NOAA Technical Memorandum NMFS-AFSC-158


Groundfish Food Habits and 

Predation on Commercially Important 

Prey Species in the Eastern Bering Sea 

From 1997 Through 2001 

by 

G. M. Lang, P. A. Livingston, and K. A. Dodd

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration 

National Marine Fisheries Service 

Alaska Fisheries Science Center 

October 2005 
NOAA Technical Memorandum NMFS 

The National Marine Fisheries Service's Alaska Fisheries Science Center 

uses the NOAA Technical Memorandum series to issue informal scientific and 

technical publications when complete formal review and editorial processing 

are not appropriate or feasible. Documents within this series reflect sound 

professional work and may be referenced in the formal scientific and technical 

literature. 

The NMFS-AFSC Technical Memorandum series of the Alaska Fisheries 

Science Center continues the NMFS-F/NWC series established in 1970 by the 

Northwest Fisheries Center. The NMFS-NWFSC series is currently used by 

the Northwest Fisheries Science Center. 

This document should be cited as follows: 

Lang, G. M., P. A. Livingston, and K. A. Dodd. 2005. Groundfish food 

habits and predation on commercially important prey species in the 

eastern Bering Sea from 1997 through 2001. U.S. Dep. Comer., NOAA 

Tech. Memo. NMFS-AFSC-158, 230 p. 

Reference in this document to trade names does not imply endorsement by 

the National Marine Fisheries Service, NOAA. 
NOAA Technical Memorandum NMFS-AFSC-158


Groundfish Food Habits and 

Predation on Commercially Important 

Prey Species in the Eastern Bering Sea 

From 1997 Through 2001 

by 

G. M. Lang, P. A. Livingston, and K. A. Dodd

Alaska Fisheries Science Center 

7600 Sand Point Way N.E. 

Seattle, WA 98115 

www.afsc.noaa.gov 

U.S. DEPARTMENT OF COMMERCE

Carlos M. Gutierrez, Secretary 

National Oceanic and Atmospheric Administration 

Vice Admiral Conrad C. Lautenbacher, Jr., U.S. Navy (ret.), Under Secretary and Administrator 

National Marine Fisheries Service 

William T. Hogarth, Assistant Administrator for Fisheries 

October 2005 
This document is available to the public through: 

National Technical Information Service 

U.S. Department of Commerce 

5285 Port Royal Road 

Springfield, VA 22161 

www.ntis.gov 
iii

EXECUTIVE SUMMARY 

This document summarizes groundfish predation on commercially important 

stocks of fish and crab on the eastern Bering Sea continental shelf from 1997 through 

2001. The amount of predation is calculated using estimates of predator biomass, daily 

ration, and the proportion of various prey categories in the stomach contents. Estimates 

are presented in terms of number and biomass of prey consumed during the main 

sampling period of May through September of each year. 

Predator and Prey Species 

The following groundfish predators are included in this report because they are 

dominant members of the eastern Bering Sea shelf fish fauna that consume the 

following prey: 

 

 Groundfish predators Commercially important prey

 Walleye pollock Walleye pollock 

 Pacific cod Pacific cod 

 Yellowfin sole Yellowfin sole 

 Greenland turbot Greenland turbot 

 Arrowtooth flounder Arrowtooth flounder 

 Flathead sole Flathead sole 

 Pacific halibut Northern rock sole 

 Alaska plaice Pacific halibut 

 Northern rock sole Pacific herring 

 Skates King crabs 

 Snow crab 

 Tanner crab 

 Capelin 

 

 

Total Groundfish Consumption Estimates

The total amount (metric tons) of each prey estimated to have been consumed 

from May through September for 1984 through 2001 is presented in Tables 1 and 2. 

These estimates are the sum of the consumption by each predator species. Unlike 

some previous reports, the estimated consumption of walleye pollock (Theragra 
iv

chalcogramma) does not include cannibalism for the period October through December 

due to low sample sizes. Biomass consumed was converted to the number consumed 

using available prey size information. When prey size information was lacking (e.g., 

Alaska plaice; Table 2) or incomplete for a predator, the number consumed is an 

underestimate and is shown in parentheses. 

Estimated numbers-at-age of snow crab (Chionoecetes opilio), Tanner crab (C. 

bairdi), and walleye pollock consumed by groundfish predators are presented in Tables 

3-5 and Figures 1-3. Relative to the 1993-1996 reporting period, total numbers of age-0 

snow crab consumed were generally greater from 1997 through 2001; however, age-1 

consumption was less than previous years. Consumption of age-0 Tanner crab was 

somewhat larger while consumption of older age-groups was smaller than in the 1993-

1996 report. Age-0 walleye pollock consumption was low relative to the 1993-1996 

period, possibly indicating low recruitment. Consumption of age-0 walleye pollock was 

highest in 2001. 
v

Table 1.--Estimated total biomass (metric tons) by year of commercially important prey consumed by g May through September in the eastern Bering Sea. Consumption of walleye pollock includes  estimates for 1985-96. 

Year 

Prey 1984 1985 1986 1987 1988 1989 1990 King crabs 2,684 1,136 2,867 845 568 1,935 348 Snow crab 98,818 132,467 149,078 151,242 62,173 129,343 149,049 1(Chionoecetes opilio)

)

Tanner crab 63,189 89,991 48,822 107,134 55,825 88,520 63,432 (Chionoecetes bairdiPacific cod 13,430 9,978 9,302 8,881 1,330 7,762 42,534 Walleye pollock 314,783* 1,443,121 1,158,022 697,131 706,000 745,825 1,813,469 8Pacific herring 0 19,322 44,440 12,286 5,440 79 16,410 Atka mackerel 0 0 0 1,650 0 0 3,187 Arrowtooth flounder 4,327 15,436 781 13,761 0 464 832 Flathead sole 9,787 5,929 13,993 1,965 1,454 25,718 7,325 Rock sole 8,020 20,843 38,804 18,552 5,156 15,283 6,309 Yellowfin sole 56,291 28,359 42,330 17,394 9,671 7,190 5,203 Greenland turbot 3,919 0 0 0 16 17,635 12,922 Pacific halibut 89 0 0 0 185 0 0 Alaska plaice 0 0 0 0 0 13 0 

*

 Walleye pollock cannibalism estimate was not available for 1984. 
vi

Table 1.--Continued. 

Year 

Prey 1993 1994 1995 1996 1997 1998 1999 2000 King crabs 2,066 5,126 6,286 5,025 2,111 1,515 3,475 1,588 Snow crab 170,588 

)

 268,499 243,405 252,082 166,404 81,253 69,433 144,612 

(Chionoecetes opilio

Tanner crab 257,256 

)

 62,987 84,696 78,773 79,500 91,664 75,040 33,436 

(Chionoecetes bairdiPacific cod 9,835 30,190 15,319 7,563 6,142 4,522 4,894 1,337 Walleye pollock 1,315,784 1,745,306 2,293,032 2,087,906 1,048,302 516,284 711,000 512,646 Pacific herring 124 2,353 8,369 3,248 29 4,5810 51,046 19,309 Atka mackerel 0 0 0 0 0 0 0 0 Arrowtooth flounder 5,837 1,601 7,682 8,508 2,248 0 729 1,647 Flathead sole 18,542 26,428 4,795 37,492 9,039 2,171 2,747 4,716 Rock sole 74,572 40,289 38,340 37,293 14,476 4,418 13,363 26,764 Yellowfin sole 15,871 23,538 28,979 3,236 21,323 6,109 4,906 5,798 Greenland turbot 15,360 286 5 1,442 9,468 13 462Pacific halibut 1,126 2,189 14 59 105 1,303 Alaska plaice 45 574 0 0 
vii

Table 2.--Estimated number (millions) by year of commercially important prey consumed by groundfish  September in the eastern Bering Sea. Values in parentheses indicate underestimates due to  data. Consumption of walleye pollock includes cannibalism estimates for 1985-2001. 

Year 

Prey 1984 1985 1986 1987 1988 1989 King crabs (35,566)a (2) (5) (1) 8 (3) 

Snow crab (30,921) 12,235 13,042 (10,666) 11,870 (20,805) 67

(Chionoecetes opilio) 

Tanner crab (152,850) (13,926) 9,898 42,632 14,659 (27,244) 20

(Chionoecetes bairdi) 

Pacific cod (1,124) 3,263 (76) 8,194 2 (75) (6,Walleye pollock (47,832)b (664,467) (160,511) 91,049 56,858 554,766 (228,

Pacific herring 0 (303) (554) (23) 140 (1) (Atka mackerel 0 0 0 8 0 0 Arrowtooth flounder 1,920 (3) (40) 3,791 0 (101) Flathead sole 363 2,128 381 210 761 (4,292) (4Rock sole 23,611 5,514 1,688 1,531 (5,809) 1,694 Yellowfin sole 480 313 651 63,767 (87) 16,909 Greenland turbot 81,721 0 0 0 17 (30,328) 34Pacific halibut 728 0 0 0 665 0 Alaska plaice 0 0 0 0 0 9 
viii

Year

Table 2.--Continued. 

Prey 1993 1994 1995 1996 1997 1998 1999 2000 King crabs (0) (513) (1) (0) (2) (0) (0) (0)Snow crab (21,085) 20,169 (99,400) (17595) 38,779 27,027 11,993 10,963 (Chionoecetes opilio) Tanner crab 18,842 9,680 (6,495) 6,563 55,107 (8,498) 12,708 30,764 (Chionoecetes bairdi) Pacific cod 6,516 (1,327) (27) (270) 45 167 6 (29) Walleye pollock 284,406 770,195 386,085 650,679 (259,764) 28,227 (75,629) 65,590 Pacific herring 8 74 (271) 25 (0) (1) (1,123) (339) Atka mackerel 0 0 0 0 Arrowtooth flounder (90) 25 84 2,768 41 57 (24) Flathead sole 2,452 542 454 194,859 1,166 143 116 132 Rock sole 17,117 256,594 816 20,343 1,756 81,044 175 136,785 Yellowfin sole 172 513 428 302 217 83 46 64 Greenland turbot 88,186 1,075 11 9,138 (14,176) 30 2,341Pacific halibut 1,695 (0) 30 1,585 1,421 42 Alaska plaice (0) (7,146) (0) 0 
ix

Ye

a Most king crab consumed in 1984 were blue king crab megalops larvae. bWalleye pollock cannibalism estimate was n

Table 3.--Estimated number (millions) of snow crab, Chionoecetes opilio, consumed by age by ground through September in the eastern Bering Sea. 

ar 

 Age 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 

- - - - - 312.07 - 2,386.71 12,414.24 3,474.40 21.00 

1 28,596.70 7,001.20 5,880.00 5,293.27 10,016.68 17,238.94 7,486.98 5,843.12 2,980.90 17,026.00 2 1,700.50 4,385.50 6,464.40 2,808.65 920.02 2,530.76 499.14 151.02 63.38 2,520.00 3 559.10 792.00 655.90 1,513.75 530.21 925.31 90.36 96.84 33.56 1,322.00 4 64.60 56.20 41.50 16.23 68.96 102.14 47.76 6.46 42.83 137.00 5 - - - 9.02 - 4.14 3.54 - 19.23 50.00 6 - - - 13.20 - 4.14 - - - 10.00 

Year 

 Age 1996 1997 1998 1999 2000 2001 

- - 14,902 378 8,460 19,579 126 

1 11,816.00 35,847 5,281 1,715 6,718 6,950 2 2,653.00 3,036 2,235 1,849 3,571 6,009 3 3,008.00 1,294 574 664 746 2,451 4 75.00 28 30 20 116 95 5 43.00 - - - 10 - 6 - - - - 23 - 
x

Ye

Table 4.--Estimated number (millions) of Tanner crab, Chionoecetes bairdi, consumed by age by groun through September in the eastern Bering Sea. 

ar 

 Age 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 

 - 139,312.90 5,371.70 3,370.70 27,883.16 1,074.11 18,646.08 6.83 730.54 - 744.00 

 1 13,161.40 7,693.00 6,644.70 10,637.84 13,204.82 7,925.99 62,464.29 29,376.67 34,918.99 15,413.00  2 296.30 650.50 191.10 576.12 361.90 549.16 4,737.75 4,319.00 2,596.80 2,074.00  3 87.60 197.60 6.50 98.75 11.84 82.06 637.84 457.88 432.76 474.00  4 - 12.90 - - 2.76 32.45 91.31 52.94 78.21 64.00  5 - - - - 2.76 8.05 - 3.49 13.94 54.00 

 6 - - - - - - - - 1.26 18.00 

Year 

 Age 1996 1997 1998 1999 2000 2001 

- 469.00 16,608 4,082 2,423 4,809 80 

1 5,240.00 21,915 22,236 9,309 5,816 4,184 2 591.00 240 562 230 294 673 3 263.00 16 123 19 37 42 4 - - 24 12 6 9 5 - 0 0 0 0 0 6 - 0 0 0 0 0 
xi

Ye

Table 5.--Estimated number (millions) of walleye pollock, Theragra chalcogramma, consumed by age b May through September in the eastern Bering Sea. 

ar 

 Age 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 

- 43,819.42 642,951.50 121,822.70 80,252.80 43,635.30 544,371.20 177,071.06 8,962.40 31,857.13 258,642.00 

1 4,042.00 26,667.90 37,203.10 9,220.75 11,826.20 9,193.03 48,480.70 20,871.53 13,966.42 22,985.00 2 188.10 546.60 1,092.10 1,627.61 673.74 486.78 1,981.31 823.98 1,019.12 1,423.00 3 152.50 210.00 347.90 205.46 187.25 156.48 344.22 151.73 705.12 632.00 4 77.30 97.00 59.20 33.13 230.55 164.29 187.53 98.44 201.42 238.00 5 50.50 48.90 67.00 13.04 126.82 154.44 124.37 54.12 80.51 245.00 

6+ 39.70 32.00 87.10 9.50 135.65 216.17 161.53 157.27 232.43 241.00 

Year 

 Age 1996 1997 1998 1999 2000 2001 

- 634,703.00 233,607 22,999 60,947 58,974 160,227 

1 14,153.00 24,510 4,189 13,551 5,491 26,164 2 1,005.00 738 462 351 593 1,378 3 132.00 318 105 363 344 435 4 279.00 225 146 115 105 135 5 153.00 221 161 85 17 110 

6+ 254.00 145 165 217 64 167 
0

 2 

 4 

6+ 1984

1986

1988

1990

1992

1994

1996

1998

2000

Age

Walleye pollock

Figure 1.--Estimated number at-age of walleye pollock (Theragra chalcogramma) consumed by ground months 5 through 9 from 1984 to 2001 in the eastern Bering Sea. (There was no cannibalis walleye pollock in 1984). 

xii
0

3

6 1984

1986

1988

1990

1992

1994

1996

1998

2000

Age

C. bairdi

Figure 2.--Estimated number at-age of Tanner crabs (C. bairdi) consumed by groundfish during month 1984 to 2001 in the eastern Bering Sea. 

xiii
0

3

6 1984

1986

1988

1990

1992

1994

1996

1998

2000

Age

C. opilio

Figure 3.--Estimated number at-age of snow crabs (C. opilio) consumed by groundfish during months 5 

xiv

 1984 to 2001 in the eastern Bering Sea. 
xv

CONTENTS 

EXECUTIVE SUMMARY..........................................................................................iii

Predator and Prey Species...................................................................................iii

Total Groundfish Consumption Estimates ............................................................iii

INTRODUCTION...................................................................................................... 1

METHODS............................................................................................................... 2

Sample Collection and Laboratory Analysis ......................................................... 2

Data Analysis........................................................................................................ 2

RESULTS AND DISCUSSION................................................................................. 7

Groundfish Predation on Commercially Important Prey........................................ 7

King Crabs ........................................................................................................ 7

Snow and Tanner Crabs ................................................................................. 11

Roundfish........................................................................................................ 18

Flatfish ............................................................................................................ 25

Offal ................................................................................................................ 35

CONCLUSIONS..................................................................................................... 36

CITATIONS............................................................................................................ 38

Appendix A- Diet of major groundfish species collected from the eastern Bering 

Sea in 1997............................................................................................................ 41

Appendix B- Diet of major groundfish species collected from the eastern Bering 

Sea in 1998............................................................................................................ 75

Appendix C- Diet of major groundfish species collected from the eastern Bering 

Sea in 1999.......................................................................................................... 103

Appendix D- Diet of major groundfish species collected from the eastern Bering 

Sea in 2000.......................................................................................................... 135
xvi

Appendix E- Diet of major groundfish species collected from the eastern Bering 

Sea in 2001.......................................................................................................... 167

Appendix F-Estimates of fish and crab prey consumption by groundfish populations 

and predator biomass by year, stratum, predator and predator size group.......... 189 
INTRODUCTION

 

Many large marine fish are predators of either juvenile or small adult fish and 

crab. Because predation forms the largest part of natural mortality of young fish and 

crab, it is important to estimate the magnitude of predation loss on commercially 

important populations. Population models that assume constant natural mortality rates 

due to a lack of information on actual rates can be improved by providing more accurate 

estimates of predation losses. The move toward multispecies management of stocks 

can be helped through studying the food web connections between components of 

marine ecosystems, which include fish, crabs, marine mammals, and seabirds. 

 The primary purpose of the Resource Ecology and Ecosystem Modeling Program 

(REEM) of the Resource Ecology and Fisheries Management Division (REFM) at the 

Alaska Fisheries Science Center (AFSC) is to study the consumption of commercially 

important fish or crab by key fish predators in the eastern Bering Sea. These fish and 

the prey they consume are commercially important species that form a major part of the 

biomass in the eastern Bering Sea. Program objectives include providing impact 

assessments relating to fish predation effects on prey species populations, improving 

population model estimates of predation mortality by marine fish, and detecting possible 

changes in abundance and distribution of juvenile fish and crab populations. 

 

This report presents the progress of the REEM Program in analyzing available 

data from 1997 through 2001 on the predation of commercially important fish and crab 

species. The first section details the methods used to estimate the total biomass and 

numbers of prey consumed by the major groundfish species in the area. The second 

section summarizes the consumption of commercially important prey by all the major 

predators. Appendices summarize the diet and total prey consumption by the following 

predators: walleye pollock, Pacific cod (Gadus macrocephalus), yellowfin sole (Limanda 

aspera), flathead sole (Hippoglossoides elassodon), northern rock sole (Lepidopsetta 

polyxystra), Alaska plaice (Pleuronectes quadrituberculatus), Greenland turbot 

(Reinhardtius hippoglossoides), arrowtooth flounder (Atheresthes stomias), Pacific 

halibut (Hippoglossus stenolepis), and skates (Rajidae). This is the fifth in a series of 

reports (Livingston 1991; Livingston et al. 1993; Livingston and deReynier 1996, Lang et 

al. 2003) detailing the diets and consumption estimates of commercially important 

groundfish in the eastern Bering Sea. 
2

 

METHODS

Sample Collection and Laboratory Analysis 

Stomachs were collected from major groundfish species during 1997, 1998, 

1999, 2000, and 2001 in the eastern Bering Sea (Fig. 4). Samples were collected from 

fish taken primarily during May through September using bottom and pelagic trawl gear 

on research and commercial fishing vessels. Sampling occurred throughout the day, 

although most sampling occurred between 0600 and 2000 ADT. For all species, 

stomachs were removed at sea and placed in cloth bags labeled with information 

regarding the location of capture, fork length, sex, and spawning condition of the fish. 

Fish showing evidence of regurgitation (i.e., food in the mouth or throat or a flaccid 

stomach) were not included in the sample. Stomachs were preserved in 10% buffered 

formalin and later transferred to 70% ethyl alcohol. Prey fish and crab were identified to 

the lowest taxonomic level possible and enumerated. Wet weights were recorded after 

the contents were blotted with paper towels. Standard length (SL) measurements of 

prey fish and carapace width (CW) or length (CL) of crab prey were determined when 

possible. 

 

The prey category "offal" was used if the ingested item had obviously been 

discarded from a fish processor (i.e., a consumed fish head sliced off with a clean 

diagonal cut). 

Data Analysis 

Prey Consumption by Predator Populations

Estimates of the total biomass of each prey species consumed by the continental 

shelf portion of each groundfish population were calculated according to 

 Ci = DRi × D × Bi × Pi , Eq. (1) 

where Ci is the consumption (by weight) of a prey species by size group i of a predator 

species, DRi is the daily ration (as a proportion of body weight daily) of predator size 

group i, D is the number of days in the sampling period when the prey species was 

vulnerable to predation, Bi is the biomass of the predator size group i, and Pi is the 

proportion by weight of the prey species in the diet of predator size group i. 
Total consumption estimates (Equation 1) were computed for each major eastern 

Bering Sea stratum (Fig. 4). These strata were devised by the Resource Assessment 

and Conservation Engineering (RACE) Division of the AFSC to reflect, in general, 

natural boundaries based on bottom depth. Strata 1 and 2 are considered the inner 

continental shelf (< 50 m), strata 3 and 4 are the middle shelf (50-100 m), and strata 5 

and 6 are the outer shelf zones (100-200 m). 

175.0 W 170.0 W 165.0 W 160.0 W

53.0 N

55.5 N

58.0 N

60.5 N

1

2

3

4

5

6

Alaska

Figure 4.--Map of the eastern Bering Sea showing strata used in this report. 

Predator size groupings used for total consumption estimates were based on 

size groupings used previously (Livingston et al. 1986, Livingston 1991, Livingston et al. 

1993, Lang et al. 2003) and on knowledge of each predator's diet. If consumption of 

commercially important prey groups differed among predator sizes, then predator size 

groups were chosen to minimize such consumption differences within a size group. 

Daily ration (DR) estimates were derived using some basic bioenergetic 

considerations as an alternative to using rations estimated from gastric evacuation rate 

models and field-estimated stomach content weights. As Livingston et al. (1986) found, 

estimates derived from gastric evacuation rate models tend to be lower than expected 

based on known annual growth patterns of eastern Bering Sea species. Part of the 

3
4

problem with rations estimated in this fashion may be due to undetected regurgitation of 

stomach contents from field collections. It is believed that more realistic rations can be 

derived using bioenergetic variables such as annual growth increments and food 

conversion efficiency estimates; thus, that is the approach used here. Daily growth in 

weight of each species size group was estimated from annual growth increments by 

length and length-weight relationships for each species. A gross conversion efficiency 

rate of food to somatic tissue for juvenile fish was assumed to be 25% and for adult fish 

was assumed to be 10% based on estimates presented by Brett and Groves (1979). 

Daily growth increments could thus be converted to the amount of food required to 

produce that growth. When the daily food requirements are divided by mean fish weight, 

the result is daily ration expressed as a fraction of body weight. Daily rations of each 

species by size group used were: 

Predator Predator size (cm) Daily ration 

Pacific cod <30 0.012 

30-59 0.009 

>60 0.007 

Walleye pollock <30 0.011 

30-39 0.011 

40-49 0.008 

>50 0.004 

Greenland turbot <30 0.011 

30-49 0.013 

>50 0.005 

Arrowtooth flounder <20 0.009 

20-39 0.009 

>40 0.007 

Pacific halibut <30 0.014 

30-59 0.010 

>60 0.004 

Flathead sole all sizes 0.007 

Yellowfin sole all sizes 0.004 

Alaska plaice all sizes 0.005 

Northern rock sole all sizes 0.007 

Skates all sizes 0.007 
5

 

The time period of analysis (D) for total consumption estimates by all predator 

species was May through September, or 153 days. The analysis was restricted to this 

time period because most stomach samples were collected during this period and 

survey estimates of groundfish biomass were obtained at this time. Insufficient numbers 

of stomach samples were taken in each stratum and unquantified migrations of fish into 

different strata occur outside of this time period. Thus, total consumption estimates 

made outside of this time period would not be reliable. Since May through September 

probably represent most of the main feeding and growth period for groundfish in the 

eastern Bering Sea, these total consumption estimates can be considered conservative 

estimates of total annual predation removals by these groundfish populations. 

Total consumption estimates of king crabs (family Lithodidae) by Pacific cod 

were restricted to a 31-day period during May through September when it is most likely 

that soft-shell (newly molted) king crabs were available.Total consumption estimates for 

walleye pollock cannibalism were restricted to the period between May and September 

for 1997 through 2001. 

Predator biomass estimates (B) (listed in Appendix F) for flathead sole, rock sole, 

Alaska plaice, Greenland turbot, arrowtooth flounder, yellowfin sole, Pacific halibut, and 

skates were obtained from RACE Division bottom trawl survey data1

. These trawl 

surveys are conducted in the eastern Bering Sea during May to August of each year. 

Biomass estimates of arrowtooth flounder and Greenland turbot include only the shelf 

portion of the populations. Biomass estimates of walleye pollock, a semipelagic fish, 

were obtained from age-structured model results2. Biomass estimates of Pacific cod 

were obtained from length-structured model results3

. Biomasses of species obtained 

from model outputs were apportioned into each stratum by using the proportion of the 

trawl survey biomass found in each stratum. 

1 Gary Walters, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA, 98115, Pers. 

Commun., 2002. 

2 James Ianelli, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA, 98115, Pers. 

Commun., 2002. 

3 Grant Thompson, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA, 98115, 

Pers. Commun., 2002. 

 

The proportion by weight of each prey item in the diet of each predator size 

group was calculated for each stratum in the following fashion. First, all stomach content 

data for a particular predator size group that were collected in a stratum during May 

through September in a given year were used. Estimates of the percentage by weight of 

a given prey item in the stomach contents were then calculated for each 20 nautical 

mile square in the stratum where stomachs were collected. The estimated percent by 
6

weight of the prey item in the whole stratum was then calculated as the average of the 

percentages from each 20 nautical mile square. Standard errors of the stratum 

percentages were derived from the variance between squares. 

For strata where prey size information was available, total consumption 

estimates in terms of biomass were converted to number of prey. The size frequency of 

a particular prey in the stomach contents of a given predator size group from a stratum 

in a particular year during May through September was used along with the lengthweight relationship for the prey to convert biomass consumed within a particular prey 

size interval to number consumed. If prey size information for a given predator size 

group was not available for a given stratum, the size frequency of that prey in all strata 

combined for the predator size group was used. Finally, when no prey size information 

was available, the number consumed could not be estimated. 

Snow and Tanner crabs and walleye pollock were assigned to approximate age 

groups based on the following age-length conversions: 

Age Carapace width (mm) Standard length (cm) 

(years) Snow crab Tanner crab Walleye pollock 

0 <5 <9 <10 

1 5-24 9-34 10-19 

2 25-39 35-49 20-27 

3 40-59 50-69 28-33 

4 60-74 70-84 34-37 

5 75-94 85-104 38-40 

6+ >95 >105 >41 
7

RESULTS AND DISCUSSION 

Groundfish Predation on Commercially Important Prey 

The total impact of groundfish predation on a particular prey species was 

estimated by summing the individual predator species’ removals described in the 

appendices. Comparison of total fish predation with each predator species' removals 

provides an indication of which predator population tends to be the most important 

source of mortality for a prey population. Also, comparison of total predation removals 

with prey population size demonstrates the relative importance of predation as a source 

of mortality. Finally, interannual fluctuations in predation on a particular age group of 

prey may give early indications of year-class strength before the year class is vulnerable 

to assessment by trawl survey. The total consumption of each important prey group is 

summarized in terms of estimated biomass and numbers removed by groundfish 

predation in the eastern Bering Sea for segments of the years 1997 through 2001. 

King Crabs

Tables 6-7 present the estimated total biomass and number of king crabs 

consumed by all groundfish predators during May through September for 1997 through 

2001. 

Red king crab--Pacific cod was the main predator of red king crabs (Paralithodes 

camtschatica) and king crabs that could not be identified to the species level 

(Paralithodes spp., Lithodidae). Most of the unidentified king crabs consumed by Pacific 

cod were assumed to be red king crabs based on the locations where the unidentified 

king crabs were consumed. These crabs were assumed to be soft-shell females based 

on the location and timing of consumption by Pacific cod. Walleye pollock were minor 

predators on unidentified king crabs and probably consumed pelagic larvae. Pacific 

halibut and skates also consumed small amounts of unidentified king crab. The largest 

amounts of king crab consumed were by Pacific cod consuming king crab legs in all 

years except 2000 and 2001. Pacific cod consumption of red king crab and unidentified 

king crab (not including legs only consumption) was 1,988, 1,086, 2,941, 1,489, and 75 

metric tons (t) in 1997, 1998, 1999, 2000, and 2001, respectively. 

Groundfish predation on king crab in terms of biomass during these 5 years was 

somewhat lower than the estimated predation for the 1993-96 period, which ranged 

from 2,066 t to 6,286 t (Lang et al., 2003). Abundance of female red king crab (Rugolo 

et al. 2003) during 1997 through 2001 was about the same as the abundance during 

1990 through 1992 and 1993 through 1996 although there was a spike in abundance 

estimates in 1996 through 1998. However, there was no corresponding spike in 
8

groundfish predation. Consumption of king crab legs was higher in 1998 and 1999 than 

the consumption of whole crabs while the converse was true in 1997, 2000, and 2001. 

Consumption by size figures for red king crab are not presented in this report due to low 

numbers of measurable individuals. 
9

Table 6.--Estimated biomass (metric tons) of king crabs consumed by groundfish by 

 year during months 5 through 9 in the eastern Bering Sea. 

Prey Predator 1997 1998 1999 2000 2001

King crab legs Pacific cod 1,052 7,917 9,553 443 

Total 1,052 7,917 9,553 443 

Lithodidae Pacific cod 938 1,086 1,667 1,064 75

 Pacific halibut 117 49 

 Skates 1,208

 Walleye pollock 2

Total 1,057 1,086 2,925 1,064 75 

Paralithodes spp. Pacific cod 1,050 188 425 

Skates 25

 Walleye pollock 4 <1

 Total 1054 <1 213 425 

Red king crab Pacific cod 429 337 99 

Total 429 337 99 
10

Table 7.--Estimated numbers (millions) of king crabs consumed by groundfish by year 

 during months 5 through 9 in the eastern Bering Sea. Values in parentheses 

 indicate cells with some missing prey size information and therefore are 

 underestimates of the total number consumed. 

Prey Predator 1997 1998 1999 2000 2001

King crab legs Pacific cod 

Total 

Lithodidae Pacific cod (0) (0) (0) (0) (0)

 Pacific halibut (0) (0)

 Skates (0)

 Walleye pollock (0)

Total (0) (0) (0) (0) (0)

Paralithodes spp. Pacific cod (0) (0) (0) 

Skates (0)

 Walleye pollock (2) (0)

 Total (2) (0) (0) (0) 

Red king crab Pacific cod (0) (0) (<1) 

Total (0) (0) (<1) 
11

Snow and Tanner Crabs

The estimated total biomass of snow and Tanner crabs consumed by groundfish 

predators is presented in Table 8. Table 9 presents data on the estimated number of 

snow and Tanner crabs consumed in areas where prey size information was available. 

Because this information was limited the reported values should be considered the 

minimum number consumed by groundfish predators. The biomass and number of 

snow and Tanner crab removed by prey size are shown in Figures 5-7. 

Snow crabs--The main predator of snow crabs, in terms of estimated biomass removed, 

was Pacific cod, consuming at least 75% of the total biomass removals of snow crabs in 

all 5 years. The remaining predators were flathead sole, walleye pollock, Pacific halibut, 

northern rock sole, skates, Alaska plaice, and yellowfin sole. Biomass of snow crabs 

consumed by Pacific cod was highest in 2001 (160,353 t) and lowest in 1999 (62,848 t), 

and numbers consumed by Pacific cod showed a similar trend during the time period. 

Similar to the 1993 through 1996 period, consumption of snow crab by groundfish 

predators other than Pacific cod did not occur every year, particularly in 1998 and 2001, 

and was least prevalent in the small-mouthed flatfish. This could indicate the availability 

of fewer small snow crab in the 1993 through 2001 period compared to the 1990 

through 1992 where consumption was more widespread across all predators. 

Most of the snow crab consumed in 1997 through 2000 were less than 25 mm 

CW or approximately age 0 to age 1. Rugolo et al. (2003) show a steady decline in the 

numbers of snow crab through 1999 with a slight increase in population size in 2000 

and 2001. Declines in predation consistent with populaton declines indicate that 

monitoring the amount of predation on small crabs by these predators may provide early 

indications of the presence of abundant year classes of crabs. 

Tanner crabs--Estimated total biomass of Tanner crabs consumed by all predators was 

highest in 1998 (91,664 t) and lowest in 2000 (33,435 t). Like snow crabs, most of the 

biomass removed was due to Pacific cod predation except in 1997 when flathead sole 

was the largest consumer. Pacific cod (1999-2001) and flathead sole (1997,1998) also 

consumed the largest number of mostly small (< 25 mm CW) Tanner crab. Total 

number consumed was highest in 1997 (38,779 million) but was much lower than the 

estimate of total number consumed in 1984, which was 152,850 million (Livingston 

1991). This may be an indication that there has not been any significant recruitment of 

Tanner crab since 1984. Rugolo et al. (2003) show increased population estimates in 

the 1999-2004 time period. The occurrence of greater consumption estimates of small 

Tanner crabs by groundfish predators in 1997 and 1998 may be an early indication of 

the stronger recruitment in subsequent years. 
12

Unidentified Chionoecetes—Estimated total biomass and numbers consumed of 

unidentified Chionoecetes were lower in all years than in the previous reporting period, 

1993-1996 (Lang et al. 2003). Given the increase in estimates of Tanner and snow 

crabs, this is likely a result of improved identification to the species level of small crab. 
13

Table 8.--Estimated biomass (metric tons) of snow crabs (Chionoecetes opilio), Tanner 

 crabs (C. bairdi), and unidentified Chionoecetes consumed by groundfish by 

 year during months 5 through 9 in the eastern Bering Sea (n.s.= not 

 sampled). 

Prey Predator 1997 1998 1999 2000 2001 

Tanner crab Arrowtooth flounder 11 

Flathead sole 31,235 40,080 19,114 8,041 

Greenland turbot n.s 6 n.s

Northern rock sole 1513 213 

Pacific cod 23,172 44,515 36,475 19,043 44,816

Pacific halibut 2,764 6,816 4,357 

Skates 14,292 15,089 6,340 3,842

Yellowfin sole 6,525 40

Total 79,500 91,664 75,040 33,435 48,657 

 

Snow crab Alaska plaice 6,089 94 n.s

Flathead sole 3,282 224 

Northern rock sole 3,725 1,506 3,695 

Pacific cod 126,788 77,024 62,848 108,811 160,353

Pacific halibut 4,192 4,135 3,309 

Skates 12,955 1,547 26,794 11,984

Walleye pollock 3,074 

Yellowfin sole 9374 2,238 

 Total 166,404 81,253 69,434 144,612 172,338 

Unid. Chionoecetes Alaska plaice 1,064 n.s

Flathead sole 361 8,467 4,990 124 

Northern rock sole 5,443

Pacific cod 8,885 17,901 38,496 53,041 32,167

Pacific halibut 2,611 853 474 

Skates 11,838 1,828 21,978 46,437 41,872

Walleye pollock 1 2 20 

Yellowfin sole 3,023 197

Total 33,226 29,245 65,941 99,621 74,038 
14

Table 9.--Estimated numbers (millions) of snow crabs (Chionoecetes opilio), Tanner 

 crabs (C. bairdi), and unidentified Chionoecetes consumed by groundfish by 

 year during months 5 through 9 in the eastern Bering Sea. Values in 

 parentheses indicate cells with some missing prey size information and 

 therefore are underestimates of the total number consumed (n.s.= not 

 sampled). 

Prey Predator 1997 1998 1999 2000 2001 

Tanner crab Arrowtooth flounder 31 

Flathead sole 21,690 22,172 6,976 9,070 

Greenland turbot n.s. 2 n.s.

Northern rock sole 4,092 576 

Pacific cod 2,285 3,784 3,053 1,211 3,846

Pacific halibut 215 386 230 

Skates 3,723 1,733 650 335

Yellowfin sole 6,775 109

Total 38,779 27,027 11,993 10,963 4,180

 

Snow crab Alaska plaice 8,295 (0) n.s.

Flathead sole 3,717 615 

Northern rock sole 12,996 7,928 19,446 

Pacific cod 25,747 8,123 3,940 8,355 10,742

Pacific halibut 139 374 64 

Skates 1,293 160 2,444 1,926

Walleye pollock 87 

Yellowfin sole 2,920 432 

 Total 55,107 (8,498) 12,708 30,764 12,669

Unid. Chionoecetes Alaska plaice (0) n.s.

Flathead sole 724 39,938 12,327 (0) 

Northern rock sole 319

Pacific cod 1,461 10,315 8,802 (6,589) 3,422

Pacific halibut (298) (68) 63 

Skates 1,610 1,583 4,763 3,629 3,565

Walleye pollock (0) 

Yellowfin sole 10,803

Total (15,216) (51,904) (25,955) (10,218) 6,987
1997 (months 5-9)

0

15,000

30,000

5 30 55 80

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

15,000

30,000

5 30 55 80

Number 

1997 (months 5-9)

0

15,000

30,000

5 30 55 80

Number 

1999 (months 5-9)

0

15,000

30,000

5 30 55 80

Biomass 

1999 (months 5-9)

0

15,000

30,000

5 30 55 80

Number 

2000 (months 5-9)

0

15,000

30,000

5 30 55 80

Biomass 

2000 (months 5-9)

0

15,000

30,000

5 30 55 80

Number 

2001 (months 5-9)

0

15,000

30,000

5 30 55 80

C. opilio carapace width (mm)

Biomass 

2001 (months 5-9)

0

15,000

30,000

5 30 55 80

C. opilio carapace width (mm)

Number

1998 (months 5-9)

0

15,000

30,000

5 30 55 80

Biomass 

Figure 5.--Estimated biomass (metric tons) and numbers (millions) of snow crab (C. 

 opilio) consumed by groundfish predators during May through September in 

 1997 through 2001 in the eastern Bering Sea by prey size. 

15
1997 (months 5-9)

0

10,000

20,000

5 30 55 80

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

10,000

20,000

5 30 55 80

Number

1997 (months 5-9)

0

10,000

20,000

5 30 55 80

Number 

1999 (months 5-9)

0

10,000

20,000

5 30 55 80

Biomass 

1999 (months 5-9)

0

10,000

20,000

5 30 55 80

Number 

2000 (months 5-9)

0

10,000

20,000

5 30 55 80

Biomass 

2000 (months 5-9)

0

10,000

20,000

5 30 55 80

Number 

2001 (months 5-9)

0

10,000

20,000

5 30 55 80

C. bairdi carapace width (mm)

Biomass 

2001 (months 5-9)

0

10,000

20,000

5 30 55 80

C. bairdi carapace width (mm)

Number 

1998 (months 5-9)

0

10,000

20,000

5 30 55 80

Biomass 

Figure 6.--Estimated biomass (metric tons) and numbers (millions) of Tanner crab (C. 

 bairdi) consumed by groundfish predators during May through September in 

 1997 through 2001 in the eastern Bering Sea by prey size. 

16
1997 (months 5-9)

0

15,000

30,000

0 25 50 75

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

12,500

25,000

0 25 50 75

Number

1997 (months 5-9)

0

12,500

25,000

0 25 50 75

Number 

1999 (months 5-9)

0

15,000

30,000

0 25 50 75

Biomass 

1999 (months 5-9)

0

12,500

25,000

0 25 50 75

Number

2000 (months 5-9)

0

15,000

30,000

0 25 50 75

Biomass 

2000 (months 5-9)

0

12,500

25,000

0 25 50 75

Number 

2001 (months 5-9)

0

15,000

30,000

0 25 50 75

Chionoecetes spp. carapace width (mm)

Biomass 

2001 (months 5-9)

0

12,500

25,000

0 25 50 75

Chionoecetes spp. carapace width (mm)

Number 

1998 (months 5-9)

0

15,000

30,000

0 25 50 75

Biomass 

Figure 7.--Estimated biomass (metric tons) and numbers (millions) of unidentified 

 Chionoecetes consumed by groundfish predators during May through 

 September in 1997 through 2001 in the eastern Bering Sea by prey size. 

17
18

Roundfish 

Roundfish, for the purposes of this report, is defined as any groundfish species 

that is not a flatfish. Total estimated biomass and minimum numbers of Pacific cod, 

walleye pollock, Pacific herring (Clupea pallasi), and capelin (Mallotus villosus) 

consumed by all groundfish predators are summarized in Tables 10-11 and Figures 8-

11. 

Pacific cod--Total estimated biomass of Pacific cod consumed by groundfish predators 

(Table 10) was highest in 2001 (13,464 t) and lowest in 2000 (1,337 t). Predators on 

Pacific cod include Pacific cod, walleye pollock, skates, Pacific halibut, and arrowtooth 

flounder. Unlike the 1993-1996 period, yellowfin sole, Alaska plaice, and Greenland 

turbot were not seen consuming Pacific cod (Lang et al. 2003). Pacific cod cannibalism 

was the largest source of predation mortality in 1999 and 2000. The number consumed 

was highest in 1998 (167 million) and was primarily due to Pacific halibut predation of 

age-1 prey (Fig 8.). There does not seem to be any relationship between the number of 

age-0 Pacific cod consumed in a year and the strength of that Pacific cod year class. 

For example, Thompson and Dorn (2004) reported that the 1997, 1998 and 2001 year 

classes were below average while the 2000 year class was average and the 1999 year 

class as above average. Our data show the opposite trend in terms of biomass and 

numbers of age-0 and age-1 Pacific cod consumed. It appears that Pacific cod is not a 

major dietary component of any groundfish species. Therefore, consumption of Pacific 

cod tends to be a sporadic occurrence that may not necessarily be related to its 

abundance. 

Walleye pollock--Walleye pollock was consumed by most of the major groundfish 

predators considered here. Walleye pollock cannibalism dominated walleye pollock 

removals in terms of numbers in all years and was also the largest in terms of biomass 

in 1997 and 1999. Arrowtooth flounder was the first or second largest consumer of 

walleye pollock in terms of biomass removals in all years. Pacific cod and skates also 

consumed large amounts of walleye pollock in terms of biomass. 

Sizes of walleye pollock consumed by predators indicate most were age-0 (less 

than 10 cm SL) in all years (Fig. 9). Pacific cod tended to consume a wide range of 

walleye pollock sizes, mainly from 5 to 50 cm SL. The largest number of age-0 walleye 

pollock were consumed during 1997, and overall numbers consumed were lower than in 

the 1993-1996 period (Lang et al. 2003). Generally, the numbers of age-0 consumed 

corresponds well with the age-1 model estimates of Ianelli et al. (2004) for the following 

year. The number of age-1 walleye pollock consumed also corresponds well with the 

model estimates for a given year. 

 

Pacific herring--Pacific cod, Pacific halibut, walleye pollock, and skates consumed 

Pacific herring. Walleye pollock consumed the most herring in 1997, 1999, and 2000 

while Pacific cod were the dominant predator in 1999 and 2001. No groundfish predator 
19

Table 10.--Estimated biomass (metric tons) of roundfish consumed by groundfish by 

 year during months 5 through 9 in the eastern Bering Sea (n.s. = not 

 sampled). 

Prey Predator 1997 1998 1999 2000 2001 

Capelin Arrowtooth flounder 97 448 2,337

Pacific cod 49 278 56 4,064

Pacific halibut 2371 733 2,006 1,614 

Walleye pollock 3,905 9,158 9,420

Total 2,517 1,011 5,967 11,220 15,821

Unid. Osmerids Alaska plaice 17

Arrowtooth flounder 22,644

Pacific cod 4,098 444 1,119 368 664

Pacific halibut 229 655 1,158

Skates 12

Walleye pollock 140 6,926 1,805 7,964

Yellowfin sole 33,552

 Total 37,879 1,239 31,877 2,174 8,628

Pacific cod Arrowtooth flounder 6,243

Pacific cod 1,995 944 4,353 759 5,903

Pacific halibut 4,148 3,578 541 

Skates 1,318

Walleye pollock 578 

 Total 6,142 4,522 4,895 1,337 13,464

Pacific herring Pacific cod 3,764 16,880 1,747 8,483

Pacific halibut 5 817 502 

Skates 1,265 3,760 1,671

Walleye pollock 24 32,399 13,803 5,165

 Total 29 4,581 51,046 19,309 15,319

Walleye pollock Arrowtooth flounder 288,135 194,191 155,127 159,353 187,655

Flathead sole 30,346 11,432 68,829 12,433 

Greenland turbot 21,099 n.s. 12,455 11,841 n.s.

Northern rock sole 10,456 

Pacific cod 125,037 116,972 124,462 86,155 118,572

Pacific halibut 43,714 52,054 34,165 7,066 

Skates 123,403 39,101 111,204 65,965 131,954

Walleye pollock 401,791 95,625 181,738 159,115 145,885

Yellowfin sole 14,777 2,649 23,021 263 

Total 1,048,302 512,023 711,000 512,646 584,066
20

Table 11.--Estimated numbers (millions) of roundfish consumed by groundfish by year 

 during months 5 through 9 in the eastern Bering Sea (n.s. = not sampled). 

 Values in parentheses indicate cells with some missing prey size 

 information and therefore are underestimates of the total number consumed. 

Prey Predator 1997 1998 1999 2000 2001 

Capelin Arrowtooth flounder 11 143 365

Pacific cod 24 (0) 2

Pacific halibut 290 (39) 187 102 

Walleye pollock 297 1,563 1,233

Total 325 (39) 486 1,808 2,008

Pacific cod Arrowtooth flounder (0)

Pacific cod 2 35 6 (0) 62

Pacific halibut 43 133 1 

Skate 1

Walleye pollock 29 

 Total 45 167 6 (29) (63)

Pacific herring Pacific cod (0) (542) (40) (21)

Pacific halibut (0) 1 (0) 

Skates 37 25 18

Walleye pollock (0) 544 273 180

 

 Total (0) (1) (1,123) (339) (219)

Walleye pollock Arrowtooth flounder (5,583) 1,983 2,521 7,425 5,696

Flathead sole 2,918 1,016 6,860 4,143 

Greenland turbot 78 n.s. (21) 12 n.s.

Northern rock sole 4,251 

Yellowfin sole 10,083 1,808 6,006 33 

Pacific cod 1,897 1,686 1,893 2,664 1,784

Pacific halibut 431 468 538 121 

Skates 599 268 253 401 394

Walleye pollock 238,175 20,989 57,537 46,539 87,325

Total (259,764) 28,217 (75,629) 65,590 95,199
1997 (months 5-9)

0

2,000

4,000

100 150 200 250 300 350 400 450

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

50

100

100 150 200 250 300 350 400 450

Number 

1997 (months 5-9)

0

50

100

100 150 200 250 300 350 400 450

Number

1999 (months 5-9)

0

2,000

4,000

100 150 200 250 300 350 400 450

Biomass 

1999 (months 5-9)

0

50

100

100 150 200 250 300 350 400 450

Number

2000 (months 5-9)

0

2,000

4,000

100 150 200 250 300 350 400 450

Biomass 

2000 (months 5-9)

0

50

100

100 150 200 250 300 350 400 450

Number 

2001 (months 5-9)

0

2,000

4,000

100 150 200 250 300 350 400 450

Pacific cod standard length (mm)

Biomass 

2001 (months 5-9)

0

50

100

100 150 200 250 300 350 400 450

Pacific cod standard length (mm)

Number 

1998 (months 5-9)

0

2,000

4,000

100 150 200 250 300 350 400 450

Biomass 

Figure 8.--Estimated biomass (metric tons) and numbers (millions) of Pacific cod 

 consumed by groundfish predators during May through September in 1997 

 through 2001 in the eastern Bering Sea by prey size. 

21
1997 (months 5-9)

0

62,500

125,000

0 100 200 300 400 500 600

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

25,000

50,000

0 100 200 300 400 500 600

Number 

1997 (months 5-9)

0

75,000

150,000

0 100 200 300 400 500 600

Number

1999 (months 5-9)

0

62,500

125,000

0 100 200 300 400 500 600

Biomass 

1999 (months 5-9)

0

50,000

100,000

0 100 200 300 400 500 600

Number 

2000 (months 5-9)

0

62,500

125,000

0 100 200 300 400 500 600

Biomass 

2000 (months 5-9)

0

25,000

50,000

75,000

0 100 200 300 400 500 600

Number 

2001 (months 5-9)

0

62,500

125,000

0 100 200 300 400 500 600

Walleye pollock standard length (mm)

Biomass 

2001 (months 5-9)

0

50,000

100,000

0 100 200 300 400 500 600

Walleye pollock standard length (mm)

Number 

1998 (months 5-9)

0

62,500

125,000

0 100 200 300 400 500 600

Biomass 

Figure 9.--Estimated biomass (metric tons) and numbers (millions) of walleye pollock 

 consumed by groundfish predators during May through September in 1997 

 through 2001 in the eastern Bering Sea by prey size. 

22
1997 (months 5-9)

0

6,000

12,000

10 60 110 160 210 260 310 360

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

125

250

10 60 110 160 210 260 310 360

Number 

1997 (months 5-9)

0

125

250

10 60 110 160 210 260 310 360

Number 

1999 (months 5-9)

0

6,000

12,000

10 60 110 160 210 260 310 360

Biomass 

1999 (months 5-9)

0

125

250

10 60 110 160 210 260 310 360

Number 

2000 (months 5-9)

0

6,000

12,000

10 60 110 160 210 260 310 360

Biomass 

2000 (months 5-9)

0

125

250

10 60 110 160 210 260 310 360

Number

2001 (months 5-9)

0

6,000

12,000

10 60 110 160 210 260 310 360

Pacific herring standard length (mm)

Biomass 

2001 (months 5-9)

0

125

250

10 60 110 160 210 260 310 360

Pacific herring standard length (mm)

Number

1998 (months 5-9)

0

6,000

12,000

10 60 110 160 210 260 310 360

Biomass 

Figure 10.--Estimated biomass (metric tons) and numbers (millions) of Pacific herring 

 consumed by groundfish predators during May through September in 1997 

 through 2001 in the eastern Bering Sea by prey size. 

