfin goby - - -

Inshore lizardfish - - -

Menidia sp. - - -

Naked goby - - -

Northern pipefish - - -

Oyster toadfish - - -

Rock gunnel - - -

Skilletfish - - -

Smallmouth 

flounder

- - -

Summer flounder - - -

Threespine 

stickleback

- - -

White perch 1 - -

Winter flounder - - -