23
1997 (months 5-9)

0

2,000

4,000

40 90 140

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

250

500

750

40 90 140

Number 

1997 (months 5-9)

0

250

500

750

40 90 140

Number 

1999 (months 5-9)

0

2,000

4,000

40 90 140

Biomass 

1999 (months 5-9)

0

250

500

750

40 90 140

Number 

2000 (months 5-9)

0

2,000

4,000

40 90 140

Biomass 

2000 (months 5-9)

0

250

500

750

40 90 140

Number 

2001 (months 5-9)

0

2,000

4,000

40 90 140

Capelin standard length (mm)

Biomass 

2001 (months 5-9)

0

250

500

750

40 90 140

Capelin standard length (mm)

Number 

1998 (months 5-9)

0

2,000

4,000

40 90 140

Biomass 

Figure 11.--Estimated biomass (metric tons) and numbers (millions) of capelin 

 consumed by groundfish predators during May through September in 1997 

 through 2001 in the eastern Bering Sea by prey size. 

24
25

consumed Pacific herring in each of the 5 years. The biomass of Pacific herring 

consumed by predators was highest in 1999 (51,046 t) and was much lower in the other 

4 years. 

Little size information was available on the Pacific herring consumed by 

groundfish. However, those consumed in 1999 and 2000 were primarily immature (< 20 

cm SL). Pacific herring predation by groundfish tended to be sporadic in time and space 

and may depend on encounter rates of Pacific herring schools rather than overall 

biomass. Furthermore, most of the Pacific herring available during the summer feeding 

period on the shelf are immature because adults have moved inshore to spawn. Pacific 

herring may constitute a larger fraction of the diet of groundfish predators in other time 

periods when adult Pacific herring have migrated to outer shelf waters for the winter 

feeding period. However, we have insufficient samples during autumn and winter to 

quantify Pacific herring consumption during those periods. 

Osmerids (Smelts)--Smelts were consumed by several groundfish species in 1997 

through 2001: Alaska plaice, arrowtooth flounder, yellowfin sole, Pacific cod, Pacific 

halibut, skates, and walleye pollock. Pacific cod and walleye pollock were the primary 

consumers of Osmerids in most years. Due to improved identification techniques we 

were able to identify capelin more often during this study period and these results are 

separate from the unidentified osmerid results. Capelin consumption was small relative 

to walleye pollock consumption during the 1997-2001 study period; however, capelin 

consumption was similar to Pacific herring consumption by these predators. 

Flatfish

Arrowtooth flounder--Arrowtooth flounder were consumed by arrowtooth flounder, 

Pacific cod, and walleye pollock (Tables 12-13). Estimated total biomass consumed 

ranged from 729 t in 1999 to 3,740 t in 2001. No arrowtooth flounder were found in the 

diets of groundfish during 1998. Pacific cod consumed the most arrowtooth flounder by 

weight in all years. Estimated numbers of arrowtooth flounder consumed were highest 

for Pacific cod in all years except 1997, when arrowtooth flounder cannibalism was 

three times greater. 

Total biomass consumed in each year can be compared with the estimated 

standing stock of arrowtooth flounder to determine the relative importance of predation 

on the arrowtooth flounder population. Total consumption in each year, expressed as a 

percentage of trawl-estimated biomass of arrowtooth flounder, is less than 2%. This is a 

small percentage of the arrowtooth flounder population, suggesting that predation is 

probably not a major source of mortality. Examination of possible predation impact on 

arrowtooth flounder too small to be assessed by the trawl survey is not possible given 

the current state of knowledge about juvenile arrowtooth flounder abundance. 
26

Consumption estimates of arrowtooth flounder were lower in 1997 through 2001 than in 

1993 through 1996 (Lang et al. 2003) despite average to above-average recruitment 

during 1997-1999 and below-average recruitment in 2000 and 2001 (Wilderbuer and 

Sample 2003). 

Flathead sole--Estimated total biomass of flathead sole consumed by groundfish 

predators was highest in 2001 (14,719 t) while the largest estimated number consumed 

was in 1997. Most of the biomass consumption was by Pacific cod, skates, and 

arrowtooth flounder. Other predators of flathead sole included Pacific halibut and 

walleye pollock. 

Most of the flathead sole consumed were less than 20 cm SL or younger than 

age 3. Walters and Wilderbuer (1990) report that flathead sole do not recruit to trawl 

fisheries until age 3, and although some age-2 fish are caught in research trawls, they 

are probably not fully recruited. This precludes a relevant comparison of predator 

removals of juveniles with the juvenile flathead sole population size. Similar to Pacific 

cod consumption of large numbers of age-0 flathead sole in 1996, skates consumed 

large numbers of flathead sole that were possibly age-1 in 1997 (Fig. 13). This might be 

an indication of an abundant year class produced in 1996. 

Northern rock sole--Total estimated biomass of northern rock sole consumed by 

groundfish predators ranged from 4,418 t in 1998 to 26,764 t in 2000. The number of 

northern rock sole consumed ranged from 175 million in 1999 to 136,785 million in 

2000. Pacific cod was the most important predator in terms of biomass and number of 

removals in all years except 2000 (walleye pollock). Other predators included Pacific 

halibut, skates, Greenland turbot, and arrowtooth flounder. Size composition of northern 

rock sole consumed was predominantly less than 5 cm in all years (Fig. 14). Most of 

these sizes are probably not fully vulnerable to trawl surveys. However, Wilderbuer and 

Walters (2003) report the presence of a large 2000 year class that is beginning to show 

up in the trawl survey. The presence of a strong 2000 year class is consistent with the 

large consumption estimate of age-0 northern rock sole seen here. Increased predation 

coincident with strong year classes indicates that monitoring the amount of predation on 

age-0 northern rock sole by these predators may provide early indications of the 

presence of abundant year classes. 

Yellowfin sole--Pacific cod, walleye pollock, skates, and Pacific halibut were predators 

of yellowfin sole during the 1997 to 2001 period. Pacific cod predation in terms of 

biomass and number dominated all years except 1997 and 1999 (skates). Consumption 

by all groundfish in terms of biomass was somewhat varied across years, ranging from 

4,906 t in 1999 to 21,323 t in 1997. Consumption was somewhat lower in this period 

than in the 1993 to 1996 period. These changes in consumption are consistent with the 

population estimates according to stock synthesis model results (Wilderbuer and Nichol 

2003). 
27

Most predation was on yellowfin sole ranging from 3 to 25 cm SL (ages 3-10) 

(Fig. 15). When estimates of total yellowfin sole consumption in terms of biomass are 

compared to the biomass estimated from trawl surveys, it appears that groundfish 

predation constitutes only a small proportion (~1%) of the standing stock biomass. 

Greenland turbot--Walleye pollock was the only groundfish that consumed Greenland 

turbot (Tables 12-13). The amount consumed was highest in 1997. Sizes of Greenland 

turbot consumed by walleye pollock (Fig. 16) ranged from 1 to 4 cm SL (probably age 0). It 

is unclear whether there is a relationship between the number consumed at age 0 and 

estimates of recruitment at age 1 from Ianelli et al. (2003). Our data show the largest 

numbers of Greenland turbot, presumably age 0, were consumed in 1997 and Ianelli et al. 

(2003) show that the 1997 year class was equal to other year classes at age 1 where 

smaller numbers were consumed. 

Pacific halibut--Pacific halibut was consumed by Pacific cod, skates, and walleye 

pollock (Tables 12-13). Sizes consumed ranged mostly from 1 to 2 cm SL (probably age 

0). The size of Pacific halibut consumed suggests they were post-larvae that had not yet 

settled to the bottom. Deriso (1987) suggests that Pacific halibut may be transported 

into the Bering Sea from the Gulf of Alaska. It is possible that groundfish consumption of 

Pacific halibut is a transitory phenomenon, occurring during restricted time periods 

when postlarvae are swept into shallow waters and start settling to the bottom. 

Alaska plaice—Alaska plaice were only consumed in small amounts relative to other 

flatfish prey by walleye pollock in 2001. The consumption estimates were 3 t and 2 

million. Consumption was focused on Alaska plaice of 4 cm SL, likely age-0 fish. 

Consumption estimates such as these suggest that predation mortality by groundfish 

has an insignificant impact on the Alaska plaice population. 
28

Table 12.--Estimated biomass (metric tons) of flatfish consumed by groundfish by year 

 during months 5 through 9 in the eastern Bering Sea (n.s. = not sampled). 

Prey Predator 1997 1998 1999 2000 2001 

Alaska plaice Walleye pollock 3

Total 3

Arrowtooth flounder Arrowtooth flounder 1,019 

Pacific cod 1,230 729 1,220 3,740

Walleye pollock 427 

Total 2,248 729 1,647 3,740

Flathead sole Arrowtooth flounder 10,643

Pacific cod 5,878 1,957 2,747 4,309 2,687

Pacific halibut 405 145

Skates 2,755 407 1,390

Walleye pollock 70 

Total 9,039 2,171 2,747 4,716 14,719

 

Greenland turbot Walleye pollock 9,468 13 462 

Total 9,468 13 462 

Pacific halibut Pacific cod 1,303 

Pacific halibut 39

Walleye pollock 105

 Total 105 1,303 39 

Northern rock sole Greenland turbot n.s. 874 n.s.

Pacific cod 7,673 3,684 8,150 4,313 5,040

Pacific halibut 293 65 497 

Skates 6,358 624 4,339 3,676

Walleye pollock 151 45 21,954 1,105

Total 14,476 4,418 13,363 26,764 9,820

 Yellowfin sole Pacific cod 7,596 4,165 2,368 4,076 10,188

Pacific halibut 1,732 1,944

Skates 11,995 2,486 1,723 1,844

Walleye pollock 52 

Total 21,323 6,109 4,906 5,798 12,033
29

Table 13.--Estimated numbers (millions) of flatfish consumed by groundfish by year 

 during months 5 through 9 in the eastern Bering Sea. Values in parentheses 

 indicate cells with some missing prey size information and therefore are 

 underestimates of the total number consumed. 

Prey Predator 1997 1998 1999 2000 2001 

Alaska plaice Walleye pollock 2

Total 2

Arrowtooth flounder Arrowtooth flounder 30 

Pacific cod 11 57 24 57

Walleye pollock (0) 

Total 41 57 (24) 57

Flathead sole Arrowtooth flounder 19

Pacific cod 195 86 116 116 24

Pacific halibut 2 32

Skates 969 16 35

Walleye pollock 24 

Total 1,166 143 116 132 78

 

Greenland turbot Walleye pollock (14,176) 30 2,341 

Total (14,176) 30 2,341 

Pacific halibut Pacific cod 42 

Pacific halibut 105

Walleye pollock 1,421

 Total 1,421 42 105

Northern rock sole Greenland turbot n.s. n.s.

Pacific cod 127 80,960 151 122 250

Pacific halibut 33 1 51 

Skates 123 63 24 88

Walleye pollock 1,474 19 136,613 55

Total 1,756 81,044 175 136,785 393

 Yellowfin sole Pacific cod 13 59 20 19 138

Pacific halibut 25 25

Skates 179 21 45 43

Walleye pollock 5 

Total 217 83 46 64 181
1997 (months 5-9)

0

2,000

4,000

50 100 150 200 250 300 350

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

2,000

4,000

50 100 150 200 250 300 350

Biomass 

1998 (months 5-9)

0

25

50

50 100 150 200 250 300 350

Number

1997 (months 5-9)

0

25

50

50 100 150 200 250 300 350

Number 

1999 (months 5-9)

0

2,000

4,000

50 100 150 200 250 300 350

Biomass 

1999 (months 5-9)

0

25

50

50 100 150 200 250 300 350

Number 

2000 (months 5-9)

0

2,000

4,000

50 100 150 200 250 300 350

Biomass 

2000 (months 5-9)

0

25

50

50 100 150 200 250 300 350

Number 

2001 (months 5-9)

0

2,000

4,000

50 100 150 200 250 300 350

Arrowtooth flounder standard length (mm)

Biomass 

2001 (months 5-9)

0

25

50

50 100 150 200 250 300 350

Arrowtooth flounder standard length (mm)

Number 

 

Figure 12.--Estimated biomass (metric tons) and numbers (millions) of arrowtooth 

 flounder consumed by groundfish predators during May through 

 September in 1997 through 2001 in the eastern Bering Sea by prey size. 

30
1997 (months 5-9)

0

2,000

4,000

30 80 130 180 230 280

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

500

1,000

30 80 130 180 230 280

Number 

1997 (months 5-9)

0

500

1,000

30 80 130 180 230 280

Number

1999 (months 5-9)

0

2,000

4,000

30 80 130 180 230 280

Biomass 

1999 (months 5-9)

0

500

1,000

30 80 130 180 230 280

Number

2000 (months 5-9)

0

2,000

4,000

30 80 130 180 230 280

Biomass 

2000 (months 5-9)

0

500

1,000

30 80 130 180 230 280

Number 

2001 (months 5-9)

0

5,000

10,000

30 80 130 180 230 280

Flathead sole standard length (mm)

Biomass 

2001 (months 5-9)

0

500

1,000

30 80 130 180 230 280

Flathead sole standard length (mm)

Number 

1998 (months 5-9)

0

2,000

4,000

30 80 130 180 230 280

Biomass 

Figure 13.--Estimated biomass (metric tons) and numbers (millions) of flathead sole 

 consumed by groundfish predators during May through September in 1997 

 through 2001 in the eastern Bering Sea by prey size. 

31
1997 (months 5-9)

0

6,000

12,000

0 50 100 150 200 250

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

25,000

50,000

75,000

0 50 100 150 200 250

Number 

1997 (months 5-9)

0

500

1,000

0 50 100 150 200 250

Number

1999 (months 5-9)

0

6,000

12,000

0 50 100 150 200 250

Biomass 

1999 (months 5-9)

0

500

1,000

0 50 100 150 200 250

Number

2000 (months 5-9)

0

6,000

12,000

0 50 100 150 200 250

Biomass 

2000 (months 5-9)

0

25,000

50,000

75,000

0 50 100 150 200 250

Number 

2001 (months 5-9)

0

6,000

12,000

0 50 100 150 200 250

Northern rock sole standard length (mm)

Biomass 

2001 (months 5-9)

0

500

1,000

0 50 100 150 200 250

Northern rock sole standard length (mm)

Number 

1998 (months 5-9)

0

6,000

12,000

0 50 100 150 200 250

Biomass 

Figure 14.--Estimated biomass (metric tons) and numbers (millions) of northern rock 

 sole consumed by groundfish predators during May through September in 

 1997 through 2001 in the eastern Bering Sea by prey size. 

32
1997 (months 5-9)

0

6,000

12,000

60 110 160 210 260 310

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

125

250

60 110 160 210 260 310

Number 

1997 (months 5-9)

0

125

250

60 110 160 210 260 310

Number 

1999 (months 5-9)

0

6,000

12,000

60 110 160 210 260 310

Biomass 

1999 (months 5-9)

0

125

250

60 110 160 210 260 310

Number

2000 (months 5-9)

0

6,000

12,000

60 110 160 210 260 310

Biomass 

2000 (months 5-9)

0

125

250

60 110 160 210 260 310

Number

2001 (months 5-9)

0

6,000

12,000

60 110 160 210 260 310

Yellowfin sole standard length (mm)

Biomass 

2001 (months 5-9)

0

125

250

60 110 160 210 260 310

Yellowfin sole standard length (mm)

Number

1998 (months 5-9)

0

6,000

12,000

60 110 160 210 260 310

Biomass 

Figure 15.--Estimated biomass (metric tons) and numbers (millions) of yellowfin sole 

 consumed by groundfish predators during May through September in 1997 

 through 2001 in the eastern Bering Sea by prey size. 

33
1997 (months 5-9)

0

2,500

5,000

20 30 40 50

Biomass 

Pacific cod

Walleye pollock

Flathead sole

Pacific halibut

N. rock sole Skates Yellowfin sole

Greenland turbot

Alaska plaice Arrowtooth flounder

1998 (months 5-9)

0

5,000

10,000

20 30 40 50

Number

1997 (months 5-9)

0

5,000

10,000

20 30 40 50

Number (miilions)

1999 (months 5-9)

0

2,500

5,000

20 30 40 50

Biomass 

1999 (months 5-9)

0

5,000

10,000

20 30 40 50

Number 

2000 (months 5-9)

0

2,500

5,000

20 30 40 50

Biomass 

2000 (months 5-9)

0

5,000

10,000

20 30 40 50

Number

2001 (months 5-9)

0

2,500

5,000

20 30 40 50

Greenland turbot standard length (mm)

Biomass 

2001 (months 5-9)

0

5,000

10,000

20 30 40 50

Greenland turbot standard length (mm)

Number 

1998 (months 5-9)

0

2,500

5,000

20 30 40 50

Biomass 

Figure 16.--Estimated biomass (metric tons) and numbers (millions) of Greenland 

 turbot consumed by groundfish predators during May through September 

 in 1997 through 2001 in the eastern Bering Sea by prey size. 

34
35

Offal

Several groundfish species consumed fish processing offal during the 1997 to 

2001 period (Table 14). Pacific cod, walleye pollock, arrowtooth flounder, northern rock 

sole, yellowfin sole, Pacific halibut, Greenland turbot and skates consumed offal. In 

general, walleye pollock and skates tended to consume the most offal. Total amounts of 

offal consumed varied across years, ranging from 45,265 t in 2001 to 105,124 t in 1999, 

approximately half the amount seen in the 1990-92 period (Livingston and deReynier 

1996) and similar to that seen in the 1993-1996 period (Lang et al. 2003). Because 

most of these groundfish predators are predators of pollock and most of the offal 

produced is from processing of pollock, there is probably not much disruption of normal 

energy pathways due to offal consumption. 

Table 14.--Estimated biomass (metric tons) of offal consumed by groundfish by year 

 during months 5 through 9 in the eastern Bering Sea. 

Prey Predator 1997 1998 1999 2000 2001 

Offal Arrowtooth flounder 10,393 1,519 10,643

Greenland turbot 252 405 

Northern rock sole 18 

Pacific cod 5,054 20,634 4,263 1,916 16,922

Pacific halibut 225 2,078 2,908 

Skates 18,225 22,321 19,793 4,778 17,497

Walleye pollock 49,053 13,568 63,149 64,119 203

Yellowfin sole 10,470 14,606 

 Total 93,690 60,119 105,124 70,813 45,265
36

 CONCLUSIONS 

Total numbers of age-0 snow crab consumed were generally greater from 1997 

through 2001 than in previous years; however, age-1 consumption was less than 

previous years. Consumption of age-0 Tanner crab was somewhat larger while 

consumption of older age-groups was smaller than in the 1993-1996 report. 

Inconsistencies between age-0 and age-1 predation on these species make it difficult to 

use these data as a means for estimating potential year-class strength. Walleye pollock 

cannibalism was the most important source of groundfish predation on age-0 walleye 

pollock. Age-0 walleye pollock consumption was low relative to the 1993-1996 period, 

possibly indicating low recruitment. Consumption of age-0 walleye pollock was highest 

in 1997. Fluctuations in the consumption of age-0 and age-1 walleye pollock were 

consistent with the model estimates of population size at age. A better understanding of 

Tanner and snow crab size at-age and of the juvenile abundances of both these crabs 

as well as walleye pollock are needed to determine whether predation is a densitydependent factor controlling population size. 

In many cases, groundfish appeared to be an early sampler of Tanner and snow 

crab abundance, and several flatfish species as these predators are consuming prey 

that are not yet available to the assessment surveys. Again, more information on 

juvenile abundance of these prey species may determine whether this predation is an 

early indicator of the presence of abundant year classes. 

Consumption estimates for all prey should be viewed at the present time more as 

indices of consumption rather than actual consumption for several reasons. First, most 

of the calculations consider only the time period from May through September in each 

year. Although this is the main feeding period for most fishes in the eastern Bering Sea, 

consumption of prey certainly occurs during other parts of the year. Inadequate 

numbers and spatial distribution of stomach samples during other parts of the year 

combined with gaps in knowledge about the seasonal migrations of groundfish 

predators make calculation of predation in other parts of the year difficult without 

seasonal resource assessment surveys in the area. 

Predation estimates during the time period considered here may be 

underestimates for prey that are consumed year-round, such as Tanner and snow crabs 

that are consumed by Pacific cod. Estimates for groundfish predation on newly settling 

stages of crabs and flatfishes may be overestimates if the prey species are not available 

to the predator during the whole time period. Also, for prey that have a very limited 

spatial distribution within a stratum, such as red and blue king crabs, inadequate 

stomach sampling throughout the whole stratum can provide biased estimates of 

consumption. For these prey, consumption estimates would be biased upwards if 

sampling were concentrated more in areas where king crabs occur and estimates would 

be biased downwards if stomach sampling were not performed in king crab areas. 
37

Estimates of total numbers consumed are based upon measurable prey (SL or 

CW) and as such are underestimates for some prey because prey size could not always 

be determined due to advanced digestion of the prey. Similarly, total consumption 

estimates in terms of biomass may be underestimates of total groundfish predation if 

important groundfish predators of a particular prey have not been sampled. 

Skate identification to the species level was not consistent enough for the 1997 

through 2001 samples to allow diet analysis by species. However the biomass of skates 

is increasing in the eastern Bering Sea and consideration of their predation impact is 

becoming more important. Therefore, future reports should detail skate diet by species.
CITATIONS 

 

Brett, J. R., and T. D. D. Groves. 1979. Physiological energetics. In W. S. Hoar, D. J. 

 Randall, and J. R. Brett (editors), Fish physiology, Vol. VIII: Bioenergetics and 

 growth, p.279-352. Academic Press, New York. 

Deriso, R. B. 1987. Pacific halibut: Biology, fishery, and management. Northwest 

 Environ. J. 3:129-144. 

Ianelli, J. N., S. Barbeaux, G. Walters, T. Honkalehto, and N. Williamson. 2003. Stock 

 assessment of walleye pollock. In Stock assessment and fishery evaluation report 

 of the Bering Sea/Aleutian Islands region. North Pacific Fishery Management 

 Council, 605 W. 4th Ave., Suite 306, Anchorage, AK 99501. 

Ianelli, J. N., T. K. Wilderbuer, and T. M. Sample. 2003. Stock assessment of 

 Greenland turbot. In Stock assessment and fishery evaluation report of the Bering 

 Sea/Aleutian Islands region. North Pacific Fishery Management Council, 605 W. 

 4th Ave., Suite 306, Anchorage, AK 99501. 

Lang, G. M., C. W. Derrah and P. A. Livingston 2003. Groundfish food habits and 

 predation on commercially important prey species in the eastern Bering Sea from 

 1993 to 1996. U. S. Dep. Commer., AFSC Proc. Rep. 2003-04. 351 p. 

Livingston, P. A. 1991. Groundfish food habits and predation on commercially important 

 prey species in the eastern Bering Sea from 1984 to 1986. U. S. Dep. Commer., 

 NOAA Tech. Memo. NMFS F/NWC-207. 

Livingston, P. A., D. A. Dwyer, D. L. Wencker, M. S. Yang, and G. M. Lang. 1986. 

 Trophic interactions of key fish species in the eastern Bering Sea. Int. N. Pac. Fish. 

 Comm. Bull. 47:49-65. 

Livingston, P. A., A. Ward, G. M. Lang, and M-S. Yang. 1993. Groundfish food habits 

 and predation on commercially important prey species in the eastern Bering Sea 

 from 1987 to 1989. U. S. Dep. Commer., NOAA Tech. Memo. NMFS-AFSC-11. 

 192 p. 

Livingston, P. A. and Y. deReynier 1996. Groundfish food habits and predation on 

 commercially important prey species in the eastern Bering Sea from 1990 to 1992. 

 AFSC Proc. Rep. 96-04. 214p. Alaska Fish. Sci. Cent., Natl. Mar. Fish. Serv., 

 NOAA, 7600 Sand Point Way NE., Seattle, WA 98115. 

Rugolo, L.J., C. E. Armistead, J. A. Haaga, R.A. MacIntosh, and R.S. Otto. 2003. 

 Report to industry on the 2003 eastern Bering Sea crab survey. AFSC Processed 

 Rep. 2003-11, 62 p. Alaska Fish. Sci. Cent., Natl. Mar. Fish. Serv., NOAA, 7600 

 Sand Point Way NE., Seattle, WA 98115. 

Thompson, G. G. and M. W. Dorn. 2003. Pacific cod. In Stock assessment and fishery 

 evaluation report of the Bering Sea/Aleutian Islands region. North Pacific 

 Fishery Management Council, 605 W. 4th Ave., Suite 306, Anchorage, AK 99501. 

38
Walters, G.E., and T. K. Wilderbuer. 1990. Other flatfish. In L-L. Low and R. E. Narita 

 (editors), Condition of groundfish resources in the Bering Sea-Aleutian Islands 

 region as assessed in 1988, p. 123-141. U.S. Dep. Commer., NOAA Tech. Memo. 

 NMFS F/NWC-178. 

Wilderbuer, T. K., and D. Nichol. 2003. Yellowfin sole. In Stock assessment and 

 fishery evaluation document for groundfish resources in the Bering 

 Sea/Aleutian Islands region. North Pacific Fishery Management Council, 605 W. 

 4th Ave., Suite 306, Anchorage, AK 99501. 

Wilderbuer,T. K., and T. M. Sample. 2003. Arrowtooth flounder. In Stock assessment 

 and fishery evaluation report of the Bering Sea/Aleutian Islands region. North 

 Pacific Fishery Management Council, 605 W. 4th Ave., Suite 306, Anchorage, 

 AK 99501. 

Wilderbuer,T. K., and G. Walters. 2003. Rock sole. In Stock assessment and fishery 

 evaluation report of the Bering Sea/Aleutian Islands region. North Pacific Fishery 

 Management Council, 605 W. 4th Ave., Suite 306, Anchorage, AK 99501. 

39

Appendix A- Diet of major groundfish species collected 

from the eastern Bering Sea in 1997 

Table A-1.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Alaska plaice (Pleuronectes quadrituberculatus) 

 collected in the eastern Bering Sea in 1997, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Porifera (sponge) 0.29 0.00

Polychaeta (worm) 85.17 8.53

Euphrosinidae 0.58 0.02

Phyllodocidae (polychaete) 16.57 0.41

Syllidae (polychaete) 0.58 0.00

Nereidae (polychaete) 30.52 1.93

Nephtyidae (polychaete) 26.16 14.68

Glyceridae (polychaete) 0.58 0.00

Goniadidae (polychaete) 15.99 0.09

Onuphidae (polychaete) 0.87 1.69

Lumbrineridae 0.87 0.16

Arabellidae (polychaete) 0.29 0.01

Orbiniidae (polychaete) 14.53 0.41

Spionidae (polychaete) 0.58 0.17

Chaetopteridae (polychaete) 4.36 3.01

Cirratulidae (polychaete) 0.29 0.00

Flabelligeridae (polychaete) 3.49 0.42

Brada sp. (polychaete) 2.62 0.02

Flabelligera affinis (polychaete) 0.58 0.28

Scalibregmidae 0.87 0.13

Scalibregma inflatum 0.58 0.21

Opheliidae (polychaete) 10.47 1.32

Travisia sp. (polychaete) 1.74 0.30

Travisia forbesii (polychaete) 0.29 0.04

Sternaspidae (polychaete) 0.29 0.00

Sternaspis scutata (polychaete) 1.45 0.18

Capitellidae (polychaete) 0.29 0.00

Maldanidae (polychaete) 43.90 7.59

Pectinariidae (polychaete) 1.74 0.31

Ampharetidae (polychaete) 17.73 4.01

Terebellidae (polychaete) 8.72 6.11

Artacama sp. (polychaete) 2.91 1.05

Artacama proboscidea (polychaete) 0.58 0.16

Trichobranchidae (polychaete) 0.87 0.06

Terebellides stroemi (polychaete) 0.29 0.05

Sabellidae (polychaete) 2.03 0.91

Capitellida 0.29 0.00

Phyllodocida (pllychaete) 2.03 0.33

Sabellida (polychaete) 3.49 0.13

Terebellida (polychaete) 2.91 0.63

Hirudinea (leech) 0.87 0.11

Gastropoda (snail) 14.53 0.60

Bivalvia (clam) 44.48 4.15

Yoldia sp. (clam) 0.29 0.13

Yoldia scissurata (clam) 11.34 7.10

Cardiidae (cockles) 0.58 0.01

43
Table A-1.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Clinocardium sp. (cockle) 0.29 0.00

Clinocardium ciliatum (Iceland cockle) 0.29 0.00

Spisula polynyma (clam) 2.91 0.89

Copepoda 0.29 0.00

Calanoida (copepod) 0.29 0.00

Cumacea (cumacean) 7.27 0.01

Isopoda (isopod) 0.58 0.00

Gammaridea (amphipod) 62.50 2.44

Ampeliscidae (amphipod) 0.58 0.01

Maera loveni (amphipod) 0.58 0.22

Protomedeia sp. (amphipod) 22.38 0.31

Caprellidea (amphipod) 2.62 0.01

Crangonidae (shrimp) 0.29 0.05

Reptantia (crab) 1.74 0.24

Decapoda Reptantia legs (for unident. crabs) 0.29 0.00

Paguridae (hermit crab) 0.29 0.01

Decapoda brachyura (crab) 0.29 0.02

Chionoecetes sp. (snow and Tanner crab) 0.87 0.04

Chionoecetes opilio (snow crab) 1.16 0.80

Pinnotheridae (pea crab) 0.29 0.00

Sipuncula (marine worm) 2.62 7.32

Echiura (marine worm) 14.53 4.68

Echiurus sp. (marine worm) 0.58 0.05

Echiurus echiurus (marine worm) 17.73 8.88

Priapulida (worm) 2.03 2.39

Ophiuroidae Ophiurida (brittle star) 19.19 1.42

Brittle star legs 2.62 0.02

Ophiuridae (brittle star) 0.58 0.01

Sand dollar 6.40 0.08

Holothuroidea (sea cucumber) 1.74 0.93

Urochordata (tunicate) 0.29 0.00

Ammodytes hexapterus (Pacific sand lance) 0.29 0.09

Unidentified organic material 4.65 0.64

Sand 0.29 0.01

Unidentified worm-like organism 2.33 0.86

Unidentified tube 3.20 0.09

Total non-empty stomachs = 344

Total prey number = 8,956

Total prey weight = 1520 g

Total empty stomachs = 16

Number of hauls = 69

44
Table A-2.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of arrowtooth flounder (Atheresthes stomias) 

 collected in the eastern Bering Sea in 1997, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Cnidaria 0.32 0.00

Polychaeta (worm) 4.55 0.01

Nuculana sp. (clam) 0.32 0.01

Crustacea 0.32 0.00

Calanoida (copepod) 0.32 0.00

Mysidacea Mysida (mysid) 0.65 0.01

Gammaridea (amphipod) 2.27 0.01

Euphausiacea (euphausiid) 6.17 0.43

Euphausiidae (euphausiid) 11.69 0.57

Thysanoessa sp. (euphausiid) 0.32 0.01

Thysanoessa inermis (euphausiid) 0.65 0.02

Decapoda (shrimp and crab) 0.97 0.03

Natantia (shrimp) 0.32 0.00

Caridea (shrimp) 1.62 0.04

Oplophoridae (shrimp) 0.32 0.03

Pandalidae (shrimp) 0.65 0.01

Pandalus sp. (shrimp) 0.65 0.04

Pandalus borealis (shrimp) 1.30 0.16

Crangonidae (shrimp) 1.62 0.15

Crangon sp. (shrimp) 0.97 0.03

Crangon communis (shrimp) 0.65 0.03

Argis sp. (shrimp) 0.32 0.04

Ophiuroidea Euryalina (basket star) 0.32 0.01

Ophiuridae (brittle star) 0.32 0.00

Osteichthyes Teleostei (fish) 10.06 0.54

Non-gadoid fish remains 1.62 0.36

Mallotus villosus (capelin) 0.32 0.08

Gadidae (gadid fish) 5.84 1.22

Theragra chalcogramma (walleye pollock) 51.30 92.83

Zoarcidae (eelpout) 0.97 0.26

Cottoidei (sculpin) 0.32 0.46

Triglops scepticus (spectacled sculpin) 0.32 0.27

Stichaeidae (prickleback) 1.95 0.54

Ammodytes hexapterus (Pacific sand lance) 0.32 0.07

Pleuronectidae (flatfish) 0.65 0.12

Atheresthes stomias (arrowtooth flounder) 0.32 0.27

Unidentified organic material 0.32 0.00

Fishery offal 0.32

Total non-empty stomachs = 308

Total prey number = 504

Total prey weight = 8,280 g

Total empty stomachs = 131

Number of hauls = 48

45
Table A-3.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Pacific cod (Gadus macrocephalus) collected in 

 the eastern Bering Sea in 1997, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 24.24 0.83

Aphroditidae (sea mouse) 0.51 0.42

Polynoidae (polychaete) 6.73 0.11

Phyllodocidae (polychaete) 1.94 0.02

Nereidae (polychaete) 0.08 0.00

Nephtyidae (polychaete) 3.96 0.10

Goniadidae (polychaete) 0.42 0.00

Lumbrineridae 0.25 0.01

Brada sp. (polychaete) 0.17 0.00

Opheliidae (polychaete) 0.08 0.00

Maldanidae (polychaete) 0.08 0.00

Ampharetidae (polychaete) 0.42 0.00

Terebellidae (polychaete) 0.08 0.01

Hirudinea (leech) 0.67 0.11

Gastropoda (snail) 2.02 0.63

Natica sp. (moonsnail) 0.08 0.01

Polinices pallida (snail) 0.08 0.01

Buccinidae (snail) 0.08 0.00

Buccinum sp. (snail) 0.25 0.02

Neptuneidae (snail) 0.08 0.01

Neptunea sp. (snail) 0.17 0.06

Bivalvia (clam) 2.53 0.13

Yoldia scissurata (clam) 0.17 0.00

Cyclocardia sp. (cardita clam) 0.08 0.00

Cyclocardia crebricostata (thickribbed cardita) 0.08 0.00

Astarte sp. (clam) 0.08 0.01

Cardiidae (cockles) 0.08 0.01

Cephalopoda (squid and octopus) 0.25 0.03

Octopoda (octopus) 2.36 1.05

Crustacea 1.01 0.01

Copepoda 0.59 <0.01 

Mysidacea Mysida (mysid) 10.61 0.09

Mysidae (mysid) 4.29 0.36

Neomysis rayii (mysid) 0.42 0.01

Cumacea (cumacean) 0.59 0.00

Isopoda (isopod) 0.08 0.00

Peracarida Isopoda Valvifera 0.08 0.00

Gammaridea (amphipod) 26.52 0.54

Ampeliscidae (amphipod) 3.87 0.10

Maera loveni (amphipod) 0.08 0.00

Protomedeia sp. (amphipod) 2.53 0.01

Anonyx sp. (amphipod) 2.36 0.02

Caprellidea (amphipod) 2.10 0.01

Euphausiacea (euphausiid) 0.51 0.01

Euphausiidae (euphausiid) 1.26 0.01

46
Table A-3.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Thysanoessa sp. (euphausiid) 0.17 0.00

Thysanoessa inermis (euphausiid) 0.08 0.00

Thysanoessa raschii (euphausiid) 0.08 0.04

Decapoda (shrimp and crab) 0.08 0.00

Natantia (shrimp) 0.42 0.02

Caridea (shrimp) 7.58 0.17

Hippolytidae (shrimp) 1.68 0.03

Spirontocaris sp. (shrimp) 0.08 0.00

Spirontocaris lamellicornis (shrimp) 0.08 0.00

Spirontocaris arcuata (shrimp) 0.76 0.02

Lebbeus sp. (shrimp) 0.08 0.00

Eualus sp. (shrimp) 0.08 0.00

Pandalidae (shrimp) 3.20 0.22

Pandalus sp. (shrimp) 0.51 0.01

Pandalus borealis (shrimp) 1.52 0.26

Pandalus goniurus (shrimp) 0.59 0.07

Pandalus montagui tridens (shrimp) 0.17 0.00

Pandalopsis sp. (shrimp) 0.08 0.00

Crangonidae (shrimp) 6.57 0.16

Crangon sp. (shrimp) 0.84 0.01

Crangon dalli (shrimp) 15.57 1.04

Crangon communis (shrimp) 5.98 0.24

Argis sp. (shrimp) 0.84 0.05

Argis lar (shrimp) 1.35 0.13

Argis dentata (shrimp) 0.17 0.01

Argis ovifer (shrimp) 0.08 0.00

Reptantia (crab) 1.77 0.16

Anomura (crab) 0.17 0.00

Paguridae (hermit crab) 26.85 7.23

Pagurus ochotensis (hermit crab) 0.08 0.03

Lithodidae (king crab) 0.84 1.08

Lithodidae (king crab - legs only) 0.17 0.04

Paralithodes sp. (king crab) 0.67 0.74

Decapoda brachyura (crab) 0.34 0.11

Majidae (spider crab) 0.17 0.03

Majidae legs (for C. opilio, C. bairdi, etc) 0.34 0.04

Hyas sp. (lyre crab) 0.25 0.09

Hyas lyratus (lyre crab) 0.25 0.06

Hyas coarctatus (lyre crab) 0.42 0.15

Chionoecetes sp. (snow and Tanner crab) 5.47 1.07

Chionoecetes opilio (snow crab) 23.74 15.40

Chionoecetes bairdi (Tanner crab) 9.76 3.39

Atelecyclidae (crab) 0.08 0.34

Telmessus cheiragonus (hair crab) 0.34 0.50

Erimacrus isenbeckii (Korean horse-hair crab) 0.08 0.00

Cancridae (crab) 0.08 0.00

Cancer sp. (crab) 0.08 0.00

Pinnotheridae (pea crab) 0.25 0.01

47
Table A-3.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Pinnixa sp. (pea crab) 0.08 0.00

Sipuncula (marine worm) 1.01 0.15

Echiura (marine worm) 7.41 1.36

Echiuroinea (marine worm) 0.08 0.00

Echiurus echiurus (marine worm) 2.53 0.34

Priapulida (worm) 0.08 0.10

Ectoprocta (bryozoan) 0.08 0.00

Asteroidea (starfish) 0.08 0.02

Ctenodiscus crispatus (mud sea star) 0.17 0.03

Ophiuroidea Euryalina (basket star) 0.08 0.00

Ophiuroidae Ophiurida (brittle star) 0.17 0.00

Holothuroidea (sea cucumber) 0.08 0.00

Urochordata (tunicate) 0.08 0.01

Ascidiacea (sea squirt) 0.08 0.00

Rajidae (skate) 0.08 0.03

Osteichthyes Teleostei (fish) 7.83 0.55

Non-gadoid fish remains 7.49 1.57

Fish eggs 0.08 0.01

Osmeridae (smelts) 0.08 0.12

Mallotus villosus (capelin) 0.08 0.00

Thaleichthys pacificus (eulachon) 0.08 0.06

Gadidae (gadid fish) 1.35 0.23

Gadus macrocephalus (Pacific cod) 0.34 1.92

Theragra chalcogramma (walleye pollock) 16.92 38.91

Zoarcidae (eelpout) 8.42 6.03

Cottoidei (sculpin) 0.84 0.20

Artediellus sp. (sculpin) 0.08 0.00

Agonidae (poacher) 0.67 0.08

Occella dodecaedron (Bering poacher) 0.08 0.05

Sarritor frenatus (sawback poacher) 0.17 0.07

Stichaeidae (prickleback) 2.69 0.64

Cryptacanthodes aleutensis (dwarf wrymouth) 0.08 0.02

Ammodytes hexapterus (Pacific sand lance) 1.52 0.69

Pleuronectidae (flatfish) 3.54 1.85

Atheresthes stomias (arrowtooth flounder) 0.17 1.25

Hippoglossoides elassodon (flathead sole) 0.84 0.53

Hippoglossoides robustus (Bering flounder) 0.08 0.13

Lepidopsetta sp. (rock sole type) 0.51 0.95

Lepidopsetta bilineata (southern rock sole) 0.08 0.20

Lepidopsetta polyxystra (northern rock sole) 0.51 0.51

Pleuronectes asper (yellowfin sole) 0.25 2.17

Unidentified organic material 2.19 0.06

Unidentified eggs 0.25 0.01

Unidentified worm-like organism 1.09 0.15

Fishery offal 0.42 1.16

Unidentified tube 0.08 <0.01 

Unidentified algae 0.08 0.00

Rocks 0.93 0.08

48
Table A-3.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Unidentified material 0.08 0.00

Total non-empty stomachs = 1,188

Total prey number = 8159

Total prey weight = 53,157 g

Total empty stomachs = 6

Number of hauls = 86

49
Table A-4.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of flathead sole (Hippoglossoides elassodon) 

 collected in the eastern Bering Sea in 1997, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Annelida (worm) 0.41 0.01

Polychaeta (worm) 18.03 4.99

Polynoidae (polychaete) 0.41 0.27

Nereidae (polychaete) 2.46 0.44

Maldanidae (polychaete) 0.41 0.86

Mollusca 0.82 0.03

Gastropoda (snail) 1.64 0.05

Bivalvia (clam) 3.28 2.72

Nuculana sp. (clam) 2.87 0.41

Yoldia sp. (clam) 1.23 0.70

Pectinidae (scallops) 0.41 0.33

Chlamys sp. (scallop) 0.82 0.24

Cardiidae (cockles) 0.41 0.02

Crustacea 2.05 0.03

Calanoida (copepod) 0.82 0.00

Mysidacea Mysida (mysid) 13.93 1.05

Mysidae (mysid) 16.39 10.61

Cumacea (cumacean) 6.97 0.26

Isopoda (isopod) 0.82 0.03

Amphipoda (amphipod) 1.64 0.01

Gammaridea (amphipod) 26.23 3.70

Ampeliscidae (amphipod) 4.10 0.60

Caprellidea (amphipod) 0.41 0.02

Caprellidae (amphipod) 0.41 0.00

Euphausiacea (euphausiid) 0.82 0.33

Euphausiidae (euphausiid) 6.97 2.36

Decapoda (shrimp and crab) 0.41 0.01

Natantia (shrimp) 0.41 0.01

Caridea (shrimp) 2.87 0.64

Hippolytidae (shrimp) 0.82 0.03

Spirontocaris arcuata (shrimp) 0.41 0.16

Pandalidae (shrimp) 1.23 3.14

Pandalus sp. (shrimp) 0.82 0.50

Crangonidae (shrimp) 3.28 0.84

Crangon sp. (shrimp) 12.70 6.34

Crangon alaskensis (shrimp) 0.41 0.12

Crangon dalli (shrimp) 4.10 3.62

Crangon communis (shrimp) 0.41 0.10

Reptantia (crab) 0.82 0.01

Paguridae (hermit crab) 3.28 1.96

Decapoda brachyura (crab) 1.64 0.20

Majidae legs (for C. opilio, C. bairdi, etc) 0.41 0.01

Chionoecetes sp. (snow and Tanner crab) 1.64 0.22

Chionoecetes opilio (snow crab) 0.41 0.10

Chionoecetes bairdi (Tanner crab) 7.79 3.33

50
Table A-4.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Pinnotheridae (pea crab) 0.41 0.06

Sipuncula (marine worm) 0.41 0.57

Echiura (marine worm) 1.64 2.19

Ophiuroidae Ophiurida (brittle star) 25.82 21.14

Brittle star legs 2.87 0.63

Ophiura sarsi (brittle star) 4.10 8.94

Urochordata (tunicate) 0.82 0.02

Osteichthyes Teleostei (fish) 1.23 0.02

Non-gadoid fish remains 0.82 0.45

Gadidae (gadid fish) 0.82 0.54

Theragra chalcogramma (walleye pollock) 3.69 13.04

Stichaeidae (prickleback) 0.41 0.52

Lumpenus maculatus (daubed shanny) 0.41 0.18

Unidentified organic material 2.46 0.10

Unidentified worm-like organism 0.82 0.10

Unidentified tube 2.05 0.11

Total non-empty stomachs = 244

Total prey number = 900

Total prey weight = 446 g

Total empty stomachs = 34

Number of hauls = 30

51
Table A-5.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Greenland turbot (Reinhardtius hippoglossoides) 

 collected in the eastern Bering Sea in 1997, May through September. 

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 2.50 0.00

Mysidacea Mysida (mysid) 2.50 0.00

Isopoda (isopod) 2.50 0.02

Gammaridea (amphipod) 7.50 0.00

Euphausiacea (euphausiid) 15.00 0.00

Osteichthyes Teleostei (fish) 12.50 0.07

Gadidae (gadid fish) 10.00 2.66

Theragra chalcogramma (walleye pollock) 50.00 96.60

Fishery offal 2.50 0.64

Total non-empty stomachs = 40

Total prey number = 42

Total prey weight = 4,673 g

Total empty stomachs = 9

Number of hauls = 15

52
Table A-6.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Pacific halibut (Hippoglossus stenolepis) collected 

 in the eastern Bering Sea in 1997, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 1.81 0.02

Mollusca 0.36 0.01

Gastropoda (snail) 2.17 0.03

Cephalopoda (squid and octopus) 2.17 0.34

Teuthoidea (squid) 1.08 0.66

Octopoda (octopus) 5.42 7.14

Mysidacea Mysida (mysid) 4.33 0.04

Mysidae (mysid) 1.08 0.01

Gammaridea (amphipod) 1.08 0.00

Euphausiidae (euphausiid) 2.89 0.01

Natantia (shrimp) 2.17 0.01

Caridea (shrimp) 1.44 0.01

Pandalidae (shrimp) 0.72 0.01

Pandalus sp. (shrimp) 0.36 0.00

Pandalus borealis (shrimp) 0.36 0.03

Pandalus goniurus (shrimp) 0.72 0.01

Crangonidae (shrimp) 7.58 0.13

Crangon sp. (shrimp) 6.50 0.11

Crangon dalli (shrimp) 1.44 0.04

Crangon communis (shrimp) 0.36 0.01

Argis sp. (shrimp) 0.72 0.02

Reptantia (crab) 2.89 0.10

Anomura (crab) 2.89 0.06

Paguridae (hermit crab) 19.49 3.96

Paguridae legs (hermit crabs) 1.08 0.06

Elassachirus tenuimanus 0.36 0.04

Lithodidae (king crab) 0.36 0.07

Decapoda brachyura (crab) 1.44 0.28

Decapoda Reptantia legs (for unident. crabs) 0.36 0.04

Majidae (spider crab) 1.81 0.08

Oregonia gracilis (decorator crab) 0.72 0.01

Hyas sp. (lyre crab) 2.53 0.63

Hyas lyratus (lyre crab) 1.08 0.08

Chionoecetes sp. (snow and Tanner crab) 5.42 1.56

Chionoecetes opilio (snow crab) 11.55 6.28

Chionoecetes bairdi (Tanner crab) 9.39 2.13

Telmessus cheiragonus (hair crab) 0.36 0.02

Cancer oregonensis (pygmy Cancer crab) 2.89 0.50

Echiura (marine worm) 0.36 0.01

Ectoprocta (bryozoan) 0.72 0.00

Ascidiacea (sea squirt) 0.36 0.00

Rajidae (skate) 0.36 0.08

Bathyraja parmifera (Alaska skate) 0.72 0.40

Osteichthyes Teleostei (fish) 9.39 1.07

Non-gadoid fish remains 9.39 1.24

53
Table A-6.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Clupea pallasi (Pacific herring) 0.36 0.01

Osmeridae (smelts) 2.53 0.14

Mallotus villosus (capelin) 3.97 1.17

Thaleichthys pacificus (eulachon) 0.36 0.24

Gadidae (gadid fish) 10.83 2.09

Eliginus gracilis (saffron cod) 0.72 0.13

Gadus macrocephalus (Pacific cod) 4.33 4.50

Theragra chalcogramma (walleye pollock) 38.63 50.04

Zoarcidae (eelpout) 0.36 0.01

Cottoidei (sculpin) 2.17 0.48

Cottidae (sculpin) 0.72 0.32

Triglops sp. (sculpin) 0.36 0.04

Agonidae (poacher) 1.08 0.20

Sarritor frenatus (sawback poacher) 0.36 0.15

Stichaeidae (prickleback) 1.44 0.18

Lumpenus fabricii (slender eelblenny) 0.36 0.05

Ammodytes sp. (sandlance) 4.33 0.31

Ammodytes hexapterus (Pacificsand lance) 6.50 0.50

Pleuronectiformes Pleuronectoidei (flatfish) 5.05 0.98

Pleuronectidae (flatfish) 6.86 4.77

Hippoglossoides robustus (Bering flounder) 0.36 0.70

Lepidopsetta sp. (rock sole type) 0.36 0.22

Lepidopsetta polyxystra (northern rock sole) 0.36 0.01

Pleuronectes asper (yellowfin sole) 2.17 1.41

Pleuronectes proboscideus (longhead dab) 2.89 3.07

Unidentified organic material 1.08 0.10

Fishery offal 1.08 0.81

Unidentified tube 0.36

Total non-empty stomachs = 277

Total prey number = 1,489

Total prey weight = 24,442 g

Total empty stomachs = 16

 Number of hauls = 66 

54
Table A-7.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of northern rock sole (Lepidopsetta polyxystra) 

 collected in the eastern Bering Sea in 1997, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Foraminiferida (protozoan) 0.52 0.00

Polychaeta (worm) 61.30 11.02

Polynoidae (polychaete) 0.78 0.33

Phyllodocidae (polychaete) 7.53 0.08

Nereidae (polychaete) 11.17 9.05

Nephtyidae (polychaete) 16.62 19.01

Nephtys sp. (polychaete) 0.52 0.02

Goniadidae (polychaete) 17.40 0.47

Goniada sp. (polychaete) 0.26 0.00

Onuphidae (polychaete) 0.26 0.02

Lumbrineridae 2.08 0.33

Orbiniidae (polychaete) 11.17 0.66

Spionidae (polychaete) 0.26 0.01

Chaetopteridae (polychaete) 0.52 0.08

Flabelligeridae (polychaete) 1.30 0.18

Brada sp. (polychaete) 1.56 0.06

Flabelligera sp. (polychaete) 0.26 0.01

Scalibregmidae 0.26 0.09

Scalibregma inflatum 1.82 0.47

Opheliidae (polychaete) 8.05 2.24

Travisia sp. (polychaete) 4.16 1.68

Travisia forbesii (polychaete) 1.82 0.51

Maldanidae (polychaete) 20.52 9.07

Pectinariidae (polychaete) 1.30 0.07

Cistenides sp. (polychaete) 0.26 0.02

Ampharetidae (polychaete) 5.71 0.48

Terebellidae (polychaete) 2.86 2.12

Trichobranchidae (polychaete) 0.52 0.07

Sabellidae (polychaete) 0.52 0.13

Eunicida (polychaete) 0.26 0.00

Phyllodocida (pllychaete) 0.26 0.00

Sabellida (polychaete) 2.86 0.14

Terebellida (polychaete) 0.26 0.18

Hirudinea (leech) 0.26 0.07

Gastropoda (snail) 1.82 0.09

Nudibranchia (sea slug) 0.26 0.03

Bivalvia (clam) 43.38 2.61

Yoldia sp. (clam) 0.26 0.16

Yoldia scissurata (clam) 5.19 1.87

Cardiidae (cockles) 0.52 0.02

Clinocardium sp. (cockle) 0.26 0.01

Spisula sp. (clam) 0.26 0.01

Spisula polynyma (clam) 0.26 0.15

Crustacea 0.52 0.00

Cirripedia (barnacle) 0.26 0.02

Mysidae (mysid) 2.86 0.15

55
Table A-7.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Pseudomma truncatum (mysid) 1.30 0.07

Cumacea (cumacean) 16.88 0.10

Isopoda (isopod) 0.52 0.00

Peracarida Isopoda Valvifera 0.26 0.02

Gammaridea (amphipod) 54.03 3.26

Ampeliscidae (amphipod) 17.66 2.99

Ampelisca sp. (amphipod) 1.56 0.47

Ampelisca macrocephala (amphipod) 0.26 0.08

Gammaridae (amphipod) 0.26 0.03

Protomedeia sp. (amphipod) 15.06 0.68

Anonyx sp. (amphipod) 1.56 0.09

Caprellidea (amphipod) 3.12 0.10

Thysanoessa sp. (euphausiid) 0.52 0.00

Caridea (shrimp) 0.26 0.00

Crangon sp. (shrimp) 0.26 0.02

Crangon dalli (shrimp) 0.26 0.07

Reptantia (crab) 1.30 0.08

Decapoda Reptantia legs (for unident. crabs) 0.26 0.00

Paguridae (hermit crab) 1.30 0.49

Chionoecetes sp. (snow and Tanner crab) 1.04 0.45

Chionoecetes opilio (snow crab) 1.04 0.21

Chionoecetes bairdi (Tanner crab) 0.26 0.05

Sipuncula (marine worm) 1.30 1.00

Echiura (marine worm) 5.45 1.74

Echiurus echiurus (marine worm) 20.52 9.32

Priapulida (worm) 2.86 6.23

Ectoprocta (bryozoan) 0.26 0.03

Ophiuroidae Ophiurida (brittle star) 8.57 1.23

Brittle star legs 1.82 0.14

Ophiuridae (brittle star) 1.56 0.32

Sand dollar 2.08 0.04

Clypeasteridae (sand dollar) 0.52 0.04

Holothuroidea (sea cucumber) 3.12 0.95

Urochordata (tunicate) 2.86 0.27

Ascidiacea (sea squirt) 0.52 0.11

Ascidia sp. (tunicate) 3.64 0.31

Larvacea Copelata 0.26 0.03

Osteichthyes Teleostei (fish) 0.52 0.03

Non-gadoid fish remains 0.78 0.07

Scorpaenidae 0.26 0.07

Ammodytes sp. (sand lance) 0.26 0.07

Ammodytes hexapterus (Pacific sand lance) 1.56 4.14

Unidentified organic material 11.43 0.52

Unidentified worm-like organism 2.34 0.23

Fishery offal 0.52 0.00

Unidentified tube 1.82 0.04

56
Table A-7.--Continued. 

Total non-empty stomachs = 385

Total prey number = 10,794

Total prey weight = 689 g

Total empty stomachs = 40

Number of hauls = 80

57
Table A-8.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of skates collected in the eastern Bering Sea in 1997, 

 May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 18.09 0.31

Polynoidae (polychaete) 0.71 0.02

Opheliidae (polychaete) 0.35 0.02

Bivalvia (clam) 1.06 0.00

Teuthoidea (squid) 0.35 0.00

Crustacea 1.42 0.01

Mysidacea Mysida (mysid) 10.99 0.20

Mysidae (mysid) 4.96 0.03

Cumacea (cumacean) 4.26 0.01

Amphipoda (amphipod) 0.35 0.00

Gammaridea (amphipod) 24.47 0.57

Ampeliscidae (amphipod) 4.96 0.28

Caprellidae (amphipod) 0.35 0.00

Euphausiacea (euphausiid) 1.42 0.01

Euphausiidae (euphausiid) 4.96 0.01

Natantia (shrimp) 2.84 0.05

Caridea (shrimp) 3.19 0.03

Hippolytidae (shrimp) 2.84 0.13

Eualus sp. (shrimp) 2.84 0.13

Pandalidae (shrimp) 1.42 0.03

Pandalus sp. (shrimp) 1.06 0.02

Pandalus borealis (shrimp) 0.35 0.01

Pandalus goniurus (shrimp) 1.06 0.10

Crangonidae (shrimp) 10.28 4.20

Crangon sp. (shrimp) 11.35 1.50

Crangon alaskensis (shrimp) 0.35 0.01

Crangon dalli (shrimp) 2.48 0.32

Crangon communis (shrimp) 1.06 0.03

Argis sp. (shrimp) 14.54 9.10

Argis lar (shrimp) 0.35 0.01

Argis ovifer (shrimp) 0.35 0.03

Reptantia (crab) 9.57 0.44

Decapoda Reptantia legs (for unident. crabs) 0.35 0.00

Anomura (crab) 1.77 0.31

Paguridae (hermit crab) 11.70 1.69

Pagurus sp. (hermit crab) 0.71 0.13

Decapoda brachyura (crab) 0.71 0.03

Decapoda brachyura legs (for unident. crabs) 0.35 0.01

Majidae (spider crab) 4.26 0.36

Majidae legs (for C. opilio, C. bairdi, etc) 0.35 0.00

Oregonia gracilis (decorator crab) 0.35 0.01

Chionoecetes sp. (snow and Tanner crab) 13.12 1.50

Chionoecetes opilio (snow crab) 5.32 0.96

Chionoecetes bairdi (Tanner crab) 3.55 0.59

Osteichthyes Teleostei (fish) 10.28 0.48

Non-gadoid fish remains 3.55 0.26

58
Table A-8.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Gadidae (gadid fish) 5.32 3.46

Theragra chalcogramma (walleye pollock) 18.44 39.85

Zoarcidae (eelpout) 3.55 3.69

Cottoidei (sculpin) 2.48 0.06

Cottidae (sculpin) 0.35 1.40

Agonidae (poacher) 3.90 2.36

Stichaeidae (prickleback) 12.41 4.44

Lumpenus maculatus (daubed shanny) 1.06 0.61

Ammodytes sp. (sandlance) 2.48 1.13

Pleuronectiformes Pleuronectoidei (flatfish) 5.67 1.42

Pleuronectidae (flatfish) 9.22 5.65

Hippoglossoides elassodon (flathead sole) 0.71 0.05

Lepidopsetta sp. (rock sole type) 0.35 0.07

Lepidopsetta polyxystra (northern rock sole) 1.42 2.22

Pleuronectes asper (yellowfin sole) 1.42 2.54

Pleuronectes proboscideus (longhead dab) 0.35 0.48

Unidentified organic material 0.35 0.00

Fishery offal 3.19 6.64

Total non-empty stomachs = 282

Total prey number = 1,775

Total prey weight = 10,491 g

Total empty stomachs = 39

 Number of hauls = 54

59
Table A-9.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of walleye pollock (Theragra chalcogramma) 

 collected in the eastern Bering Sea in 1997, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Annelida (worm) 0.04 0.01

Polychaeta (worm) 2.33 0.17

Polynoidae (polychaete) 0.15 0.00

Phyllodocidae (polychaete) 0.04 0.00

Tomopteridae (polychaete) 0.09 0.00

Nereidae (polychaete) 0.07 0.04

Nephtyidae (polychaete) 0.11 0.01

Goniadidae (polychaete) 0.42 0.01

Orbiniidae (polychaete) 0.02 0.00

Hirudinea (leech) 0.02 0.00

Pteropoda 1.72 0.02

Thecosomata (pteropod) 0.66 0.02

Bivalvia (clam) 0.24 0.00

Cephalopoda (squid and octopus) 0.07 0.00

Teuthoidea (squid) 0.40 0.00

Gonatidae (squid) 0.02 0.00

Octopoda (octopus) 0.02 0.10

Crustacea 3.26 0.12

Ostracoda 0.02 0.00

Copepoda 0.02 <0.01 

Calanoida (copepod) 43.02 4.99

Calanidae (copepod) 1.19 0.02

Candacia sp. (copepod) 0.02 0.00

Harpacticoida (copepod) 0.02 <0.01 

Peracarida Mysidacea (mysid) 0.04 0.00

Mysidacea Mysida (mysid) 7.22 1.84

Mysidae (mysid) 3.39 0.28

Meterythrops sp. (mysid) 0.02 0.01

Neomysis rayii (mysid) 0.02 0.00

Pseudomma sp. (mysid) 0.07 0.00

Cumacea (cumacean) 3.28 0.15

Diastylopsis sp. (cumacean) 0.02 0.00

Oxyurostylis sp. (cumacean) 0.02 0.00

Leptocuma sp. (cumacean) 0.02 0.00

Isopoda (isopod) 0.09 0.00

Phreatoicidea (Isopod suborder) 0.02 0.00

Amphipoda (amphipod) 0.09 0.00

Gammaridea (amphipod) 8.39 0.61

Ampeliscidae (amphipod) 1.72 0.19

Protomedeia sp. (amphipod) 0.40 0.00

Anonyx sp. (amphipod) 0.22 0.01

Amphipoda Hyperiidea (amphipod) 12.89 1.64

Hyperiidae (amphipod) 0.18 0.00

Caprellidea (amphipod) 0.29 0.00

Caprellidae (amphipod) 0.04 0.00

Euphausiacea (euphausiid) 44.63 40.99

60
Table A-9.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Euphausiidae (euphausiid) 17.69 8.50

Thysanoessa sp. (euphausiid) 8.81 7.78

Thysanoessa inermis (euphausiid) 2.00 1.24

Thysanoessa raschii (euphausiid) 2.93 3.07

Thysanoessa spinifera (euphausiid) 0.70 0.68

Decapoda (shrimp and crab) 0.93 0.05

Penaeidae 0.02 0.00

Natantia (shrimp) 0.88 0.02

Caridea (shrimp) 2.38 0.45

Hippolytidae (shrimp) 0.40 0.15

Spirontocaris arcuata (shrimp) 0.04 0.01

Lebbeus groenlandicus (shrimp) 0.04 0.01

Eualus sp. (shrimp) 0.07 0.01

Eualus townsendi (shrimp) 0.02 0.01

Pandalidae (shrimp) 1.39 0.52

Pandalus sp. (shrimp) 0.11 0.02

Pandalus borealis (shrimp) 0.33 0.23

Pandalus goniurus (shrimp) 0.35 0.18

Pandalus jordani (shrimp) 0.02 0.00

Crangonidae (shrimp) 0.79 0.08

Crangon sp. (shrimp) 0.09 0.02

Crangon alaskensis (shrimp) 0.02 0.00

Crangon dalli (shrimp) 2.53 3.36

Crangon communis (shrimp) 0.33 0.06

Argis sp. (shrimp) 0.15 0.04

Argis lar (shrimp) 0.11 0.03

Argis crassa (shrimp) 0.02 0.00

Reptantia (crab) 0.70 0.01

Anomura (crab) 1.08 0.01

Paguridae (hermit crab) 1.28 0.01

Lithodidae (king crab) 0.07 0.00

Paralithodes sp. (king crab) 0.11 0.00

Paralithodes platypus (blue king crab) 0.51 0.01

Decapoda brachyura (crab) 0.26 0.02

Chionoecetes sp. (snow and Tanner crab) 0.02 0.00

Echiura (marine worm) 0.35 0.13

Echiuridae (marine worm) 0.09 0.04

Echiurus echiurus (marine worm) 0.11 0.07

Ophiuroidae Ophiurida (brittle star) 0.04 0.00

Holothuroidea (sea cucumber) 0.02 0.00

Chaetognatha (arrow worm) 5.77 0.17

Sagitta sp. (arrow worm) 2.93 0.15

Urochordata (tunicate) 0.02 0.00

Ascidia sp. (tunicate) 0.13 <0.01 

Thaliacea (pelagic salp) 0.07 0.01

Larvacea Copelata 11.61 2.70

Oikopleura sp. 1.06 0.50

Misc. fish 0.44 0.01

61
Table A-9.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Osteichthyes Teleostei (fish) 5.86 0.80

Non-gadoid fish remains 0.51 0.30

Fish eggs 0.02 <0.01 

Clupea pallasi (Pacific herring) 0.04 0.00

Gadidae (gadid fish) 0.93 0.79

Theragra chalcogramma (walleye pollock) 5.37 13.39

Zoarcidae (eelpout) 0.02 0.01

Scorpaenidae 0.02 0.00

Cottoidei (sculpin) 0.44 0.05

Hemilepidotus hemilepidotus (red Irish lord) 0.02 0.00

Myoxocephalus sp. (sculpin) 0.02 0.00

Agonidae (poacher) 0.04 0.02

Liparis sp. (snailfish) 0.02 0.00

Ptilichthys goodei (quillfish) 0.02 0.00

Stichaeidae (prickleback) 0.09 0.06

Lumpenus maculatus (daubed shanny) 0.02 0.00

Poroclinus rothrocki (whitebarred pricklback) 0.02 0.01

Ammodytes sp. (sandlance) 0.09 0.13

Ammodytes hexapterus (Pacificsand lance) 0.20 0.37

Pleuronectidae (flatfish) 0.29 0.06

Lepidopsetta sp. (rock sole type) 0.07 0.00

Reinhardtius hippoglossoides (Greenland turbot) 0.33 0.24

Hippoglossus stenolepis (Pacific halibut) 0.11 0.00

Aves (bird part) 0.02 0.00

Unidentified organic material 2.97 0.19

Sand 0.02 <0.01 

Unidentified eggs 0.02 <0.01 

Unidentified worm-like organism 0.18 0.01

Fishery offal 0.62 1.91

Unidentified tube 0.09 0.00

Wood 0.02 0.00

Rocks 0.04 0.00

Total non-empty stomachs = 4,540

Total prey number = 22,245

Total prey weight = 23,687 g

Total empty stomachs = 91

Number of hauls = 264

62
Table A-10.--Prey items (expressed in mean percent frequency of occurrence and 

 mean percent total weight) of yellowfin sole (Limanda aspera) collected in 

 the eastern Bering Sea in 1997, May through September. 

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Annelida (worm) 0.86 0.06

Polychaeta (worm) 25.29 8.23

Nephtyidae (polychaete) 0.29 0.27

Maldanidae (polychaete) 0.29 0.25

Pectinariidae (polychaete) 0.29 0.01

Gastropoda (snail) 2.01 0.37

Bivalvia (clam) 23.56 16.88

Nuculana sp. (clam) 1.44 1.08

Yoldia sp. (clam) 0.57 0.45

Cyclocardia sp. (cardita clam) 0.29 0.02

Cardiidae (cockles) 0.57 0.04

Clinocardium ciliatum (Iceland cockle) 0.57 1.48

Serripes groenlandicus (Greenland cockle) 0.29 0.48

Crustacea 1.15 0.08

Calanoida (copepod) 0.29 0.00

Cirripedia (barnacle) 0.29 0.00

Mysidacea Mysida (mysid) 1.15 0.09

Mysidae (mysid) 0.57 0.04

Cumacea (cumacean) 15.52 0.57

Isopoda (isopod) 0.57 0.51

Amphipoda (amphipod) 3.45 0.33

Gammaridea (amphipod) 38.51 5.68

Caprellidea (amphipod) 0.29 0.02

Caprellidae (amphipod) 0.29 0.01

Euphausiidae (euphausiid) 4.60 3.85

Caridea (shrimp) 1.15 0.24

Crangonidae (shrimp) 2.01 0.57

Crangon sp. (shrimp) 0.29 0.08

Crangon dalli (shrimp) 0.57 0.87

Reptantia (crab) 2.87 0.40

Paguridae (hermit crab) 3.16 3.08

Decapoda brachyura (crab) 1.15 0.53

Majidae (spider crab) 0.57 0.16

Majidae legs (for C. opilio, C. bairdi, etc) 0.29 <0.01 

Oregonia sp. (decorator crab) 0.29 0.98

Chionoecetes sp. (snow and Tanner crab) 0.86 0.77

Chionoecetes opilio (snow crab) 1.44 1.08

Chionoecetes bairdi (Tanner crab) 0.86 0.56

Sipuncula (marine worm) 0.29 <0.01

Echiura (marine worm) 8.05 21.36

Echiuridae (marine worm) 1.15 5.49

Priapulida (worm) 0.29 1.43

Ectoprocta (bryozoan) 1.72 0.20

Ophiuroidae Ophiurida (brittle star) 22.70 7.90

63
64

Table A-10.--Continued. 

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Brittle star legs 0.29 0.17

Echinacea sp. (sea urchin) 1.15 0.06

Clypeasteridae (sand dollar) 2.87 0.21

Sand dollar 0.29 0.00

Holothuroidea (sea cucumber) 3.16 2.56

Chaetognatha (arrow worm) 0.29 0.00

Urochordata (tunicate) 0.29 0.02

Larvacea Copelata 2.59 1.03

Osteichthyes Teleostei (fish) 2.01 0.37

Osmeridae (smelts) 0.29 2.66

Theragra chalcogramma (walleye pollock) 0.29 0.16

Ammodytes sp. (sand lance) 0.57 0.64

Pleuronectidae (flatfish) 0.29 0.44

Unidentified organic material 4.60 1.54

Sand 0.57 0.11

Unidentified worm-like organism 1.72 2.86

Fishery offal 0.29 <0.01 

Unidentified tube 2.59 0.25

Total non-empty stomachs = 348

Total prey number = 983

Total prey weight = 530 g

Total empty stomachs = 153

Number of hauls = 55 
 Misc. Worms Misc. Crustaceans Amph

 Misc. Prey Polychaetes Unidentified Walle Brittlestars Clams Chionoecetes Misc

Prey Key

0%

10%20%30%40%50%60%70%80%90%

100%

<20 20-29 30-39 

Alaska plaice length (cm)

Percent by weight

Figure A-1.--Diet composition of Alaska plaice, in terms of average percent by weight, during months 5  predator size in the eastern Bering Sea; N=number of full stomachs. 

65
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

1997 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 40-49 

Arrowtooth flounder length (cm)

Percent by weight

N 26 28 73 79 

Figure A-2.--Diet composition of arrowtooth flounder, in terms of average percent by weight, during mo by predator size in the eastern Bering Sea; N=number of full stomachs. 

66
 Offal Misc. Crustaceans Lithodidae Walleye Pollo

 Misc. Prey Unidentified Pleuronectidae Misc. Fish

 Chionoecetes

1997 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

70-79

Pacific cod length (cm)

Percent by weight

N= 144 83 138 172 244 242 87 

Prey Key

Figure A-3.--Diet composition of Pacific cod, in terms of average percent by weight, during months 5 th predator size in the eastern Bering Sea; N=number of full stomachs. 

67
 Misc. Worms Misc. Crustaceans Amphip

 Misc. Prey Polychaetes Unidentified Walleye 

 Brittlestars Clams Chionoecetes Misc. Fi

Prey Key

1997 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 

Flathead sole length (cm)

Percent by weight

N= 18 60 137 

>

Figure A-4.--Diet composition of flathead sole, in terms of average percent by weight, during months 5  predator size in the eastern Bering Sea; N=number of full stomachs. 

68
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

1997 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 40-49 

Greenland Turbot length (cm)

Percent by weight

N 1 

Figure A-5.--Diet composition of Greenland turbot, in terms of average percent by weight, during mont predator size in the eastern Bering Sea; N=number of full stomachs. 

69
 Offal Misc. Crustaceans Lithodidae Walleye 

 Misc. Prey Unidentified Pleuronectidae Misc. Fis

 Chionoecetes

1997 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

Pacific halibut length (cm)

Percent by weight

N= 2 0 40 27 22 55 63 

Prey Key

Figure A-6.--Diet composition of Pacific halibut, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs. 

70
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

1997 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 40-49 

Walleye pollock length (cm)

Percent by weight

N 640 292 348 1001 

Figure A-7.--Diet composition of walleye pollock, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs.

71
 Misc. Worms Misc. Crustaceans 

 Misc. Prey Polychaetes Unidentified 

 Brittlestars Clams Chionoecetes 

Prey Key

1997 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 

Northern rock sole length (cm)

Percent by weight

N= 45 188 141 

Figure A-8.--Diet composition of northern rock sole, in terms of average percent by weight, during mon by predator size in the eastern Bering Sea; N=number of full stomachs. 

72
 Offal Misc. Crustaceans Lithodidae Walleye Polloc

 Misc. Prey Unidentified Pleuronectidae Misc. Fish

 Chionoecetes

1997 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

70-79

Skate length (cm)

Percent by weight

N= 8 22 21 39 37 38 69 

Prey Key

Figure A-9.--Diet composition of skates, in terms of average percent by weight, during months 5 throug size in the eastern Bering Sea; N=number of full stomachs. 

73
 Misc. Worms Misc. Crustaceans 

 Misc. Prey Polychaetes Unidentified  Brittlestars Clams Chionoecetes 

Prey Key

1997 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 

Yellowfin sole length (cm)

Percent by weight

N= 31 130 153 

Figure A-10.--Diet composition of Pacific halibut, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs. 

74
Appendix B- Diet of major groundfish species collected 

from the eastern Bering Sea in 1998 

Table B-1.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Alaska plaice (Pleuronectes quadrituberculatus) 

 collected in the eastern Bering Sea in 1998, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Foraminiferida Textulariina (foram) 0.52 0.00

Polychaeta (worm) 68.04 4.45

Polynoidae (polychaete) 28.35 0.80

Phyllodocidae (polychaete) 2.06 0.10

Nereidae (polychaete) 3.09 0.07

Nephtyidae (polychaete) 22.16 6.36

Glyceridae (polychaete) 0.52 0.01

Goniadidae (polychaete) 10.31 0.07

Onuphidae (polychaete) 1.55 0.04

Lumbrineridae 3.61 1.08

Orbiniidae (polychaete) 22.16 0.10

Spionidae (polychaete) 1.03 0.01

Chaetopteridae (polychaete) 2.58 2.02

Flabelligeridae (polychaete) 2.06 0.44

Brada sp. (polychaete) 6.70 0.31

Scalibregma inflatum 1.55 0.37

Opheliidae (polychaete) 6.70 0.40

Travisia sp. (polychaete) 1.55 0.13

Travisia forbesii (polychaete) 0.52 0.41

Sternaspis scutata (polychaete) 4.64 0.46

Capitellidae (polychaete) 1.55 0.29

Maldanidae (polychaete) 42.78 7.59

Pectinariidae (polychaete) 0.52 0.18

Ampharetidae (polychaete) 14.95 3.24

Terebellidae (polychaete) 6.70 8.45

Artacama sp. (polychaete) 1.03 0.15

Trichobranchidae (polychaete) 5.67 0.29

Terebellides stroemi (polychaete) 1.03 0.18

Sabellida (polychaete) 2.06 0.04

Terebellida (polychaete) 2.06 0.09

Mollusca 0.52 0.00

Gastropoda (snail) 17.01 0.42

Bivalvia (clam) 46.39 3.37

Yoldia scissurata (clam) 13.92 12.55

Clinocardium ciliatum (Iceland cockle) 0.52 0.01

Crustacea 0.52 0.01

Cumacea (cumacean) 6.70 0.02

Isopoda (isopod) 3.61 0.00

Gammaridea (amphipod) 51.55 1.51

Ampeliscidae (amphipod) 13.92 0.28

Maera sp. (amphipod) 0.52 0.01

Maera loveni (amphipod) 1.03 0.03

Protomedeia sp. (amphipod) 2.58 0.03

Anonyx sp. (amphipod) 3.09 0.03

Crangon sp. (shrimp) 0.52 0.01

Paguridae (hermit crab) 0.52 0.05

77
Table B-1.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Chionoecetes opilio (snow crab) 0.52 0.03

Sipuncula (marine worm) 4.12 6.86

Echiura (marine worm) 18.04 6.55

Echiurus echiurus (marine worm) 11.86 22.11

Priapulida (worm) 1.55 0.97

Ectoprocta (bryozoan) 1.55 0.01

Ophiuroidae Ophiurida (brittle star) 18.04 1.23

Brittle star legs 2.06 0.00

Sand dollar 0.52 0.02

Holothuroidea (sea cucumber) 5.67 3.96

Pentamera sp. 0.52 0.62

Ascidiacea (sea squirt) 0.52 0.03

Larvacea Copelata 1.55 0.00

Non-gadoid fish remains 0.52 0.15

Unidentified organic material 22.68 0.60

Unidentified worm-like organism 3.61 0.35

Unidentified tube 3.61 0.03

Rocks 1.55 0.03

Total non-empty stomachs = 194

Total prey number = 2,986

Total prey weight = 930 g

Total empty stomachs = 9

Number of hauls = 41 

78
Table B-2.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of arrowtooth flounder (Atheresthes stomias) 

 collected in the eastern Bering Sea in 1998, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 0.85 0.00

Bivalvia (clam) 0.43 0.00

Nuculana sp. (clam) 0.43 0.00

Mysidacea Mysida (mysid) 1.28 0.01

Gammaridea (amphipod) 2.56 0.01

Euphausiacea (euphausiid) 6.84 1.08

Euphausiidae (euphausiid) 18.80 0.71

Natantia (shrimp) 1.28 0.02

Caridea (shrimp) 1.71 0.06

Hippolytidae (shrimp) 0.85 0.02

Pandalidae (shrimp) 2.14 0.06

Pandalus sp. (shrimp) 2.14 0.12

Pandalus borealis (shrimp) 0.85 0.15

Crangonidae (shrimp) 3.85 0.04

Crangon sp. (shrimp) 5.56 0.12

Crangon dalli (shrimp) 0.43 0.01

Argis sp. (shrimp) 0.43 0.01

Paguridae (hermit crab) 0.43 0.02

Misc. fish 0.43 0.00

Osteichthyes Teleostei (fish) 8.97 0.22

Non-gadoid fish remains 3.85 0.27

Gadidae (gadid fish) 10.26 2.28

Theragra chalcogramma (walleye pollock) 42.74 92.14

Zoarcidae (eelpout) 2.56 0.92

Cottoidei (sculpin) 1.71 0.22

Cottidae (sculpin) 0.43 0.09

Stichaeidae (prickleback) 1.28 0.32

Ammodytes hexapterus (Pacific sand lance) 0.43 0.10

Unidentified organic material 0.43 <0.01 

Fishery offal 0.43 1.00

Total non-empty stomachs = 234

Total prey number = 312

Total prey weight = 5,808 g

Total empty stomachs = 185

 Number of hauls = 45

79
Table B-3.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Pacific cod (Gadus macrocephalus) collected in 

 the eastern Bering Sea in 1998, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 34.73 0.88

Aphroditidae (sea mouse) 0.25 0.14

Polynoidae (polychaete) 0.19 0.01

Phyllodocidae (polychaete) 0.68 0.00

Nephtyidae (polychaete) 0.12 0.00

Scalibregmidae 0.06 0.01

Maldanidae (polychaete) 0.12 0.00

Sabellaridae 0.06 0.00

Hirudinea (leech) 0.06 0.04

Mollusca 0.25 0.02

Gastropoda (snail) 5.37 0.56

Naticidae (snail) 0.06 0.00

Buccinum sp. (snail) 0.06 0.00

Neptuneidae (snail) 0.12 0.03

Neptunea sp. (snail) 0.06 <0.01 

Pteropoda 0.12 0.00

Bivalvia (clam) 2.65 0.08

Nuculana sp. (clam) 0.19 0.00

Nuculana fossa (clam) 0.37 0.00

Yoldia sp. (clam) 0.06 0.00

Pectinidae (scallops) 0.06 0.00

Cardiidae (cockles) 0.06 0.00

Cephalopoda (squid and octopus) 0.62 0.06

Teuthoidea (squid) 1.05 0.22

Octopoda (octopus) 2.34 1.72

Crustacea 2.47 0.02

Calanoida (copepod) 1.42 0.00

Cirripedia (barnacle) 0.19 0.00

Mysidacea Mysida (mysid) 5.61 0.06

Mysidae (mysid) 5.92 0.05

Cumacea (cumacean) 1.54 0.00

Isopoda (isopod) 0.31 0.00

Amphipoda (amphipod) 0.37 0.00

Gammaridea (amphipod) 31.34 0.28

Ampeliscidae (amphipod) 0.19 0.00

Amphipoda Hyperiidea (amphipod) 0.56 0.00

Caprellidea (amphipod) 0.12 0.00

Caprellidae (amphipod) 0.25 0.00

Euphausiacea (euphausiid) 2.04 0.17

Bentheuphausiidae 0.06 0.02

Euphausiidae (euphausiid) 10.61 0.35

Thysanoessa sp. (euphausiid) 0.06 0.00

Thysanoessa raschii (euphausiid) 0.06 0.01

Natantia (shrimp) 3.27 0.03

Caridea (shrimp) 4.57 0.09

Hippolytidae (shrimp) 2.10 0.11

80
Table B-3.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Spirontocaris sp. (shrimp) 0.62 0.01

Lebbeus sp. (shrimp) 0.06 0.00

Lebbeus groenlandicus (shrimp) 0.06 0.01

Eualus sp. (shrimp) 0.37 0.01

Pandalidae (shrimp) 4.81 0.28

Pandalus sp. (shrimp) 1.67 0.10

Pandalus borealis (shrimp) 1.23 0.25

Pandalus goniurus (shrimp) 1.11 0.13

Crangonidae (shrimp) 17.09 0.41

Crangon sp. (shrimp) 9.19 0.23

Crangon alaskensis (shrimp) 0.49 0.01

Crangon dalli (shrimp) 8.45 0.70

Crangon communis (shrimp) 1.17 0.11

Argis sp. (shrimp) 1.85 0.09

Argis lar (shrimp) 0.74 0.08

Argis dentata (shrimp) 0.12 0.00

Argis ovifer (shrimp) 0.12 0.01

Reptantia (crab) 6.11 0.43

Decapoda Reptantia legs (for unident. crabs) 0.37 0.01

Anomura (crab) 0.31 0.05

Paguridae (hermit crab) 16.59 3.16

Paguridae legs (hermit crabs) 0.19 0.01

Pagurus sp. (hermit crab) 0.12 0.04

Lithodidae (king crab) 0.25 0.10

Lithodidae (king crab - legs only) 0.19 0.10

Paralithodes sp. (king crab) 0.06 0.03

Paralithodes camtschatica (red king crab) 0.06 0.43

Decapoda brachyura (crab) 0.74 0.03

Decapoda brachyura legs (for unident. crabs) 0.31 0.03

Majidae (spider crab) 0.12 0.02

Majidae legs (for C. opilio, C. bairdi, etc) 0.31 0.06

Hyas sp. (lyre crab) 0.62 0.13

Hyas coarctatus (lyre crab) 0.19 0.08

Chionoecetes sp. (snow and Tanner crab) 8.14 1.34

Chionoecetes opilio (snow crab) 14.99 6.43

Chionoecetes bairdi (Tanner crab) 15.42 5.26

Telmessus cheiragonus (hair crab) 0.80 0.35

Erimacrus isenbeckii (Korean horse-hair crab) 0.12 0.03

Cancridae (crab) 0.12 0.00

Cancer oregonensis (pygmy Cancer crab) 0.12 0.00

Pinnotheridae (pea crab) 0.93 0.05

Pinnixa sp. (pea crab) 0.62 0.01

Sipuncula (marine worm) 0.31 0.06

Echiura (marine worm) 8.82 0.65

Echiurus sp. (marine worm) 0.12 0.01

Echiurus echiurus (marine worm) 0.80 0.05

Priapulida (worm) 0.68 0.10

Ectoprocta (bryozoan) 0.25 0.01

81
Table B-3.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Ctenodiscus crispatus (mud sea star) 0.06 0.01

Ophiuroidae Ophiurida (brittle star) 0.31 0.04

Brittle star legs 0.06 0.00

Ophiuridae (brittle star) 0.06 0.00

Ophiura sarsi (brittle star) 0.06 0.00

Holothuroidea (sea cucumber) 0.12 0.02

Urochordata (tunicate) 0.19 0.03

Larvacea Copelata 0.06 0.00

Lampetra tridentatus (Pacific lamprey) 0.06 0.24

Bathyraja parmifera (Alaska skate) 0.06 0.13

Bathyraja sp. (skate) 0.06 0.03

Osteichthyes Teleostei (fish) 7.40 0.44

Non-gadoid fish remains 5.37 0.32

Nemichthyidae (snipe eel) 0.06 0.00

Clupeidae 0.12 0.00

Clupea pallasi (Pacific herring) 0.19 0.20

Salmonidae (salmon, whitefish) 0.06 0.02

Osmeridae (smelts) 0.25 0.01

Mallotus villosus (capelin) 0.12 0.01

Gadidae (gadid fish) 2.84 0.84

Gadus macrocephalus (Pacific cod) 0.25 0.10

Theragra chalcogramma (walleye pollock) 21.96 52.93

Zoarcidae (eelpout) 5.00 1.86

Lycodes sp. (eelpout unid) 0.19 0.11

Lycodes brevipes (shortfin eelpout) 0.62 0.44

Scorpaeniformes (rockfish and cottid) 0.06 0.00

Pleurogrammus monopterygius (Atka mackerel) 0.06 0.05

Cottoidei (sculpin) 1.73 0.60

Cottidae (sculpin) 0.62 0.09

Dasycottus setiger (spinyhead sculpin) 0.06 0.03

Icelinus sp. 0.12 0.01

Icelinus borealis (Northern Sculpin) 0.12 0.01

Triglops sp. (sculpin) 0.06 0.01

Agonidae (poacher) 1.05 0.15

Aspidophoroides bartoni (Aleutian alligatorfish) 0.06 0.01

Podothecus acipenserinus (sturgeon poacher) 0.12 0.03

Occella dodecaedron (Bering poacher) 0.06 0.02

Sarritor frenatus (sawback poacher) 0.06 0.01

Trichodon trichodon (Pacific sandfish) 0.12 0.24

Stichaeidae (prickleback) 2.71 0.34

Lumpenus fabricii (slender eelblenny) 0.06 0.00

Lumpenus sagitta (snake prickleback) 0.06 0.00

Lumpenus maculatus (daubed shanny) 0.19 0.02

Poroclinus rothrocki (whitebarred pricklback) 0.12 0.02

Cryptacanthodes aleutensis (dwarf wrymouth) 0.06 0.01

Ammodytes sp. (sand lance) 1.05 0.31

Ammodytes hexapterus (Pacific sand lance) 0.86 0.27

Pleuronectiformes Pleuronectoidei (flatfish) 1.17 0.26

82
Table B-3.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Pleuronectidae (flatfish) 4.57 1.65

Hippoglossoides elassodon (flathead sole) 0.19 0.09

Lepidopsetta sp. (rock sole type) 0.19 0.30

Lepidopsetta bilineata (southern rock sole) 0.06 0.01

Lepidopsetta polyxystra (northern rock sole) 0.25 0.43

Pleuronectes asper (yellowfin sole) 0.43 0.54

Pleuronectes proboscideus (longhead dab) 0.06 0.02

Aves (bird part) 0.19 0.00

Unidentified organic material 1.97 0.13

Unidentified eggs 0.12 0.01

Unidentified worm-like organism 0.56 0.03

Fishery offal 4.32 9.91

Unidentified tube 0.19 0.00

Unidentified algae 0.86 0.03

Rocks 0.49 0.02

Total non-empty stomachs = 1,621

Total prey number = 8,330

Total prey weight = 85,451 g

Total empty stomachs = 17

Number of hauls = 156

83
Table B-4.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of flathead sole (Hippoglossoides elassodon) 

 collected in the eastern Bering Sea in 1998, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 10.29 2.39

Sternaspidae (polychaete) 0.74 0.06

Gastropoda (snail) 1.47 0.56

Bivalvia (clam) 7.35 9.40

Nuculana sp. (clam) 2.21 0.10

Crustacea 1.47 0.01

Ostracoda 0.74 0.02

Calanoida (copepod) 2.94 0.01

Mysidacea Mysida (mysid) 9.56 0.90

Mysidae (mysid) 22.79 8.59

Cumacea (cumacean) 2.94 0.02

Gammaridea (amphipod) 16.91 0.56

Euphausiidae (euphausiid) 7.35 1.62

Caridea (shrimp) 2.21 2.13

Pandalidae (shrimp) 5.88 6.22

Pandalus sp. (shrimp) 0.74 0.38

Pandalus borealis (shrimp) 1.47 3.98

Crangonidae (shrimp) 20.59 29.50

Crangon sp. (shrimp) 0.74 0.29

Reptantia (crab) 1.47 0.05

Paguridae (hermit crab) 7.35 15.78

Chionoecetes sp. (snow and Tanner crab) 1.47 0.41

Chionoecetes bairdi (Tanner crab) 4.41 2.96

Echiura (marine worm) 1.47 0.46

Ophiuroidae Ophiurida (brittle star) 30.15 6.27

Brittle star legs 1.47 0.90

Osteichthyes Teleostei (fish) 0.74 0.01

Non-gadoid fish remains 0.74 0.47

Theragra chalcogramma (walleye pollock) 0.74 0.13

Zoarcidae (eelpout) 2.21 1.03

Icelus sp. (sculpin) 0.74 4.48

Unidentified worm-like organism 0.74 0.01

Unidentified tube 6.62 0.31

Total non-empty stomachs = 136

Total prey number = 381

Total prey weight = 173 g

Total empty stomachs = 73

Number of hauls = 23

84
Table B-5.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Pacific Halibut (Hippoglossus stenolepis) collected 

 in the eastern Bering Sea in 1998, May through September. 

 Mean % 

F.O 

Mean % 

Prey Name Weight 

Polychaeta (worm) 0.83 0.00

Hirudinea (leech) 0.28 0.03

Mollusca 0.28 0.01

Gastropoda (snail) 3.03 0.05

Bivalvia (clam) 1.10 0.04

Octopoda (octopus) 2.75 1.10

Mysidae (mysid) 3.58 0.01

Gammaridea (amphipod) 0.55 0.00

Euphausiidae (euphausiid) 1.93 0.01

Thysanoessa sp. (euphausiid) 0.28 0.00

Natantia (shrimp) 0.83 0.02

Caridea (shrimp) 1.38 0.01

Eualus sp. (shrimp) 0.55 0.00

Pandalidae (shrimp) 1.38 0.04

Pandalus sp. (shrimp) 2.20 0.03

Pandalus borealis (shrimp) 0.55 0.04

Pandalus goniurus (shrimp) 0.28 0.18

Pandalus montagui tridens (shrimp) 0.28 0.00

Crangonidae (shrimp) 6.06 0.06

Crangon sp. (shrimp) 4.96 0.07

Crangon dalli (shrimp) 2.75 0.03

Argis sp. (shrimp) 0.55 0.02

Reptantia (crab) 2.75 0.01

Anomura (crab) 0.28 0.00

Paguridae (hermit crab) 23.69 3.90

Paguridae legs (hermit crabs) 3.31 0.06

Pagurus ochotensis (hermit crab) 0.28 0.35

Decapoda brachyura (crab) 0.55 0.12

Majidae (spider crab) 0.28 0.01

Oregonia sp. (decorator crab) 0.28 0.03

Oregonia gracilis (decorator crab) 0.28 0.02

Hyas sp. (lyre crab) 1.93 0.07

Hyas lyratus (lyre crab) 0.55 0.29

Chionoecetes sp. (snow and Tanner crab) 3.03 0.46

Chionoecetes opilio (snow crab) 8.54 2.31

Chionoecetes bairdi (Tanner crab) 6.89 2.67

Telmessus cheiragonus (hair crab) 0.83 0.04

Erimacrus isenbeckii (Korean horse-hair crab) 1.93 0.38

Pinnixa sp. (pea crab) 0.28 0.00

Echiura (marine worm) 0.55 0.03

Holothuroidea (sea cucumber) 0.28 0.01

Osteichthyes Teleostei (fish) 4.96 0.51

Non-gadoid fish remains 4.96 0.47

Clupea pallasi (Pacific herring) 0.55 0.85

Osmeridae (smelts) 2.48 0.26

Mallotus villosus (capelin) 1.38 0.08

85
Table B-5.--Continued. 

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Gadidae (gadid fish) 4.96 0.61

Gadus macrocephalus (Pacific cod) 3.03 0.97

Theragra chalcogramma (walleye pollock) 37.19 60.28

Zoarcidae (eelpout) 2.48 1.62

Cottoidei (sculpin) 4.13 0.97

Cottidae (sculpin) 1.65 0.28

Myoxocephalus sp. (sculpin) 0.28 0.40

Agonidae (poacher) 1.65 0.15

Podothecus acipenserinus (sturgeon poacher) 0.28 0.19

Sarritor frenatus (sawback poacher) 0.28 0.01

Stichaeidae (prickleback) 0.55 0.07

Ammodytes sp. (sand lance) 6.06 0.34

Ammodytes hexapterus (Pacific sand lance) 7.44 0.57

Pleuronectiformes Pleuronectoidei (flatfish) 3.58 3.99

Pleuronectidae (flatfish) 14.05 6.66

Hippoglossoides elassodon (flathead sole) 0.28 0.03

Hippoglossoides robustus (Bering flounder) 0.28 0.02

Lepidopsetta polyxystra (northern rock sole) 0.55 0.15

Pleuronectes asper (yellowfin sole) 4.41 3.63

Pleuronectes proboscideus (longhead dab) 1.38 1.48

Aves (bird part) 0.28 0.00

Unidentified organic material 0.28 0.01

Unidentified eggs 0.55 0.00

Fishery offal 1.93 1.38

Unidentified tube 0.28 0.00

Overboard material (non-fishery) 0.28 1.46

Total non-empty stomachs = 363

Total prey number = 1,418

Total prey weight = 31,856 g

Total empty stomachs = 34

Number of hauls = 81

86
Table B-6.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of northern rock sole (Lepidopsetta polyxystra) 

 collected in the eastern Bering Sea in 1998, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Porifera (sponge) 0.44 0.00

Annelida (worm) 0.44 0.11

Polychaeta (worm) 71.18 6.62

Polynoidae (polychaete) 20.52 0.70

Phyllodocidae (polychaete) 16.59 0.30

Nereidae (polychaete) 10.92 0.30

Nephtyidae (polychaete) 17.03 7.55

Goniadidae (polychaete) 27.07 0.39

Onuphidae (polychaete) 0.87 0.05

Lumbrineridae 1.31 0.10

Orbiniidae (polychaete) 24.45 0.95

Spionidae (polychaete) 1.31 0.40

Chaetopteridae (polychaete) 0.44 0.01

Cirratulidae (polychaete) 0.44 0.00

Flabelligeridae (polychaete) 3.49 0.60

Brada sp. (polychaete) 3.06 1.19

Scalibregma inflatum 0.44 0.29

Opheliidae (polychaete) 5.24 0.45

Travisia sp. (polychaete) 4.80 2.56

Capitellidae (polychaete) 0.44 0.04

Maldanidae (polychaete) 25.33 3.65

Ampharetidae (polychaete) 17.47 4.30

Terebellidae (polychaete) 3.49 5.38

Trichobranchidae (polychaete) 1.31 0.67

Sabellidae (polychaete) 0.87 0.05

Sabellida (polychaete) 1.31 0.08

Terebellida (polychaete) 0.44 0.00

Mollusca 1.31 0.04

Gastropoda (snail) 9.61 0.10

Bivalvia (clam) 62.88 5.67

Nuculana sp. (clam) 0.44 0.15

Yoldia scissurata (clam) 7.42 1.88

Cardiidae (cockles) 1.75 0.83

Clinocardium ciliatum (Iceland cockle) 3.06 1.53

Crustacea 3.49 0.18

Mysidacea Mysida (mysid) 1.31 0.03

Mysidae (mysid) 7.86 0.32

Cumacea (cumacean) 28.38 0.38

Isopoda (isopod) 3.49 0.04

Anthuridea (Isopod) 0.44 0.00

Peracarida Isopoda Valvifera 1.31 0.18

Gammaridea (amphipod) 74.67 3.73

Ampeliscidae (amphipod) 11.35 1.02

Protomedeia sp. (amphipod) 5.68 0.04

Anonyx sp. (amphipod) 7.42 0.91

87
Table B-6.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Caprellidea (amphipod) 1.75 0.02

Euphausiacea (euphausiid) 2.18 0.13

Euphausiidae (euphausiid) 1.75 0.08

Euphausia pacifica (euphausiid) 0.44 0.05

Natantia (shrimp) 0.44 0.05

Caridea (shrimp) 1.75 0.54

Reptantia (crab) 1.75 0.05

Paguridae (hermit crab) 1.31 0.37

Chionoecetes bairdi (Tanner crab) 0.44 0.06

Sipuncula (marine worm) 2.18 2.72

Echiura (marine worm) 7.86 1.34

Echiurus echiurus (marine worm) 11.35 13.05

Priapulida (worm) 3.49 14.19

Ectoprocta (bryozoan) 2.18 0.02

Ophiuroidae Ophiurida (brittle star) 19.21 2.84

Brittle star legs 2.62 0.06

Sand dollar 2.18 0.30

Holothuroidea (sea cucumber) 5.68 3.31

Ascidiacea (sea squirt) 0.87 0.02

Ascidia sp. (tunicate) 0.44 0.01

Larvacea Copelata 3.93 0.13

Ammodytes hexapterus (Pacific sand lance) 0.87 4.46

Unidentified organic material 21.40 1.50

Unidentified worm-like organism 5.24 0.86

Unidentified tube 2.62 0.07

Total non-empty stomachs = 229

Total prey number = 5,804

Total prey weight = 297 g

Total empty stomachs = 22

Number of hauls = 43

88
Table B-7.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of skates collected in the eastern Bering Sea in 1998, 

 May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 12.50 0.27

Crustacea 5.00 0.13

Mysidae (mysid) 17.50 0.07

Gammaridea (amphipod) 45.00 1.87

Euphausiidae (euphausiid) 7.50 0.02

Caridea (shrimp) 15.00 0.58

Crangonidae (shrimp) 7.50 0.68

Crangon sp. (shrimp) 5.00 0.25

Crangon dalli (shrimp) 5.00 0.20

Argis sp. (shrimp) 20.00 3.95

Argis lar (shrimp) 7.50 2.79

Reptantia (crab) 17.50 0.75

Decapoda Reptantia legs (for unident. crabs) 2.50 0.00

Paguridae (hermit crab) 27.50 1.69

Paguridae legs (hermit crabs) 2.50 0.31

Decapoda brachyura (crab) 5.00 0.23

Majidae (spider crab) 5.00 0.11

Chionoecetes sp. (snow and Tanner crab) 7.50 0.71

Osteichthyes Teleostei (fish) 2.50 0.10

Non-gadoid fish remains 5.00 0.28

Gadidae (gadid fish) 5.00 0.38

Theragra chalcogramma (walleye pollock) 20.00 52.73

Cottidae (sculpin) 2.50 0.07

Agonidae (poacher) 2.50 1.02

Stichaeidae (prickleback) 5.00 0.04

Pleuronectidae (flatfish) 2.50 1.14

Lepidopsetta polyxystra (northern rock sole) 2.50 1.06

Fishery offal 5.00 28.52

Total non-empty stomachs = 40

Total prey number = 58

Total prey weight = 818 g

Total empty stomachs = 12

Number of hauls = 7

89
Table B-8.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of walleye pollock (Theragra chalcogramma) collected 

 in the eastern Bering Sea in 1998, May through September. 

Mean % 

F.O 

Mean % 

Prey Name Weight 

Hydrozoa 0.07 0.02

Annelida (worm) 0.04 <0.01 

Polychaeta (worm) 3.15 0.20

Polynoidae (polychaete) 0.04 0.00

Mollusca 0.07 0.01

Gastropoda (snail) 0.04 0.00

Pteropoda 0.04 0.00

Bivalvia (clam) 0.14 0.00

Cephalopoda (squid and octopus) 0.07 0.00

Teuthoidea (squid) 0.07 0.00

Octopoda (octopus) 0.04 0.00

Crustacea 1.52 0.02

Copepoda 0.04 0.00

Calanoida (copepod) 49.40 12.51

Malacostraca Leptostraca 0.07 0.00

Mysidacea Mysida (mysid) 6.77 0.29

Mysidae (mysid) 0.14 0.00

Cumacea (cumacean) 3.15 0.03

Isopoda (isopod) 0.04 0.00

Amphipoda (amphipod) 0.22 0.00

Gammaridea (amphipod) 6.99 0.09

Amphipoda Hyperiidea (amphipod) 5.90 0.02

Hyperiidae (amphipod) 0.33 0.00

Caprellidea (amphipod) 0.04 0.00

Euphausiacea (euphausiid) 28.12 31.97

Euphausiidae (euphausiid) 39.67 36.49

Thysanoessa inermis (euphausiid) 0.25 0.02

Thysanoessa raschii (euphausiid) 0.18 1.62

Decapoda (shrimp and crab) 0.58 0.02

Natantia (shrimp) 2.64 0.26

Caridea (shrimp) 1.09 0.26

Hippolytidae (shrimp) 0.36 0.11

Pandalidae (shrimp) 0.65 0.16

Pandalus sp. (shrimp) 0.33 0.07

Pandalus borealis (shrimp) 0.43 0.25

Pandalus goniurus (shrimp) 0.18 0.07

Pandalopsis sp. (shrimp) 0.22 0.03

Crangonidae (shrimp) 1.30 0.19

Crangon sp. (shrimp) 2.21 0.68

Crangon dalli (shrimp) 1.09 0.26

Crangon communis (shrimp) 0.11 0.01

Argis sp. (shrimp) 0.22 0.05

Reptantia (crab) 2.86 0.02

Paguridae (hermit crab) 0.54 0.02

Paralithodes sp. (king crab) 0.04 0.00

Decapoda brachyura (crab) 0.04 <0.01

90
Table B-8.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Majidae (spider crab) 0.11 <0.01

Echiura (marine worm) 0.33 0.15

Ophiuroidae Ophiurida (brittle star) 0.04 0.00

Brittle star legs 0.07 0.00

Chaetognatha (arrow worm) 8.03 0.28

Urochordata (tunicate) 0.04 0.00

Larvacea Copelata 1.27 0.24

Osteichthyes Teleostei (fish) 3.91 1.46

Non-gadoid fish remains 0.54 0.07

Fish eggs 0.04 0.00

Osmeridae (smelts) 0.04 0.02

Bathylagidae (deepsea smelts) 0.04 0.00

Myctophidae (lanternfish) 0.11 0.19

Gadidae (gadid fish) 0.76 0.76

Theragra chalcogramma (walleye pollock) 3.40 4.82

Zoarcidae (eelpout) 0.07 0.02

Scorpaeniformes (rockfish and cottid) 0.07 0.00

Scorpaenidae 0.04 0.00

Hexagrammidae (greenling) 0.04 0.00

Cottoidei (sculpin) 0.07 0.02

Hemilepidotus hemilepidotus (red Irish lord) 0.04 0.00

Icelinus sp. 0.04 0.00

Agonidae (poacher) 0.11 0.04

Stichaeidae (prickleback) 0.07 0.06

Lumpenus sp. (prickleback) 0.04 0.00

Ammodytes sp. (sand lance) 0.18 0.18

Ammodytes hexapterus (Pacific sand lance) 0.14 0.04

Pleuronectiformes Pleuronectoidei (flatfish) 0.18 0.01

Hippoglossoides elassodon (flathead sole) 0.04 0.02

Lepidopsetta sp. (rock sole type) 0.04 0.01

Reinhardtius hippoglossoides (Greenland turbot) 0.04 0.00

Unidentified organic material 6.12 5.02

Sand 0.04 <0.01

Unidentified worm-like organism 0.04 0.00

Fishery offal 0.33 0.74

Unidentified tube 0.04 0.00

Unidentified algae 0.14 0.01

Rocks 0.04 <0.01

Total non-empty stomachs = 2,763

Total prey number = 4,491

Total prey weight = 19,826 g

Total empty stomachs = 227

Number of hauls = 217

91
Table B-9.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of yellowfin sole (Limanda aspera) collected in the 

 eastern Bering Sea in 1998, May through September 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Foraminiferida Textulariina (foram) 0.55 0.00

Hydrozoa 0.55 0.07

Hydrozoa Hydroida (hydroid) 0.28 <0.01 

Anthozoa (anemome) 0.55 1.88

Polychaeta (worm) 38.50 15.76

Polynoidae (polychaete) 0.55 0.08

Nereidae (polychaete) 0.28 0.01

Nephtyidae (polychaete) 0.55 0.23

Maldanidae (polychaete) 0.28 0.33

Mollusca 0.55 0.84

Gastropoda (snail) 7.76 2.48

Crepidula grandis (grand slipper shell) 0.28 0.17

Pteropoda 0.28 <0.01

Bivalvia (clam) 25.76 8.04

Nuculana sp. (clam) 0.55 0.18

Yoldia sp. (clam) 1.66 3.71

Cardiidae (cockles) 1.11 0.03

Crustacea 2.49 0.05

Calanoida (copepod) 0.83 0.13

Cirripedia (barnacle) 0.55 0.12

Mysidacea Mysida (mysid) 1.39 0.10

Mysidae (mysid) 0.83 0.04

Cumacea (cumacean) 14.68 0.69

Gammaridea (amphipod) 41.27 3.59

Ampeliscidae (amphipod) 0.83 0.04

Caprellidae (amphipod) 1.94 0.07

Euphausiacea (euphausiid) 2.49 0.25

Euphausiidae (euphausiid) 7.48 2.03

Natantia (shrimp) 0.28 0.00

Caridea (shrimp) 0.28 0.08

Spirontocaris sp. (shrimp) 0.28 0.15

Crangonidae (shrimp) 0.28 0.10

Reptantia (crab) 1.11 0.17

Decapoda Reptantia legs (for unident. crabs) 0.28 0.01

Paguridae (hermit crab) 4.71 4.20

Majidae (spider crab) 0.55 0.98

Hyas sp. (lyre crab) 0.28 0.17

Chionoecetes sp. (snow and Tanner crab) 0.28 0.27

Chionoecetes bairdi (Tanner crab) 0.28 0.02

Pinnotheridae (pea crab) 0.28 0.16

Sipuncula (marine worm) 1.39 6.97

Echiura (marine worm) 3.32 11.38

Echiurus echiurus (marine worm) 0.55 2.23

Priapulida (worm) 1.39 6.18

Asteroidea (starfish) 0.28 0.00

92
93

Table B-9.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Ophiuroidae Ophiurida (brittle star) 22.71 6.99

Brittle star legs 2.22 0.18

Echinoidea (sea urchin and sand dollar) 0.28 0.00

Echinacea sp. (sea urchin) 4.43 0.55

Echinoidea Clypeasteroida (sand dollar) 4.71 1.17

Sand dollar 0.28 0.00

Holothuroidea (sea cucumber) 5.54 10.62

Urochordata (tunicate) 3.32 1.80

Ascidiacea (sea squirt) 0.28 0.01

Theragra chalcogramma (walleye pollock) 0.55 0.48

Unidentified organic material 2.22 0.90

Unidentified eggs 0.55 0.21

Unidentified worm-like organism 0.28 0.02

Fishery offal 0.28 0.37

Unidentified tube 0.83 0.15

Unidentified algae 0.83 0.09

Rocks 0.28 1.69

Total non-empty stomachs = 361

Total prey number = 759

Total prey weight = 509 g 

Total empty stomachs = 180

Number of hauls = 57
 Misc. Worms Misc. Crustaceans Amphi

 Misc. Prey Polychaetes Unidentified Walley

 Brittlestars Clams Chionoecetes Misc. F

Prey Key

1998 (months 5-9)

0%

10%20%30%40%50%60%70%80%90%

100%

<20 20-29 30-39 

Alaska plaice length (cm)

Percent by weight

N 0 19 110 

Figure B-1.--Diet composition of Alaska plaice, in terms of average percent by weight, during months 5  predator size in the eastern Bering Sea; N=number of full stomachs.

94
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

1998 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 40-49 

Arrowtooth flounder length (cm)

Percent by weight

N 15 54 47 59 

Figure B-2.--Diet composition of arrowtooth flounder, in terms of average percent by weight, during mo by predator size in the eastern Bering Sea; N=number of full stomachs.

95
 Offal Misc. Crustaceans Lithodidae Walleye Polloc

 Misc. Prey Unidentified Pleuronectidae Misc. Fish

 Chionoecetes

Prey Key

1998 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

70-79

Pacific cod length (cm)

Percent by weight

N= 86 116 305 159 199 232 138 

Figure B-3.--Diet composition of Pacific cod, in terms of average percent by weight, during months 5 th

96

 predator size in the eastern Bering Sea; N=number of full stomachs. 
 Misc. Worms Misc. Crustaceans Am

 Misc. Prey Polychaetes Unidentified W

 Brittlestars Clams Chionoecetes Mi

Prey Key

1998 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 

Flathead sole length (cm)

Percent by weight

N 18 35 74 

Figure B-4.--Diet composition of flathead sole, in terms of average percent by weight, during months 5  predator size in the eastern Bering Sea; N=number of full stomachs. 

97
 Offal Misc. Crustaceans Lithodidae Walleye P

 Misc. Prey Unidentified Pleuronectidae Misc. Fish

 Chionoecetes

1998 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

7079

Pacific halibut length (cm)

Percent by weight

N 1 2 41 91 38 50 47 

Prey Key

Figure B-5.--Diet composition of Pacific halibut, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs.

98
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

1998 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 40-49 

Walleye pollock length (cm)

Percent by weight

N 336 214 122 664 

Figure B-6.--Diet composition of walleye pollock, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs. 

99
 Misc. Worms Misc. Crustaceans Am

 Misc. Prey Polychaetes Unidentified W

 Brittlestars Clams Chionoecetes Mi

Prey Key

1998 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 

Northern rock sole length (cm)

Percent by weight

N 17 124 78 

Figure B-7.--Diet composition of northern rock sole, in terms of average percent by weight, during mon predator size in the eastern Bering Sea; N=number of full stomachs.

100
 Offal Misc. Crustaceans Lithodidae Walleye 

 Misc. Prey Unidentified Pleuronectidae Misc. Fi

 Chionoecetes

1998 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

Skate length (cm)

Percent by weight

N 0 5 11 7 3 68

Prey Key

Figure B-8.--Diet composition of skates, in terms of average percent by weight, during months 5 throug size in the eastern Bering Sea; N=number of full stomachs.

101
 Misc. Worms Misc. Crustaceans 

 Misc. Prey Polychaetes Unidentified 

 Brittlestars Clams Chionoecetes 

Prey Key

1998 (months 5-9)

0%

10%20%30%40%50%60%70%80%90%

100%

<20 20-29 30-39 

Yellowfin sole length (cm)

Percent by weight

N 12 119 188 

Figure B-9.--Diet composition of yellowfin sole, in terms of average percent by weight, during months 5  predator size in the eastern Bering Sea; N=number of full stomachs.

102
Appendix C- Diet of major groundfish species collected 

 from the eastern Bering Sea in 1999 

Table C-1.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Alaska plaice (Pleuronectes quadrituberculatus) 

 collected in the eastern Bering Sea in 1999, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Porifera (sponge) 2.24 1.19

Anthozoa (anemome) 0.90 0.09

Polychaeta (worm) 83.86 53.95

Polynoidae (polychaete) 0.90 0.05

Nephtyidae (polychaete) 4.48 3.23

Opheliidae (polychaete) 1.35 0.55

Sternaspidae (polychaete) 0.45 0.04

Maldanidae (polychaete) 9.42 3.29

Ampharetidae (polychaete) 0.45 0.25

Mollusca 0.45 0.09

Gastropoda (snail) 6.73 0.28

Bivalvia (clam) 18.83 3.44

Calanoida (copepod) 0.90 0.00

Cumacea (cumacean) 0.90 0.00

Isopoda (isopod) 0.45 0.04

Gammaridea (amphipod) 20.63 1.10

Amphipoda Hyperiidea (amphipod) 4.93 0.13

Reptantia (crab) 0.90 0.01

Majidae (spider crab) 0.45 0.07

Sipuncula (marine worm) 4.48 23.22

Echiura (marine worm) 9.42 6.54

Priapulida (worm) 0.90 0.77

Ophiuroidae Ophiurida (brittle star) 6.28 0.22

Echinoidea Clypeasteroida (sand dollar) 4.93 0.13

Holothuroidea (sea cucumber) 0.45 0.58

Hemichordata (acorn worm) 0.90 <0.1 

Non-gadoid fish remains 0.45 0.04

Osmeridae (smelts) 0.45 0.00

Unidentified worm-like organism 0.90 0.08

Unidentified tube 0.45 0.03

Total non-empty stomachs = 223

Total prey number = 135

Total prey weight = 1,170 g

Total empty stomachs = 68

Number of hauls = 30

105
Table C-2.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of arrowtooth flounder (Atheresthes stomias) collected 

 in the eastern Bering Sea in 1999, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Bivalvia (clam) 0.62 0.01

Gammaridea (amphipod) 2.47 0.00

Euphausiidae (euphausiid) 11.11 0.25

Caridea (shrimp) 0.62 0.01

Pandalidae (shrimp) 0.62 0.05

Pandalus borealis (shrimp) 0.62 0.05

Crangonidae (shrimp) 2.47 0.02

Crangon sp. (shrimp) 3.09 0.06

Reptantia (crab) 4.32 0.08

Ophiuroidae Ophiurida (brittle star) 0.62 0.00

Urochordata (tunicate) 0.62 0.03

Osteichthyes Teleostei (fish) 6.79 0.23

Non-gadoid fish remains 1.23 0.50

Osmeridae (smelts) 0.62 0.10

Gadidae (gadid fish) 14.81 5.64

Theragra chalcogramma (walleye pollock) 54.32 92.47

Zoarcidae (eelpout) 0.62 0.13

Cottoidei (sculpin) 0.62 0.05

Stichaeidae (prickleback) 0.62 0.10

Ammodytes hexapterus (Pacific sand lance) 0.62 0.22

Pleuronectidae (flatfish) 0.62 0.00

Unidentified worm-like organism 0.62 <0.01 

Total non-empty stomachs = 162

Total prey number = 169

Total prey weight = 6,278 g

Total empty stomachs = 171 

 Number of hauls = 41

106
Table C-3.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Pacific cod (Gadus macrocephalus) collected in the 

 eastern Bering Sea in 1999, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Porifera (sponge) 0.11 0.02

Scyphozoa (jellyfish) 0.05 0.00

Anthozoa (anemome) 0.16 0.02

Polychaeta (worm) 31.11 0.75

Aphroditidae (sea mouse) 0.43 0.09

Phyllodocidae (polychaete) 0.33 0.00

Nephtyidae (polychaete) 0.38 0.02

Cirratulidae (polychaete) 0.05 0.00

Opheliidae (polychaete) 0.05 0.00

Sternaspidae (polychaete) 0.05 0.00

Maldanidae (polychaete) 0.05 0.01

Hirudinea (leech) 0.38 0.05

Mollusca 0.81 0.08

Gastropoda (snail) 3.96 0.18

Fusitriton oregonensis (snail) 0.05 0.04

Thecosomata (pteropod) 0.05 <0.01 

Bivalvia (clam) 2.93 0.05

Nuculana sp. (clam) 0.33 0.00

Nuculana fossa (clam) 0.11 0.00

Cardiidae (cockles) 0.05 0.00

Cephalopoda (squid and octopus) 0.54 0.06

Teuthoidea (squid) 0.70 0.06

Octopoda (octopus) 3.09 0.24

Crustacea 2.44 0.03

Calanoida (copepod) 0.43 0.00

Mysidacea Mysida (mysid) 5.31 0.05

Mysidae (mysid) 7.64 0.06

Cumacea (cumacean) 0.22 0.00

Isopoda (isopod) 0.22 0.00

Amphipoda (amphipod) 0.33 0.00

Gammaridea (amphipod) 23.96 0.22

Ampeliscidae (amphipod) 0.49 0.00

Amphipoda Hyperiidea (amphipod) 4.01 0.01

Hyperiidae (amphipod) 0.05 0.00

Caprellidea (amphipod) 0.70 0.00

Caprellidae (amphipod) 0.22 0.00

Euphausiacea (euphausiid) 1.52 0.17

Euphausiidae (euphausiid) 5.04 0.03

Thysanoessa raschii (euphausiid) 0.05 0.00

Decapoda (shrimp and crab) 0.05 <0.01 

Natantia (shrimp) 7.43 0.66

Caridea (shrimp) 4.23 0.10

Hippolytidae (shrimp) 1.90 0.04

Eualus sp. (shrimp) 0.05 0.00

Pandalidae (shrimp) 5.42 0.31

Pandalus sp. (shrimp) 1.73 0.37

107
Table C-3.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Pandalus borealis (shrimp) 1.41 0.24

Pandalus goniurus (shrimp) 0.33 0.01

Pandalus jordani (shrimp) 0.05 0.01

Pandalus montagui tridens (shrimp) 0.05 0.00

Crangonidae (shrimp) 8.83 0.23

Crangon sp. (shrimp) 5.09 0.10

Crangon alaskensis (shrimp) 0.27 0.00

Crangon dalli (shrimp) 3.96 0.10

Crangon communis (shrimp) 0.27 0.01

Sclerocrangon boreas (shrimp) 0.05 0.00

Argis sp. (shrimp) 0.65 0.03

Argis lar (shrimp) 0.43 0.03

Reptantia (crab) 6.99 0.50

Decapoda Reptantia legs (for unident. crabs) 0.05 0.00

Anomura (crab) 0.16 0.01

Paguridae (hermit crab) 14.09 2.90

Paguridae legs (hermit crabs) 0.60 0.06

Pagurus sp. (hermit crab) 0.54 0.15

Elassochirus cavimanus (purple hermit crab) 0.05 0.02

Lithodidae (king crab) 1.30 1.59

Lithodidae (king crab - legs only) 0.54 0.27

Paralithodes sp. (king crab) 0.38 0.28

Paralithodes camtschatica (red king crab) 0.05 0.19

Decapoda brachyura (crab) 1.03 0.18

Oxyrhyncha 0.11 0.02

Decapoda brachyura legs (for unident. crabs) 0.27 0.07

Majidae (spider crab) 0.54 0.04

Majidae legs (for C. opilio, C. bairdi, etc) 0.05 0.04

Hyas sp. (lyre crab) 0.16 0.03

Hyas lyratus (lyre crab) 0.05 0.00

Hyas coarctatus (lyre crab) 0.11 0.02

Chionoecetes sp. (snow and Tanner crab) 9.81 1.90

Chionoecetes opilio (snow crab) 7.64 2.81

Chionoecetes bairdi (Tanner crab) 9.54 2.30

Telmessus cheiragonus (hair crab) 0.11 0.02

Cancridae (crab) 0.11 0.00

Pinnotheridae (pea crab) 0.38 0.00

Pinnixa sp. (pea crab) 1.30 0.07

Insecta (insect) 0.05 0.00

Sipuncula (marine worm) 0.49 0.09

Echiura (marine worm) 9.97 0.74

Priapulida (worm) 0.05 0.02

Ectoprocta (bryozoan) 0.22 0.00

Asteroidea (starfish) 0.11 0.00

Ctenodiscus crispatus (mud sea star) 0.11 0.01

Ophiuroidea Euryalina (basket star) 0.11 0.03

Ophiuroidae Ophiurida (brittle star) 0.81 0.01

Echinoidea (sea urchin and sand dollar) 0.05 0.00

108
Table C-3.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Urochordata (tunicate) 0.16 0.00

Ascidiacea (sea squirt) 0.05 0.00

Styela rustica (sea potato) 0.11 0.02

Boltenia sp. (sea onion) 0.11 0.01

Thaliacea (pelagic salp) 0.05 0.00

Bathyraja sp. (skate) 0.05 0.05

Osteichthyes Teleostei (fish) 9.49 0.41

Non-gadoid fish remains 3.85 0.47

Fish eggs 0.05 0.03

Clupeoidei 0.22 0.02

Clupeidae 0.49 0.08

Alosa sapidissima (American shad) 0.05 0.02

Clupea pallasi (Pacific herring) 2.01 1.03

Osmeridae (smelts) 0.38 0.05

Mallotus villosus (capelin) 0.05 0.01

Myctophidae (lanternfish) 0.05 0.03

Stenobrachius sp. (lampfish) 0.11 0.12

Gadidae (gadid fish) 7.05 2.12

Gadus macrocephalus (Pacific cod) 0.27 1.23

Theragra chalcogramma (walleye pollock) 20.43 50.46

Zoarcidae (eelpout) 3.58 0.83

Lycodes sp. (eelpout unid) 0.05 0.02

Lycodes palearis (wattled eelpout) 0.05 0.09

Pleurogrammus monopterygius (Atka mackerel) 0.05 0.37

Cottoidei (sculpin) 0.70 0.07

Icelus spiniger (thorny sculpin) 0.05 0.01

Cottidae (sculpin) 0.22 0.02

Artediellus sp. (sculpin) 0.11 0.00

Dasycottus setiger (spinyhead sculpin) 0.05 0.06

Agonidae (poacher) 0.81 0.03

Aspidophoroides bartoni (Aleutian alligatorfish) 0.11 0.01

Asterotheca sp. (poacher) 0.11 0.01

Podothecus acipenserinus (sturgeon poacher) 0.16 0.06

Cyclopteridae (snailfish) 0.05 0.01

Bathymasteridae (ronquils) 0.05 0.01

Bathymaster signatus (searcher) 0.22 0.81

Stichaeidae (prickleback) 0.87 0.11

Lumpenella longirostris (longsnout prickleback) 0.05 0.00

Cryptacanthodes aleutensis (dwarf wrymouth) 0.05 0.01

Zaprora silenus (prowfish) 0.05 0.04

Ammodytes hexapterus (Pacific sand lance) 0.22 0.01

Pleuronectiformes Pleuronectoidei (flatfish) 1.36 0.75

Pleuronectidae (flatfish) 3.52 4.16

Atheresthes stomias (arrowtooth flounder) 0.22 0.12

Hippoglossoides elassodon (flathead sole) 0.33 0.20

Lepidopsetta sp. (rock sole type) 0.76 1.89

Lepidopsetta polyxystra (northern rock sole) 0.38 1.24

Pleuronectes asper (yellowfin sole) 0.22 0.48

109
Table C-3.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Aves (bird part) 0.05 0.00

Unidentified organic material 0.92 0.06

Sand 0.05 0.00

Unidentified eggs 0.05 0.00

Unidentified worm-like organism 0.60 0.03

Fishery offal 5.96 13.21

Unidentified tube 0.27 0.00

Overboard material (non-fishery) 0.05 0.29

Wood 0.11 0.00

Unidentified algae 0.43 0.00

Total non-empty stomachs = 1,845

Total prey number = 15,596

Total prey weight = 118,810 g

Total empty stomachs = 47

Number of hauls = 215

 

110
Table C-4.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of flathead sole (Hippoglossoides elassodon) collected 

 in the eastern Bering Sea in 1999, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 23.71 4.63

Nephtyidae (polychaete) 0.43 0.07

Terebellidae (polychaete) 0.43 0.01

Bivalvia (clam) 6.47 8.85

Nuculana sp. (clam) 0.43 0.02

Yoldia sp. (clam) 3.88 2.45

Pectinidae (scallops) 1.72 0.23

Calanoida (copepod) 2.59 0.03

Peracarida Mysidacea (mysid) 0.43 0.01

Mysidacea Mysida (mysid) 4.31 0.99

Mysidae (mysid) 3.88 0.69

Cumacea (cumacean) 2.16 0.03

Isopoda (isopod) 0.86 0.07

Gammaridea (amphipod) 8.62 0.83

Ampeliscidae (amphipod) 0.43 0.02

Amphipoda Hyperiidea (amphipod) 1.29 0.03

Euphausiidae (euphausiid) 1.29 0.04

Caridea (shrimp) 0.86 0.46

Pandalidae (shrimp) 1.29 1.70

Pandalus sp. (shrimp) 1.29 2.07

Pandalus borealis (shrimp) 0.43 0.47

Crangonidae (shrimp) 1.29 1.06

Crangon sp. (shrimp) 2.16 1.44

Crangon dalli (shrimp) 3.02 1.58

Crangon communis (shrimp) 0.43 0.41

Paguridae (hermit crab) 6.47 5.36

Pagurus sp. (hermit crab) 1.29 3.37

Majidae (spider crab) 0.43 0.15

Majidae legs (for C. opilio, C. bairdi, etc) 0.43 0.03

Chionoecetes sp. (snow and Tanner crab) 3.02 0.48

Chionoecetes opilio (snow crab) 1.29 0.27

Chionoecetes bairdi (Tanner crab) 4.74 3.12

Pinnixa sp. (pea crab) 0.86 0.19

Echiura (marine worm) 0.43 3.32

Ophiuroidae Ophiurida (brittle star) 39.66 22.17

Osteichthyes Teleostei (fish) 0.86 0.13

Non-gadoid fish remains 1.29 0.50

Gadidae (gadid fish) 1.29 1.37

Theragra chalcogramma (walleye pollock) 9.05 30.60

Cottoidei (sculpin) 0.43 0.07

Pleuronectidae (flatfish) 0.43 0.34

Unidentified tube 1.72 0.35

Rocks 0.43 0.00

111
Table C-4.--Continued. 

Total non-empty stomachs = 232

Total prey number = 223

Total prey weight = 518 g

Total empty stomachs = 80

Number of hauls = 38

112
Table C-5.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Greenland turbot (Reinhardtius hippoglossoides) 

 collected in the eastern Bering Sea in 1999, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Mysidacea Mysida (mysid) 2.33 0.00

Gammaridea (amphipod) 4.65 0.00

Caridea (shrimp) 2.33 0.00

Chionoecetes bairdi (Tanner crab) 2.33 0.01

Osteichthyes Teleostei (fish) 6.98 0.00

Non-gadoid fish remains 2.33 0.05

Gadidae (gadid fish) 13.95 3.05

Theragra chalcogramma (walleye pollock) 62.79 87.73

Zoarcidae (eelpout) 2.33 0.01

Pleuronectidae (flatfish) 2.33 0.24

Lepidopsetta bilineata (southern rock sole) 2.33 1.18

Fishery offal 4.65 7.72

Total non-empty stomachs = 43

Total prey number = 53

Total prey weight = 8,090 g

Total empty stomachs = 25

Number of hauls = 23

113
Table C-6.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Pacific halibut (Hippoglossus stenolepis) collected 

 in the eastern Bering Sea in 1999, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 0.84 0.01

Mollusca 0.42 0.05

Gastropoda (snail) 0.84 0.01

Bivalvia (clam) 0.42 0.02

Cephalopoda (squid and octopus) 0.84 0.63

Octopoda (octopus) 1.68 3.03

Crustacea 0.42 <0.01 

Mysidacea Mysida (mysid) 0.84 0.00

Mysidae (mysid) 5.46 0.06

Isopoda (isopod) 0.42 0.00

Gammaridea (amphipod) 0.84 0.01

Euphausiidae (euphausiid) 2.10 0.02

Natantia (shrimp) 3.36 0.03

Caridea (shrimp) 1.68 0.06

Hippolytidae (shrimp) 0.42 0.00

Pandalidae (shrimp) 1.68 0.56

Pandalus borealis (shrimp) 0.84 0.10

Crangonidae (shrimp) 2.52 0.02

Crangon sp. (shrimp) 5.46 0.09

Crangon dalli (shrimp) 1.26 0.01

Reptantia (crab) 1.26 0.00

Paguridae (hermit crab) 29.41 4.35

Paguridae legs (hermit crabs) 2.52 0.03

Pagurus sp. (hermit crab) 2.94 0.75

Lithodidae (king crab) 0.42 <0.01

Decapoda brachyura (crab) 0.84 0.01

Oxyrhyncha 0.84 0.03

Majidae (spider crab) 0.84 0.08

Chionoecetes sp. (snow and Tanner crab) 4.20 0.63

Chionoecetes opilio (snow crab) 2.94 2.40

Chionoecetes bairdi (Tanner crab) 7.98 1.51

Echiura (marine worm) 1.68 0.39

Ectoprocta (bryozoan) 0.42 0.00

Urochordata (tunicate) 0.42 0.04

Osteichthyes Teleostei (fish) 10.92 0.62

Non-gadoid fish remains 5.04 0.17

Clupeidae 0.42 0.29

Clupea pallasi (Pacific herring) 0.84 0.70

Osmeridae (smelts) 3.78 0.48

Mallotus villosus (capelin) 3.78 0.75

Gadidae (gadid fish) 13.03 3.65

Gadus macrocephalus (Pacific cod) 0.42 4.08

Theragra chalcogramma (walleye pollock) 27.31 68.31

Zoarcidae (eelpout) 1.68 0.14

Lycodes sp. (eelpout unid) 0.42 0.18

114
Table C-6.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Lycodes palearis (wattled eelpout) 0.42 0.10

Cottoidei (sculpin) 0.84 0.12

Myoxocephalus sp. (sculpin) 0.42 0.80

Agonidae (poacher) 0.42 0.06

Ammodytes sp. (sand lance) 0.42 0.05

Ammodytes hexapterus (Pacific sand lance) 0.42 0.04

Pleuronectiformes Pleuronectoidei (flatfish) 0.42 0.16

Pleuronectidae (flatfish) 1.26 0.56

Unidentified worm-like organism 0.42 <0.01

Fishery offal 2.10 3.46

Total non-empty stomachs = 238

Total prey number = 546

Total prey weight = 19,884 g

Total empty stomachs = 199

Number of hauls = 67

115
Table C-7.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of northern rock sole (Lepidopsetta polyxystra) 

 collected in the eastern Bering Sea in 1999, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Anthozoa (anemome) 0.25 0.03

Polychaeta (worm) 77.19 54.03

Phyllodocidae (polychaete) 0.25 <0.01

Nephtyidae (polychaete) 3.76 5.46

Eunicidae 0.25 <0.01

Cirratulidae (polychaete) 1.25 1.90

Opheliidae (polychaete) 3.26 4.13

Maldanidae (polychaete) 2.51 1.94

Gastropoda (snail) 0.25 0.04

Pteropoda 0.50 0.01

Bivalvia (clam) 12.53 2.57

Yoldia sp. (clam) 1.00 0.39

Cardiidae (cockles) 0.50 0.21

Mysidacea Mysida (mysid) 2.26 0.22

Mysidae (mysid) 1.75 0.09

Cumacea (cumacean) 3.51 0.06

Isopoda (isopod) 0.75 0.03

Gammaridea (amphipod) 21.80 2.39

Amphipoda Hyperiidea (amphipod) 3.01 0.06

Caprellidea (amphipod) 0.25 0.00

Euphausiacea (euphausiid) 0.25 0.00

Natantia (shrimp) 0.75 0.30

Caridea (shrimp) 0.25 0.00

Crangonidae (shrimp) 0.75 0.16

Crangon dalli (shrimp) 1.25 0.78

Argis sp. (shrimp) 0.25 0.20

Paguridae (hermit crab) 0.50 0.14

Chionoecetes opilio (snow crab) 0.25 0.04

Sipuncula (marine worm) 2.76 11.49

Echiura (marine worm) 3.01 4.51

Priapulida (worm) 0.25 0.30

Ophiuroidae Ophiurida (brittle star) 14.04 3.45

Echinoidea Clypeasteroida (sand dollar) 3.76 0.43

Holothuroidea (sea cucumber) 0.25 0.12

Osteichthyes Teleostei (fish) 0.75 0.05

Ammodytes sp. (sand lance) 3.76 3.42

Unidentified organic material 0.25 <0.01

Unidentified worm-like organism 0.75 0.33

Unidentified tube 1.25 0.18

Rocks 1.00 <0.01

116
Table C-7.--Continued. 

Total non-empty stomachs = 399

Total prey number = 335

Total prey weight = 859.452g

Total empty stomachs = 73

Number of hauls = 55 

117
Table C-8.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of skates collected in the eastern Bering Sea in 1999, 

 May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Cnidaria 0.29 0.02

Scyphozoa (jellyfish) 0.58 0.03

Polychaeta (worm) 21.68 1.73

Polynoidae (polychaete) 0.58 0.01

Gastropoda (snail) 0.29 0.01

Cephalopoda (squid and octopus) 0.29 0.02

Teuthoidea (squid) 0.29 0.00

Crustacea 2.89 0.05

Mysidacea Mysida (mysid) 5.78 0.10

Mysidae (mysid) 1.45 0.03

Isopoda (isopod) 0.87 0.01

Gammaridea (amphipod) 44.80 4.18

Amphipoda Hyperiidea (amphipod) 0.58 0.00

Euphausiacea (euphausiid) 1.16 0.02

Euphausiidae (euphausiid) 5.49 0.02

Decapoda (shrimp and crab) 0.29 <0.01 

Natantia (shrimp) 8.38 1.79

Caridea (shrimp) 2.60 0.09

Hippolytidae (shrimp) 0.29 0.00

Spirontocaris sp. (shrimp) 0.58 0.01

Pandalidae (shrimp) 3.76 0.54

Pandalus sp. (shrimp) 0.29 0.01

Pandalus borealis (shrimp) 1.45 0.27

Crangonidae (shrimp) 6.94 0.46

Crangon sp. (shrimp) 2.02 0.18

Crangon alaskensis (shrimp) 0.58 0.04

Crangon dalli (shrimp) 1.45 0.19

Argis sp. (shrimp) 1.16 0.13

Argis lar (shrimp) 0.29 0.05

Reptantia (crab) 6.07 0.54

Paguridae (hermit crab) 34.97 10.59

Pagurus sp. (hermit crab) 0.87 0.26

Lithodidae (king crab) 1.16 3.34

Lithodidae (king crab - legs only) 0.29 0.11

Paralithodes sp. (king crab) 0.29 0.14

Decapoda brachyura (crab) 2.89 1.26

Majidae (spider crab) 2.89 0.55

Majidae legs (for C. opilio, C. bairdi, etc) 2.02 1.20

Hyas lyratus (lyre crab) 0.29 0.12

Chionoecetes sp. (snow and Tanner crab) 18.21 4.78

Chionoecetes opilio (snow crab) 3.47 1.21

Chionoecetes bairdi (Tanner crab) 2.89 3.13

Echiura (marine worm) 0.29 0.00

Holothuroidea (sea cucumber) 0.29 0.01

Osteichthyes Teleostei (fish) 4.62 0.60

118
Table C-8.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Non-gadoid fish remains 4.34 0.95

Clupeidae 0.58 0.69

Clupea pallasi (Pacific herring) 1.16 0.44

Oncorhynchus sp. (salmon) 0.29 6.66

Osmeridae (smelts) 0.29 0.00

Gadidae (gadid fish) 3.18 0.89

Theragra chalcogramma (walleye pollock) 10.69 35.03

Zoarcidae (eelpout) 4.62 3.45

Lycodes brevipes (shortfin eelpout) 0.58 0.17

Gasterosteus aculeatus (3-spined stickleback) 0.29 0.01

Cottoidei (sculpin) 0.58 0.28

Agonidae (poacher) 0.29 0.04

Podothecus acipenserinus (sturgeon poacher) 0.29 0.01

Cyclopteridae (snailfish) 0.29 0.03

Stichaeidae (prickleback) 1.73 0.34

Ammodytes sp. (sand lance) 0.29 0.14

Ammodytes hexapterus (Pacific sand lance) 0.87 0.40

Pleuronectidae (flatfish) 4.91 2.54

Hippoglossoides elassodon (flathead sole) 0.29 0.64

Lepidopsetta polyxystra (northern rock sole) 1.16 5.93

Pleuronectes asper (yellowfin sole) 0.29 0.48

Unidentified organic material 0.29 0.01

Unidentified eggs 0.29 0.01

Fishery offal 2.02 3.00

Total non-empty stomachs = 346

Total prey number = 685

Total prey weight = 9,535 g

Total empty stomachs = 44

Number of hauls = 62

119
Table C-9.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of walleye pollock (Theragra chalcogramma) collected 

 in the eastern Bering Sea in 1999, May through September. 

Mean % 

F.O 

Mean % 

Prey Name Weight 

Scyphozoa (jellyfish) <0.01 0.02

Polychaeta (worm) 4.40 0.66

Polynoidae (polychaete) 0.10 0.00

Nephtyidae (polychaete) 0.02 0.04

Mollusca 0.04 0.00

Gastropoda (snail) 0.10 0.06

Pteropoda 3.34 0.37

Thecosomata (pteropod) 1.67 0.12

Gymnosomata (pteropod) 0.02 0.00

Bivalvia (clam) 0.16 0.00

Cephalopoda (squid and octopus) 0.12 0.01

Teuthoidea (squid) 0.14 0.00

Octopoda (octopus) 0.06 0.00

Crustacea 1.59 0.14

Copepoda 9.33 2.05

Calanoida (copepod) 41.66 10.43

Calanidae (copepod) 0.10 0.01

<0.01 Harpacticoida (copepod) 0.02

Cirripedia (barnacle) 0.02 0.00

Mysidacea Mysida (mysid) 3.42 1.62

Mysidae (mysid) 9.55 6.29

<0.01 Petalophthalmus sp. (mysid) 0.02

Cumacea (cumacean) 1.45 0.05

Amphipoda (amphipod) 0.12 0.02

Gammaridea (amphipod) 7.40 0.45

Ampeliscidae (amphipod) 0.60 0.19

Ampelisca sp. (amphipod) 0.02 0.00

Amphipoda Hyperiidea (amphipod) 11.42 0.49

Hyperiidae (amphipod) 0.48 0.01

<0.01 Caprellidea (amphipod) 0.02

Caprellidae (amphipod) 0.02 0.00

Euphausiacea (euphausiid) 7.20 2.78

Euphausiidae (euphausiid) 57.68 34.11

Euphausia pacifica (euphausiid) 0.06 0.00

Thysanoessa sp. (euphausiid) 0.02 0.01

Thysanoessa inermis (euphausiid) 0.32 0.03

Decapoda (shrimp and crab) 0.18 0.01

Natantia (shrimp) 1.07 0.20

Caridea (shrimp) 2.59 0.27

Pasiphaea pacifica (shrimp) 0.02 0.00

Hippolytidae (shrimp) 1.09 0.28

Eualus sp. (shrimp) 0.02 0.00

Pandalidae (shrimp) 1.67 1.06

Pandalus sp. (shrimp) 0.20 0.08

Pandalus borealis (shrimp) 0.12 0.09

Crangonidae (shrimp) 4.68 4.59

120
Table C-9.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Crangon sp. (shrimp) 0.72 0.45

Crangon alaskensis (shrimp) 0.36 0.15

Crangon dalli (shrimp) 1.89 2.05

Crangon communis (shrimp) 0.08 0.01

Argis sp. (shrimp) 0.26 0.15

Argis dentata (shrimp) 0.02 0.00

Reptantia (crab) 5.21 0.73

Decapoda Reptantia legs (for unident. crabs) 0.02 0.04

Anomura (crab) 0.06 0.00

Paguridae (hermit crab) 0.52 0.05

Decapoda brachyura (crab) 0.08 0.00

Chionoecetes sp. (snow and Tanner crab) 0.02 0.00

Telmessus cheiragonus (hair crab) 0.02 0.68

Echiura (marine worm) 0.58 0.33

Ectoprocta (bryozoan) 0.04 0.00

Asteroidea (starfish) 0.04 0.00

Ctenodiscus crispatus (mud sea star) 0.02 0.01

Ophiuroidae Ophiurida (brittle star) 0.02 0.00

Brittle star legs 0.02 0.00

Holothuroidea (sea cucumber) 0.02 0.01

Chaetognatha (arrow worm) 3.64 0.08

Urochordata (tunicate) 0.02 0.01

Thaliacea (pelagic salp) 0.04 0.01

Larvacea Copelata 5.27 2.11

Misc. fish 0.12 0.02

Osteichthyes 0.06 0.01

Osteichthyes Teleostei (fish) 3.56 0.99

Non-gadoid fish remains 1.49 0.50

Fish eggs 0.04 0.00

Clupeoidei 0.06 0.10

Clupeidae 0.10 0.07

Clupea pallasi (Pacific herring) 2.13 9.28

Osmeridae (smelts) 0.34 0.33

Mallotus villosus (capelin) 0.28 1.08

Thaleichthys pacificus (eulachon) 0.08 0.36

Bathylagus stilbius (California smoothtongue) 0.02 0.01

Gadidae (gadid fish) 2.59 1.18

Theragra chalcogramma (walleye pollock) 4.50 9.53

Zoarcidae (eelpout) 0.04 0.04

Scorpaeniformes (rockfish and cottid) 0.02 0.00

Cottoidei (sculpin) 0.18 0.02

Cottidae (sculpin) 0.02 0.00

Hemilepidotus sp. (sculpin) 0.06 0.00

Agonidae (poacher) 0.04 0.00

Pallasina barbata (tubenose poacher) 0.02 0.00

Stichaeidae (prickleback) 0.06 0.04

Ammodytes sp. (sand lance) 0.46 0.45

Ammodytes hexapterus (Pacific sand lance) 0.76 0.36

121
Table C-9.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Pleuronectiformes Pleuronectoidei (flatfish) 0.22 0.06

Pleuronectidae (flatfish) 0.18 0.43

Pleuronectes asper (yellowfin sole) 0.02 0.02

Reinhardtius hippoglossoides (Greenland turbot) 0.02 0.01

Aves (bird part) 0.02 0.00

Unidentified organic material 0.62 0.04

<0.01 Sand 0.02

Unidentified eggs 0.04 0.00

Unidentified worm-like organism 0.10 0.03

Fishery offal 0.56 1.63

Unidentified tube 0.08 0.00

Unidentified algae 0.04 0.00

<0.01 Unidentified material 0.06

Total non-empty stomachs = 4,974

Total prey number = 9,332

Total prey weight = 33,346 g

Total empty stomachs = 339

Number of hauls = 336

122
Table C-10.--Prey items (expressed in mean percent frequency of occurrence and 

 mean percent total weight) of yellowfin sole (Limanda aspera) collected in 

 the eastern Bering Sea in 1999, May through September. 

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Porifera (sponge) 0.27 0.01

Hydrozoa Hydroida (hydroid) 0.27 0.20

Scyphozoa (jellyfish) 4.35 3.03

Polychaeta (worm) 39.95 18.90

Phyllodocidae (polychaete) 1.09 0.17

Nephtyidae (polychaete) 0.82 1.26

Mollusca 0.54 <0.01 

Gastropoda (snail) 0.54 0.04

Pteropoda 1.36 <0.01

Nudibranchia dendronotoidea (nudibranch) 0.54 0.05

Bivalvia (clam) 24.46 16.28

Yoldia sp. (clam) 0.82 2.06

Clinocardium ciliatum (Iceland cockle) 0.27 0.33

Crustacea 0.27 <0.01

Cirripedia (barnacle) 0.27 0.01

Mysidacea Mysida (mysid) 3.53 2.20

Mysidae (mysid) 0.82 0.11

Cumacea (cumacean) 9.51 0.72

Isopoda (isopod) 0.82 0.05

Gammaridea (amphipod) 26.63 3.40

Ampeliscidae (amphipod) 1.63 0.21

Amphipoda Hyperiidea (amphipod) 10.60 0.67

Caprellidea (amphipod) 0.27 0.00

Euphausiidae (euphausiid) 4.89 2.97

Natantia (shrimp) 0.54 0.00

Caridea (shrimp) 0.54 0.27

Crangonidae (shrimp) 0.27 0.00

Crangon sp. (shrimp) 0.54 0.50

Crangon dalli (shrimp) 0.54 0.46

Reptantia (crab) 0.82 0.06

Decapoda Reptantia legs (for unident. crabs) 0.27 0.08

Paguridae (hermit crab) 1.90 0.76

Pagurus sp. (hermit crab) 0.27 0.20

Decapoda Reptantia legs (for unident. crabs) 0.27 0.06

Pinnotheridae (pea crab) 1.36 0.08

Sipuncula (marine worm) 0.54 1.16

Echiura (marine worm) 9.51 21.47

Priapulida (worm) 0.27 0.06

Ectoprocta (bryozoan) 4.35 2.99

Ophiuroidae Ophiurida (brittle star) 20.65 6.19

Echinoidea (sea urchin and sand dollar) 9.24 2.22

Sand dollar 0.54 0.05

Holothuroidea (sea cucumber) 1.09 0.89

Ascidiacea (sea squirt) 0.27 <0.01

123
124

Table C-10.--Continued. 

Total non-empty stomachs = 368

Total prey number = 738

Total prey weight = 461 g

Total empty stomachs = 228

Number of hauls = 58

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Ascidia sp. (tunicate) 0.54 0.10

Non-gadoid fish remains 0.27 0.57

Theragra chalcogramma (walleye pollock) 0.27 0.57

Cyclopteridae (snailfish) 0.27 0.39

Ammodytes hexapterus (Pacific sand lance) 0.82 0.23

Unidentified eggs 0.27 <0.01

Unidentified worm-like organism 1.63 0.20

Fishery offal 0.82 <0.01

Unidentified tube 1.90 0.21

Unidentified algae 0.27

Unidentified material 0.27

<0.01

0.30
 Misc. Worms Misc. Crustaceans A

 Misc. Prey Polychaetes Unidentified W

 Brittlestars Clams Chionoecetes M

Prey Key

1999 (months 5-9)

0%

10%20%30%40%50%60%70%80%90%

100%

<20 20-29 30-39 

Alaska plaice length (cm)

Percent by weight

N 0 49 115 

Figure C-1.--Diet composition of Alaska plaice, in terms of average percent by weight, during months 5  predator size in the eastern Bering Sea; N=number of full stomachs. 

125
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

1999 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 40-49 

Arrowtooth flounder length (cm)

Percent by weight

N 3 20 37 50 

Figure C-2.--Diet composition of arrowtooth flounder, in terms of average percent by weight, during mo by predator size in the eastern Bering Sea; N=number of full stomachs. 

126
 Offal Misc. Crustaceans Lithodidae Walleye 

 Misc. Prey Unidentified Pleuronectidae Misc. Fi

 Chionoecetes

1999 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

Pacific cod length (cm)

Percent by weight

N 146 159 115 306 145 219 107 

Prey Key

Figure C-3.--Diet composition of Pacific cod, in terms of average percent by weight, during months 5 th predator size in the eastern Bering Sea; N=number of full stomachs. 

127
 Misc. Worms Misc. Crustaceans Amph

 Misc. Prey Polychaetes Unidentified Walle

 Brittlestars Clams Chionoecetes Misc

Prey Key

1999 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 

Flathead sole length (cm)

Percent by weight

N 8 50 123 

Figure C-4.--Diet composition of flathead sole, in terms of average percent by weight, during months 5  predator size in the eastern Bering Sea; N=number of full stomachs. 

128
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

1999 (months 5-9)

0%

20%40%60%80%

100%

20-29 30-39 40-49 

Greenland turbot length (cm)

Percent by weight

N 22 3 

Figure C-5.--Diet composition of Greenland turbot, in terms of average percent by weight, during mont predator size in the eastern Bering Sea; N=number of full stomachs.

129
 Offal Misc. Crustaceans Lithodidae Walleye Pollo

 Misc. Prey Unidentified Pleuronectidae Misc. Fish

 Chionoecetes

1999 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

70-79

Pacific halibut length (cm)

Percent by weight

N 1 12 21 75 45 19 19 

Prey Key

Figure C-6.--Diet composition of Pacific halibut, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs. 

130
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

1999 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 40-49 

Walleye pollock length (cm)

Percent by weight

N 575 302 662 1086 

Figure C-7.--Diet composition of walleye pollock, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs.

131
 Misc. Worms Misc. Crustaceans Am

 Misc. Prey Polychaetes Unidentified Wa

 Brittlestars Clams Chionoecetes Mis

Prey Key

1999 (months 5-9)

0%

10%20%30%40%50%60%70%80%90%

100%

<20 20-29 30-39 

Northern rock sole length (cm)

Percent by weight

N 38 169 163 

Figure C-8.--Diet composition of northern rock sole, in terms of average percent by weight, during mon predator size in the eastern Bering Sea; N=number of full stomachs.

132
 Offal Misc. Crustaceans Lithodidae Walleye Pollo

 Misc. Prey Unidentified Pleuronectidae Misc. Fish

 Chionoecetes

1999 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

70-79

Skate length (cm)

Percent by weight

N 11 35 79 62 43 47 49 

Prey Key

Figure C-9.--Diet composition of skates, in terms of average percent by weight, during months 5 throug size in the eastern Bering Sea; N=number of full stomachs. 

133
 Misc. Worms Misc. Crustaceans 

 Misc. Prey Polychaetes Unidentified 

 Brittlestars Clams Chionoecetes 

Prey Key

1999 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 

Yellowfin sole length (cm)

Percent by weight

N 44 154 156 

Figure C-10.--Diet composition of yellowfin sole, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs.

134
Appendix D- Diet of major groundfish species collected 

from the eastern Bering Sea in 2000 

Table D-1.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Alaska plaice (Pleuronectes quadrituberculatus) 

 collected in the eastern Bering Sea in 2000, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 49.49 16.29

Polynoidae (polychaete) 1.01 0.01

Phyllodocidae (polychaete) 4.04 0.07

Nephtyidae (polychaete) 18.18 18.45

Goniadidae (polychaete) 1.01 0.02

Onuphidae (polychaete) 3.03 0.34

Arabellidae (polychaete) 1.01 1.05

Orbiniidae (polychaete) 3.03 1.12

Flabelligeridae (polychaete) 2.02 1.11

Opheliidae (polychaete) 6.06 1.72

Sternaspidae (polychaete) 14.14 8.92

Maldanidae (polychaete) 31.31 5.78

Oweniidae (polychaete) 4.04 0.02

Pectinariidae (polychaete) 1.01 0.20

Ampharetidae (polychaete) 6.06 0.76

Terebellidae (polychaete) 1.01 0.12

Gastropoda (snail) 2.02 0.02

Bivalvia (clam) 41.41 25.98

Mysidacea Mysida (mysid) 1.01 0.06

Cumacea (cumacean) 3.03 0.01

Isopoda (isopod) 1.01 0.02

Gammaridea (amphipod) 28.28 4.11

Ampeliscidae (amphipod) 3.03 0.69

Amphipoda Hyperiidea (amphipod) 2.02 0.05

Sipuncula (marine worm) 1.01 7.67

Echiura (marine worm) 1.01 4.48

Ophiuroidae Ophiurida (brittle star) 8.08 0.71

Ophiura sarsi (brittle star) 1.01 0.02

Sand dollar 1.01 0.19

Total non-empty stomachs = 99

Total prey number = 943

Total prey weight = 416 g

Total empty stomachs = 6

Number of hauls = 13

 

137
Table D-2.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of arrowtooth flounder (Atheresthes stomias) collected 

 in the eastern Bering Sea in 2000, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 2.56 0.08

Opheliidae (polychaete) 0.23 0.00

Mollusca 0.47 0.03

Bivalvia (clam) 0.93 0.03

Cephalopoda (squid and octopus) 0.23 0.01

Teuthoidea (squid) 0.47 0.54

Crustacea 1.40 0.01

Calanoida (copepod) 1.17 0.00

Mysidae (mysid) 5.36 0.16

Cumacea (cumacean) 0.23 0.00

Amphipoda (amphipod) 0.23 0.00

Gammaridea (amphipod) 2.80 0.02

Amphipoda Hyperiidea (amphipod) 0.47 0.00

Euphausiacea (euphausiid) 0.23 0.01

Euphausiidae (euphausiid) 20.75 2.61

Natantia (shrimp) 5.36 0.33

Caridea (shrimp) 4.90 0.73

Hippolytidae (shrimp) 0.23 0.06

Eualus sp. (shrimp) 0.23 0.05

Eualus biunguis (shrimp) 0.23 0.11

Pandalidae (shrimp) 1.86 0.42

Pandalus sp. (shrimp) 0.93 0.17

Pandalus borealis (shrimp) 1.17 0.43

Pandalus goniurus (shrimp) 0.47 0.06

Pandalopsis sp. (shrimp) 0.47 0.36

Pandalopsis dispar (sidestripe shrimp) 0.70 0.46

Crangonidae (shrimp) 1.86 0.04

Crangon sp. (shrimp) 0.70 0.03

Crangon dalli (shrimp) 0.47 0.03

Crangon communis (shrimp) 0.70 0.04

Argis lar (shrimp) 0.47 0.02

Reptantia (crab) 0.23 0.00

Chionoecetes bairdi (Tanner crab) 0.23 0.00

Ophiuroidae Ophiurida (brittle star) 0.47 0.00

Ophiura sarsi (brittle star) 0.23 0.20

Chaetognatha (arrow worm) 0.47 0.00

Osteichthyes Teleostei (fish) 11.42 0.88

Non-gadoid fish remains 3.03 2.81

Osmeridae (smelts) 0.23 0.67

Thaleichthys pacificus (eulachon) 0.23 1.18

Mallotus villosus (capelin) 0.23 0.02

Myctophidae (lanternfish) 0.23 0.00

138
Table D-2.--Continued. 

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Gadidae (gadid fish) 7.46 3.29

Theragra chalcogramma (walleye pollock) 34.27 74.70

Zoarcidae (eelpout) 0.93 0.42

Lycodapus fierasfer (black mouth eelpout) 0.23 0.15

Lycodes sp. (eelpout unid) 0.47 0.14

Lycodes brevipes (shortfin eelpout) 0.93 1.00

Lycodes palearis (wattled eelpout) 0.23 0.57

Coryphaenoides cinereus (popeye grenadier) 0.23 4.20

Pleurogrammus monopterygius (Atka mackerel) 0.23 0.25

Cottoidei (sculpin) 0.47 0.33

Icelus spiniger (thorny sculpin) 0.47 0.17

Triglops sp. (sculpin) 0.23 0.71

Podothecus acipenserinus (sturgeon poacher) 0.23 0.10

Stichaeidae (prickleback) 0.70 0.11

Ammodytes hexapterus (Pacific sand lance) 0.70 0.06

Pleuronectidae (flatfish) 0.23 0.02

Unidentified organic material 0.23 0.02

Sand 1.40 0.02

Unidentified worm-like organism 0.23 0.01

Fishery offal 1.40 1.10

Total non-empty stomachs = 429

Total prey number = 6,689

Total prey weight = 7,486 g

Total empty stomachs = 200

Number of hauls = 100

139
Table D-3.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Pacific cod (Gadus macrocephalus) collected in the 

 eastern Bering Sea in 2000, May through September. 

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Porifera (sponge) 0.05 0.01

Cnidaria 0.20 0.02

Scyphozoa (jellyfish) 0.05 0.00

Anthozoa (anemome) 0.15 0.10

Polychaeta (worm) 28.34 1.10

Aphroditidae (sea mouse) 0.85 0.19

Polynoidae (polychaete) 0.05 0.00

Phyllodocidae (polychaete) 1.30 0.03

Tomopteridae (polychaete) 0.05 0.00

Nereidae (polychaete) 0.20 0.01

Nephtyidae (polychaete) 1.05 0.04

Goniadidae (polychaete) 0.10 0.00

Onuphidae (polychaete) 0.15 0.00

Lumbrineridae 0.20 0.00

Flabelligeridae (polychaete) 0.10 0.01

Scalibregmidae 0.10 0.00

Capitellidae (polychaete) 0.20 0.00

Maldanidae (polychaete) 0.80 0.03

Pectinariidae (polychaete) 0.05 0.00

Ampharetidae (polychaete) 0.10 0.00

Hirudinea (leech) 0.10 0.00

Mollusca 0.25 0.01

Gastropoda (snail) 4.56 0.50

Pteropoda 0.10 0.00

Thecosomata (pteropod) 0.05 0.00

Bivalvia (clam) 1.05 0.03

Nuculana sp. (clam) 0.15 0.00

Yoldia sp. (clam) 0.05 0.00

Cardiidae (cockles) 0.05 0.00

Cephalopoda (squid and octopus) 0.70 0.32

Teuthoidea (squid) 1.15 0.19

Octopoda (octopus) 2.31 1.22

Crustacea 1.00 0.01

Copepoda 0.05 0.00

Calanoida (copepod) 0.25 0.00

Large calanoid (copepod) > 5mm 0.05 0.00

Cirripedia (barnacle) 0.20 0.01

Mysidacea Mysida (mysid) 8.02 0.06

Mysidae (mysid) 2.41 0.02

Cumacea (cumacean) 0.65 0.00

Isopoda (isopod) 0.85 0.00

Amphipoda (amphipod) 0.05 0.00

Gammaridea (amphipod) 25.63 0.49

Ampeliscidae (amphipod) 1.55 0.02

Amphipoda Hyperiidea (amphipod) 3.06 0.02

140
Table D-3.--Continued. 

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Caprellidea (amphipod) 0.95 0.00

Caprellidae (amphipod) 0.15 0.00

Euphausiacea (euphausiid) 1.20 0.02

Euphausiidae (euphausiid) 3.61 0.08

Thysanoessa sp. (euphausiid) 0.05 0.00

Decapoda (shrimp and crab) 0.05 0.00

Natantia (shrimp) 5.02 0.15

Caridea (shrimp) 3.61 0.07

Hippolytidae (shrimp) 4.11 0.08

Spirontocaris arcuata (shrimp) 0.10 0.00

Eualus sp. (shrimp) 0.30 0.02

Eualus barbata (shrimp) 0.05 0.01

Eualus biunguis (shrimp) 0.05 0.00

Heptacarpus moseri (shrimp) 0.10 0.00

Pandalidae (shrimp) 5.87 0.39

Pandalus sp. (shrimp) 2.51 0.23

Pandalus borealis (shrimp) 2.81 0.31

Pandalus goniurus (shrimp) 0.60 0.04

Pandalus jordani (shrimp) 0.65 0.03

Pandalus montagui tridens (shrimp) 0.60 0.09

Pandalopsis sp. (shrimp) 0.25 0.11

Pandalopsis dispar (sidestripe shrimp) 0.10 0.04

Crangonidae (shrimp) 11.03 0.25

Crangon sp. (shrimp) 6.67 0.21

Crangon alaskensis (shrimp) 0.30 0.01

Crangon dalli (shrimp) 7.22 0.32

Crangon communis (shrimp) 2.31 0.08

Argis sp. (shrimp) 0.55 0.02

Argis lar (shrimp) 0.45 0.02

Argis dentata (shrimp) 0.05 0.00

Argis alaskensis (shrimp) 0.10 0.00

Argis crassa 0.05 0.01

Reptantia (crab) 7.47 0.65

Decapoda Reptantia legs (for unident. crabs) 0.50 0.08

Anomura (crab) 0.05 0.02

Paguridae (hermit crab) 18.05 4.34

Paguridae legs (hermit crabs) 1.35 0.15

Pagurus sp. (hermit crab) 0.25 0.12

Elassochirus cavimanus (purple hermit crab) 0.05 0.00

Lithodidae (king crab) 0.25 0.48

Lithodidae (king crab - legs only) 0.15 0.45

Paralithodes sp. (king crab) 0.35 0.75

Paralithodes camtschatica (red king crab) 0.10 0.33

Munida quadrispina (pinch bug) 0.10 0.01

Decapoda brachyura (crab) 0.90 0.21

Oxyrhyncha 0.20 0.02

Decapoda brachyura legs (for unident. crabs) 0.35 0.03

Majidae (spider crab) 1.96 0.32

141
Table D-3.--Continued. 

 

Mean % 

F.O 

Mean % 

Prey Name Weight 

Majidae legs (for C. opilio, C. bairdi, etc) 0.80 0.21

Oregonia gracilis (decorator crab) 0.10 0.02

Hyas sp. (lyre crab) 0.20 0.01

Hyas lyratus (lyre crab) 0.15 0.03

Hyas coarctatus (lyre crab) 0.10 0.02

Chionoecetes sp. (snow and Tanner crab) 9.23 2.43

Chionoecetes opilio (snow crab) 12.99 5.91

Chionoecetes bairdi (Tanner crab) 10.03 2.92

Pugettia richii (kelp crab) 0.05 0.00

Cherilia longipes (decorator crab) 0.05 0.00

Telmessus cheiragonus (hair crab) 0.15 0.02

Erimacrus isenbeckii (Korean horse-hair crab) 0.05 0.28

Cancer oregonensis (pygmy Cancer crab) 0.10 0.01

Pinnotheridae (pea crab) 0.30 0.01

Pinnixa sp. (pea crab) 0.50 0.01

Sipuncula (marine worm) 0.15 0.01

Echiura (marine worm) 8.38 0.81

Echiuridae (marine worm) 0.20 0.00

Priapulida (worm) 0.20 0.01

Ectoprocta (bryozoan) 0.30 0.00

Asteroidea (starfish) 0.05 0.00

Ctenodiscus crispatus (mud sea star) 0.05 0.01

Ophiuroidae Ophiurida (brittle star) 0.25 0.00

Ophiura sarsi (brittle star) 0.10 0.00

Holothuroidea (sea cucumber) 0.05 0.12

Chaetognatha (arrow worm) 0.05 0.00

Urochordata (tunicate) 0.35 0.02

Ascidia sp. (tunicate) 0.05 0.01

Thaliacea (pelagic salp) 0.15 0.01

Larvacea Copelata 0.05 0.00

Rajidae (skate) 0.05 0.00

Osteichthyes Teleostei (fish) 4.71 0.17

Non-gadoid fish remains 2.01 0.24

Fish eggs 0.05 0.02

Clupea pallasi (Pacific herring) 0.20 0.09

Osmeridae (smelts) 0.25 0.03

Mallotus villosus (capelin) 0.05 0.00

Gadidae (gadid fish) 5.62 1.38

Gadus macrocephalus (Pacific cod) 0.40 0.22

Theragra chalcogramma (walleye pollock) 18.61 46.85

Zoarcidae (eelpout) 4.46 2.43

Lycodes sp. (eelpout unid) 0.65 0.27

Lycodes brevipes (shortfin eelpout) 0.25 0.15

Lycodes palearis (wattled eelpout) 0.40 0.33

Scorpaenidae 0.05 0.02

Cottoidei (sculpin) 1.35 0.24

Icelus spiniger (thorny sculpin) 0.10 0.06

Cottidae (sculpin) 0.15 0.02

142
Table D-3.--Continued. 

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Dasycottus setiger (spinyhead sculpin) 0.05 0.00

Triglops pingeli (ribbed sculpin) 0.10 0.00

Agonidae (poacher) 0.80 0.15

Aspidophoroides bartoni (Aleutian alligatorfish) 0.20 0.01

Podothecus acipenserinus (sturgeon poacher) 0.15 0.02

Sarritor frenatus (sawback poacher) 0.10 0.01

Cyclopteridae (snailfish) 0.20 0.02

Paraliparis sp. (snailfish) 0.05 0.00

Bathymaster signatus (searcher) 0.10 0.17

Stichaeidae (prickleback) 1.60 0.33

Allolumpenus hypochromus (y-prickleback) 0.05 0.02

Lumpenus maculatus (daubed shanny) 0.20 0.02

Poroclinus rothrocki (whitebarred pricklback) 0.10 0.01

Cryptacanthodes aleutensis (dwarf wrymouth) 0.10 0.01

Pholis sp. (gunnel) 0.05 0.01

Ammodytes sp. (sand lance) 0.15 0.03

Ammodytes hexapterus (Pacific sand lance) 1.60 0.24

Pleuronectiformes Pleuronectoidei (flatfish) 1.45 0.47

Pleuronectidae (flatfish) 2.91 2.15

Atheresthes stomias (arrowtooth flounder) 0.15 0.15

Hippoglossoides elassodon (flathead sole) 0.45 0.52

Lepidopsetta sp. (rock sole type) 0.05 0.06

Lepidopsetta bilineata (southern rock sole) 0.10 0.32

Lepidopsetta polyxystra (northern rock sole) 0.45 0.67

Pleuronectes asper (yellowfin sole) 0.30 1.83

Hippoglossus stenolepis (Pacific halibut) 0.05 0.08

Aves (bird part) 0.05 0.00

Unidentified organic material 0.80 0.04

Unidentified eggs 0.25 0.26

Fishery offal 5.07 11.95

Unidentified tube 0.10 0.00

Overboard material (non-fishery) 0.05 0.00

Unidentified algae 0.20 0.01

Rocks 0.35 0.01

Total non-empty stomachs = 1,994

Total prey number = 9,071

Total prey weight = 108,097 g

Total empty stomachs = 60

Number of hauls = 247

143
Table D-4.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of flathead sole (Hippoglossoides elassodon) collected 

 in the eastern Bering Sea in 2000, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 11.24 0.76

Phyllodocidae (polychaete) 1.12 0.00

Nephtyidae (polychaete) 1.12 0.25

Flabelligeridae (polychaete) 4.49 2.97

Maldanidae (polychaete) 2.25 0.96

Bivalvia (clam) 5.62 1.56

Nuculana sp. (clam) 6.74 1.47

Yoldia sp. (clam) 2.25 10.42

Chlamys sp. (scallop) 2.25 0.15

Calanoida (copepod) 1.12 0.01

Large calanoid (copepod) > 5mm 1.12 0.00

Mysidacea Mysida (mysid) 8.99 6.70

Mysidae (mysid) 12.36 0.96

Cumacea (cumacean) 1.12 0.07

Isopoda (isopod) 1.12 0.01

Gammaridea (amphipod) 10.11 0.87

Amphipoda Hyperiidea (amphipod) 5.62 0.04

Natantia (shrimp) 1.12 0.01

Hippolytidae (shrimp) 4.49 0.85

Pandalus sp. (shrimp) 1.12 1.19

Pandalus goniurus (shrimp) 1.12 0.47

Pandalus jordani (shrimp) 1.12 0.51

Crangonidae (shrimp) 4.49 0.75

Crangon dalli (shrimp) 8.99 4.00

Crangon communis (shrimp) 1.12 0.54

Paguridae (hermit crab) 3.37 7.61

Chionoecetes sp. (snow and Tanner crab) 2.25 3.50

Chionoecetes bairdi (Tanner crab) 5.62 0.82

Ophiuroidae Ophiurida (brittle star) 41.57 13.64

Ophiuridae (brittle star) 2.25 0.31

Ophiura sarsi (brittle star) 7.87 10.26

Ophiopholis aculenta (ubiquitous brittle star) 1.12 0.02

Theragra chalcogramma (walleye pollock) 8.99 27.94

Ammodytes hexapterus (Pacific sand lance) 1.12 0.33

Unidentified tube 1.12 0.02

Total non-empty stomachs = 89

Total prey number = 1,152

Total prey weight = 206 g

Total empty stomachs = 11

Number of hauls = 8

144
Table D-5.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Greenland turbot (Reinhardtius hippoglossoides) 

 collected in the eastern Bering Sea in 2000, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 1.85 0.00

Gastropoda (snail) 1.85 0.00

Teuthoidea (squid) 18.52 15.39

Crustacea 1.85 0.00

Mysidae (mysid) 16.67 0.00

Euphausiidae (euphausiid) 1.85 0.00

Natantia (shrimp) 3.70 0.01

Caridea (shrimp) 1.85 0.01

Hippolytidae (shrimp) 3.70 0.10

Eualus sp. (shrimp) 1.85 0.05

Decapoda brachyura (crab) 1.85 0.04

Majidae (spider crab) 1.85 0.18

Chionoecetes angulatus (triangle Tanner crab) 3.70 1.95

Osteichthyes Teleostei (fish) 11.11 0.08

Non-gadoid fish remains 7.41 0.02

Leuroglossus schmidti (northern smoothtongue) 11.11 1.62

Gadidae (gadid fish) 5.56 3.01

Theragra chalcogramma (walleye pollock) 9.26 33.74

Coryphaenoides cinereus (popeye grenadier) 1.85 1.14

Icelus sp. (sculpin) 1.85 0.02

Careproctus sp. (snailfish) 1.85 4.30

Careproctus cypselurus (blackfinned redsnail) 1.85 1.53

Unidentified organic material 1.85 0.03

Total non-empty stomachs = 54

Total prey number = 91

Total prey weight = 5,630 g

Total empty stomachs = 57

Number of hauls = 18

145
Table D-6.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Pacific halibut (Hippoglossus stenolepis) collected 

 in the eastern Bering Sea in 2000, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 3.03 0.00

Mysidacea Mysida (mysid) 15.15 0.16

Mysidae (mysid) 3.03 0.11

Gammaridea (amphipod) 3.03 0.08

Crangonidae (shrimp) 3.03 0.06

Crangon alaskensis (shrimp) 3.03 0.03

Crangon dalli (shrimp) 12.12 0.54

Paguridae (hermit crab) 30.30 6.42

Oregonia gracilis (decorator crab) 9.09 1.66

Pugettia gracilis (kelp crab) 3.03 0.30

Non-gadoid fish remains 3.03 0.01

Mallotus villosus (capelin) 9.09 6.86

Gadidae (gadid fish) 9.09 0.35

Theragra chalcogramma (walleye pollock) 21.21 74.47

Zoarcidae (eelpout) 3.03 0.58

Cottoidei (sculpin) 3.03 0.33

Agonidae (poacher) 3.03 1.21

Podothecus acipenserinus (sturgeon poacher) 3.03 2.20

Ammodytes sp. (sand lance) 3.03 1.01

Ammodytes hexapterus (Pacific sand lance) 9.09 2.20

Pleuronectidae (flatfish) 3.03 0.70

Lepidopsetta bilineata (southern rock sole) 3.03 0.32

Lepidopsetta polyxystra (northern rock sole) 3.03 0.40

Total non-empty stomachs = 33

Total prey number = 120

Total prey weight = 1,029 g

Total empty stomachs = 3

Number of hauls = 4

146
Table D-7.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of northern rock sole (Lepidopsetta polyxystra) 

 collected in the eastern Bering Sea in 2000, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Scyphozoa (jellyfish) 0.88 0.01

Polychaeta (worm) 38.94 18.46

Polynoidae (polychaete) 0.88 0.16

Phyllodocidae (polychaete) 5.31 0.54

Nereidae (polychaete) 1.77 0.07

Nephtyidae (polychaete) 19.47 9.12

Goniadidae (polychaete) 0.88 0.01

Eunicidae 0.88 0.03

Lumbrineridae 0.88 0.69

Arabellidae (polychaete) 1.77 0.69

Orbiniidae (polychaete) 0.88 0.11

Cirratulidae (polychaete) 0.88 0.24

Flabelligeridae (polychaete) 7.08 8.35

Opheliidae (polychaete) 12.39 4.10

Maldanidae (polychaete) 18.58 5.08

Oweniidae (polychaete) 8.85 1.10

Pectinariidae (polychaete) 3.54 0.21

Ampharetidae (polychaete) 1.77 1.68

Terebellidae (polychaete) 2.65 0.78

Bivalvia (clam) 15.04 3.61

Yoldia sp. (clam) 0.88 0.19

Clinocardium ciliatum (Iceland cockle) 0.88 0.12

Mya sp. (soft shell clam) 0.88 0.18

Teuthoidea (squid) 0.88 2.23

Mysidacea Mysida (mysid) 8.85 8.92

Cumacea (cumacean) 6.19 0.08

Gammaridea (amphipod) 29.20 3.17

Amphipoda Hyperiidea (amphipod) 10.62 0.86

Caprellidea (amphipod) 0.88 0.00

Thysanoessa raschii (euphausiid) 0.88 0.86

Crangonidae (shrimp) 5.31 1.98

Crangon dalli (shrimp) 3.54 2.15

Paguridae (hermit crab) 0.88 0.04

Chionoecetes opilio (snow crab) 3.54 0.90

Sipuncula (marine worm) 1.77 1.18

Echiura (marine worm) 9.73 17.69

Ectoprocta (bryozoan) 1.77 0.04

Ophiuroidae Ophiurida (brittle star) 9.73 0.98

Ophiuroidae ophiurida chilophiurina (brittle star) 0.88 0.07

Ophiura sarsi (brittle star) 5.31 0.68

Sand dollar 0.88 0.33

Chaetognatha (arrow worm) 0.88 0.01

Urochordata (tunicate) 0.88 0.72

Larvacea Copelata 0.88 0.01

Gadidae (gadid fish) 0.88 0.82

147
Table D-7.—Continued. 

Mean % Mean % 

Prey Name F.O Weight 

Theragra chalcogramma (walleye pollock) 0.88 0.75

Total non-empty stomachs = 113

Total prey number = 1,801

Total prey weight = 189 g

Total empty stomachs = 23

Number of hauls = 12

148
Table D-8.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of skates collected in the eastern Bering Sea in 2000, 

 May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 28.10 1.17

Polynoidae (polychaete) 0.29 0.00

Eunoe nodosa (polychaete) 0.14 0.01

Phyllodocidae (polychaete) 0.14 0.00

Nereidae (polychaete) 0.43 0.00

Nephtyidae (polychaete) 1.85 0.10

Goniadidae (polychaete) 0.29 0.00

Opheliidae (polychaete) 0.29 0.04

Ophelina acuminata (polychaete) 0.29 0.01

Pectinariidae (polychaete) 0.14 0.00

Gastropoda (snail) 0.71 0.02

Bivalvia (clam) 1.43 0.00

Cephalopoda (squid and octopus) 0.29 0.00

Teuthoidea (squid) 3.71 0.36

Teuthoidea oegopsida (squid) 0.14 0.00

Octopoda (octopus) 0.43 0.05

Crustacea 1.71 0.03

Calanoida (copepod) 0.29 0.00

Large calanoid (copepod) > 5mm 0.14 0.00

Mysidacea Mysida (mysid) 6.42 0.20

Mysidae (mysid) 20.83 0.64

Cumacea (cumacean) 1.43 0.00

Isopoda (isopod) 0.71 0.01

Gammaridea (amphipod) 41.65 2.04

Ampeliscidae (amphipod) 6.70 0.46

Amphipoda Hyperiidea (amphipod) 0.71 0.01

Caprellidea (amphipod) 0.43 0.00

Euphausiacea (euphausiid) 1.71 0.02

Euphausiidae (euphausiid) 8.27 0.04

Thysanoessa inermis (euphausiid) 0.14 0.00

Thysanoessa raschii (euphausiid) 0.14 0.00

Decapoda (shrimp and crab) 0.14 0.00

Natantia (shrimp) 3.71 0.16

Caridea (shrimp) 5.14 0.17

Hippolytidae (shrimp) 6.99 0.58

Spirontocaris sp. (shrimp) 0.14 0.00

Spirontocaris ochotensis (shrimp) 0.29 0.00

Spirontocaris arcuata (shrimp) 0.29 0.03

Lebbeus sp. (shrimp) 0.14 0.00

Lebbeus groenlandicus (shrimp) 0.14 0.01

Eualus sp. (shrimp) 0.57 0.02

Eualus biunguis (shrimp) 0.29 0.01

Eualus avinus (shrimp) 0.14 0.00

Heptacarpus sp. (shrimp) 0.29 0.00

Pandalidae (shrimp) 1.71 0.09

149
Table D-8.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Pandalus sp. (shrimp) 0.29 0.00

Pandalus borealis (shrimp) 0.43 0.02

Pandalus goniurus (shrimp) 1.43 0.06

Pandalus jordani (shrimp) 0.14 0.00

Pandalopsis sp. (shrimp) 0.14 0.01

Crangonidae (shrimp) 7.28 0.80

Crangon sp. (shrimp) 9.13 1.47

Crangon alaskensis (shrimp) 0.57 0.03

Crangon dalli (shrimp) 11.70 3.98

Crangon communis (shrimp) 0.86 0.04

Argis sp. (shrimp) 2.57 0.20

Argis lar (shrimp) 5.56 0.90

Argis dentata (shrimp) 0.29 0.04

Argis alaskensis (shrimp) 0.43 0.06

Argis crassa 0.14 0.00

Reptantia (crab) 16.41 5.48

Decapoda Reptantia legs (for unident. crabs) 0.57 0.69

Paguridae (hermit crab) 14.98 2.80

Paguridae legs (hermit crabs) 0.71 0.08

Pagurus sp. (hermit crab) 0.57 0.14

Elassochirus sp. 0.14 0.01

Decapoda brachyura (crab) 1.14 0.18

Majidae (spider crab) 1.14 0.19

Majidae legs (for C. opilio, C. bairdi, etc) 0.43 0.02

Oregonia gracilis (decorator crab) 0.14 0.01

Hyas sp. (lyre crab) 0.57 0.18

Hyas lyratus (lyre crab) 0.29 0.09

Hyas coarctatus (lyre crab) 0.14 0.00

Chionoecetes sp. (snow and Tanner crab) 19.97 9.45

Chionoecetes opilio (snow crab) 11.84 10.33

Chionoecetes bairdi (Tanner crab) 6.28 2.80

Chionoecetes tanneri (grooved Tanner crab) 0.14 0.34

Echiura (marine worm) 0.43 0.03

Ectoprocta (bryozoan) 1.00 0.01

Ophiuroidae Ophiurida (brittle star) 0.29 0.00

Holothuroidea (sea cucumber) 0.43 0.03

Urochordata (tunicate) 0.14 0.01

Osteichthyes Teleostei (fish) 2.85 0.17

Non-gadoid fish remains 4.71 0.50

Clupea pallasi (Pacific herring) 0.43 0.74

Bathylagidae (deepsea smelts) 0.14 0.00

Bathylagus pacificus (slender blacksmelt) 0.14 0.06

Myctophidae (lanternfish) 2.00 0.21

Gadidae (gadid fish) 1.71 0.76

Gadus macrocephalus (Pacific cod) 0.14 0.28

Theragra chalcogramma (walleye pollock) 9.13 28.74

Zoarcidae (eelpout) 1.43 1.85

Lycodes sp. (eelpout unid) 0.14 0.05

150
Table D-8.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Lycodes brevipes (shortfin eelpout) 0.29 0.11

Lycodes palearis (wattled eelpout) 0.29 0.88

Cottoidei (sculpin) 1.14 0.05

Cottidae (sculpin) 0.57 0.16

Gymnocanthus sp. (sculpin) 0.14 0.05

Gymnocanthus galeatus (sculpin) 0.14 0.19

Agonidae (poacher) 1.14 0.20

Aspidophoroides bartoni (Aleutian alligatorfish) 0.14 0.03

Occella dodecaedron (Bering poacher) 0.71 0.67

Pallasina barbata (tubenose poacher) 0.14 0.01

Cyclopteridae (snailfish) 0.57 0.08

Trichodon trichodon (Pacific sandfish) 0.29 1.50

Bathymaster signatus (searcher) 0.14 0.01

Stichaeidae (prickleback) 0.57 0.10

Ammodytes sp. (sand lance) 0.14 0.11

Ammodytes hexapterus (Pacific sand lance) 6.99 5.38

Pleuronectiformes Pleuronectoidei (flatfish) 1.00 0.54

Pleuronectidae (flatfish) 4.85 3.74

Errex zachirus (rex sole) 0.14 0.78

Hippoglossoides elassodon (flathead sole) 0.29 0.21

Limanda sp. 0.14 0.01

Pleuronectes asper (yellowfin sole) 0.43 0.66

Pleuronectes proboscideus (longhead dab) 0.29 0.24

Unidentified eggs 0.14 0.01

Fishery offal 0.86 4.11

Unidentified tube 0.57 0.01

Unidentified algae 0.57 0.00

Total non-empty stomachs = 701

Total prey number = 8,190

Total prey weight = 19,600 g

Total empty stomachs = 76

Number of hauls = 137

151
Table D-9.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of walleye pollock (Theragra chalcogramma) collected 

 in the eastern Bering Sea in 2000, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Foraminiferida (protozoan) 0.03 0.00

Scyphozoa (jellyfish) 0.08 0.00

Polychaeta (worm) 4.63 0.48

Phyllodocidae (polychaete) 0.08 0.00

Nephtyidae (polychaete) 0.13 0.02

Maldanidae (polychaete) 0.05 0.00

Mollusca 0.05 0.04

Gastropoda (snail) 0.08 0.00

Colus halli (snail) 0.03 0.02

Pteropoda 0.21 0.00

Thecosomata (pteropod) 0.03 0.00

Gymnosomata (pteropod) 0.77 0.01

Bivalvia (clam) 0.13 0.01

Cephalopoda (squid and octopus) 0.08 0.00

Teuthoidea (squid) 0.62 0.23

Octopoda (octopus) 0.03 0.00

Crustacea 1.70 0.08

Copepoda 5.35 0.91

Calanoida (copepod) 37.76 8.16

Calanidae (copepod) 0.03 0.00

Calanus sp. 0.49 0.17

Large calanoid (copepod) > 5mm 0.59 0.10

Medium calanoid (copepod) 2-5mm 2.19 0.62

Small calanod (copepod) 2mm 0.18 0.00

Mysidacea Mysida (mysid) 5.53 1.97

Mysidae (mysid) 13.09 3.03

Cumacea (cumacean) 4.19 0.11

Lampropidae (cumacean) 0.03 0.00

Isopoda (isopod) 0.05 0.00

Amphipoda (amphipod) 0.18 0.00

Gammaridea (amphipod) 11.39 1.84

Ampeliscidae (amphipod) 1.52 0.53

Amphipoda Hyperiidea (amphipod) 20.14 1.78

Hyperiidae (amphipod) 0.03 0.00

Caprellidea (amphipod) 0.26 0.00

Caprellidae (amphipod) 0.03 0.00

Euphausiacea (euphausiid) 15.66 7.40

Euphausiidae (euphausiid) 51.77 37.28

Thysanoessa sp. (euphausiid) 1.88 1.47

Thysanoessa inermis (euphausiid) 0.62 0.56

Thysanoessa raschii (euphausiid) 0.46 0.34

Thysanoessa spinifera (euphausiid) 0.36 0.57

Decapoda (shrimp and crab) 0.59 0.00

Natantia (shrimp) 2.39 0.36

Caridea (shrimp) 2.26 0.37

Hippolytidae (shrimp) 0.64 0.29

152
Table D-9.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Spirontocaris ochotensis (shrimp) 0.03 0.00

Eualus sp. (shrimp) 0.15 0.02

Eualus biunguis (shrimp) 0.03 0.00

Eualus gaimurdii (shrimp) 0.10 0.01

Eualus avinus (shrimp) 0.05 0.01

Pandalidae (shrimp) 0.77 0.20

Pandalus sp. (shrimp) 0.31 0.05

Pandalus borealis (shrimp) 0.18 0.08

Pandalus goniurus (shrimp) 1.47 1.15

Pandalus jordani (shrimp) 0.08 0.01

Pandalus montagui tridens (shrimp) 0.18 0.01

Crangonidae (shrimp) 4.68 1.01

Crangon sp. (shrimp) 2.03 0.43

Crangon alaskensis (shrimp) 1.49 0.45

Crangon dalli (shrimp) 4.89 1.85

Crangon communis (shrimp) 0.21 0.04

Argis sp. (shrimp) 0.21 0.07

Argis lar (shrimp) 0.08 0.05

Argis alaskensis (shrimp) 0.03 0.00

Reptantia (crab) 1.34 0.01

Decapoda Reptantia legs (for unident. crabs) 0.03 0.00

Anomura (crab) 0.28 0.00

Paguridae (hermit crab) 1.39 0.08

Decapoda brachyura (crab) 0.05 0.00

Hyas lyratus (lyre crab) 0.03 0.10

Chionoecetes sp. (snow and Tanner crab) 0.03 0.00

Chionoecetes opilio (snow crab) 0.03 0.06

Echiura (marine worm) 0.77 0.44

Ectoprocta (bryozoan) 0.10 0.01

Echinodermata (sea star, cucumber, urchin) 0.03 0.00

Ophiuroidae Ophiurida (brittle star) 0.03 0.00

Chaetognatha (arrow worm) 9.36 0.20

Urochordata (tunicate) 0.08 0.01

Larvacea Copelata 1.26 0.29

Misc. fish 0.03 0.00

Osteichthyes 0.03 0.00

Osteichthyes Teleostei (fish) 5.89 1.79

Non-gadoid fish remains 1.75 1.31

Fish eggs 0.08 0.00

Clupeidae 0.03 0.00

Clupea pallasi (Pacific herring) 0.18 0.87

Salmonidae (salmon, whitefish) 0.03 0.00

Osmeridae (smelts) 0.23 0.23

Mallotus villosus (capelin) 1.16 2.52

Thaleichthys pacificus (eulachon) 0.03 0.01

Leuroglossus schmidti (northern smoothtongue) 0.13 0.13

Myctophidae (lanternfish) 0.05 0.01

Stenobrachius sp. (lampfish) 0.03 0.00

153
Table D-9.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Gadidae (gadid fish) 2.62 1.35

Gadus macrocephalus (Pacific cod) 0.05 0.11

Theragra chalcogramma (walleye pollock) 6.94 13.20

Zoarcidae (eelpout) 0.03 0.01

Scorpaeniformes (rockfish and cottid) 0.03 0.00

Cottoidei (sculpin) 0.21 0.07

Cottidae (sculpin) 0.08 0.00

Agonidae (poacher) 0.08 0.01

Stichaeidae (prickleback) 0.05 0.02

Zaprora silenus (prowfish) 0.03 0.18

Ammodytes sp. (sand lance) 0.03 0.01

Ammodytes hexapterus (Pacific sand lance) 1.11 0.57

Pleuronectiformes Pleuronectoidei (flatfish) 0.03 0.00

Pleuronectidae (flatfish) 0.15 0.06

Atheresthes evermanni (Kamchatka flounder) 0.03 0.06

Atheresthes stomias (arrowtooth flounder) 0.03 0.01

Lepidopsetta sp. (rock sole type) 0.05 0.00

Lepidopsetta polyxystra (northern rock sole) 0.21 0.22

Microstomus pacificus (Dover sole) 0.03 0.00

Unidentified organic material 1.41 0.16

Sand 0.03 0.01

Unidentified eggs 0.05 0.00

Unidentified worm-like organism 0.05 0.01

Fishery offal 0.41 1.61

Unidentified tube 0.08 0.00

Wood 0.03 0.00

Unidentified algae 0.13 0.05

Rocks 0.05 0.00

Unidentified material 0.03 0.00

Total non-empty stomachs = 3,888

Total prey number = 219,389

Total prey weight = 29,748 g

Total empty stomachs = 162

Number of hauls = 292

154
Table D-10.--Prey items (expressed in mean percent frequency of occurrence and 

 mean percent total weight) of yellowfin sole (Limanda aspera) collected in 

 the eastern Bering Sea in 2000, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Foraminiferida (protozoan) 1.64 0.00

Scyphozoa (jellyfish) 4.10 1.54

Polychaeta (worm) 34.43 11.32

Phyllodocidae (polychaete) 0.82 0.04

Nereidae (polychaete) 0.82 0.13

Nephtyidae (polychaete) 4.92 2.05

Onuphidae (polychaete) 0.82 0.02

Opheliidae (polychaete) 0.82 0.06

Capitellidae (polychaete) 0.82 0.41

Maldanidae (polychaete) 3.28 2.74

Oweniidae (polychaete) 5.74 0.74

Pectinariidae (polychaete) 1.64 0.32

Ampharetidae (polychaete) 0.82 0.74

Hirudinea (leech) 0.82 0.42

Gastropoda (snail) 4.92 4.06

Bivalvia (clam) 15.57 5.66

Yoldia sp. (clam) 0.82 1.16

Cardiidae (cockles) 1.64 0.80

Siliqua sp.(razor clam) 1.64 1.84

Cephalopoda (squid and octopus) 0.82 1.74

Mysidacea Mysida (mysid) 9.02 5.64

Mysidae (mysid) 3.28 0.15

Cumacea (cumacean) 9.84 0.47

Isopoda (isopod) 0.82 0.09

Amphipoda (amphipod) 0.82 0.00

Gammaridea (amphipod) 32.79 8.48

Amphipoda Hyperiidea (amphipod) 11.48 0.27

Caprellidea (amphipod) 1.64 0.00

Euphausiidae (euphausiid) 0.82 0.01

Natantia (shrimp) 0.82 0.00

Pandalidae (shrimp) 0.82 0.01

Crangonidae (shrimp) 2.46 0.50

Crangon alaskensis (shrimp) 0.82 0.99

Crangon dalli (shrimp) 3.28 2.63

Crangon communis (shrimp) 0.82 0.32

Reptantia (crab) 0.82 4.28

Paguridae (hermit crab) 7.38 9.05

Paguridae legs (hermit crabs) 0.82 2.36

Chionoecetes opilio (snow crab) 1.64 1.20

Echiura (marine worm) 8.20 14.74

Priapulida (worm) 0.82 0.20

Ectoprocta (bryozoan) 1.64 0.21

Ophiuroidae Ophiurida (brittle star) 16.39 8.43

Ophiura sarsi (brittle star) 0.82 0.90

Echinoidea (sea urchin and sand dollar) 1.64 0.00

155
156

Table D-10.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Urochordata (tunicate) 0.82 0.11

Larvacea Copelata 0.82 0.00

Theragra chalcogramma (walleye pollock) 0.82 0.14

Unidentified organic material 1.64 0.40

Unidentified worm-like organism 4.10 2.63

Total non-empty stomachs = 122

Total prey number = 3,537

Total prey weight = 291 g

Total empty stomachs = 31

Number of hauls = 11

 
 Misc. Worms Misc. Crustaceans 

 Misc. Prey Polychaetes Unidentified 

 Brittlestars Clams Chionoecetes 

Prey Key

2000 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 

Alaska plaice length (cm)

Percent by weight

N 0 19 41 

Figure D-1.--Diet composition of Alaska plaice, in terms of average percent by weight, during months 5  predator size in the eastern Bering Sea; N=number of full stomachs. 

157
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

2000 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 40-49 

Arrowtooth flounder length (cm)

Percent by weight

N 42 60 62 85 

Figure D-2.--Diet composition of arrowtooth flounder, in terms of average percent by weight, during mo by predator size in the eastern Bering Sea; N=number of full stomachs. 

158
 Offal Misc. Crustaceans Lithodidae Walleye Pollock

 Misc. Prey Unidentified Pleuronectidae Misc. Fish

 Chionoecetes

2000 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

70-79

Pacific cod length (cm)

Percent by weight

N 215 95 162 234 304 225 81 

Prey Key

Figure D-3.--Diet composition of Pacific cod, in terms of average percent by weight, during months 5 th predator size in the eastern Bering Sea; N=number of full stomachs. 

159
 Misc. Worms Misc. Crustaceans Amphi

 Misc. Prey Polychaetes Unidentified Walley

 Brittlestars Clams Chionoecetes Misc. F

Prey Key

2000 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 

Flathead sole length (cm)

Percent by weight

N 6 29 19 

Figure D-4.--Diet composition of flathead sole, in terms of average percent by weight, during months 5  predator size in the eastern Bering Sea; N=number of full stomachs. 

160
 Offal Misc. Crustaceans Lithodidae Walley

 Misc. Prey Unidentified Pleuronectidae Misc. F

 Chionoecetes

2000 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

Pacific halibut length (cm)

Percent by weight

N 4 3 9 010 22

Prey Key

Figure D-5.--Diet composition of Pacific halibut, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs. 

161
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

2000 (months 5-9)

0%

10%20%30%40%50%60%70%80%90%

100%

<20 20-29 30-39 40-49 

Walleye pollock length (cm)

Percent by weight

N 541 101 241 762 

Figure D-6.--Diet composition of walleye pollock, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs. 

162
 Offal Misc. Crustaceans Lithodidae Walleye Pollock

 Misc. Prey Unidentified Pleuronectidae Misc. Fish

 Chionoecetes

2000 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

70-79

Skate length (cm)

Percent by weight

N 11 65 83 120 76 59 73 

Prey Key

Figure D-7.--Diet composition of skate, in terms of average percent by weight, during months 5 through  in the eastern Bering Sea; N=number of full stomachs. 

163
 Misc. Worms Misc. Crustaceans Amph

 Misc. Prey Polychaetes Unidentified Walle

 Brittlestars Clams Chionoecetes Misc

Prey Key

2000 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 

Northern rock sole length (cm)

Percent by weight

N 20 43 33 

Figure D-8.--Diet composition of northern rock sole, in terms of average percent by weight, during mon predator size in the eastern Bering Sea; N=number of full stomachs. 

164
 Misc. Worms Misc. Crustaceans 

 Misc. Prey Polychaetes Unidentified 

 Brittlestars Clams Chionoecetes 

Prey Key

2000 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 

Yellowfin sole length (cm)

Percent by weight

N 14 44 50 

Figure D-9.--Diet composition of yellowfin sole, in terms of average percent by weight, during months 5  predator size in the eastern Bering Sea; N=number of full stomachs. 

165

Appendix E- Diet of major groundfish species collected 

from the eastern Bering Sea in 2001 

Table E-1.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of arrowtooth flounder (Atheresthes stomias) collected 

 in the eastern Bering Sea in 2001, May through September. 

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 4.04 0.07

Aphroditidae (sea mouse) 0.34 0.72

Bivalvia (clam) 0.34 0.00

Octopoda (octopus) 1.01 2.43

Crustacea 0.34 0.00

Mysidae (mysid) 5.05 0.08

Gammaridea (amphipod) 1.01 0.00

Amphipoda Hyperiidea (amphipod) 1.01 0.00

Euphausiacea (euphausiid) 0.34 0.00

Euphausiidae (euphausiid) 18.86 1.08

Thysanoessa spinifera (euphausiid) 0.34 0.00

Sergestidae (sergestid shrimp) 0.34 0.08

Sergestes similis (Pacific sergestid) 0.34 0.04

Natantia (shrimp) 1.68 0.01

Caridea (shrimp) 1.01 0.01

Hippolytidae (shrimp) 0.34 0.00

Pandalidae (shrimp) 2.02 0.21

Pandalus sp. (shrimp) 0.67 0.07

Pandalus borealis (shrimp) 0.34 0.05

Pandalus jordani (shrimp) 0.34 0.02

Crangonidae (shrimp) 3.03 0.07

Crangon sp. (shrimp) 0.67 0.03

Argis sp. (shrimp) 1.01 0.08

Anomura (crab) 0.34 0.00

Ectoprocta (bryozoan) 0.34 0.03

Ophiuridae (brittle star) 0.34 0.00

Osteichthyes Teleostei (fish) 6.06 0.18

Non-gadoid fish remains 1.35 0.09

Mallotus villosus (capelin) 0.67 0.52

Bathylagidae (deepsea smelts) 0.34 0.34

Gadidae (gadid fish) 13.80 7.89

Gadus macrocephalus (Pacific cod) 0.34 0.03

Theragra chalcogramma (walleye pollock) 36.36 71.26

Zoarcidae (eelpout) 2.02 1.98

Lycodes palearis (wattled eelpout) 0.34 0.94

Trichodon trichodon (Pacific sandfish) 0.34 4.32

Stichaeidae (prickleback) 0.67 0.14

Ammodytes hexapterus (Pacific sand lance) 0.34 0.03

Pleuronectiformes Pleuronectoidei (flatfish) 0.34 0.46

Pleuronectidae (flatfish) 1.01 0.47

Hippoglossoides elassodon (flathead sole) 0.34 5.47

Unidentified organic material 0.34 0.00

Unidentified eggs 0.34 0.39

Fishery offal 0.34 0.40

 

169
Table E-1.--Continued. 

Total non-empty stomachs = 297

Total prey number = 424

Total prey weight = 3966.862g

Total empty stomachs = 335

Number of hauls = 67

170
Table E-2.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Pacific cod (Gadus macrocephalus) collected in the 

 eastern Bering Sea in 2001, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Foraminiferida (protozoan) 0.06 0.00

Anthozoa (anemome) 0.17 0.02

Polychaeta (worm) 35.64 1.39

Aphroditidae (sea mouse) 0.28 0.13

Polynoidae (polychaete) 0.11 0.00

Phyllodocidae (polychaete) 0.94 0.02

Nereidae (polychaete) 0.33 0.00

Nephtyidae (polychaete) 0.72 0.10

Lumbrineridae 0.06 0.00

Flabelligeridae (polychaete) 0.06 0.00

Capitellidae (polychaete) 0.11 0.00

Sabellaridae 0.06 0.00

Pectinariidae (polychaete) 0.11 0.00

Eunicida (polychaete) 0.06 0.00

Hirudinea (leech) 0.17 0.01

Mollusca 0.33 0.06

Gastropoda (snail) 5.03 0.70

Neptunea sp. (snail) 0.06 0.01

Bivalvia (clam) 5.41 0.24

Cardiidae (cockles) 0.11 0.02

Cephalopoda (squid and octopus) 0.72 0.46

Teuthoidea (squid) 0.61 0.03

Octopoda (octopus) 3.65 2.88

Crustacea 2.27 0.07

Calanoida (copepod) 0.50 0.00

Cirripedia (barnacle) 0.06 0.00

Malacostraca Leptostraca 0.06 0.00

Mysidacea Mysida (mysid) 2.93 0.30

Mysidae (mysid) 13.43 0.27

Cumacea (cumacean) 4.92 0.02

Isopoda (isopod) 0.66 0.01

Idoteidae (isopod) 0.06 0.00

Amphipoda (amphipod) 0.06 0.00

Gammaridea (amphipod) 33.70 0.61

Ampeliscidae (amphipod) 2.65 0.03

Haustoriidae (amphipod) 0.06 0.00

Amphipoda Hyperiidea (amphipod) 3.31 0.02

Caprellidea (amphipod) 0.94 0.00

Caprellidae (amphipod) 0.11 0.00

Eucarida 0.06 0.00

Euphausiacea (euphausiid) 0.94 0.06

Euphausiidae (euphausiid) 8.90 0.85

Thysanoessa inermis (euphausiid) 0.11 0.02

Natantia (shrimp) 2.93 0.08

Caridea (shrimp) 6.69 0.38

171
Table E-2.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Hippolytidae (shrimp) 2.38 0.15

Spirontocaris arcuata (shrimp) 0.06 0.00

Lebbeus sp. (shrimp) 0.06 0.00

Eualus sp. (shrimp) 0.28 0.02

Eualus barbata (shrimp) 0.06 0.00

Eualus biunguis (shrimp) 0.11 0.00

Eualus pusiolus (shrimp) 0.11 0.00

Eualus avinus (shrimp) 0.22 0.00

Pandalidae (shrimp) 2.98 0.27

Pandalus sp. (shrimp) 0.94 0.06

Pandalus borealis (shrimp) 1.82 0.31

Pandalus goniurus (shrimp) 1.27 0.24

Pandalus jordani (shrimp) 0.50 0.06

Pandalus montagui tridens (shrimp) 0.22 0.03

Pandalus platyceros (shrimp) 0.11 0.03

Crangonidae (shrimp) 12.43 0.52

Crangon sp. (shrimp) 8.01 0.35

Crangon alaskensis (shrimp) 1.60 0.21

Crangon stylirostris (shrimp) 0.11 0.00

Crangon dalli (shrimp) 9.12 0.85

Crangon communis (shrimp) 3.37 0.20

Argis sp. (shrimp) 1.44 0.07

Argis lar (shrimp) 0.66 0.10

Argis dentata (shrimp) 0.06 0.00

Argis alaskensis (shrimp) 0.06 0.00

Reptantia (crab) 10.61 1.13

Decapoda Reptantia legs (for unident. crabs) 0.06 0.00

Anomura (crab) 0.06 0.02

Paguridae (hermit crab) 15.41 4.89

Paguridae legs (hermit crabs) 0.50 0.04

Pagurus sp. (hermit crab) 0.17 0.08

Lithodidae (king crab) 0.11 0.01

Munida quadrispina (pinch bug) 0.06 0.00

Munidopsis sp. (squat lobster) 0.06 0.00

Decapoda brachyura (crab) 1.55 0.26

Decapoda brachyura legs (for unident. crabs) 0.06 0.00

Majidae (spider crab) 0.28 0.16

Majidae legs (for C. opilio, C. bairdi, etc) 0.22 0.14

Oregonia gracilis (decorator crab) 0.06 0.00

Hyas sp. (lyre crab) 0.83 0.24

Hyas lyratus (lyre crab) 0.39 0.18

Hyas coarctatus (lyre crab) 0.39 0.25

Chionoecetes sp. (snow and Tanner crab) 5.64 1.67

Chionoecetes opilio (snow crab) 10.06 9.66

Chionoecetes bairdi (Tanner crab) 14.64 8.21

Atelecyclidae (crab) 0.11 0.00

Telmessus cheiragonus (hair crab) 0.55 0.26

172
Table E-2.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Erimacrus isenbeckii (Korean horse-hair crab) 0.77 0.23

Cancer oregonensis (pygmy Cancer crab) 0.28 0.02

Pinnotheridae (pea crab) 0.44 0.02

Pinnixa sp. (pea crab) 0.50 0.08

Sipuncula (marine worm) 0.11 0.01

Echiura (marine worm) 8.45 1.40

Priapulida (worm) 0.22 0.22

Ectoprocta (bryozoan) 1.49 0.02

Asteroidea (starfish) 0.06 0.00

Ophiuroidae Ophiurida (brittle star) 0.39 0.01

Ophiuridae (brittle star) 0.11 0.00

Ophiura sarsi (brittle star) 0.11 0.00

Echinoidea (sea urchin and sand dollar) 0.06 0.04

Holothuroidea (sea cucumber) 0.11 0.04

Urochordata (tunicate) 0.28 0.07

Ascidiacea (sea squirt) 0.11 0.04

Ascidia sp. (tunicate) 0.06 0.13

Boltenia echinata (sea onion) 0.17 0.03

Osteichthyes Teleostei (fish) 8.18 0.65

Non-gadoid fish remains 4.03 0.66

Fish eggs 0.06 0.00

Clupeidae 0.11 0.01

Clupea pallasi (Pacific herring) 0.50 0.74

Osmeridae (smelts) 0.28 0.06

Mallotus villosus (capelin) 0.55 0.17

Thaleichthys pacificus (eulachon) 0.11 0.03

Gadidae (gadid fish) 3.81 1.07

Gadus macrocephalus (Pacific cod) 0.50 2.28

Theragra chalcogramma (walleye pollock) 11.88 34.97

Zoarcidae (eelpout) 2.76 1.54

Lycodes sp. (eelpout unid) 0.11 0.01

Lycodes brevipes (shortfin eelpout) 0.11 0.02

Lycodes palearis (wattled eelpout) 0.33 0.28

Pleurogrammus monopterygius (Atka mackerel) 0.06 0.00

Cottoidei (sculpin) 1.38 0.34

Icelus spiniger (thorny sculpin) 0.11 0.05

Cottidae (sculpin) 0.22 0.04

Artediellus sp. (sculpin) 0.06 0.00

Agonidae (poacher) 0.77 0.13

Aspidophoroides bartoni (Aleutian alligatorfish) 0.11 0.00

Asterotheca alascana (gray starsnout) 0.06 0.01

Podothecus acipenserinus (sturgeon poacher) 0.11 0.02

Sarritor frenatus (sawback poacher) 0.06 0.00

Bathymasteridae (ronquils) 0.06 0.01

Stichaeidae (prickleback) 0.55 0.13

Poroclinus rothrocki (whitebarred pricklback) 0.06 0.23

Ammodytes sp. (sand lance) 0.22 0.06

Ammodytes hexapterus (Pacific sand lance) 2.60 0.96

173
Table E-2.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Pleuronectiformes Pleuronectoidei (flatfish) 1.55 1.32

Pleuronectidae (flatfish) 3.37 3.38

Atheresthes evermanni (Kamchatka flounder) 0.06 0.55

Atheresthes stomias (arrowtooth flounder) 0.06 0.07

Hippoglossoides elassodon (flathead sole) 0.28 0.52

Lepidopsetta sp. (rock sole type) 0.06 0.46

Lepidopsetta polyxystra (northern rock sole) 0.77 0.47

Pleuronectes asper (yellowfin sole) 0.77 2.58

Pleuronectes proboscideus (longhead dab) 0.17 0.24

Unidentified organic material 1.10 0.09

Unidentified eggs 0.44 0.01

Unidentified worm-like organism 0.28 0.05

Fishery offal 0.83 3.80

Unidentified tube 0.17 0.00

Wood 0.06 0.00

Unidentified algae 0.39 0.00

Rocks 2.10 0.09

Total non-empty stomachs = 1,810

Total prey number = 12,813

Total prey weight = 58,861 g

Total empty stomachs = 30

Number of hauls = 172

174
Table E-3.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of Pacific halibut (Hippoglossus stenolepis) collected 

 in the eastern Bering Sea in 2001, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Anthozoa (anemome) 0.90 0.02

Polychaeta (worm) 6.31 0.05

Aphroditidae (sea mouse) 0.90 0.01

Bivalvia (clam) 0.90 0.00

Teuthoidea (squid) 0.90 0.05

Octopoda (octopus) 1.80 5.81

Mysidacea Mysida (mysid) 0.90 0.00

Mysidae (mysid) 7.21 0.07

Isopoda (isopod) 2.70 0.00

Arcturidae 0.90 0.00

Gammaridea (amphipod) 0.90 0.01

Amphipoda Hyperiidea (amphipod) 0.90 0.00

Euphausiidae (euphausiid) 5.41 0.02

Caridea (shrimp) 2.70 0.03

Eualus barbata (shrimp) 0.90 0.05

Eualus biunguis (shrimp) 0.90 0.04

Pandalidae (shrimp) 0.90 0.03

Crangonidae (shrimp) 2.70 0.06

Crangon sp. (shrimp) 3.60 0.06

Crangon alaskensis (shrimp) 1.80 0.05

Crangon dalli (shrimp) 3.60 0.16

Argis sp. (shrimp) 0.90 0.02

Reptantia (crab) 3.60 0.49

Decapoda Reptantia legs (for unident. crabs) 1.80 <0.01 

Anomura (crab) 0.90 0.01

Paguridae (hermit crab) 16.22 0.89

Paguridae legs (hermit crabs) 0.90 0.02

Pagurus sp. (hermit crab) 3.60 0.27

Pagurus aleuticus 0.90 0.45

Pagurus trigonocheirus (hermit crab) 0.90 0.02

Elassochirus sp. 1.80 0.14

Elassachirus tenuimanus 0.90 0.03

Elassochirus cavimanus (purple hermit crab) 0.90 0.02

Decapoda brachyura (crab) 0.90 0.06

Hyas sp. (lyre crab) 1.80 0.36

Hyas coarctatus (lyre crab) 0.90 0.20

Chionoecetes sp. (snow and Tanner crab) 8.11 0.83

Chionoecetes bairdi (Tanner crab) 37.84 20.32

Ectoprocta (bryozoan) 0.90 0.00

Opniura leptoctenia (brittle star) 0.90 0.02

Holothuroidea (sea cucumber) 0.90 0.88

Osteichthyes Teleostei (fish) 12.61 5.90

Non-gadoid fish remains 3.60 0.72

Gadidae (gadid fish) 3.60 1.23

Gadus macrocephalus (Pacific cod) 1.80 1.76

175
Table E-3.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Theragra chalcogramma (walleye pollock) 18.92 50.37

Pleurogrammus monopterygius (Atka mackerel) 0.90 1.61

Cottoidei (sculpin) 1.80 0.20

Cottidae (sculpin) 0.90 2.73

Triglops pingeli (ribbed sculpin) 0.90 0.08

Ammodytes hexapterus (Pacific sand lance) 6.31 1.27

Pleuronectiformes Pleuronectoidei (flatfish) 2.70 0.40

Hippoglossus stenolepis (Pacific halibut) 0.90 0.02

Unidentified eggs 1.80 <0.01

Fishery offal 9.01 1.89

Unidentified tube 0.90 0.00

Total non-empty stomachs = 111

Total prey number = 6,422

Total prey weight = 3,725 g

Total empty stomachs = 21

Number of hauls = 20

176
Table E-4.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of skates collected in the eastern Bering Sea in 2001, 

 May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Cnidaria 0.13 0.00

Anthozoa (anemome) 0.13 0.00

Polychaeta (worm) 20.70 0.75

Polynoidae (polychaete) 0.26 0.01

Nephtyidae (polychaete) 0.39 0.02

Gastropoda (snail) 0.39 0.01

Bivalvia (clam) 1.16 0.02

Cephalopoda (squid and octopus) 0.13 0.00

Teuthoidea (squid) 0.39 0.38

Crustacea 1.16 0.06

Mysidacea Mysida (mysid) 1.16 0.03

Mysidae (mysid) 8.41 0.07

Cumacea (cumacean) 0.65 0.00

Isopoda (isopod) 0.52 0.01

Gammaridea (amphipod) 34.80 1.97

Ampeliscidae (amphipod) 2.20 0.04

Amphipoda Hyperiidea (amphipod) 0.78 0.01

Caprellidea (amphipod) 0.13 0.00

Euphausiacea (euphausiid) 0.78 0.01

Euphausiidae (euphausiid) 2.72 0.02

Natantia (shrimp) 2.46 0.39

Caridea (shrimp) 2.46 0.08

Hippolytidae (shrimp) 3.36 0.15

Eualus sp. (shrimp) 0.13 0.03

Eualus avinus (shrimp) 0.26 0.01

Pandalidae (shrimp) 2.07 0.09

Pandalus sp. (shrimp) 1.68 0.11

Pandalus borealis (shrimp) 0.91 0.13

Pandalus goniurus (shrimp) 1.68 0.18

Crangonidae (shrimp) 15.65 2.88

Crangon sp. (shrimp) 9.70 2.58

Crangon alaskensis (shrimp) 1.94 0.57

Crangon stylirostris (shrimp) 0.26 0.09

Crangon dalli (shrimp) 14.62 6.01

Crangon communis (shrimp) 1.81 0.11

Argis sp. (shrimp) 2.59 0.23

Argis lar (shrimp) 3.75 0.95

Argis dentata (shrimp) 0.52 0.08

Reptantia (crab) 7.37 0.97

Decapoda Reptantia legs (for unident. crabs) 0.78 0.07

Paguridae (hermit crab) 22.25 3.48

Paguridae legs (hermit crabs) 0.39 0.01

Decapoda brachyura (crab) 1.03 0.20

Decapoda brachyura legs (for unident. crabs) 0.26 0.01

Majidae (spider crab) 0.26 0.03

177
Table E-4.--Continued. 

 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Majidae legs (for C. opilio, C. bairdi, etc) 0.13 0.05

Hyas sp. (lyre crab) 0.26 0.02

Hyas lyratus (lyre crab) 0.13 0.01

Hyas coarctatus (lyre crab) 0.13 0.10

Hyas coarctatus alutaceus (lyre crab) 0.13 0.07

Chionoecetes sp. (snow and Tanner crab) 13.71 5.08

Chionoecetes opilio (snow crab) 5.82 2.78

Chionoecetes bairdi (Tanner crab) 1.68 0.57

Cancer oregonensis (pygmy Cancer crab) 0.13 0.01

Echiura (marine worm) 0.13 0.02

Ophiuridae (brittle star) 0.13 0.00

Larvacea Copelata 0.13 0.00

Osteichthyes Teleostei (fish) 3.75 0.12

Non-gadoid fish remains 1.94 0.16

Clupea pallasi (Pacific herring) 0.65 0.31

Gadidae (gadid fish) 2.46 1.35

Gadus macrocephalus (Pacific cod) 0.13 3.40

Microgadus proximus (Pacific tomcod) 0.13 0.05

Theragra chalcogramma (walleye pollock) 13.32 42.91

Zoarcidae (eelpout) 5.17 2.43

Lycodes brevipes (shortfin eelpout) 0.52 0.44

Lycodes palearis (wattled eelpout) 0.13 0.22

Lycodes raridens (marbled eelpout) 0.13 1.30

Hexagrammidae (greenling) 0.13 0.07

Cottoidei (sculpin) 0.65 0.13

Cottidae (sculpin) 0.26 0.45

Artediellus sp. (sculpin) 0.13 0.00

Myoxocephalus jaok (plain sculpin) 0.13 0.17

Agonidae (poacher) 0.78 0.17

Podothecus acipenserinus (sturgeon poacher) 0.39 0.03

Occella dodecaedron (Bering poacher) 0.13 0.00

Liparis sp. (snailfish) 0.13 0.23

Liparis gibbes (snailfish) 0.13 0.96

Trichodon trichodon (Pacific sandfish) 0.13 0.08

Bathymaster signatus (searcher) 0.13 0.00

Stichaeidae (prickleback) 1.29 0.17

Lumpenus sp. (prickleback) 0.13 0.05

Lumpenus maculatus (daubed shanny) 0.26 0.04

Ammodytes sp. (sand lance) 0.39 0.38

Ammodytes hexapterus (Pacific sand lance) 5.82 4.03

Pleuronectiformes Pleuronectoidei (flatfish) 5.17 0.74

Pleuronectidae (flatfish) 4.14 1.46

Hippoglossoides elassodon (flathead sole) 0.13 0.17

Hippoglossoides robustus (Bering flounder) 0.26 0.68

Lepidopsetta polyxystra (northern rock sole) 0.91 0.75

Pleuronectes asper (yellowfin sole) 0.39 0.99

Unidentified organic material 0.13 0.00

178
Table E-4.--Continued. 

Mean % Mean % 

Prey Name F.O Weight 

Fishery offal 2.20 4.00 

Total non-empty stomachs = 773

Total prey number = 4,634

Total prey weight = 25,577 g

Total empty stomachs = 98

Number of hauls = 136

179
Table E-5.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of walleye pollock (Theragra chalcogramma) collected 

 in the eastern Bering Sea in 2001, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Foraminiferida (protozoan) 0.03 0.00

Nematoda (worm) 0.29 0.00

Polychaeta (worm) 5.39 0.59

Polynoidae (polychaete) 0.03 0.00

Phyllodocidae (polychaete) 0.06 0.01

Nereidae (polychaete) 0.03 0.00

Nephtyidae (polychaete) 0.10 0.01

Mollusca 0.06 0.00

Gastropoda (snail) 0.19 0.02

Pteropoda 0.13 0.00

Thecosomata (pteropod) 0.03 0.00

Gymnosomata (pteropod) 0.77 0.01

Bivalvia (clam) 0.38 0.04

Cephalopoda (squid and octopus) 0.22 0.04

Teuthoidea (squid) 0.89 0.66

Loligo sp. (squid) 0.03 0.07

Octopoda (octopus) 0.16 0.01

Crustacea 2.68 0.06

Copepoda 9.86 1.06

Calanoida (copepod) 31.96 4.03

Large calanoid (copepod) > 5mm 1.79 0.51

Medium calanoid (copepod) 2-5mm 1.63 0.11

Malacostraca Leptostraca 0.06 0.00

Mysidacea Mysida (mysid) 1.53 0.15

Mysidae (mysid) 13.94 6.46

Acanthomysis sp. (mysid) 0.03 0.53

Cumacea (cumacean) 7.11 0.10

Leptocuma sp. (cumacean) 0.03 0.00

Isopoda (isopod) 0.03 0.00

Amphipoda (amphipod) 0.29 0.00

Gammaridea (amphipod) 10.62 0.47

Ampeliscidae (amphipod) 0.96 0.12

Amphipoda Hyperiidea (amphipod) 13.81 0.45

Themisto sp. (amphipod) 0.03 0.00

Caprellidea (amphipod) 0.06 0.00

Eucarida 0.03 0.00

Euphausiacea (euphausiid) 12.12 4.32

Euphausiidae (euphausiid) 53.17 41.18

Thysanoessa inermis (euphausiid) 3.73 4.63

Thysanoessa raschii (euphausiid) 0.41 0.17

Thysanoessa spinifera (euphausiid) 0.03 0.00

Decapoda (shrimp and crab) 0.83 0.04

Sergestidae (sergestid shrimp) 0.06 0.04

Sergestes similis (Pacific sergestid) 0.13 0.10

Natantia (shrimp) 1.28 0.53

180
Table E-5.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Caridea (shrimp) 1.63 0.29

Oplophoridae (shrimp) 0.06 0.02

Pasiphaeidae (shrimp) 0.03 0.01

Pasiphaea pacifica (shrimp) 0.03 0.01

Hippolytidae (shrimp) 0.38 1.14

Eualus sp. (shrimp) 0.06 0.01

Eualus gaimurdii (shrimp) 0.29 0.40

Pandalidae (shrimp) 0.54 0.22

Pandalus sp. (shrimp) 0.22 0.04

Pandalus borealis (shrimp) 0.38 0.19

Pandalus goniurus (shrimp) 0.41 0.09

Pandalus jordani (shrimp) 0.03 0.01

Crangonidae (shrimp) 2.58 2.76

Crangon sp. (shrimp) 2.84 2.55

Crangon alaskensis (shrimp) 0.51 0.96

Crangon dalli (shrimp) 3.70 5.69

Crangon communis (shrimp) 0.03 0.00

Argis sp. (shrimp) 0.10 0.05

Argis crassa 0.03 0.01

Reptantia (crab) 0.96 0.00

Paguridae (hermit crab) 1.59 0.49

Echiura (marine worm) 0.70 0.56

Ectoprocta (bryozoan) 0.22 0.03

Ophiuroidae Ophiurida (brittle star) 0.03 0.00

Ophiuridae (brittle star) 0.03 0.00

Chaetognatha (arrow worm) 5.90 0.18

Urochordata (tunicate) 0.03 0.00

Larvacea Copelata 2.84 1.28

Misc. fish 0.26 0.11

Osteichthyes 0.03 0.01

Osteichthyes Teleostei (fish) 3.03 0.17

Non-gadoid fish remains 1.40 0.34

Clupeidae 0.03 0.00

Clupea pallasi (Pacific herring) 0.54 3.29

Engraulis mordax (northern anchovy) 0.03 0.05

Osmeridae (smelts) 0.26 0.15

Mallotus villosus (capelin) 0.61 2.12

Bathylagidae (deepsea smelts) 0.06 0.01

Myctophidae (lanternfish) 0.03 0.01

Stenobrachius leucopsarus (northern lampfish) 0.13 0.07

Gadidae (gadid fish) 0.93 0.35

Theragra chalcogramma (walleye pollock) 2.74 6.05

Zoarcidae (eelpout) 0.03 0.24

Lycodes brevipes (shortfin eelpout) 0.06 0.02

Scorpaeniformes (rockfish and cottid) 0.03 0.00

Cottoidei (sculpin) 0.19 0.01

Hemilepidotus jordani (yellow Irish lord) 0.03 0.00

Agonidae (poacher) 0.16 0.17

181
Table E-5.--Continued. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Aspidophoroides bartoni (Aleutian alligatorfish) 0.03 0.01

Hypsagonus quadricornis (4-horn poacher) 0.03 0.00

Podothecus acipenserinus (sturgeon poacher) 0.03 0.02

Trichodon trichodon (Pacific sandfish) 0.10 0.50

Stichaeidae (prickleback) 0.16 0.09

Lumpenus maculatus (daubed shanny) 0.03 0.02

Ammodytes sp. (sand lance) 0.03 0.01

Ammodytes hexapterus (Pacific sand lance) 1.79 2.18

Pleuronectiformes Pleuronectoidei (flatfish) 0.22 0.02

Pleuronectidae (flatfish) 0.06 0.03

Lepidopsetta polyxystra (northern rock sole) 0.06 0.23

Pleuronectes quadrituberculatus (Alaska plaice) 0.03 0.01

Unidentified organic material 0.13 0.02

Fishery offal 0.10 0.17

Unidentified algae 0.16 0.01

Total non-empty stomachs = 3,135

Total prey number = 57,999

Total prey weight = 17,511 g

Total empty stomachs = 158

Number of hauls = 196

182
183

Table E-6.--Prey items (expressed in mean percent frequency of occurrence and mean 

 percent total weight) of yellowfin sole (Limanda aspera) collected in the 

 eastern Bering Sea in 2001, May through September. 

Prey Name 

Mean % 

F.O 

Mean % 

Weight 

Polychaeta (worm) 6.25 0.03

Mysidacea Mysida (mysid) 6.25 0.01

Gammaridea (amphipod) 6.25 0.04

Euphausiacea (euphausiid) 12.50 1.33

Thysanoessa inermis (euphausiid) 18.75 18.81

Crangon sp. (shrimp) 6.25 0.71

Crangon stylirostris (shrimp) 31.25 8.73

Crangon dalli (shrimp) 68.75 65.38

Majidae legs (for C. opilio, C. bairdi, etc) 6.25 1.70

Ophiuroidae Ophiurida (brittle star) 6.25 1.19

Holothuroidea (sea cucumber) 6.25 0.99

Osteichthyes Teleostei (fish) 6.25 0.05

Leuroglossus schmidti (northern smoothtongue) 6.25 0.41

Ammodytes sp. (sand lance) 6.25 0.62

Total non-empty stomachs = 16

Total prey number = 87

Total prey weight = 120 g

Total empty stomachs = 0

Number of hauls = 1

 

 
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

2001 (months 5-9)

0%

10%20%30%40%50%60%70%80%90%

100%

<20 20-29 30-39 40-49 

Arrowtooth flounder length (cm)

Percent by weight

N= 30 31 48 75 

Figure E-1.--Diet composition of arrowtooth flounder, in terms of average percent by weight, during mo predator size in the eastern Bering Sea; N=number of full stomachs. 

184
 Offal Misc. Crustaceans Lithodidae Walleye Pollock

 Misc. Prey Unidentified Pleuronectidae Misc. Fish

 Chionoecetes

2001 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

70-79

Pacific cod length (cm)

Percent by weight

N 215 176 240 141 223 271 88 

Prey Key

Figure E-2.--Diet composition of Pacific cod, in terms of average percent by weight, during months 5 th predator size in the eastern Bering Sea; N=number of full stomachs.

185
 Offal Misc. Crustaceans Lithodidae Walley

 Misc. Prey Unidentified Pleuronectidae Misc. F

 Chionoecetes

2001 (months 5-9)

0%

10%20%30%40%50%60%70%80%90%

100%

<20

20-29

30-39

40-49

50-59

60-69

Pacific halibut length (cm)

Percent by weight

N 8 3

Prey Key

Figure E-3.--Diet composition of Pacific halibut, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs. 

186
Prey Key Cephalopods Amphipods Copepods 

 Misc. Prey Misc. Crustaceans Euphausids Gadidae 

2001 (months 5-9)

0%

20%40%60%80%

100%

<20 20-29 30-39 40-49 

Walleye pollock length (cm)

Percent by weight

N= 392 180 82 550 

Figure E-4.--Diet composition of walleye pollock, in terms of average percent by weight, during months  predator size in the eastern Bering Sea; N=number of full stomachs.

187
 Offal Misc. Crustaceans Lithodidae Walley

 Misc. Prey Unidentified Pleuronectidae Misc. F

Chionoecetes

2001 (months 5-9)

0%

20%40%60%80%

100%

<20

20-29

30-39

40-49

50-59

60-69

Skate length (cm)

Percent by weight

N 41 103 91 132 124 95 78 

Prey Key

Figure E-5.--Diet composition of skates, in terms of average percent by weight, during months 5 throug size in the eastern Bering Sea; N=number of full stomachs. 

188
Appendix F- Estimates of fish and crab prey consumption by groundfish populations and 

predator biomass by year, stratum, predator and predator size group. 

Table F-1.-- Estimates of total fish and crab prey consumed (in metric tons) by groundfish populations in the eastern Bering Se

 from May through September by year, stratum, predator and predator size groups.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1997 1 Flathead sole 1 Walleye pollock 10.13 10.13

5 43 4209.2 

1997 1 Pacific cod 1 Walleye pollock 1.21 1.21 10 77 50.86 1997 1 Pacific cod

2 Northern rock sole 7.31 4.98 10 58 3203.96 

1997 1 Pacific cod

2 Pleuronectidae 1.03 1.03 10 58 452.87 

1997 1 Pacific cod

2 Walleye pollock 0.68 0.68 10 58 297.82 

1997 1 Pacific cod

3 King crab legs 1.94 1.94 10 46 926.03 

1997 1 Pacific cod

3 Northern rock sole 5.67 3.32 10 46 2705.51 

1997 1 Pacific cod

3 Offal 1.49 1.49 10 46 710.96 

1997 1 Pacific cod

3 Paralithodes sp. 0.41 0.4 10 46 39.95 

1997 1 Pacific cod

3 Pleuronectidae 3.45 1.92 10 46 1649.16 

1997 1 Pacific cod

3 Walleye pollock 7.96 5.54 10 46 3802.03 

1997 1 Pacific cod

3 Yellowfin sole 11.18 8.63 10 46 5337.32 

1997 1 Pacific halibut

2 Capelin 22.59 14.3

6 27 1765.37 

1997 1 Pacific halibut

2 Gadidae 8.63 6.56

6 27 674.18 

1997 1 Pacific halibut

2 Northern rock sole 1.61 1.61

6 27 126.13 

1997 1 Pacific halibut

2 Pleuronectidae 1.22 1.22

6 27 95.28 

1997 1 Pacific halibut

2 Walleye pollock 1.35 1.35

6 27 105.24 

1997 1 Pacific halibut

3 Capelin 2.68 1.63

8 28 352.52 

1997 1 Pacific halibut

3 Gadidae 0.89 0.89

8 28 117.59 

1997 1 Pacific halibut

3 Pacific cod 14.78 9.68

8 28 1944.33 

1997 1 Pacific halibut

3 Pleuronectidae 36.11 10.42

8 28 4750.7 

1997 1 Pacific halibut

3 Unid. Osmerid 0.89 0.76

8 28 117.52 

1997 1 Pacific halibut

3 Walleye pollock 10.74 6.4

8 28 1412.39 

1997 1 Pacific halibut

3 Yellowfin sole 12.16 5.99

8 28 1599.55 

1997 1 Skates 1 Gadidae 0.24 0.24

5 21 53.06 

1997 1 Skates 1 Northern rock sole 2.29 2.29

5 21 499.48 

1997 1 Skates 1 Offal 6.49 6.49

5 21 1415.88 

1997 1 Skates 1 Pleuronectidae 33.52 6.91

5 21 7315.35 

1997 1 Walleye pollock

4 Gadidae 0.36 0.31 19 201 229.74 

1997 1 Walleye pollock

4 Walleye pollock 5.88 4.4 19 201 3724.38 

1997 1 Yellowfin sole 1 Unid. Osmerid 5.3 5.3 14 86 33551.99 1997

2 Alaska plaice 1 Opilio snow crab 1.85 1.85 14 63 633.34 

1997

2 Northern rock sole 1 Bairdi Tanner crab 0.48 0.48 14 67 1512.75 

191
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1997 2 Northern rock sole 1 Unid. Chionoecetes 0.2 0.2 14 67 636.5 

1997 2 Pacific cod 1 Capelin 1.4 1.4 7 79 48.57 1997 2 Pacific cod 1 Opilio snow crab 2.69 2.69 7 79 93.66 1997 2 Pacific cod 1 Pleuronectidae 2.52 1.96 7 79 87.7 1997 2 Pacific cod 2 Flathead sole 1.08 1.08 5 19 68.35 1997 2 Pacific cod 2 Opilio snow crab 8.97 8.97 5 19 570.04 1997 2 Pacific cod 2 Pleuronectidae 0.9 0.9 5 19 57.35 1997 2 Pacific cod 2 Walleye pollock 10.75 7.77 5 19 683.13 1997 2 Pacific cod 3 Flathead sole 3.29 3.29 7 21 388.25 1997 2 Pacific cod 3 Gadidae 0.47 0.47 7 21 55.32 1997 2 Pacific cod 3 Northern rock sole 4.43 3.18 7 21 522.02 1997 2 Pacific cod 3 Opilio snow crab 11.4 5.38 7 21 1343.13 1997 2 Pacific cod 3 Pleuronectidae 24.08 10.69 7 21 2837.6 1997 2 Pacific cod 3 Unid. Chionoecetes 0.41 0.41 7 21 48.37 1997 2 Pacific cod 3 Walleye pollock 7.21 4.22 7 21 849.83 1997 2 Pacific halibut 2 Capelin 1.97 1.37 8 37 64.18 1997 2 Pacific halibut 2 Gadidae 9.09 3.93 8 37 295.61 1997 2 Pacific halibut 2 Pacific cod 7.62 5.03 8 37 247.85 1997 2 Pacific halibut 2 Pleuronectidae 0.29 0.29 8 37 9.28 1997 2 Pacific halibut 2 Unid. Osmerid 2.8 1.85 8 37 91.16 1997 2 Pacific halibut 2 Walleye pollock 18.61 8.41 8 37 605.2 1997 2 Pacific halibut 3 Gadidae 14.94 9.92 10 28 914.88 1997 2 Pacific halibut 3 Northern rock sole 2.73 2.73 10 28 167.2 1997 2 Pacific halibut 3 Pacific cod 11.39 4.93 10 28 697.79 1997 2 Pacific halibut 3 Pacific herring 0.08 0.08 10 28 4.6 1997 2 Pacific halibut 3 Pleuronectidae 16.81 8.43 10 28 1029.46 1997 2 Pacific halibut 3 Walleye pollock 17.49 11.18 10 28 1071 1997 2 Pacific halibut 3 Yellowfin sole 2.16 2.16 10 28 132.21 1997 2 Skates 1 Gadidae 0.78 0.55 6 43 262.75 1997 2 Skates 1 Northern rock sole 4.52 4.14 6 43 1528.17 1997 2 Skates 1 Opilio snow crab 0.14 0.14 6 43 47.03 1997 2 Skates 1 Pleuronectidae 16.36 5.9 6 43 5525.27 1997 2 Skates 1 Unid. Chionoecetes 0.29 0.22 6 43 97.39 1997 2 Skates 1 Walleye pollock 4.08 1.89 6 43 1379.48 

192
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1997 2 Skates 1 Yellowfin sole 4.34 2.16 6 43 1465.65 1997 2 Walleye pollock 1 Pleuronectidae 0.69 0.69 8 76 34.47 1997 2 Walleye pollock 1 Walleye pollock 6.33 5.77 8 76 317.96 1997 2 Walleye pollock 4 Gadidae 1.92 1.92 11 108 395.44 1997 2 Walleye pollock 4 Pleuronectidae 0.88 0.86 11 108 182.29 1997 2 Walleye pollock 4 Walleye pollock 19.82 10.54 11 108 4083.52 1997 2 Yellowfin sole 1 Bairdi Tanner crab 2.22 2.22 6 45 4579.59 1997 3 Arrowtooth flounder 1 Walleye pollock 31.6 31.6 3 8 179.69 1997 3 Arrowtooth flounder 2 Gadidae 25 25 4 16 4357.52 1997 3 Arrowtooth flounder 2 Walleye pollock 44.25 24.26 4 16 7712.84 1997 3 Arrowtooth flounder 3 Walleye pollock 39.86 24.41 5 16 39441.29 1997 3 Flathead sole 1 Opilio snow crab 1.1 1.1 4 36 3281.51 1997 3 Greenland turbot 3 Gadidae 4.52 0 1 2 34.13 1997 3 Greenland turbot 3 Walleye pollock 95.18 0 1 2 719.42 1997 3 Northern rock sole 1 Offal 0 0 15 84 18.03 1997 3 Northern rock sole 1 Opilio snow crab 0.33 0.33 15 84 1608.76 1997 3 Northern rock sole 1 Unid. Chionoecetes 0.57 0.57 15 84 2781.44 1997 3 Pacific cod 1 Bairdi Tanner crab 6.89 6.89 11 23 193.68 1997 3 Pacific cod 2 Arrowtooth flounder 0.15 0.15 22 154 152.98 1997 3 Pacific cod 2 Bairdi Tanner crab 2.26 1.08 22 154 2334.24 1997 3 Pacific cod 2 Gadidae 0.21 0.21 22 154 221.56 1997 3 Pacific cod 2 Lithodidae 2.42 1.68 22 154 506.89 1997 3 Pacific cod 2 Opilio snow crab 18.11 4.33 22 154 18684.94 1997 3 Pacific cod 2 Paralithodes sp. 3.63 2.61 22 154 758.06 1997 3 Pacific cod 2 Pleuronectidae 0.11 0.11 22 154 111.48 1997 3 Pacific cod 2 Unid. Osmerid 3.97 3.97 22 154 4098.49 1997 3 Pacific cod 2 Unid. Chionoecetes 1.42 0.69 22 154 1464.41 1997 3 Pacific cod 2 Walleye pollock 6.16 2.64 22 154 6352.2 1997 3 Pacific cod 3 Arrowtooth flounder 1.95 1.95 21 97 1076.69 1997 3 Pacific cod 3 Bairdi Tanner crab 2.67 1.27 21 97 1474.04 1997 3 Pacific cod 3 Gadidae 0.15 0.13 21 97 80.29 1997 3 Pacific cod 3 King crab legs 0.04 0.04 21 97 22.58 1997 3 Pacific cod 3 Lithodidae 3.85 2.75 21 97 430.77 1997 3 Pacific cod 3 Northern rock sole 2.25 1.73 21 97 1241.32 

193
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1997 3 Pacific cod 3 Offal 5 4.73 21 97 2756.72 1997 3 Pacific cod 3 Opilio snow crab 7.23 2.96 21 97 3991.43 1997 3 Pacific cod 3 Pacific cod 3.39 2.21 21 97 1868.42 1997 3 Pacific cod 3 Paralithodes sp. 2.05 1.92 21 97 229.21 1997 3 Pacific cod 3 Pleuronectidae 1.79 1.72 21 97 985.66 1997 3 Pacific cod 3 Unid. Chionoecetes 0.99 0.91 21 97 544.04 1997 3 Pacific cod 3 Walleye pollock 44.67 7.57 21 97 24652.62 1997 3 Pacific halibut 2 Bairdi Tanner crab 8.79 8.6 6 13 384.41 1997 3 Pacific halibut 2 Unid. Osmerid 0.45 0.45 6 13 19.84 1997 3 Pacific halibut 2 Walleye pollock 0.12 0.12 6 13 5.23 1997 3 Pacific halibut 3 Bairdi Tanner crab 2.04 1.6 11 30 482.2 1997 3 Pacific halibut 3 Capelin 0.8 0.8 11 30 188.78 1997 3 Pacific halibut 3 Gadidae 9.09 9.09 11 30 2149.96 1997 3 Pacific halibut 3 Lithodidae 2.45 2.45 11 30 117.33 1997 3 Pacific halibut 3 Opilio snow crab 0.8 0.8 11 30 188.53 1997 3 Pacific halibut 3 Pacific cod 5.32 5.32 11 30 1257.64 1997 3 Pacific halibut 3 Pleuronectidae 7.33 6.23 11 30 1733.79 1997 3 Pacific halibut 3 Unid. Chionoecetes 0.01 0.01 11 30 1.23 1997 3 Pacific halibut 3 Walleye pollock 58.28 13.26 11 30 13782.8 1997 3 Skates 1 Gadidae 19.83 19.83 5 16 15543.64 1997 3 Skates 1 Opilio snow crab 7.2 7.2 5 16 5647.44 1997 3 Skates 1 Pleuronectidae 8.07 8.07 5 16 6324.54 1997 3 Skates 1 Walleye pollock 1.9 1.9 5 16 1487.44 1997 3 Skates 1 Yellowfin sole 13.43 13.43 5 16 10529.82 1997 3 Walleye pollock 1 Lithodidae 0.12 0.12 20 117 2.16 1997 3 Walleye pollock 1 Paralithodes sp. 0.1 0.1 20 117 1.69 

1997 3 Walleye pollock 1 Walleye pollock 0.91 0.91 20 117 79.15 1997 3 Walleye pollock 2 Blue king crab 0.05 0.05 21 65 4.54 1997 3 Walleye pollock 2 Offal 0.73 0.73 21 65 308.58 1997 3 Walleye pollock 2 Paralithodes sp. 0 0 21 65 0.4 

1997 3 Walleye pollock 2 Walleye pollock 1.57 1.57 21 65 665.86 1997 3 Walleye pollock 3 Blue king crab 0.1 0.1 30 183 28.13 1997 3 Walleye pollock 3 Offal 0.03 0.03 30 183 44.89 1997 3 Walleye pollock 3 Paralithodes sp. 0.01 0.01 30 183 1.75 

194
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1997 3 Walleye pollock 3 Pleuronectidae 0.01 0.01 30 183 13.08 1997 3 Walleye pollock 3 Walleye pollock 2.52 1.67 30 183 3484 1997 3 Walleye pollock 4 Gadidae 0.25 0.18 41 546 771.62 1997 3 Walleye pollock 4 Greenland turbot 0.02 0.01 41 546 61.02 1997 3 Walleye pollock 4 Northern rock sole 0.05 0.04 41 546 144.4 1997 3 Walleye pollock 4 Offal 3.82 2.77 41 546 11679.56 1997 3 Walleye pollock 4 Pacific halibut 0 0 41 546 9.98 1997 3 Walleye pollock 4 Paralithodes sp. 0 0 41 546 0.33 

1997 3 Walleye pollock 4 Pleuronectidae 0.28 0.28 41 546 859.59 1997 3 Walleye pollock 4 Walleye pollock 8.91 3.46 41 546 27224.53 1997 3 Yellowfin sole 1 Offal 2.81 2.81 13 116 10470.32 1997 3 Yellowfin sole 1 Opilio snow crab 2.39 2 13 116 8907.74 1997 3 Yellowfin sole 1 Unid. Chionoecetes 0.68 0.68 13 116 2539.17 1997 3 Yellowfin sole 1 Walleye pollock 3.96 3.96 13 116 14777.03 1997 4 Alaska plaice 1 Opilio snow crab 2.76 2.76 29 131 5455.54 1997 4 Alaska plaice 1 Unid. Chionoecetes 0.54 0.5 29 131 1063.99 1997 4 Arrowtooth flounder 2 Arrowtooth flounder 14.12 14.12 5 24 1018.57 1997 4 Arrowtooth flounder 2 Capelin 1.34 1.34 5 24 96.78 1997 4 Arrowtooth flounder 2 Gadidae 19.91 18.8 5 24 1436.06 1997 4 Arrowtooth flounder 2 Walleye pollock 56.1 23.18 5 24 4046.84 1997 4 Arrowtooth flounder 3 Gadidae 10.78 7.18 5 11 1037.11 1997 4 Arrowtooth flounder 3 Walleye pollock 58.31 16.95 5 11 5611.3 1997 4 Flathead sole 1 Bairdi Tanner crab 3.75 1.99 12 88 2285.75 1997 4 Flathead sole 1 Gadidae 1.67 1.35 12 88 1015.94 1997 4 Flathead sole 1 Unid. Chionoecetes 0.33 0.23 12 88 202.41 1997 4 Flathead sole 1 Walleye pollock 20.35 8.6 12 88 12400.74 1997 4 Greenland turbot 3 Gadidae 21.47 19.68 5 7 552.22 1997 4 Greenland turbot 3 Walleye pollock 76.96 19.31 5 7 1979.27 1997 4 Northern rock sole 1 Opilio snow crab 0.36 0.21 29 132 2115.74 1997 4 Northern rock sole 1 Unid. Chionoecetes 0.34 0.34 29 132 2024.67 1997 4 Pacific cod 1 Opilio snow crab 9.35 9.35 10 48 566.47 1997 4 Pacific cod 2 Bairdi Tanner crab 2.28 1.41 18 199 3753.25 1997 4 Pacific cod 2 Gadidae 0.49 0.49 18 199 801.72 1997 4 Pacific cod 2 Opilio snow crab 17.38 4.76 18 199 28562.72 

195
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1997 4 Pacific cod 2 Unid. Chionoecetes 2.52 1.35 18 199 4142.47 1997 4 Pacific cod 2 Walleye pollock 12.66 4.36 18 199 20803.14 1997 4 Pacific cod 3 Bairdi Tanner crab 0.79 0.5 15 63 579.44 1997 4 Pacific cod 3 Gadidae 0.27 0.25 15 63 201.46 1997 4 Pacific cod 3 King crab legs 0.14 0.14 15 63 103.67 1997 4 Pacific cod 3 Opilio snow crab 37.57 8.62 15 63 27672.57 1997 4 Pacific cod 3 Pacific cod 0.17 0.17 15 63 126.08 1997 4 Pacific cod 3 Paralithodes sp. 0.15 0.15 15 63 22.27 1997 4 Pacific cod 3 Pleuronectidae 3.21 3.04 15 63 2360.78 1997 4 Pacific cod 3 Unid. Chionoecetes 0.17 0.17 15 63 122.79 1997 4 Pacific cod 3 Walleye pollock 29.72 8.81 15 63 21886.63 1997 4 Pacific cod 3 Yellowfin sole 3.07 3.07 15 63 2258.37 1997 4 Pacific halibut 2 Bairdi Tanner crab 15.88 15.79 5 11 198.99 1997 4 Pacific halibut 2 Gadidae 2.25 1.43 5 11 28.13 1997 4 Pacific halibut 2 Offal 9.58 9.58 5 11 119.99 1997 4 Pacific halibut 2 Opilio snow crab 2.07 1.34 5 11 25.96 1997 4 Pacific halibut 2 Unid. Chionoecetes 1.62 1.27 5 11 20.35 1997 4 Pacific halibut 2 Walleye pollock 26.52 15.15 5 11 332.28 1997 4 Pacific halibut 3 Bairdi Tanner crab 5.12 5.08 19 48 563.5 1997 4 Pacific halibut 3 Flathead sole 3.69 3.69 19 48 405.38 1997 4 Pacific halibut 3 Gadidae 0.92 0.49 19 48 100.98 1997 4 Pacific halibut 3 Opilio snow crab 12.15 5.72 19 48 1336.62 1997 4 Pacific halibut 3 Unid. Chionoecetes 6.02 5.28 19 48 662.24 1997 4 Pacific halibut 3 Walleye pollock 57.96 9.4 19 48 6373.7 1997 4 Skates 1 Bairdi Tanner crab 1.23 0.73 19 92 1014.18 1997 4 Skates 1 Gadidae 4.65 2.86 19 92 3849.83 1997 4 Skates 1 Northern rock sole 5.24 5.24 19 92 4330.68 1997 4 Skates 1 Offal 9.35 6.37 19 92 7734.9 1997 4 Skates 1 Opilio snow crab 2.21 1.38 19 92 1827.69 1997 4 Skates 1 Pleuronectidae 1.71 1.71 19 92 1414.02 1997 4 Skates 1 Unid. Chionoecetes 3.43 1.39 19 92 2840.01 1997 4 Skates 1 Walleye pollock 17.98 7.22 19 92 14871.81 1997 4 Walleye pollock 1 Lithodidae 0.01 0.01 25 203 0.18 1997 4 Walleye pollock 1 Walleye pollock 2.4 2.4 25 203 306.74 

196
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1997 4 Walleye pollock 2 Blue king crab 0.02 0.01 19 50 4.77 1997 4 Walleye pollock 2 Walleye pollock 2.33 2.33 19 50 3065.92 1997 4 Walleye pollock 3 Blue king crab 0.13 0.09 33 309 231 1997 4 Walleye pollock 3 Gadidae 1.26 0.8 33 309 11053.85 1997 4 Walleye pollock 3 Pleuronectidae 0.02 0.02 33 309 162.95 1997 4 Walleye pollock 3 Walleye pollock 15.77 4.7 33 309 138233.5 1997 4 Walleye pollock 4 Blue king crab 0.01 0.01 47 438 4.62 1997 4 Walleye pollock 4 Gadidae 0.2 0.16 47 438 557.97 1997 4 Walleye pollock 4 Greenland turbot 0.01 0.01 47 438 27.68 1997 4 Walleye pollock 4 Northern rock sole 0 0 47 438 6.87 1997 4 Walleye pollock 4 Pacific halibut 0 0 47 438 7.37 1997 4 Walleye pollock 4 Pacific herring 0.01 0.01 47 438 22.98 1997 4 Walleye pollock 4 Pleuronectidae 1.34 1.34 47 438 3760.77 1997 4 Walleye pollock 4 Rockfish 0.01 0.01 47 438 15.4 1997 4 Walleye pollock 4 Walleye pollock 15.54 4.12 47 438 43569.43 1997 4 Yellowfin sole 1 Bairdi Tanner crab 1.76 1.76 12 77 1945.49 1997 4 Yellowfin sole 1 Opilio snow crab 0.42 0.28 12 77 466.18 1997 4 Yellowfin sole 1 Pleuronectidae 2.03 2.03 12 77 2242.22 1997 4 Yellowfin sole 1 Unid. Chionoecetes 0.44 0.44 12 77 483.75 1997 5 Arrowtooth flounder 2 Gadidae 1.84 1.84 11 32 657.01 1997 5 Arrowtooth flounder 2 Walleye pollock 33.13 12.11 11 32 11831.86 1997 5 Arrowtooth flounder 3 Gadidae 0.91 0.91 10 47 1383.87 1997 5 Arrowtooth flounder 3 Offal 6.8 6.8 10 47 10392.62 1997 5 Arrowtooth flounder 3 Walleye pollock 57.86 15.8 10 47 88434.42 1997 5 Flathead sole 1 Bairdi Tanner crab 6.3 6.3 4 33 4531.76 1997 5 Pacific cod 2 Bairdi Tanner crab 33.54 9.57 7 41 3172.85 1997 5 Pacific cod 2 Opilio snow crab 3.07 2.74 7 41 290.77 1997 5 Pacific cod 2 Unid. Chionoecetes 2.95 1.72 7 41 279.18 1997 5 Pacific cod 2 Walleye pollock 18.77 13.91 7 41 1775.23 1997 5 Pacific cod 3 Bairdi Tanner crab 15.72 7.31 9 48 2854.47 1997 5 Pacific cod 3 Flathead sole 2.71 2.71 9 48 491.25 1997 5 Pacific cod 3 Gadidae 0.51 0.51 9 48 92.94 1997 5 Pacific cod 3 Offal 2.33 2.33 9 48 423.49 1997 5 Pacific cod 3 Opilio snow crab 5.71 3.01 9 48 1036.12 

197
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1997 5 Pacific cod 3 Pleuronectidae 0.34 0.26 9 48 61.81 1997 5 Pacific cod 3 Unid. Chionoecetes 0.66 0.59 9 48 119.36 1997 5 Pacific cod 3 Walleye pollock 42.16 11.89 9 48 7654.36 1997 5 Pacific halibut 3 Bairdi Tanner crab 6.31 4.14 4 17 780.55 1997 5 Pacific halibut 3 Opilio snow crab 6.48 6.2 4 17 802.16 1997 5 Pacific halibut 3 Pleuronectidae 2.48 2.48 4 17 306.2 1997 5 Pacific halibut 3 Walleye pollock 75.82 11.79 4 17 9378.85 1997 5 Skates 1 Bairdi Tanner crab 30.44 20.57 3 18 13277.79 1997 5 Skates 1 Gadidae 6.26 6.26 3 18 2732.81 1997 5 Skates 1 Offal 2.32 2.32 3 18 1010.07 1997 5 Skates 1 Opilio snow crab 7.86 6.24 3 18 3429.8 1997 5 Skates 1 Walleye pollock 33.18 20.42 3 18 14475.33 1997 5 Walleye pollock 3 Blue king crab 0 0 13 94 0.38 1997 5 Walleye pollock 3 Gadidae 2.11 1.4 13 94 1338.67 1997 5 Walleye pollock 3 Offal 1.53 1.53 13 94 975.03 1997 5 Walleye pollock 3 Paralithodes sp. 0 0 13 94 0.12 

1997 5 Walleye pollock 3 Walleye pollock 32.99 9.48 13 94 20974.4 1997 5 Walleye pollock 4 Gadidae 7.53 5.67 15 129 6398.12 1997 5 Walleye pollock 4 Walleye pollock 33.05 10.72 15 129 28073.38 1997 6 Arrowtooth flounder 1 Gadidae 11.11 11.11 9 151997 6 Arrowtooth flounder 1 Pleuronectidae 5.34 5.34 9 151997 6 Arrowtooth flounder 1 Walleye pollock 11.11 11.11 9 151997 6 Arrowtooth flounder 2 Gadidae 10.59 7.95 13 28 2717.42 1997 6 Arrowtooth flounder 2 Walleye pollock 43.08 13.73 13 28 11059.97 1997 6 Arrowtooth flounder 3 Gadidae 2.01 1.25 22 107 3266.94 1997 6 Arrowtooth flounder 3 Pleuronectidae 0.17 0.17 22 107 274.9 1997 6 Arrowtooth flounder 3 Walleye pollock 73.72 8.87 22 107 119817.2 1997 6 Flathead sole 1 Bairdi Tanner crab 6.5 4.47 8 69 24417.01 1997 6 Flathead sole 1 Unid. Chionoecetes 0.04 0.04 8 69 158.61 1997 6 Flathead sole 1 Walleye pollock 3.65 3.65 8 69 13736.21 1997 6 Greenland turbot 3 Gadidae 0.15 0.15 5 14 27.61 1997 6 Greenland turbot 3 Offal 1.35 1.35 5 14 251.58 1997 6 Greenland turbot 3 Walleye pollock 98.51 1.32 5 14 18399.82 1997 6 Pacific cod 2 Bairdi Tanner crab 3.15 2.23 14 83 1703.07 

198
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1997 6 Pacific cod 2 Flathead sole 2.21 1.32 14 83 1195.56 1997 6 Pacific cod 2 Gadidae 0.57 0.57 14 83 307.18 1997 6 Pacific cod 2 Opilio snow crab 11.71 3.88 14 83 6332.55 1997 6 Pacific cod 2 Pleuronectidae 0.7 0.42 14 83 378.82 1997 6 Pacific cod 2 Unid. Chionoecetes 1.19 0.59 14 83 644.31 1997 6 Pacific cod 2 Walleye pollock 3.7 2.82 14 83 2001.74 1997 6 Pacific cod 3 Bairdi Tanner crab 6.03 3 16 114 7107.16 1997 6 Pacific cod 3 Flathead sole 3.17 1.7 16 114 3734.84 1997 6 Pacific cod 3 Gadidae 0.18 0.09 16 114 211.48 1997 6 Pacific cod 3 Offal 0.99 0.99 16 114 1162.67 1997 6 Pacific cod 3 Opilio snow crab 31.93 6.35 16 114 37644.08 1997 6 Pacific cod 3 Pleuronectidae 0.25 0.18 16 114 298.93 1997 6 Pacific cod 3 Unid. Chionoecetes 1.29 0.63 16 114 1520.33 1997 6 Pacific cod 3 Walleye pollock 29.04 6.93 16 114 34227.19 1997 6 Pacific halibut 3 Bairdi Tanner crab 1.97 1.62 10 35 354.29 1997 6 Pacific halibut 3 Gadidae 0.15 0.14 10 35 26.18 1997 6 Pacific halibut 3 Offal 0.59 0.59 10 35 105.39 1997 6 Pacific halibut 3 Opilio snow crab 10.21 6.32 10 35 1838.65 1997 6 Pacific halibut 3 Unid. Chionoecetes 10.7 4.86 10 35 1927.3 1997 6 Pacific halibut 3 Walleye pollock 59.12 13.01 10 35 10646.83 1997 6 Skates 1 Flathead sole 1.71 1.63 9 53 2755.48 1997 6 Skates 1 Gadidae 0.36 0.36 9 53 578 1997 6 Skates 1 Offal 5 3.31 9 53 8064.24 1997 6 Skates 1 Opilio snow crab 1.24 1.04 9 53 2002.61 1997 6 Skates 1 Unid. Chionoecetes 5.52 3.43 9 53 8900.61 1997 6 Skates 1 Walleye pollock 56.52 14.68 9 53 91189.41 1997 6 Walleye pollock 1 Gadidae 3.19 2.49 31 394 2586.11 1997 6 Walleye pollock 1 Greenland turbot 1.45 1.45 31 394 1174.57 1997 6 Walleye pollock 1 Offal 1.36 1.23 31 394 1106.99 1997 6 Walleye pollock 1 Unid. Chionoecetes 0 0 31 394 1.42 

1997 6 Walleye pollock 1 Walleye pollock 1.86 1.39 31 394 1512 1997 6 Walleye pollock 2 Gadidae 0.02 0.02 28 199 17.57 1997 6 Walleye pollock 2 Offal 2.69 1.88 28 199 2077.04 1997 6 Walleye pollock 2 Walleye pollock 4.63 3.22 28 199 3578.09 

199
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1997 6 Walleye pollock 3 Blue king crab 0.02 0.02 39 414 16.17 1997 6 Walleye pollock 3 Gadidae 0.67 0.66 39 414 3073.28 1997 6 Walleye pollock 3 Greenland turbot 0.02 0.02 39 414 87.68 1997 6 Walleye pollock 3 Offal 4.47 3.12 39 414 20586.49 1997 6 Walleye pollock 3 Pacific halibut 0 0 39 414 7.76 1997 6 Walleye pollock 3 Pacific herring 0 0 39 414 1.46 1997 6 Walleye pollock 3 Pleuronectidae 0.11 0.1 39 414 520.66 1997 6 Walleye pollock 3 Walleye pollock 12.53 3.77 39 414 57684.95 1997 6 Walleye pollock 4 Gadidae 5.65 3.35 32 210 11189.67 1997 6 Walleye pollock 4 Greenland turbot 4.1 3.13 32 210 8116.63 1997 6 Walleye pollock 4 Offal 6.2 3.35 32 210 12274.72 1997 6 Walleye pollock 4 Pacific halibut 0.04 0.04 32 210 80.07 1997 6 Walleye pollock 4 Pleuronectidae 0.02 0.02 32 210 40.95 1997 6 Walleye pollock 4 Walleye pollock 32.94 7.19 32 210 65213.38 1998 1 Pacific cod 1 Capelin 2.23 2.23 18 79 258.99 1998 1 Pacific cod 2 Flathead sole 1.35 1.35 18 120 1179.2 1998 1 Pacific cod 2 Gadidae 0.33 0.29 18 120 288.12 1998 1 Pacific cod 2 Pleuronectidae 5.09 3.66 18 120 4442.1 1998 1 Pacific cod 2 Walleye pollock 5.9 4.13 18 120 5151.24 1998 1 Pacific cod 3 Bairdi Tanner crab 0.72 0.58 19 80 542.35 1998 1 Pacific cod 3 Gadidae 1.33 1.33 19 80 996.12 1998 1 Pacific cod 3 King crab legs 0.16 0.16 19 80 116.78 1998 1 Pacific cod 3 Lithodidae 5.76 4.97 19 80 874.01 1998 1 Pacific cod 3 Northern rock sole 2.19 1.62 19 80 1642.12 1998 1 Pacific cod 3 Offal 2.83 2.04 19 80 2118.36 1998 1 Pacific cod 3 Pacific cod 0.11 0.11 19 80 80.8 1998 1 Pacific cod 3 Pleuronectidae 20.73 5.58 19 80 15528.9 1998 1 Pacific cod 3 Red king crab 2.82 2.82 19 80 428.66 1998 1 Pacific cod 3 Unid. Osmerid 0.58 0.46 19 80 437.58 1998 1 Pacific cod 3 Unid. Chionoecetes 2.73 1.87 19 80 2047.36 1998 1 Pacific cod 3 Walleye pollock 20.18 6.01 19 80 15115.75 1998 1 Pacific cod 3 Yellowfin sole 3.12 1.79 19 80 2335.64 1998 1 Pacific halibut 2 Capelin 5.96 4.1 16 65 728.35 1998 1 Pacific halibut 2 Flathead sole 0.89 0.89 16 65 109.37 

200
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1998 1 Pacific halibut 2 Gadidae 6.23 6.01 16 65 761.18 1998 1 Pacific halibut 2 Pleuronectidae 8.68 4.14 16 65 1060.73 1998 1 Pacific halibut 2 Unid. Osmerid 1.87 1.62 16 65 228.96 1998 1 Pacific halibut 2 Walleye pollock 15.17 8.38 16 65 1854.53 1998 1 Pacific halibut 2 Yellowfin sole 1.16 1.16 16 65 141.31 1998 1 Pacific halibut 3 Capelin 0.04 0.04 17 49 4.9 1998 1 Pacific halibut 3 Gadidae 0.53 0.43 17 49 73.23 1998 1 Pacific halibut 3 Northern rock sole 0.41 0.41 17 49 56.8 1998 1 Pacific halibut 3 Pacific herring 5.95 4.57 17 49 817.18 1998 1 Pacific halibut 3 Pleuronectidae 39.77 9.03 17 49 5463.74 1998 1 Pacific halibut 3 Walleye pollock 34.08 9.88 17 49 4682.38 1998 1 Pacific halibut 3 Yellowfin sole 10.16 2.58 17 49 1396.27 1998 1 Walleye pollock 4 Gadidae 0.03 0.02 20 328 56.78 1998 1 Walleye pollock 4 Northern rock sole 0.02 0.02 20 328 45.19 1998 1 Walleye pollock 4 Unid. Osmerid 0.07 0.07 20 328 140.32 1998 1 Walleye pollock 4 Walleye pollock 0.92 0.53 20 328 1834.2 1998 2 Pacific cod 1 Bairdi Tanner crab 1.37 1.37 12 47 39.91 1998 2 Pacific cod 1 Capelin 0.65 0.65 12 47 18.84 1998 2 Pacific cod 1 Unid. Chionoecetes 10.15 7.07 12 47 295.12 1998 2 Pacific cod 1 Walleye pollock 0.18 0.18 12 47 5.35 1998 2 Pacific cod 2 Bairdi Tanner crab 1.89 1.38 11 85 239.83 1998 2 Pacific cod 2 Gadidae 2.98 2.93 11 85 377.7 1998 2 Pacific cod 2 Opilio snow crab 26.26 9.7 11 85 3326.56 1998 2 Pacific cod 2 Unid. Chionoecetes 1.73 0.8 11 85 218.98 1998 2 Pacific cod 2 Walleye pollock 13.33 6.49 11 85 1688.83 1998 2 Pacific cod 3 Bairdi Tanner crab 0.05 0.05 11 36 5.03 1998 2 Pacific cod 3 Gadidae 1.3 1.3 11 36 142.74 1998 2 Pacific cod 3 Lithodidae 0.17 0.17 11 36 3.84 1998 2 Pacific cod 3 Opilio snow crab 18.52 9.17 11 36 2026.54 1998 2 Pacific cod 3 Pacific cod 7.89 5.67 11 36 863.66 1998 2 Pacific cod 3 Pleuronectidae 3.08 1.92 11 36 337.64 1998 2 Pacific cod 3 Unid. Chionoecetes 6.24 5.54 11 36 682.83 1998 2 Pacific cod 3 Walleye pollock 4.93 2 11 36 539.23 1998 2 Pacific halibut 2 Flathead sole 0.68 0.68 5 35 35.17 

201
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1998 2 Pacific halibut 2 Gadidae 0.68 0.68 5 35 35.29 1998 2 Pacific halibut 2 Pacific cod 27.08 11.81 5 35 1408.53 1998 2 Pacific halibut 2 Pleuronectidae 4.94 3.38 5 35 257.23 1998 2 Pacific halibut 2 Unid. Osmerid 6.43 6.43 5 35 334.7 1998 2 Pacific halibut 2 Walleye pollock 32.55 17.33 5 35 1693.49 1998 2 Pacific halibut 3 Gadidae 3.03 3.03 4 11 166.42 1998 2 Pacific halibut 3 Pacific cod 34.58 21.9 4 11 1897.26 1998 2 Pacific halibut 3 Pleuronectidae 37.87 23.11 4 11 2077.93 1998 2 Pacific halibut 3 Unid. Osmerid 1.67 1.26 4 11 91.76 1998 2 Pacific halibut 3 Walleye pollock 18.15 17.71 4 11 996.07 1998 2 Pacific halibut 3 Yellowfin sole 2.29 2.29 4 11 125.45 1998 2 Skates 1 Gadidae 1.24 0 1 8 568.06 1998 2 Skates 1 Unid. Chionoecetes 3.54 0 1 8 1626.55 1998 2 Skates 1 Walleye pollock 3.06 0 1 8 1406.5 1998 2 Walleye pollock 4 Flathead sole 0.25 0.25 18 161 69.55 1998 2 Walleye pollock 4 Gadidae 0.62 0.44 18 161 171.73 1998 2 Walleye pollock 4 Walleye pollock 2.23 1.33 18 161 612.17 1998 3 Alaska plaice 1 Opilio snow crab 0.1 0.1 12 58 93.78 1998 3 Arrowtooth flounder 2 Gadidae 5.01 5.01 8 24 1877.2 1998 3 Arrowtooth flounder 2 Walleye pollock 28.37 14.45 8 24 10634.39 1998 3 Arrowtooth flounder 3 Gadidae 11.11 11.11 6 12 8217.07 1998 3 Arrowtooth flounder 3 Walleye pollock 50.35 21.96 6 12 37236.95 1998 3 Flathead sole 1 Unid. Chionoecetes 1.64 1.64 5 25 3307.8 1998 3 Pacific cod 1 Bairdi Tanner crab 4.6 4.6 10 24 184.08 1998 3 Pacific cod 1 Northern rock sole 1.56 1.56 10 24 62.58 1998 3 Pacific cod 1 Unid. Chionoecetes 7.93 5.52 10 24 317.16 1998 3 Pacific cod 2 Bairdi Tanner crab 3.96 1.8 19 142 3046.71 1998 3 Pacific cod 2 Gadidae 0.09 0.07 19 142 70.77 1998 3 Pacific cod 2 King crab legs 5.26 5.26 19 142 4047.29 1998 3 Pacific cod 2 Offal 4.92 3.39 19 142 3781.11 1998 3 Pacific cod 2 Opilio snow crab 16.7 4.82 19 142 12838.45 1998 3 Pacific cod 2 Pacific herring 0.31 0.31 19 142 241.15 1998 3 Pacific cod 2 Pleuronectidae 0.45 0.45 19 142 349.68 1998 3 Pacific cod 2 Unid. Chionoecetes 1.02 0.66 19 142 786.82 

202
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1998 3 Pacific cod 2 Walleye pollock 4.19 2.77 19 142 3219.12 1998 3 Pacific cod 2 Yellowfin sole 1.95 1.95 19 142 1495.81 1998 3 Pacific cod 3 Bairdi Tanner crab 2.84 1.4 24 98 2112.84 1998 3 Pacific cod 3 Gadidae 4.33 3.6 24 98 3221.54 1998 3 Pacific cod 3 King crab legs 5.04 4.13 24 98 3752.69 1998 3 Pacific cod 3 Lithodidae 1.38 1.38 24 98 208.07 1998 3 Pacific cod 3 Northern rock sole 2.66 1.81 24 98 1979.41 1998 3 Pacific cod 3 Offal 2.25 1.75 24 98 1676.58 1998 3 Pacific cod 3 Opilio snow crab 10.28 4.21 24 98 7648.74 1998 3 Pacific cod 3 Pleuronectidae 8.71 4.39 24 98 6484.77 1998 3 Pacific cod 3 Unid. Osmerid 0.01 0.01 24 98 5.96 1998 3 Pacific cod 3 Unid. Chionoecetes 1.52 0.77 24 98 1128.5 1998 3 Pacific cod 3 Walleye pollock 47.88 8.35 24 98 35632.43 1998 3 Pacific halibut 2 Bairdi Tanner crab 2.62 2.54 10 23 208.72 1998 3 Pacific halibut 2 Offal 4.45 4.45 10 23 355.09 1998 3 Pacific halibut 2 Opilio snow crab 1.78 1.78 10 23 141.8 1998 3 Pacific halibut 2 Unid. Chionoecetes 3.87 3.03 10 23 308.33 1998 3 Pacific halibut 2 Walleye pollock 31.44 13.33 10 23 2507.12 1998 3 Pacific halibut 3 Bairdi Tanner crab 0.66 0.49 15 37 101.47 1998 3 Pacific halibut 3 Gadidae 1.45 0.93 15 37 222.93 1998 3 Pacific halibut 3 Opilio snow crab 3.75 2.54 15 37 574.44 1998 3 Pacific halibut 3 Pleuronectidae 13.52 8.62 15 37 2072.18 1998 3 Pacific halibut 3 Walleye pollock 61.68 11.01 15 37 9451.37 1998 3 Pacific halibut 3 Yellowfin sole 0.55 0.55 15 37 83.97 1998 3 Walleye pollock 1 Walleye pollock 6.46 5.05 19 127 993.42 1998 3 Walleye pollock 2 Walleye pollock 15.16 8.87 13 46 11270.9 1998 3 Walleye pollock 3 Pleuronectidae 0.04 0.04 25 218 178.37 1998 3 Walleye pollock 3 Walleye pollock 0.48 0.48 25 218 2088.9 1998 3 Walleye pollock 4 Gadidae 0.51 0.45 32 293 621.52 1998 3 Walleye pollock 4 Offal 0.26 0.26 32 293 318.9 1998 3 Walleye pollock 4 Pleuronectidae 0.04 0.04 32 293 46.9 1998 3 Walleye pollock 4 Walleye pollock 4.33 3.03 32 293 5232.31 1998 4 Arrowtooth flounder 1 Gadidae 3.09 3.09 3 7 3.87 1998 4 Arrowtooth flounder 1 Walleye pollock 20.52 20.52 3 7 25.72 

203
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1998 4 Arrowtooth flounder 2 Gadidae 41.2 24.03 5 34 2032.92 1998 4 Arrowtooth flounder 2 Walleye pollock 34.41 21.28 5 34 1697.81 1998 4 Arrowtooth flounder 3 Gadidae 0.2 0.2 4 12 26.05 1998 4 Arrowtooth flounder 3 Walleye pollock 66.73 23.54 4 12 8739.12 1998 4 Flathead sole 1 Bairdi Tanner crab 0.67 0.67 7 40 534.18 1998 4 Flathead sole 1 Unid. Chionoecetes 0.42 0.42 7 40 333.16 1998 4 Flathead sole 1 Walleye pollock 14.29 14.29 7 40 11431.55 1998 4 Greenland turbot 3 Walleye pollock 100 0 1 1 4261.05 1998 4 Pacific cod 1 Bairdi Tanner crab 6.11 4.19 17 50 777.53 1998 4 Pacific cod 1 Opilio snow crab 2.82 2.26 17 50 359.46 1998 4 Pacific cod 1 Unid. Chionoecetes 1.34 1.03 17 50 170.23 1998 4 Pacific cod 2 Bairdi Tanner crab 9.52 2.84 19 154 9875.44 1998 4 Pacific cod 2 Gadidae 0.11 0.11 19 154 110.42 1998 4 Pacific cod 2 Offal 4.78 2.4 19 154 4959.09 1998 4 Pacific cod 2 Opilio snow crab 15.14 4.76 19 154 15701.43 1998 4 Pacific cod 2 Pacific herring 3.4 2.76 19 154 3522.84 1998 4 Pacific cod 2 Pleuronectidae 0.11 0.11 19 154 110.81 1998 4 Pacific cod 2 Unid. Chionoecetes 5.52 2.69 19 154 5727.7 1998 4 Pacific cod 2 Walleye pollock 5.02 2.47 19 154 5203.93 1998 4 Pacific cod 3 Bairdi Tanner crab 2.3 1.48 23 75 1703.91 1998 4 Pacific cod 3 Gadidae 4.07 3.86 23 75 3018.23 1998 4 Pacific cod 3 Offal 7.28 3.86 23 75 5397.63 1998 4 Pacific cod 3 Opilio snow crab 29.86 8.07 23 75 22132.49 1998 4 Pacific cod 3 Pleuronectidae 0.65 0.65 23 75 479.28 1998 4 Pacific cod 3 Unid. Chionoecetes 0.99 0.58 23 75 731.89 1998 4 Pacific cod 3 Walleye pollock 30.76 8 23 75 22799.24 1998 4 Pacific cod 3 Yellowfin sole 0.45 0.45 23 75 333.83 1998 4 Pacific halibut 2 Bairdi Tanner crab 0.38 0.27 10 37 12.21 1998 4 Pacific halibut 2 Gadidae 3.65 3.1 10 37 116.27 1998 4 Pacific halibut 2 Northern rock sole 0.24 0.24 10 37 7.7 1998 4 Pacific halibut 2 Opilio snow crab 13.85 9.68 10 37 440.74 1998 4 Pacific halibut 2 Pleuronectidae 0.27 0.27 10 37 8.72 1998 4 Pacific halibut 2 Unid. Chionoecetes 0.86 0.86 10 37 27.26 1998 4 Pacific halibut 2 Walleye pollock 6.7 6.51 10 37 213.18 

204
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1998 4 Pacific halibut 3 Gadidae 2.33 2.24 14 35 315.87 1998 4 Pacific halibut 3 Offal 8.87 7.07 14 35 1204.34 1998 4 Pacific halibut 3 Opilio snow crab 9.91 7.07 14 35 1345.83 1998 4 Pacific halibut 3 Pleuronectidae 0.72 0.72 14 35 98.15 1998 4 Pacific halibut 3 Unid. Chionoecetes 0.1 0.1 14 35 13.58 

1998 4 Pacific halibut 3 Walleye pollock 51.18 10.99 14 35 6950.04 1998 4 Pacific halibut 3 Yellowfin sole 1.45 1.45 14 35 196.53 1998 4 Skates 1 Gadidae 0.27 0.27 4 31 238.69 1998 4 Skates 1 Northern rock sole 0.71 0.71 4 31 624.05 1998 4 Skates 1 Offal 25.32 24.26 4 31 22320.68 1998 4 Skates 1 Pleuronectidae 1.21 1.21 4 31 1070.95 1998 4 Skates 1 Unid. Chionoecetes 0.23 0.21 4 31 201.08 1998 4 Skates 1 Walleye pollock 42.76 24.69 4 31 37694.06 1998 4 Walleye pollock 3 Walleye pollock 2.95 2.95 31 309 16759.56 1998 4 Walleye pollock 4 Gadidae 5.62 3.84 31 141 6947.44 1998 4 Walleye pollock 4 Greenland turbot 0.01 0.01 31 141 13.46 1998 4 Walleye pollock 4 Paralithodes sp. 0 0 31 141 0.07 

1998 4 Walleye pollock 4 Rockfish 0.01 0.01 31 141 8.59 1998 4 Walleye pollock 4 Walleye pollock 3.22 3.22 31 141 3981.46 1998 4 Yellowfin sole 1 Bairdi Tanner crab 0.02 0.02 16 115 40.19 1998 4 Yellowfin sole 1 Walleye pollock 1.17 1.17 16 115 2649.15 1998 5 Arrowtooth flounder 2 Gadidae 23.97 12.84 10 25 6275.03 1998 5 Arrowtooth flounder 2 Walleye pollock 9.71 9.71 10 25 2540.78 1998 5 Arrowtooth flounder 3 Gadidae 26.58 16.1 8 18 18602.86 1998 5 Arrowtooth flounder 3 Walleye pollock 29.7 14.81 8 18 20785.78 1998 5 Flathead sole 1 Bairdi Tanner crab 30.97 19.16 4 24 21067.71 1998 5 Pacific cod 2 Bairdi Tanner crab 50.99 8.73 9 58 5371.36 1998 5 Pacific cod 2 Gadidae 0.35 0.35 9 58 37.13 1998 5 Pacific cod 2 Opilio snow crab 2.15 1.73 9 58 226.88 1998 5 Pacific cod 2 Pleuronectidae 0.02 0.02 9 58 2.5 1998 5 Pacific cod 2 Unid. Chionoecetes 4.31 1.95 9 58 454.45 1998 5 Pacific cod 2 Walleye pollock 1.38 1.38 9 58 145.63 1998 5 Pacific cod 3 Bairdi Tanner crab 41.24 9.67 11 46 5815.72 1998 5 Pacific cod 3 Offal 8.26 7.02 11 46 1164.74 

205
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1998 5 Pacific cod 3 Opilio snow crab 0.09 0.09 11 46 12.24 1998 5 Pacific cod 3 Pleuronectidae 0.45 0.45 11 46 63.69 1998 5 Pacific cod 3 Unid. Chionoecetes 1.28 0.79 11 46 180.43 1998 5 Pacific cod 3 Walleye pollock 29.76 12.06 11 46 4196.94 1998 5 Pacific halibut 2 Bairdi Tanner crab 20.48 20.48 3 4 166.98 1998 5 Pacific halibut 2 Opilio snow crab 2.12 2.12 3 4 17.26 1998 5 Pacific halibut 2 Pacific cod 33.33 33.33 3 4 271.83 1998 5 Pacific halibut 3 Bairdi Tanner crab 43.12 14.56 8 20 4805.13 1998 5 Pacific halibut 3 Offal 0.79 0.79 8 20 88.11 1998 5 Pacific halibut 3 Opilio snow crab 4.45 3.02 8 20 495.5 1998 5 Pacific halibut 3 Unid. Chionoecetes 0.39 0.32 8 20 43.4 1998 5 Pacific halibut 3 Walleye pollock 30.25 15.04 8 20 3370.7 1998 6 Arrowtooth flounder 2 Gadidae 12.06 9.92 10 17 2315.44 1998 6 Arrowtooth flounder 2 Walleye pollock 37.84 15.52 10 17 7263.49 1998 6 Arrowtooth flounder 3 Gadidae 6.25 3.65 13 71 8836.7 1998 6 Arrowtooth flounder 3 Offal 1.07 1.07 13 71 1519.07 1998 6 Arrowtooth flounder 3 Walleye pollock 74.46 10.11 13 71 105266.8 1998 6 Flathead sole 1 Bairdi Tanner crab 5.39 5.39 5 32 18478.55 1998 6 Flathead sole 1 Unid. Chionoecetes 1.41 1.41 5 32 4825.56 1998 6 Northern rock sole 1 Bairdi Tanner crab 0.16 0.16 2 14 212.96 1998 6 Pacific cod 2 Bairdi Tanner crab 12.96 4.07 16 104 3934.34 1998 6 Pacific cod 2 Flathead sole 0.36 0.36 16 104 109.66 1998 6 Pacific cod 2 Gadidae 0.23 0.23 16 104 69.29 1998 6 Pacific cod 2 Offal 1.02 0.79 16 104 309.9 1998 6 Pacific cod 2 Opilio snow crab 8.23 3.2 16 104 2498.76 1998 6 Pacific cod 2 Pleuronectidae 0.03 0.03 16 104 9.9 1998 6 Pacific cod 2 Unid. Chionoecetes 8.11 2.72 16 104 2460.97 1998 6 Pacific cod 2 Walleye pollock 17.64 6.62 16 104 5353.64 1998 6 Pacific cod 3 Bairdi Tanner crab 13.37 2.95 19 92 10865.55 1998 6 Pacific cod 3 Flathead sole 0.82 0.82 19 92 668.08 1998 6 Pacific cod 3 Gadidae 1.43 0.87 19 92 1158.18 1998 6 Pacific cod 3 Offal 1.51 0.97 19 92 1226.57 1998 6 Pacific cod 3 Opilio snow crab 12.62 3.83 19 92 10252.38 1998 6 Pacific cod 3 Pleuronectidae 3.28 2.69 19 92 2662.56 

206
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1998 6 Pacific cod 3 Unid. Chionoecetes 3.32 2.15 19 92 2698.08 1998 6 Pacific cod 3 Walleye pollock 22.06 5.73 19 92 17920.6 1998 6 Pacific halibut 2 Bairdi Tanner crab 24 14.02 3 6 357.63 1998 6 Pacific halibut 2 Opilio snow crab 36.49 21.72 3 6 543.83 1998 6 Pacific halibut 2 Unid. Chionoecetes 4.75 4.75 3 6 70.83 1998 6 Pacific halibut 2 Walleye pollock 8.5 8.18 3 6 126.6 1998 6 Pacific halibut 3 Bairdi Tanner crab 3.84 3.5 9 36 1164.07 1998 6 Pacific halibut 3 Offal 1.42 1.42 9 36 430.01 1998 6 Pacific halibut 3 Opilio snow crab 1.9 1.14 9 36 576.02 1998 6 Pacific halibut 3 Pleuronectidae 0.02 0.02 9 36 6.11 1998 6 Pacific halibut 3 Unid. Chionoecetes 1.29 1.04 9 36 389.85 1998 6 Pacific halibut 3 Walleye pollock 66.72 9.96 9 36 20208.21 1998 6 Walleye pollock 1 Gadidae 0.36 0.36 16 172 188.87 1998 6 Walleye pollock 1 Offal 0.65 0.65 16 172 337.01 1998 6 Walleye pollock 1 Walleye pollock 0.69 0.69 16 172 358.22 1998 6 Walleye pollock 2 Offal 12.39 10.05 8 41 4611.61 1998 6 Walleye pollock 3 Gadidae 0.96 0.96 18 110 2719.34 1998 6 Walleye pollock 3 Walleye pollock 9.3 6.4 18 110 26305.73 1998 6 Walleye pollock 4 Gadidae 5.11 3.02 15 75 4972.98 1998 6 Walleye pollock 4 Offal 8.52 6.59 15 75 8300.18 1998 6 Walleye pollock 4 Walleye pollock 26.89 10.6 15 75 26188.6 1998 6 Yellowfin sole 1 Unid. Chionoecetes 3.07 0 1 9 197.38 1999 1 Flathead sole 1 Pleuronectidae 3.4 3.4 3 14 340.02 1999 1 Flathead sole 1 Walleye pollock 19.35 19.35 3 14 1936.47 1999 1 Pacific cod 1 Capelin 5.76 5.76 11 123 56.25 1999 1 Pacific cod 1 Unid. Osmerid 6.61 6.61 11 123 64.61 1999 1 Pacific cod 2 Gadidae 0.51 0.41 6 70 43.22 1999 1 Pacific cod 2 King crab legs 11.4 5.24 6 70 960.6 1999 1 Pacific cod 2 Pleuronectidae 0.95 0.7 6 70 80.14 1999 1 Pacific cod 2 Unid. Osmerid 0.43 0.43 6 70 36.01 1999 1 Pacific cod 2 Walleye pollock 11.5 11.5 6 70 969.62 1999 1 Pacific cod 3 Gadidae 1.17 0.88 9 28 221.57 1999 1 Pacific cod 3 King crab legs 7.68 5.62 9 28 1454.7 1999 1 Pacific cod 3 Lithodidae 5.86 5.7 9 28 224.85 

207
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1999 1 Pacific cod 3 Northern rock sole 7.3 4.4 9 28 1383.51 1999 1 Pacific cod 3 Paralithodes sp. 2.7 2.7 9 28 103.5 

1999 1 Pacific cod 3 Pleuronectidae 26.66 8.57 9 28 5050.45 1999 1 Pacific cod 3 Walleye pollock 11.67 4.99 9 28 2210.26 1999 1 Pacific cod 3 Yellowfin sole 1.65 1.65 9 28 312.3 1999 1 Pacific halibut 2 Capelin 21.91 11.69 11 30 1114.32 1999 1 Pacific halibut 2 Gadidae 9.35 7.54 11 30 475.27 1999 1 Pacific halibut 2 Pleuronectidae 3.28 3.28 11 30 166.57 1999 1 Pacific halibut 2 Unid. Osmerid 8.1 7.62 11 30 412.04 1999 1 Pacific halibut 2 Walleye pollock 3.24 3.24 11 30 164.98 1999 1 Pacific halibut 3 Capelin 10.24 10.24 2 3 499.71 1999 1 Pacific halibut 3 Walleye pollock 50 50 2 3 2440.66 1999 1 Walleye pollock 4 Capelin 2.43 1.76 22 286 1543.64 1999 1 Walleye pollock 4 Gadidae 1.05 0.8 22 286 667.73 1999 1 Walleye pollock 4 Pacific herring 2.71 1.81 22 286 1726.28 1999 1 Walleye pollock 4 Pleuronectidae 0.18 0.14 22 286 116.95 1999 1 Walleye pollock 4 Unid. Osmerid 0.88 0.67 22 286 559.1 1999 1 Walleye pollock 4 Walleye pollock 1.1 0.43 22 286 701.18 1999 1 Walleye pollock 4 Yellowfin sole 0.08 0.08 22 286 51.98 1999 1 Yellowfin sole 1 Offal 0.83 0.82 13 90 3503.01 1999 1 Yellowfin sole 1 Walleye pollock 5.48 5.48 13 90 23020.57 1999 2 Alaska plaice 1 Unid. Osmerid 0.02 0.02 5 45 16.53 1999 2 Flathead sole 1 Gadidae 26.34 0 1 2 32.44 1999 2 Flathead sole 1 Walleye pollock 73.66 0 1 2 90.73 1999 2 Pacific cod 2 Gadidae 3.42 3.42 2 7 50.01 1999 2 Pacific cod 2 Opilio snow crab 25.59 25.59 2 7 374.2 1999 2 Pacific cod 2 Walleye pollock 3.29 3.29 2 7 48.09 1999 2 Pacific cod 3 Gadidae 10.05 7.91 5 31 679.35 1999 2 Pacific cod 3 Lithodidae 6.29 4.32 5 31 86.17 1999 2 Pacific cod 3 Opilio snow crab 15.94 9.57 5 31 1076.89 1999 2 Pacific cod 3 Pacific herring 2.96 2.03 5 31 199.72 1999 2 Pacific cod 3 Pleuronectidae 15.76 14.93 5 31 1064.91 1999 2 Pacific cod 3 Unid. Osmerid 0.04 0.04 5 31 2.45 1999 2 Pacific cod 3 Unid. Chionoecetes 15.39 13.56 5 31 1039.88 

208
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1999 2 Pacific cod 3 Walleye pollock 8.73 3.95 5 31 590.16 1999 2 Pacific halibut 1 Walleye pollock 17.87 17.87 3 9 34.07 1999 2 Pacific halibut 2 Capelin 15.27 9.58 4 22 391.98 1999 2 Pacific halibut 2 Gadidae 6.38 4.1 4 22 163.88 1999 2 Pacific halibut 2 Pacific herring 2.63 2.63 4 22 67.54 1999 2 Pacific halibut 2 Unid. Osmerid 12.48 12.48 4 22 320.5 1999 2 Pacific halibut 2 Walleye pollock 35.28 14.71 4 22 905.8 1999 2 Pacific halibut 3 Pacific herring 20.77 20.77 2 3 434.12 1999 2 Pacific halibut 3 Pleuronectidae 4.79 4.79 2 3 100.23 1999 2 Skates 1 Lithodidae 9.28 9.28 5 13 252.67 1999 2 Skates 1 Pacific herring 0.47 0.47 5 13 63.28 1999 2 Skates 1 Paralithodes sp. 0.9 0.9 5 13 24.5 

1999 2 Skates 1 Pleuronectidae 10.17 5.96 5 13 1366.46 1999 2 Skates 1 Unid. Chionoecetes 21.12 14.61 5 13 2838.15 1999 2 Walleye pollock 1 Walleye pollock 8.51 8.51 11 74 87.37 1999 2 Walleye pollock 4 Capelin 5.99 3.63 15 203 1178.64 1999 2 Walleye pollock 4 Gadidae 1.93 0.84 15 203 380.4 1999 2 Walleye pollock 4 Pacific herring 25.27 4.81 15 203 4970.74 1999 2 Walleye pollock 4 Unid. Osmerid 0.13 0.08 15 203 25.51 1999 2 Walleye pollock 4 Walleye pollock 6.36 1.74 15 203 1252.14 1999 3 Arrowtooth flounder 2 Gadidae 14.26 10.97 9 22 5219.21 1999 3 Arrowtooth flounder 2 Pleuronectidae 0.45 0.45 9 22 165.16 1999 3 Arrowtooth flounder 2 Walleye pollock 38.62 15.5 9 22 14129.85 1999 3 Arrowtooth flounder 3 Gadidae 22.22 12.11 9 18 7299.47 1999 3 Arrowtooth flounder 3 Walleye pollock 66.67 14.44 9 18 21898.37 1999 3 Flathead sole 1 Gadidae 1.29 1.29 9 59 1928.46 1999 3 Flathead sole 1 Walleye pollock 28.58 14.47 9 59 42861.97 1999 3 Greenland turbot 3 Gadidae 99.02 0 1 1 358.29 1999 3 Pacific cod 1 Gadidae 1.77 1.29 21 69 146.24 1999 3 Pacific cod 1 King crab legs 1.48 1.48 21 69 122.32 1999 3 Pacific cod 1 Opilio snow crab 3.2 2.86 21 69 264.36 1999 3 Pacific cod 1 Unid. Osmerid 0.36 0.36 21 69 29.99 1999 3 Pacific cod 1 Walleye pollock 2.87 2.02 21 69 237.47 1999 3 Pacific cod 2 Bairdi Tanner crab 5.78 2.71 27 204 10354.66 

209
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1999 3 Pacific cod 2 Flathead sole 0.01 0.01 27 204 22.79 1999 3 Pacific cod 2 Gadidae 1.89 1 27 204 3388.12 1999 3 Pacific cod 2 King crab legs 2.69 1.92 27 204 4820.22 1999 3 Pacific cod 2 Lithodidae 0.96 0.87 27 204 347.88 1999 3 Pacific cod 2 Northern rock sole 2.4 1.67 27 204 4302.02 1999 3 Pacific cod 2 Opilio snow crab 5.11 3.71 27 204 9147.68 1999 3 Pacific cod 2 Pacific herring 1.82 1.82 27 204 3254.55 1999 3 Pacific cod 2 Pleuronectidae 0.09 0.08 27 204 162.55 1999 3 Pacific cod 2 Unid. Chionoecetes 2.97 1.48 27 204 5325.95 1999 3 Pacific cod 2 Walleye pollock 4.75 2.1 27 204 8507.97 1999 3 Pacific cod 3 Bairdi Tanner crab 2.75 1.91 35 116 2049.4 1999 3 Pacific cod 3 Gadidae 2.57 0.84 35 116 1912.92 1999 3 Pacific cod 3 King crab legs 0.15 0.15 35 116 112.19 1999 3 Pacific cod 3 Lithodidae 4.61 2.29 35 116 696.58 1999 3 Pacific cod 3 Northern rock sole 1.46 0.73 35 116 1086.7 1999 3 Pacific cod 3 Offal 1.68 1.47 35 116 1252.62 1999 3 Pacific cod 3 Opilio snow crab 4.83 3.14 35 116 3599.34 1999 3 Pacific cod 3 Pacific cod 0.68 0.68 35 116 505.68 1999 3 Pacific cod 3 Pacific herring 2.17 1.42 35 116 1617.42 1999 3 Pacific cod 3 Paralithodes sp. 0.56 0.56 35 116 84.86 1999 3 Pacific cod 3 Pleuronectidae 11.39 3.96 35 116 8486.13 1999 3 Pacific cod 3 Red king crab 2.24 2.24 35 116 337.48 1999 3 Pacific cod 3 Unid. Osmerid 1.12 1.12 35 116 832.08 1999 3 Pacific cod 3 Unid. Chionoecetes 3.26 2.37 35 116 2428.97 1999 3 Pacific cod 3 Walleye pollock 43.15 7.16 35 116 32154.23 1999 3 Pacific cod 3 Yellowfin sole 0.77 0.77 35 116 573.28 1999 3 Pacific halibut 2 Gadidae 9.09 5.52 14 37 2175.8 1999 3 Pacific halibut 2 Lithodidae 1.02 1.02 14 37 49.25 1999 3 Pacific halibut 2 Offal 7.16 7.14 14 37 1713.84 1999 3 Pacific halibut 2 Unid. Osmerid 1.78 1.78 14 37 425.89 1999 3 Pacific halibut 2 Walleye pollock 5.53 4.87 14 37 1322.36 1999 3 Pacific halibut 3 Bairdi Tanner crab 17.87 11.02 9 20 2773.56 1999 3 Pacific halibut 3 Gadidae 28.01 14.52 9 20 4347.5 1999 3 Pacific halibut 3 Opilio snow crab 1.23 1.23 9 20 190.96 

210
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1999 3 Pacific halibut 3 Pleuronectidae 3.04 3.04 9 20 472.47 1999 3 Pacific halibut 3 Unid. Chionoecetes 0.31 0.24 9 20 48.14 1999 3 Pacific halibut 3 Walleye pollock 43.82 16.87 9 20 6801.43 1999 3 Skates 1 Bairdi Tanner crab 7.95 5.3 10 56 6708.78 1999 3 Skates 1 Gadidae 8.74 4.58 10 56 7377.62 1999 3 Skates 1 Lithodidae 5.59 5.59 10 56 955.71 1999 3 Skates 1 Northern rock sole 1.34 1.34 10 56 1131.91 1999 3 Skates 1 Offal 0.75 0.54 10 56 633.25 1999 3 Skates 1 Pleuronectidae 0.82 0.61 10 56 694.61 1999 3 Skates 1 Unid. Osmerid 0.01 0.01 10 56 12.23 1999 3 Skates 1 Unid. Chionoecetes 8.37 4.1 10 56 7066.34 1999 3 Skates 1 Walleye pollock 23.78 10.14 10 56 20080.03 1999 3 Walleye pollock 1 Gadidae 3.27 2.88 24 130 340.8 1999 3 Walleye pollock 1 Offal 0.94 0.94 24 130 98.17 1999 3 Walleye pollock 1 Walleye pollock 8.72 5.31 24 130 908.56 1999 3 Walleye pollock 2 Gadidae 0.55 0.55 18 134 98.47 1999 3 Walleye pollock 2 Offal 1.1 1.1 18 134 196.86 1999 3 Walleye pollock 2 Walleye pollock 1.05 1.05 18 134 188.1 1999 3 Walleye pollock 3 Gadidae 0.88 0.6 25 232 758.09 1999 3 Walleye pollock 3 Offal 4.56 2.98 25 232 3929.7 1999 3 Walleye pollock 3 Pleuronectidae 0.05 0.05 25 232 46.92 1999 3 Walleye pollock 3 Walleye pollock 0.57 0.39 25 232 487.75 1999 3 Walleye pollock 4 Capelin 0.47 0.47 37 466 1049.18 1999 3 Walleye pollock 4 Gadidae 2.02 1.08 37 466 4457.05 1999 3 Walleye pollock 4 Offal 1.27 1.27 37 466 2809.36 1999 3 Walleye pollock 4 Pacific herring 0.76 0.47 37 466 1687.23 1999 3 Walleye pollock 4 Pleuronectidae 0.04 0.03 37 466 81.19 1999 3 Walleye pollock 4 Unid. Osmerid 2.66 1.93 37 466 5872.93 1999 3 Walleye pollock 4 Walleye pollock 15.75 4.13 37 466 34791.38 1999 3 Yellowfin sole 1 Offal 5.08 5.08 12 85 11102.81 1999 4 Arrowtooth flounder 2 Gadidae 5.65 5.65 2 6 118.04 1999 4 Arrowtooth flounder 2 Walleye pollock 86.8 13.2 2 6 1811.93 1999 4 Arrowtooth flounder 3 Gadidae 0.46 0.46 2 5 4.97 1999 4 Arrowtooth flounder 3 Walleye pollock 99.51 0.49 2 5 1084.9 

211
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1999 4 Flathead sole 1 Bairdi Tanner crab 0.62 0.32 10 62 252.84 1999 4 Flathead sole 1 Gadidae 1.52 1.03 10 62 615.92 1999 4 Flathead sole 1 Opilio snow crab 0.55 0.55 10 62 223.5 1999 4 Flathead sole 1 Unid. Chionoecetes 0.04 0.04 10 62 14.47 1999 4 Flathead sole 1 Walleye pollock 28.86 12.06 10 62 11687.5 1999 4 Greenland turbot 2 Walleye pollock 50 50 2 2 64.64 1999 4 Northern rock sole 1 Opilio snow crab 0.6 0.6 10 59 1506.41 1999 4 Pacific cod 1 Gadidae 0.96 0.69 22 99 88.96 1999 4 Pacific cod 1 Pacific herring 0.12 0.12 22 99 10.72 1999 4 Pacific cod 1 Unid. Chionoecetes 0.03 0.02 22 99 3.03 1999 4 Pacific cod 1 Walleye pollock 9.82 4.86 22 99 908.78 1999 4 Pacific cod 2 Bairdi Tanner crab 3.74 2.05 24 140 5179.35 1999 4 Pacific cod 2 Gadidae 0.11 0.11 24 140 159.26 1999 4 Pacific cod 2 King crab legs 1.4 1.24 24 140 1935.2 1999 4 Pacific cod 2 Opilio snow crab 13.6 4.4 24 140 18850.36 1999 4 Pacific cod 2 Pacific herring 4.33 2.72 24 140 6004.54 1999 4 Pacific cod 2 Unid. Chionoecetes 4.9 1.78 24 140 6785.49 

1999 4 Pacific cod 2 Walleye pollock 9.9 5.04 24 140 13721.08 1999 4 Pacific cod 3 Arrowtooth flounder 0.04 0.04 22 112 35.28 1999 4 Pacific cod 3 Bairdi Tanner crab 0.36 0.22 22 112 314.29 1999 4 Pacific cod 3 Flathead sole 1.6 1.6 22 112 1390.39 1999 4 Pacific cod 3 Gadidae 7.3 3.24 22 112 6340.77 1999 4 Pacific cod 3 King crab legs 0.17 0.17 22 112 147.59 1999 4 Pacific cod 3 Northern rock sole 1.59 1.31 22 112 1377.55 1999 4 Pacific cod 3 Offal 0.38 0.38 22 112 334.54 1999 4 Pacific cod 3 Opilio snow crab 14.93 4.11 22 112 12976.74 1999 4 Pacific cod 3 Pacific cod 0.58 0.58 22 112 506.6 1999 4 Pacific cod 3 Pacific herring 6.33 2.89 22 112 5500.02 1999 4 Pacific cod 3 Pleuronectidae 2.28 1.48 22 112 1984.17 1999 4 Pacific cod 3 Unid. Chionoecetes 15.02 6.01 22 112 13052.62 1999 4 Pacific cod 3 Walleye pollock 27.26 6.49 22 112 23692.72 1999 4 Pacific cod 3 Yellowfin sole 1.71 1.48 22 112 1482.76 1999 4 Pacific halibut 2 Bairdi Tanner crab 0.68 0.49 12 32 46.27 1999 4 Pacific halibut 2 Gadidae 0.64 0.36 12 32 43.83 

212
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1999 4 Pacific halibut 2 Unid. Chionoecetes 1.12 0.98 12 32 76.46 1999 4 Pacific halibut 2 Walleye pollock 0.48 0.48 12 32 32.51 1999 4 Pacific halibut 3 Bairdi Tanner crab 8.95 8.95 7 13 944.97 1999 4 Pacific halibut 3 Gadidae 24.75 14.44 7 13 2613.81 1999 4 Pacific halibut 3 Opilio snow crab 11.93 11.93 7 13 1260.21 1999 4 Pacific halibut 3 Pleuronectidae 7.12 7.12 7 13 751.99 1999 4 Pacific halibut 3 Walleye pollock 19.32 13.82 7 13 2040.16 1999 4 Skates 1 Bairdi Tanner crab 2.81 2.53 25 160 1911.72 1999 4 Skates 1 Gadidae 0.15 0.08 25 160 104.3 1999 4 Skates 1 Northern rock sole 4.72 3.37 25 160 3207.17 1999 4 Skates 1 Offal 0.88 0.88 25 160 600.68 1999 4 Skates 1 Opilio snow crab 1.04 0.71 25 160 705.71 1999 4 Skates 1 Pacific herring 1.77 1.22 25 160 1201.87 1999 4 Skates 1 Pleuronectidae 5.05 2.83 25 160 3434.66 1999 4 Skates 1 Unid. Chionoecetes 11.79 4.15 25 160 8020.95 1999 4 Skates 1 Walleye pollock 9.73 4.66 25 160 6614.04 1999 4 Skates 1 Yellowfin sole 3.66 3.66 25 160 2485.73 1999 4 Walleye pollock 1 Walleye pollock 1.76 1.76 43 340 262.53 1999 4 Walleye pollock 3 Gadidae 0.27 0.26 22 267 734.82 1999 4 Walleye pollock 3 Pacific herring 1.25 1.25 22 267 3451.68 1999 4 Walleye pollock 3 Walleye pollock 5.11 2.81 22 267 14162.88 1999 4 Walleye pollock 4 Capelin 0.07 0.07 39 410 133.85 1999 4 Walleye pollock 4 Gadidae 3.15 1.52 39 410 6208.12 1999 4 Walleye pollock 4 Offal 0.06 0.06 39 410 119.38 1999 4 Walleye pollock 4 Pacific herring 10.19 3.3 39 410 20076.22 1999 4 Walleye pollock 4 Pleuronectidae 0.02 0.02 39 410 46.39 1999 4 Walleye pollock 4 Unid. Osmerid 0.24 0.24 39 410 468.74 1999 4 Walleye pollock 4 Walleye pollock 12.94 4.07 39 410 25490.76 1999 5 Arrowtooth flounder 2 Gadidae 19.81 19.81 5 9 5175.83 1999 5 Arrowtooth flounder 2 Walleye pollock 16.7 16.7 5 9 4361.8 1999 5 Arrowtooth flounder 3 Gadidae 1.12 1.12 5 16 1279.15 1999 5 Arrowtooth flounder 3 Unid. Osmerid 19.75 19.75 5 16 22644.01 1999 5 Arrowtooth flounder 3 Walleye pollock 58.24 23.81 5 16 66783.6 1999 5 Flathead sole 1 Bairdi Tanner crab 28.04 28.04 3 21 12678.37 

213
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1999 5 Pacific cod 2 Bairdi Tanner crab 23.16 10.19 4 24 2283.07 1999 5 Pacific cod 2 Opilio snow crab 0.54 0.54 4 24 52.75 1999 5 Pacific cod 2 Pleuronectidae 2.16 2.16 4 24 212.44 1999 5 Pacific cod 2 Unid. Osmerid 1.56 1.56 4 24 154.24 1999 5 Pacific cod 2 Unid. Chionoecetes 26.25 16.8 4 24 2587.97 1999 5 Pacific cod 2 Walleye pollock 4.78 4.78 4 24 470.75 1999 5 Pacific cod 3 Bairdi Tanner crab 28.01 7.53 4 16 4282.99 1999 5 Pacific cod 3 Gadidae 5.69 5.33 4 16 869.82 1999 5 Pacific cod 3 Opilio snow crab 0.85 0.85 4 16 129.45 1999 5 Pacific cod 3 Pleuronectidae 0.18 0.18 4 16 27.8 1999 5 Pacific cod 3 Unid. Chionoecetes 10.2 4.74 4 16 1558.95 1999 5 Pacific cod 3 Walleye pollock 4.44 2.38 4 16 678.32 1999 5 Pacific halibut 2 Bairdi Tanner crab 31.88 31.88 2 8 270.26 1999 5 Pacific halibut 2 Offal 1.61 1.61 2 8 13.62 1999 5 Pacific halibut 2 Opilio snow crab 1.25 1.25 2 8 10.63 1999 5 Pacific halibut 2 Unid. Chionoecetes 20.11 20.11 2 8 170.5 1999 5 Pacific halibut 3 Bairdi Tanner crab 1.03 0.75 5 7 54.11 1999 5 Pacific halibut 3 Offal 19.74 19.74 5 7 1035.51 1999 5 Pacific halibut 3 Walleye pollock 55.97 22.95 5 7 2936.73 1999 5 Skates 1 Gadidae 0.81 0.81 6 35 822.04 1999 5 Skates 1 Opilio snow crab 0.66 0.66 6 35 670.61 1999 5 Skates 1 Unid. Chionoecetes 0.73 0.69 6 35 740.29 1999 5 Skates 1 Walleye pollock 63.08 20 6 35 63740.81 1999 5 Walleye pollock 3 Gadidae 0.05 0.05 13 101 16.71 1999 5 Walleye pollock 3 Offal 4.07 4.07 13 101 1433.27 1999 5 Walleye pollock 3 Pleuronectidae 0.12 0.09 13 101 42.3 1999 5 Walleye pollock 4 Gadidae 5.08 2.78 13 99 1015.5 1999 5 Walleye pollock 4 Offal 2.77 2.77 13 99 554.18 1999 5 Walleye pollock 4 Pacific herring 2.44 2.44 13 99 487.29 1999 5 Walleye pollock 4 Walleye pollock 14.24 6.6 13 99 2843.82 1999 6 Arrowtooth flounder 2 Gadidae 1.49 1.49 10 17 250.73 1999 6 Arrowtooth flounder 2 Walleye pollock 36.23 15.19 10 17 6106.21 1999 6 Arrowtooth flounder 3 Gadidae 10.97 6.63 16 61 5209.59 1999 6 Arrowtooth flounder 3 Walleye pollock 81.99 8.59 16 61 38950.36 

214
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1999 6 Flathead sole 1 Bairdi Tanner crab 3.79 2.87 12 67 6182.3 1999 6 Flathead sole 1 Unid. Chionoecetes 3.05 2.72 12 67 4975.73 1999 6 Flathead sole 1 Walleye pollock 7.5 5.9 12 67 12252.63 1999 6 Greenland turbot 1 Walleye pollock 100 0 2 2 178.4 1999 6 Greenland turbot 2 Gadidae 33.33 33.33 3 3 211.5 1999 6 Greenland turbot 2 Walleye pollock 66.67 33.33 3 3 422.99 1999 6 Greenland turbot 3 Bairdi Tanner crab 0.04 0.04 16 24 5.92 1999 6 Greenland turbot 3 Gadidae 6.47 6.2 16 24 905.29 1999 6 Greenland turbot 3 Northern rock sole 6.25 6.25 16 24 874.25 1999 6 Greenland turbot 3 Offal 2.89 2.01 16 24 404.5 1999 6 Greenland turbot 3 Pleuronectidae 0.06 0.06 16 24 8.71 1999 6 Greenland turbot 3 Walleye pollock 84.28 8.47 16 24 11789.29 1999 6 Pacific cod 2 Arrowtooth flounder 0.83 0.83 18 121 693.64 1999 6 Pacific cod 2 Bairdi Tanner crab 6.96 2.09 18 121 5806.36 1999 6 Pacific cod 2 Flathead sole 0.28 0.28 18 121 230.01 1999 6 Pacific cod 2 Gadidae 0.76 0.35 18 121 638.33 1999 6 Pacific cod 2 Lithodidae 0.35 0.26 18 121 58.39 1999 6 Pacific cod 2 Offal 1.71 1.71 18 121 1426.51 1999 6 Pacific cod 2 Opilio snow crab 6.25 2.48 18 121 5216.36 1999 6 Pacific cod 2 Pacific herring 0.35 0.35 18 121 293.15 1999 6 Pacific cod 2 Pleuronectidae 0.08 0.05 18 121 65.59 1999 6 Pacific cod 2 Unid. Chionoecetes 3.58 1.24 18 121 2986.07 1999 6 Pacific cod 2 Walleye pollock 4.26 1.81 18 121 3555.24 1999 6 Pacific cod 3 Bairdi Tanner crab 7.39 2.52 20 108 6205.04 1999 6 Pacific cod 3 Flathead sole 1.32 0.72 20 108 1103.77 1999 6 Pacific cod 3 Gadidae 2.2 1.09 20 108 1846.52 1999 6 Pacific cod 3 Lithodidae 1.49 1.18 20 108 253.16 1999 6 Pacific cod 3 Offal 1.49 1.49 20 108 1249.45 1999 6 Pacific cod 3 Opilio snow crab 13.3 4.27 20 108 11159.77 1999 6 Pacific cod 3 Pacific cod 3.98 3.98 20 108 3341.21 1999 6 Pacific cod 3 Pleuronectidae 0.26 0.16 20 108 219.8 1999 6 Pacific cod 3 Unid. Chionoecetes 3.25 1.56 20 108 2727.47 1999 6 Pacific cod 3 Walleye pollock 43.76 7.37 20 108 36717.32 1999 6 Pacific halibut 2 Bairdi Tanner crab 3.35 2.34 7 12 92.11 

215
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

1999 6 Pacific halibut 2 Gadidae 5.99 5.43 7 12 164.66 1999 6 Pacific halibut 2 Walleye pollock 24.69 10.04 7 12 678.56 1999 6 Pacific halibut 3 Bairdi Tanner crab 0.75 0.4 13 37 175.52 1999 6 Pacific halibut 3 Gadidae 4.91 2.86 13 37 1153.36 1999 6 Pacific halibut 3 Offal 0.62 0.62 13 37 144.94 1999 6 Pacific halibut 3 Opilio snow crab 7.87 7.22 13 37 1847.64 1999 6 Pacific halibut 3 Pacific cod 2.31 2.31 13 37 541.32 1999 6 Pacific halibut 3 Unid. Chionoecetes 0.76 0.46 13 37 178.85 1999 6 Pacific halibut 3 Walleye pollock 71.59 9.67 13 37 16807.36 1999 6 Skates 1 Bairdi Tanner crab 5.28 4.53 13 68 6468.44 1999 6 Skates 1 Gadidae 0.06 0.06 13 68 78.51 1999 6 Skates 1 Offal 15.14 7.7 13 68 18559.5 1999 6 Skates 1 Opilio snow crab 0.14 0.14 13 68 170.21 1999 6 Skates 1 Pacific salmon 5.6 5.6 13 68 6866.23 1999 6 Skates 1 Unid. Chionoecetes 2.7 1.28 13 68 3312.27 

1999 6 Skates 1 Walleye pollock 16.95 7.74 13 68 20768.77 1999 6 Walleye pollock 2 Gadidae 0.02 0.02 39 350 86.56 1999 6 Walleye pollock 2 Offal 0.04 0.04 39 350 181.69 1999 6 Walleye pollock 2 Walleye pollock 0.15 0.15 39 350 705.36 1999 6 Walleye pollock 3 Gadidae 0.2 0.16 40 470 3506.82 1999 6 Walleye pollock 3 Offal 1.29 1.14 40 470 22557.26 1999 6 Walleye pollock 3 Pleuronectidae 0.01 0.01 40 470 128.34 1999 6 Walleye pollock 3 Unid. Chionoecetes 0 0 40 470 2.41 

1999 6 Walleye pollock 3 Walleye pollock 1.91 1.42 40 470 33506.72 1999 6 Walleye pollock 4 Gadidae 4.69 2.24 34 226 15636.89 1999 6 Walleye pollock 4 Greenland turbot 0.14 0.14 34 226 461.76 1999 6 Walleye pollock 4 Offal 9.38 3.93 34 226 31269 1999 6 Walleye pollock 4 Pleuronectidae 0.17 0.17 34 226 568.63 1999 6 Walleye pollock 4 Walleye pollock 19.9 4.99 34 226 66349.04 2000 1 Arrowtooth flounder 1 Walleye pollock 87.81 0 1 3 13.3 2000 1 Arrowtooth flounder 2 Gadidae 10.96 0 1 5 12.37 2000 1 Arrowtooth flounder 2 Walleye pollock 71.72 0 1 5 80.98 2000 1 Flathead sole 1 Walleye pollock 42.61 28.99 2 14 4819.82 2000 1 Northern rock sole 1 Gadidae 2.53 2.53 3 43 34159.18 

216
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2000 1 Pacific cod 1 Gadidae 3.39 2.2 21 159 242.96 2000 1 Pacific cod 1 Unid. Osmerid 0.07 0.07 21 159 5.19 2000 1 Pacific cod 1 Unid. Chionoecetes 1.31 0.91 21 159 94.01 2000 1 Pacific cod 1 Walleye pollock 6.82 3.56 21 159 489.75 2000 1 Pacific cod 2 Bairdi Tanner crab 1.72 1.72 20 122 710.42 2000 1 Pacific cod 2 Gadidae 0.17 0.12 20 122 70.06 2000 1 Pacific cod 2 King crab legs 0.66 0.66 20 122 273.03 2000 1 Pacific cod 2 Lithodidae 4.11 4.11 20 122 343.44 2000 1 Pacific cod 2 Northern rock sole 0.66 0.66 20 122 273.29 2000 1 Pacific cod 2 Offal 0.95 0.95 20 122 392.42 2000 1 Pacific cod 2 Opilio snow crab 3.83 2.95 20 122 1578.98 2000 1 Pacific cod 2 Pacific halibut 3.16 3.16 20 122 1302.98 2000 1 Pacific cod 2 Paralithodes sp. 0 0 20 122 0.08 2000 1 Pacific cod 2 Pleuronectidae 3.06 1.77 20 122 1260.07 2000 1 Pacific cod 2 Unid. Osmerid 0.22 0.21 20 122 91.51 2000 1 Pacific cod 2 Unid. Chionoecetes 3.78 2.31 20 122 1557.97 2000 1 Pacific cod 2 Walleye pollock 5.76 3.45 20 122 2374.8 2000 1 Pacific cod 3 Flathead sole 1.13 1.13 19 40 371.56 2000 1 Pacific cod 3 Gadidae 3.93 2.17 19 40 1293.64 2000 1 Pacific cod 3 King crab legs 0.39 0.39 19 40 130 2000 1 Pacific cod 3 Northern rock sole 7.7 4.39 19 40 2539.02 2000 1 Pacific cod 3 Opilio snow crab 2 2 19 40 659.44 2000 1 Pacific cod 3 Pacific cod 1.26 0.9 19 40 415.42 2000 1 Pacific cod 3 Paralithodes sp. 5.26 5.26 19 40 351.41 2000 1 Pacific cod 3 Pleuronectidae 4.14 2.24 19 40 1362.83 2000 1 Pacific cod 3 Unid. Chionoecetes 3.67 2.38 19 40 1208.93 2000 1 Pacific cod 3 Walleye pollock 21.65 8.13 19 40 7133.65 2000 1 Pacific halibut 2 Capelin 13.69 13.69 3 17 1277.72 2000 1 Pacific halibut 2 Gadidae 0.71 0.71 3 17 66.47 2000 1 Pacific halibut 2 Northern rock sole 5.33 3.59 3 17 497.32 2000 1 Pacific halibut 2 Walleye pollock 8.56 8.56 3 17 798.78 2000 1 Pacific halibut 3 Capelin 3.68 3.68 3 6 336.2 2000 1 Pacific halibut 3 Pleuronectidae 0.72 0.72 3 6 66.11 2000 1 Pacific halibut 3 Walleye pollock 68.55 22.2 3 6 6267.58 

217
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2000 1 Skates 1 Bairdi Tanner crab 0.56 0.46 18 51 153.75 2000 1 Skates 1 Offal 2.88 2.88 18 51 783.75 2000 1 Skates 1 Opilio snow crab 9.23 5.88 18 51 2516.21 2000 1 Skates 1 Pleuronectidae 6.22 3.15 18 51 1695.64 2000 1 Skates 1 Unid. Chionoecetes 4.75 2.69 18 51 1294.43 2000 1 Skates 1 Walleye pollock 6.28 5.55 18 51 1711.2 2000 1 Skates 1 Yellowfin sole 2.36 1.93 18 51 644.14 2000 1 Walleye pollock 1 Gadidae 1.37 1.37 20 179 51.32 2000 1 Walleye pollock 1 Unid. Chionoecetes 0.53 0.53 20 179 19.72 2000 1 Walleye pollock 1 Walleye pollock 4.01 4.01 20 179 149.74 2000 1 Walleye pollock 2 Walleye pollock 77.76 2.45 2 32000 1 Walleye pollock 4 Arrowtooth flounder 0.29 0.29 28 405 426.98 2000 1 Walleye pollock 4 Capelin 3.74 1.61 28 405 5476.33 2000 1 Walleye pollock 4 Gadidae 1.1 0.5 28 405 1605.55 2000 1 Walleye pollock 4 Northern rock sole 1.77 1.07 28 405 2583.38 2000 1 Walleye pollock 4 Pacific cod 0.18 0.18 28 405 259.62 2000 1 Walleye pollock 4 Pacific herring 0.25 0.25 28 405 368.43 2000 1 Walleye pollock 4 Pleuronectidae 1.06 0.83 28 405 1547.64 2000 1 Walleye pollock 4 Unid. Osmerid 0.37 0.33 28 405 539.53 2000 1 Walleye pollock 4 Walleye pollock 9.01 3.31 28 405 13193.1 2000 2 Northern rock sole 1 Walleye pollock 3.86 3.86 2 22 10456.17 2000 2 Pacific cod 1 Walleye pollock 3.04 2.08 12 54 51.9 2000 2 Pacific cod 2 Northern rock sole 1.79 1.79 9 58 196.22 2000 2 Pacific cod 2 Offal 0.13 0.13 9 58 13.73 2000 2 Pacific cod 2 Opilio snow crab 11.79 6.07 9 58 1289.23 2000 2 Pacific cod 2 Pacific herring 2.95 2.95 9 58 322.51 2000 2 Pacific cod 2 Pleuronectidae 7.05 7.05 9 58 771.57 2000 2 Pacific cod 2 Unid. Chionoecetes 3.29 2.78 9 58 359.86 2000 2 Pacific cod 2 Walleye pollock 5.4 3.18 9 58 590.37 2000 2 Pacific cod 3 Gadidae 1.52 1.52 9 19 120.11 2000 2 Pacific cod 3 Opilio snow crab 38.02 13.21 9 19 3000.88 2000 2 Pacific cod 3 Pacific cod 0.23 0.23 9 19 18.1 2000 2 Pacific cod 3 Pleuronectidae 0.64 0.64 9 19 50.37 2000 2 Pacific cod 3 Unid. Chionoecetes 9.87 9.22 9 19 779.29 

218
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2000 2 Pacific cod 3 Walleye pollock 10.55 6.57 9 19 832.5 2000 2 Pacific halibut 2 Gadidae 51.69 0 1 2 2805.9 2000 2 Pacific halibut 3 Gadidae 100 0 1 1 3915.58 2000 2 Skates 1 Bairdi Tanner crab 1.79 1.79 10 80 724.03 2000 2 Skates 1 Gadidae 0.15 0.15 10 80 62.1 2000 2 Skates 1 Opilio snow crab 7.95 6.74 10 80 3222.09 2000 2 Skates 1 Pacific herring 0.06 0.06 10 80 24.42 2000 2 Skates 1 Pleuronectidae 6.14 3.2 10 80 2488.69 2000 2 Skates 1 Unid. Chionoecetes 18.09 5.57 10 80 7329.29 2000 2 Skates 1 Walleye pollock 2.68 1.48 10 80 1087.28 2000 2 Walleye pollock 4 Capelin 0.41 0.32 14 164 204.74 2000 2 Walleye pollock 4 Gadidae 2.63 1.42 14 164 1329.56 2000 2 Walleye pollock 4 Northern rock sole 0.93 0.64 14 164 468.45 2000 2 Walleye pollock 4 Pacific cod 0.63 0.63 14 164 318.1 2000 2 Walleye pollock 4 Pacific herring 2.18 2.18 14 164 1099.14 2000 2 Walleye pollock 4 Unid. Osmerid 0.72 0.7 14 164 364.24 2000 2 Walleye pollock 4 Walleye pollock 12.57 4.33 14 164 6347.42 2000 3 Arrowtooth flounder 2 Capelin 1.47 1.47 10 43 447.66 2000 3 Arrowtooth flounder 2 Gadidae 11.93 9.85 10 43 3621.12 2000 3 Arrowtooth flounder 2 Walleye pollock 31.08 14 10 43 9437.68 2000 3 Arrowtooth flounder 3 Gadidae 1.22 0.97 12 31 499.38 2000 3 Arrowtooth flounder 3 Walleye pollock 60.33 13.59 12 31 24736.52 2000 3 Pacific cod 1 Northern rock sole 0.16 0.16 16 59 4.31 2000 3 Pacific cod 1 Walleye pollock 0.38 0.38 16 59 10.14 2000 3 Pacific cod 2 Bairdi Tanner crab 0.36 0.3 18 140 367.6 2000 3 Pacific cod 2 Flathead sole 2.3 2.3 18 140 2344.97 2000 3 Pacific cod 2 Gadidae 0.39 0.19 18 140 393.22 2000 3 Pacific cod 2 Lithodidae 3.44 3.44 18 140 710.18 2000 3 Pacific cod 2 Opilio snow crab 9.81 3.67 18 140 9979.93 2000 3 Pacific cod 2 Pleuronectidae 2.26 1.31 18 140 2301.6 2000 3 Pacific cod 2 Unid. Osmerid 0.27 0.27 18 140 271.89 2000 3 Pacific cod 2 Unid. Chionoecetes 8.07 2.98 18 140 8209.67 2000 3 Pacific cod 2 Walleye pollock 6.44 3.79 18 140 6550.55 2000 3 Pacific cod 3 Bairdi Tanner crab 4.01 2.87 20 80 1869.19 

219
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2000 3 Pacific cod 3 Flathead sole 0.88 0.74 20 80 411.6 2000 3 Pacific cod 3 Gadidae 0.4 0.24 20 80 188.24 2000 3 Pacific cod 3 King crab legs 0.09 0.09 20 80 40.44 2000 3 Pacific cod 3 Lithodidae 0.11 0.11 20 80 10.37 2000 3 Pacific cod 3 Northern rock sole 2.04 2.04 20 80 952.43 2000 3 Pacific cod 3 Opilio snow crab 8.36 5 20 80 3895.94 2000 3 Pacific cod 3 Pacific cod 0.01 0.01 20 80 5.15 2000 3 Pacific cod 3 Pacific herring 0.02 0.02 20 80 10.09 2000 3 Pacific cod 3 Paralithodes sp. 0.77 0.77 20 80 72.98 2000 3 Pacific cod 3 Pleuronectidae 1.55 1.07 20 80 720.08 2000 3 Pacific cod 3 Red king crab 1.05 1.05 20 80 98.85 2000 3 Pacific cod 3 Unid. Chionoecetes 1.83 1.01 20 80 851.25 2000 3 Pacific cod 3 Walleye pollock 46.03 9.19 20 80 21444.96 2000 3 Pacific cod 3 Yellowfin sole 8.75 5.35 20 80 4075.8 2000 3 Skates 1 Bairdi Tanner crab 1.87 0.92 25 90 1081.75 2000 3 Skates 1 Gadidae 1.29 1.29 25 90 747.5 2000 3 Skates 1 Offal 5.4 3.78 25 90 3129.7 2000 3 Skates 1 Opilio snow crab 1.34 0.75 25 90 774.66 2000 3 Skates 1 Pleuronectidae 4.76 2.54 25 90 2756.7 2000 3 Skates 1 Unid. Chionoecetes 10.68 3.84 25 90 6189.26 2000 3 Skates 1 Walleye pollock 4.07 3.29 25 90 2356.11 2000 3 Skates 1 Yellowfin sole 1.86 1.86 25 90 1078.52 2000 3 Walleye pollock 1 Gadidae 1.42 1.2 22 143 132.27 2000 3 Walleye pollock 1 Walleye pollock 5.26 4.37 22 143 488.59 2000 3 Walleye pollock 2 Gadidae 7.58 6.8 11 45 2428.72 2000 3 Walleye pollock 2 Walleye pollock 5.61 5.61 11 45 1797.79 2000 3 Walleye pollock 3 Gadidae 1.84 1.36 24 189 14975.64 2000 3 Walleye pollock 3 Northern rock sole 2.32 2.32 24 189 18902.26 2000 3 Walleye pollock 3 Pleuronectidae 0.14 0.14 24 189 1163.22 2000 3 Walleye pollock 3 Walleye pollock 1.88 1.16 24 189 15348.19 2000 3 Walleye pollock 4 Capelin 0.75 0.45 41 441 3477.19 2000 3 Walleye pollock 4 Gadidae 1.85 1.17 41 441 8556.16 2000 3 Walleye pollock 4 Opilio snow crab 0.66 0.66 41 441 3074.18 2000 3 Walleye pollock 4 Pacific herring 1.79 1.79 41 441 8305.94 

220
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2000 3 Walleye pollock 4 Pleuronectidae 0.42 0.41 41 441 1939.58 2000 3 Walleye pollock 4 Unid. Osmerid 0.19 0.19 41 441 901.87 2000 3 Walleye pollock 4 Walleye pollock 4.18 2.11 41 441 19368.72 2000 4 Arrowtooth flounder 2 Gadidae 52.09 27.72 4 10 3406.03 2000 4 Arrowtooth flounder 2 Walleye pollock 17.61 17.61 4 10 1151.9 2000 4 Arrowtooth flounder 3 Gadidae 20 20 5 11 1842.76 2000 4 Arrowtooth flounder 3 Walleye pollock 57.33 23.53 5 11 5282.39 2000 4 Flathead sole 1 Walleye pollock 14.11 14.11 2 8 7613.08 2000 4 Northern rock sole 1 Opilio snow crab 1.4 1.4 2 16 3694.69 2000 4 Pacific cod 1 Unid. Chionoecetes 2.32 2.32 14 37 62.01 2000 4 Pacific cod 1 Walleye pollock 13.16 8.95 14 37 352.41 2000 4 Pacific cod 2 Bairdi Tanner crab 0.93 0.47 25 172 1757.29 2000 4 Pacific cod 2 Gadidae 1.32 0.63 25 172 2485.02 2000 4 Pacific cod 2 Opilio snow crab 26.72 5.88 25 172 50483.53 2000 4 Pacific cod 2 Pacific herring 0.75 0.56 25 172 1414.12 2000 4 Pacific cod 2 Unid. Chionoecetes 11 4.37 25 172 20789.08 

2000 4 Pacific cod 2 Walleye pollock 4.55 2.38 25 172 8601.22 2000 4 Pacific cod 3 Bairdi Tanner crab 4.7 3.1 26 59 2121.48 2000 4 Pacific cod 3 Northern rock sole 0.77 0.77 26 59 347.57 2000 4 Pacific cod 3 Opilio snow crab 34.91 6.23 26 59 15743.24 2000 4 Pacific cod 3 Pacific cod 0.48 0.48 26 59 217.69 2000 4 Pacific cod 3 Pleuronectidae 2.54 2.54 26 59 1146.57 2000 4 Pacific cod 3 Unid. Chionoecetes 8.31 2.84 26 59 3746.4 2000 4 Pacific cod 3 Walleye pollock 13.72 4.98 26 59 6185.1 2000 4 Skates 1 Bairdi Tanner crab 3.58 1.26 32 177 3364.68 2000 4 Skates 1 Flathead sole 0.43 0.43 32 177 407.06 2000 4 Skates 1 Gadidae 0.04 0.04 32 177 35.24 2000 4 Skates 1 Offal 0.92 0.92 32 177 864.22 2000 4 Skates 1 Opilio snow crab 18.69 4.81 32 177 17570.23 2000 4 Skates 1 Pacific herring 3.97 2.82 32 177 3735.65 2000 4 Skates 1 Pleuronectidae 0.5 0.5 32 177 474 2000 4 Skates 1 Unid. Chionoecetes 18.62 4.2 32 177 17502.72 2000 4 Skates 1 Walleye pollock 11.59 4.29 32 177 10893.58 2000 4 Walleye pollock 3 Gadidae 0.02 0.02 26 223 214.6 

221
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2000 4 Walleye pollock 3 Walleye pollock 0.5 0.5 26 223 4363.51 2000 4 Walleye pollock 4 Gadidae 2.1 1.41 39 333 6335.08 2000 4 Walleye pollock 4 Pacific herring 1.33 1.32 39 333 4029.16 2000 4 Walleye pollock 4 Walleye pollock 7.19 2.68 39 333 21714.01 2000 4 Yellowfin sole 1 Opilio snow crab 2.26 2.26 4 44 2238.38 2000 4 Yellowfin sole 1 Walleye pollock 0.27 0.27 4 44 262.51 2000 5 Arrowtooth flounder 1 Gadidae 1.46 1.46 4 13 26.16 2000 5 Arrowtooth flounder 2 Bairdi Tanner crab 0.02 0.02 7 24 11.46 2000 5 Arrowtooth flounder 2 Gadidae 2.42 2.42 7 24 1273.16 2000 5 Arrowtooth flounder 2 Walleye pollock 28.97 16.77 7 24 15268.5 2000 5 Arrowtooth flounder 3 Gadidae 8.22 8.22 6 10 4488.89 2000 5 Arrowtooth flounder 3 Walleye pollock 23.3 16.66 6 10 12723.72 2000 5 Flathead sole 1 Bairdi Tanner crab 12.07 0 1 15 6327.86 2000 5 Flathead sole 1 Unid. Chionoecetes 0.24 0 1 15 123.56 2000 5 Pacific cod 2 Arrowtooth flounder 0.74 0.74 10 68 81.76 2000 5 Pacific cod 2 Bairdi Tanner crab 10.98 5.24 10 68 1205.84 2000 5 Pacific cod 2 Flathead sole 0.22 0.22 10 68 23.92 2000 5 Pacific cod 2 Gadidae 3.93 3.3 10 68 431.12 2000 5 Pacific cod 2 Offal 1.82 1.82 10 68 200.3 2000 5 Pacific cod 2 Opilio snow crab 0.93 0.62 10 68 101.7 2000 5 Pacific cod 2 Pleuronectidae 2.31 2.27 10 68 253.86 2000 5 Pacific cod 2 Unid. Chionoecetes 10.09 4.84 10 68 1107.22 2000 5 Pacific cod 3 Bairdi Tanner crab 31.38 9.62 10 48 5081.18 2000 5 Pacific cod 3 Flathead sole 0.06 0.06 10 48 9.2 2000 5 Pacific cod 3 Gadidae 0.3 0.3 10 48 48.84 2000 5 Pacific cod 3 Opilio snow crab 13.22 6.13 10 48 2139.58 2000 5 Pacific cod 3 Pacific cod 0.08 0.08 10 48 13.57 2000 5 Pacific cod 3 Pleuronectidae 2.24 2.24 10 48 363.23 2000 5 Pacific cod 3 Unid. Chionoecetes 9.03 2.9 10 48 1462.22 2000 5 Pacific cod 3 Walleye pollock 9.65 7.86 10 48 1562.05 2000 5 Skates 1 Bairdi Tanner crab 0.35 0.35 6 41 94.34 2000 5 Skates 1 Opilio snow crab 7.58 6.25 6 41 2042.76 2000 5 Skates 1 Pleuronectidae 2.46 2.46 6 41 664.33 2000 5 Skates 1 Unid. Chionoecetes 11.19 4.34 6 41 3017.71 

222
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2000 5 Skates 1 Walleye pollock 52.02 15.09 6 41 14023.36 2000 6 Arrowtooth flounder 2 Gadidae 1.54 1.27 12 40 360.52 2000 6 Arrowtooth flounder 2 Walleye pollock 43.16 13.7 12 40 10088.7 2000 6 Arrowtooth flounder 3 Gadidae 8.43 5.65 18 84 12317.72 2000 6 Arrowtooth flounder 3 Walleye pollock 55.15 10.85 18 84 80568.92 2000 6 Flathead sole 1 Bairdi Tanner crab 1.27 0 1 19 1713.14 2000 6 Greenland turbot 3 Gadidae 24.51 0 1 1 3843.46 2000 6 Greenland turbot 3 Walleye pollock 75.49 0 1 1 11840.57 2000 6 Pacific cod 2 Bairdi Tanner crab 4.14 2.1 18 140 2919.82 2000 6 Pacific cod 2 Flathead sole 1.41 1.41 18 140 998.32 2000 6 Pacific cod 2 Gadidae 3.28 1.12 18 140 2315.56 2000 6 Pacific cod 2 Opilio snow crab 9.91 3.35 18 140 6994.74 2000 6 Pacific cod 2 Pleuronectidae 0.38 0.36 18 140 269.85 2000 6 Pacific cod 2 Unid. Chionoecetes 8 2.74 18 140 5649.54 

2000 6 Pacific cod 2 Walleye pollock 9.3 4.09 18 140 6565.72 2000 6 Pacific cod 3 Arrowtooth flounder 1.44 1.44 21 113 1138.6 2000 6 Pacific cod 3 Bairdi Tanner crab 3.82 1.6 21 113 3010.14 2000 6 Pacific cod 3 Flathead sole 0.19 0.19 21 113 149.45 2000 6 Pacific cod 3 Gadidae 0.61 0.39 21 113 480.37 2000 6 Pacific cod 3 Offal 1.66 1.15 21 113 1309.86 2000 6 Pacific cod 3 Opilio snow crab 16.42 4.85 21 113 12943.83 2000 6 Pacific cod 3 Pacific cod 0.11 0.11 21 113 88.98 2000 6 Pacific cod 3 Pleuronectidae 0.96 0.6 21 113 754.73 2000 6 Pacific cod 3 Unid. Chionoecetes 9.09 3.14 21 113 7163.49 2000 6 Pacific cod 3 Walleye pollock 29.7 7.03 21 113 23409.88 2000 6 Skates 1 Bairdi Tanner crab 0.9 0.9 17 63 921.55 2000 6 Skates 1 Gadidae 0.61 0.51 17 63 616.78 2000 6 Skates 1 Opilio snow crab 0.66 0.54 17 63 667.9 2000 6 Skates 1 Pleuronectidae 7.96 5.31 17 63 8112.68 2000 6 Skates 1 Unid. Chionoecetes 10.89 6.16 17 63 11103.17 2000 6 Skates 1 Walleye pollock 35.22 9.62 17 63 35893.57 2000 6 Walleye pollock 1 Offal 0.13 0.13 17 116 43.52 2000 6 Walleye pollock 1 Walleye pollock 1.07 1.07 17 116 352.33 2000 6 Walleye pollock 2 Gadidae 0.16 0.16 31 170 779.26 

223
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2000 6 Walleye pollock 2 Offal 2.58 1.86 31 170 12553.82 2000 6 Walleye pollock 2 Walleye pollock 1.52 1.52 31 170 7417.79 2000 6 Walleye pollock 3 Gadidae 0.79 0.57 37 304 10743.95 2000 6 Walleye pollock 3 Offal 1.93 1.7 37 304 26429.92 2000 6 Walleye pollock 3 Walleye pollock 2.3 1.19 37 304 31406.34 2000 6 Walleye pollock 4 Gadidae 2.75 1.67 35 245 7783.84 2000 6 Walleye pollock 4 Offal 8.87 4.38 35 245 25091.3 2000 6 Walleye pollock 4 Walleye pollock 13.14 4.53 35 245 37167.59 2001 1 Arrowtooth flounder 2 Capelin 25.59 25.59 2 9 88.45 2001 1 Arrowtooth flounder 2 Walleye pollock 66.73 17.91 2 9 230.63 2001 1 Arrowtooth flounder 3 Gadidae 50 50 2 2 187.43 2001 1 Arrowtooth flounder 3 Walleye pollock 47.5 47.5 2 2 178.05 2001 1 Pacific cod 1 Capelin 0.86 0.86 24 136 139.1 2001 1 Pacific cod 1 Pleuronectidae 1.94 1.25 24 136 313.48 2001 1 Pacific cod 1 Walleye pollock 1.9 1.9 24 136 307.91 2001 1 Pacific cod 2 Bairdi Tanner crab 0.37 0.21 16 113 328 2001 1 Pacific cod 2 Capelin 2.65 2.28 16 113 2375.92 2001 1 Pacific cod 2 Gadidae 1.11 0.9 16 113 999.34 2001 1 Pacific cod 2 Northern rock sole 3.94 3.25 16 113 3533.18 2001 1 Pacific cod 2 Opilio snow crab 5.46 4.24 16 113 4891.38 2001 1 Pacific cod 2 Pacific cod 0.3 0.3 16 113 272.21 2001 1 Pacific cod 2 Pleuronectidae 9.28 3.97 16 113 8318.71 2001 1 Pacific cod 2 Unid. Chionoecetes 0.57 0.57 16 113 511.57 2001 1 Pacific cod 2 Walleye pollock 0.98 0.79 16 113 876.97 2001 1 Pacific cod 2 Yellowfin sole 1.56 1.23 16 113 1396.31 2001 1 Pacific cod 3 Capelin 1.94 1.34 25 77 919.91 2001 1 Pacific cod 3 Flathead sole 1.36 1.36 25 77 645.32 2001 1 Pacific cod 3 Gadidae 1.79 0.95 25 77 849.97 2001 1 Pacific cod 3 Northern rock sole 2.35 2.12 25 77 1112.71 2001 1 Pacific cod 3 Offal 1.92 1.92 25 77 909.88 2001 1 Pacific cod 3 Opilio snow crab 2.4 2.34 25 77 1136.06 2001 1 Pacific cod 3 Pacific herring 2.62 2.62 25 77 1243.49 2001 1 Pacific cod 3 Pleuronectidae 23.16 5.87 25 77 10982.37 2001 1 Pacific cod 3 Unid. Chionoecetes 0.01 0.01 25 77 6.25 

224
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2001 1 Pacific cod 3 Walleye pollock 10.85 4.21 25 77 5143.76 2001 1 Pacific cod 3 Yellowfin sole 7.97 4.37 25 77 3779.3 2001 1 Pacific halibut 1 Pacific halibut 2.72 2.72 3 11 39.37 2001 1 Skates 1 Flathead sole 4.02 4.02 23 96 1389.63 2001 1 Skates 1 Gadidae 0.24 0.17 23 96 84.36 2001 1 Skates 1 Northern rock sole 10.62 4.82 23 96 3675.63 2001 1 Skates 1 Offal 0.13 0.13 23 96 45.78 2001 1 Skates 1 Opilio snow crab 0.03 0.03 23 96 9.88 2001 1 Skates 1 Pacific cod 3.81 3.81 23 96 1317.84 2001 1 Skates 1 Pacific herring 0.5 0.5 23 96 173.8 2001 1 Skates 1 Pleuronectidae 9.7 2.37 23 96 3356.95 2001 1 Skates 1 Unid. Chionoecetes 0.32 0.3 23 96 109.35 2001 1 Skates 1 Walleye pollock 0.38 0.19 23 96 130.36 2001 1 Skates 1 Yellowfin sole 5.33 3.73 23 96 1844.26 2001 1 Walleye pollock 2 Walleye pollock 26.37 26.37 2 3 1310.33 2001 1 Walleye pollock 4 Alaska plaice 0 0 24 303 2.99 2001 1 Walleye pollock 4 Capelin 7.72 3.77 24 303 8649.61 2001 1 Walleye pollock 4 Gadidae 0.67 0.35 24 303 755.72 2001 1 Walleye pollock 4 Northern rock sole 0.99 0.69 24 303 1105.18 2001 1 Walleye pollock 4 Pacific herring 2.53 1.66 24 303 2834.64 2001 1 Walleye pollock 4 Pleuronectidae 0.21 0.14 24 303 232.72 2001 1 Walleye pollock 4 Unid. Osmerid 0.07 0.07 24 303 76.22 2001 1 Walleye pollock 4 Walleye pollock 6.83 3.06 24 303 7658.93 2001 2 Pacific cod 1 Capelin 2.87 2.87 9 85 79.83 2001 2 Pacific cod 1 Unid. Osmerid 2.76 2.76 9 85 76.75 2001 2 Pacific cod 1 Walleye pollock 5.33 3.73 9 85 148.25 2001 2 Pacific cod 2 Capelin 1.24 1.24 7 27 108.85 2001 2 Pacific cod 2 Gadidae 0.51 0.51 7 27 44.69 2001 2 Pacific cod 2 Northern rock sole 3.54 3.54 7 27 312.32 2001 2 Pacific cod 2 Opilio snow crab 7.22 3.49 7 27 635.78 2001 2 Pacific cod 2 Pleuronectidae 4.01 2.92 7 27 352.92 2001 2 Pacific cod 2 Unid. Osmerid 3.69 2.41 7 27 324.91 2001 2 Pacific cod 2 Unid. Chionoecetes 3.97 3.97 7 27 350.01 2001 2 Pacific cod 2 Walleye pollock 8.32 7.66 7 27 733.16 

225
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2001 2 Pacific cod 3 Capelin 0.59 0.59 10 25 75.65 2001 2 Pacific cod 3 Gadidae 0.44 0.44 10 25 55.48 2001 2 Pacific cod 3 Northern rock sole 0.09 0.09 10 25 10.86 2001 2 Pacific cod 3 Opilio snow crab 16.73 10.31 10 25 2132.99 2001 2 Pacific cod 3 Pacific cod 8.8 5.86 10 25 1121.82 2001 2 Pacific cod 3 Pacific herring 2.83 2.57 10 25 360.77 2001 2 Pacific cod 3 Pleuronectidae 7.91 3.17 10 25 1008.43 2001 2 Pacific cod 3 Walleye pollock 4.58 3.08 10 25 584.06 2001 2 Pacific cod 3 Yellowfin sole 8.99 6.08 10 25 1145.87 2001 2 Skates 1 Pacific herring 4 2.74 5 40 1480.42 2001 2 Skates 1 Pleuronectidae 6.88 3.81 5 40 2546.81 2001 2 Walleye pollock 4 Capelin 1.59 1.59 9 113 770.89 2001 2 Walleye pollock 4 Gadidae 0.02 0.02 9 113 10.56 2001 2 Walleye pollock 4 Pacific herring 4.54 2.39 9 113 2201.17 2001 2 Walleye pollock 4 Pleuronectidae 0.38 0.38 9 113 183.63 2001 2 Walleye pollock 4 Unid. Osmerid 0.11 0.11 9 113 52.57 2001 2 Walleye pollock 4 Walleye pollock 9.01 5.51 9 113 4369.79 2001 3 Arrowtooth flounder 2 Gadidae 17.44 10.76 9 20 9682.86 2001 3 Arrowtooth flounder 2 Walleye pollock 56.75 14.79 9 20 31503.31 2001 3 Arrowtooth flounder 3 Gadidae 17 10.14 10 27 10215.64 2001 3 Arrowtooth flounder 3 Pleuronectidae 20 13.33 10 27 12018.55 2001 3 Arrowtooth flounder 3 Walleye pollock 25.57 13.37 10 27 15364.77 2001 3 Pacific cod 2 Bairdi Tanner crab 3.99 2.82 18 172 6524.36 2001 3 Pacific cod 2 Capelin 0.22 0.22 18 172 364.95 2001 3 Pacific cod 2 Gadidae 1.73 0.71 18 172 2832.65 2001 3 Pacific cod 2 Lithodidae 0.07 0.07 18 172 21.75 2001 3 Pacific cod 2 Offal 2.18 2.18 18 172 3571.1 2001 3 Pacific cod 2 Opilio snow crab 3.54 2.04 18 172 5789.63 2001 3 Pacific cod 2 Pacific herring 3.84 3.67 18 172 6282.41 2001 3 Pacific cod 2 Pleuronectidae 3.02 1.92 18 172 4944.44 2001 3 Pacific cod 2 Unid. Osmerid 0.16 0.16 18 172 262.43 2001 3 Pacific cod 2 Unid. Chionoecetes 2.48 1.3 18 172 4050.8 2001 3 Pacific cod 2 Walleye pollock 5.61 2.44 18 172 9178.48 2001 3 Pacific cod 3 Arrowtooth flounder 0.74 0.74 27 84 598.93 

226
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2001 3 Pacific cod 3 Bairdi Tanner crab 5.82 2.02 27 84 4702.57 2001 3 Pacific cod 3 Flathead sole 2.53 2.29 27 84 2041.78 2001 3 Pacific cod 3 Gadidae 1.19 0.55 27 84 962.66 2001 3 Pacific cod 3 Offal 2.63 1.95 27 84 2125.05 2001 3 Pacific cod 3 Opilio snow crab 3.13 2.05 27 84 2528.1 2001 3 Pacific cod 3 Pacific cod 1.03 1.03 27 84 829.48 2001 3 Pacific cod 3 Pacific herring 0.71 0.71 27 84 577.88 2001 3 Pacific cod 3 Pleuronectidae 4.73 2.06 27 84 3826.81 2001 3 Pacific cod 3 Unid. Chionoecetes 0.46 0.39 27 84 371.81 2001 3 Pacific cod 3 Walleye pollock 25.7 6.81 27 84 20774.86 2001 3 Pacific cod 3 Yellowfin sole 4.78 3.04 27 84 3866.87 2001 3 Skates 1 Gadidae 0.62 0.35 28 144 428.73 2001 3 Skates 1 Offal 2.3 2.26 28 144 1598.96 2001 3 Skates 1 Opilio snow crab 0.22 0.22 28 144 155.54 2001 3 Skates 1 Pacific herring 0.02 0.02 28 144 17.13 2001 3 Skates 1 Pleuronectidae 3.2 1.47 28 144 2230.7 2001 3 Skates 1 Unid. Chionoecetes 9.4 4.41 28 144 6547.18 

2001 3 Skates 1 Walleye pollock 19.98 6.22 28 144 13918.04 2001 3 Walleye pollock 1 Offal 0.24 0.24 23 172 203.14 2001 3 Walleye pollock 1 Walleye pollock 2.37 1.75 23 172 2033.95 2001 3 Walleye pollock 3 Gadidae 2.78 2.31 23 68 8397.96 2001 3 Walleye pollock 3 Unid. Osmerid 2.59 2.59 23 68 7835.12 2001 3 Walleye pollock 3 Walleye pollock 6.76 4.87 23 68 20437.91 2001 3 Walleye pollock 4 Gadidae 3.67 2.3 29 302 15804.81 2001 3 Walleye pollock 4 Walleye pollock 8.01 3.86 29 302 34492.82 2001 4 Arrowtooth flounder 2 Pleuronectidae 33.33 33.33 3 5 1783.22 2001 4 Arrowtooth flounder 2 Walleye pollock 59.46 30.38 3 5 3180.95 2001 4 Arrowtooth flounder 3 Gadidae 18.09 18.09 2 7 2134.8 2001 4 Arrowtooth flounder 3 Walleye pollock 81.2 18.8 2 7 9580.15 2001 4 Greenland turbot 3 Walleye pollock 100 0 1 1 2213.15 2001 4 Pacific cod 1 Gadidae 1.58 1.58 17 105 275.92 2001 4 Pacific cod 1 Opilio snow crab 1.49 1.49 17 105 260.34 2001 4 Pacific cod 1 Unid. Chionoecetes 0.09 0.09 17 105 15.23 2001 4 Pacific cod 1 Walleye pollock 8.33 5.72 17 105 1456.47 

227
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2001 4 Pacific cod 2 Bairdi Tanner crab 4.27 2.85 17 136 10750.57 2001 4 Pacific cod 2 Gadidae 1.03 0.5 17 136 2582.58 2001 4 Pacific cod 2 Opilio snow crab 21.25 4.96 17 136 53509.01 2001 4 Pacific cod 2 Pleuronectidae 0.73 0.55 17 136 1849.49 2001 4 Pacific cod 2 Unid. Chionoecetes 3.71 1.97 17 136 9331.32 2001 4 Pacific cod 2 Walleye pollock 6.58 3.26 17 136 16562.19 2001 4 Pacific cod 3 Atka mackerel 0.03 0.03 33 106 38.01 2001 4 Pacific cod 3 Bairdi Tanner crab 3.57 1.85 33 106 4102.61 2001 4 Pacific cod 3 Gadidae 0.56 0.48 33 106 647.35 2001 4 Pacific cod 3 Lithodidae 0.23 0.23 33 106 52.9 2001 4 Pacific cod 3 Offal 1.23 1.23 33 106 1413.59 2001 4 Pacific cod 3 Opilio snow crab 50.51 5.85 33 106 58100.97 2001 4 Pacific cod 3 Pacific cod 1.07 0.93 33 106 1228.45 2001 4 Pacific cod 3 Pacific herring 0.02 0.02 33 106 18.39 2001 4 Pacific cod 3 Pleuronectidae 1.9 1.18 33 106 2185.14 2001 4 Pacific cod 3 Unid. Chionoecetes 3.62 1.79 33 106 4163.01 2001 4 Pacific cod 3 Walleye pollock 13.39 4.62 33 106 15408.79 2001 4 Skates 1 Bairdi Tanner crab 1.54 1.03 25 180 1795.02 2001 4 Skates 1 Gadidae 4.93 3.99 25 180 5747.11 2001 4 Skates 1 Offal 5.04 4 25 180 5877.38 2001 4 Skates 1 Opilio snow crab 6.07 2.27 25 180 7076.37 2001 4 Skates 1 Pleuronectidae 0.11 0.08 25 180 126.25 2001 4 Skates 1 Unid. Chionoecetes 14.23 4.51 25 180 16590.02 2001 4 Skates 1 Walleye pollock 26.62 7.49 25 180 31037.57 2001 4 Walleye pollock 4 Gadidae 1.83 1.4 30 236 5327.38 2001 4 Walleye pollock 4 Pacific herring 0.04 0.04 30 236 129.01 2001 4 Walleye pollock 4 Pleuronectidae 1.2 1.19 30 236 3494.2 2001 4 Walleye pollock 4 Walleye pollock 7.44 3.71 30 236 21682.15 2001 5 Arrowtooth flounder 2 Gadidae 20.09 13.66 8 16 10366.76 2001 5 Arrowtooth flounder 2 Walleye pollock 37.5 18.3 8 16 19354.25 2001 5 Arrowtooth flounder 3 Flathead sole 14.29 14.29 7 13 10642.53 2001 5 Arrowtooth flounder 3 Gadidae 0.65 0.65 7 13 486.82 2001 5 Arrowtooth flounder 3 Offal 14.29 14.29 7 13 10642.53 2001 5 Arrowtooth flounder 3 Walleye pollock 28.96 17.78 7 13 21575.28 

228
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2001 5 Pacific cod 2 Bairdi Tanner crab 27.33 6.6 5 51 4733.1 2001 5 Pacific cod 2 Offal 2.17 2.17 5 51 376.39 2001 5 Pacific cod 2 Opilio snow crab 0.62 0.62 5 51 106.61 2001 5 Pacific cod 2 Unid. Chionoecetes 2.01 1.71 5 51 348.82 2001 5 Pacific cod 2 Walleye pollock 8.6 7.94 5 51 1489.88 2001 5 Pacific cod 3 Bairdi Tanner crab 33.92 14.24 6 16 3657.18 2001 5 Pacific cod 3 Offal 8.97 5.9 6 16 967.26 2001 5 Pacific cod 3 Pleuronectidae 2.93 2.93 6 16 315.66 2001 5 Pacific cod 3 Unid. Chionoecetes 3.81 2.7 6 16 410.88 2001 5 Pacific cod 3 Walleye pollock 16.5 11.55 6 16 1779.34 2001 5 Skates 1 Bairdi Tanner crab 1.81 1.05 7 49 926.5 2001 5 Skates 1 Gadidae 0.78 0.78 7 49 398.34 2001 5 Skates 1 Offal 13.09 13.07 7 49 6691.26 2001 5 Skates 1 Opilio snow crab 3.11 2.98 7 49 1589.15 2001 5 Skates 1 Unid. Chionoecetes 10.32 5.78 7 49 5273.82 2001 5 Skates 1 Walleye pollock 55.78 16.72 7 49 28502.83 2001 5 Walleye pollock 4 Walleye pollock 5.63 2.82 14 158 3423.42 2001 6 Arrowtooth flounder 2 Capelin 7.69 7.69 13 29 2248.54 2001 6 Arrowtooth flounder 2 Gadidae 30.78 13.25 13 29 8998.58 2001 6 Arrowtooth flounder 2 Walleye pollock 29.43 12.79 13 29 8603.04 2001 6 Arrowtooth flounder 3 Gadidae 17.72 5.71 23 82 25666.74 2001 6 Arrowtooth flounder 3 Pacific cod 4.31 4.31 23 82 6242.82 2001 6 Arrowtooth flounder 3 Walleye pollock 53.91 9.22 23 82 78084.94 2001 6 Pacific cod 2 Bairdi Tanner crab 8.25 4.44 17 105 6132.41 2001 6 Pacific cod 2 Gadidae 1.51 1.11 17 105 1121.61 2001 6 Pacific cod 2 Offal 6 4.88 17 105 4458.5 2001 6 Pacific cod 2 Opilio snow crab 14.15 5.42 17 105 10521.85 2001 6 Pacific cod 2 Pleuronectidae 0.73 0.5 17 105 539.36 2001 6 Pacific cod 2 Unid. Chionoecetes 9.01 4.03 17 105 6701.77 2001 6 Pacific cod 2 Walleye pollock 6.18 3.25 17 105 4598.08 2001 6 Pacific cod 3 Arrowtooth flounder 2.53 2.53 16 105 3141.27 2001 6 Pacific cod 3 Bairdi Tanner crab 3.13 1.57 16 105 3884.84 2001 6 Pacific cod 3 Gadidae 2.31 1.23 16 105 2871.16 2001 6 Pacific cod 3 Northern rock sole 0.06 0.06 16 105 70.54 

229
Table F-1.--Continued.

YEAR STR PREDATOR

PREDATOR 

SIZE 

GROUP PREY

MEAN % 

WEIGHT

SE 

MEAN % 

WEIGHT

NO. OF 

STATIONS

NO. OF FULL 

STOMACHS

BIOMASS 

CONSUMED 

(TONS)

SE 

C

2001 6 Pacific cod 3 Offal 2.5 1.88 16 105 3100.68 2001 6 Pacific cod 3 Opilio snow crab 16.7 4.43 16 105 20740.72 2001 6 Pacific cod 3 Pacific cod 1.97 1.97 16 105 2451.32 2001 6 Pacific cod 3 Unid. Chionoecetes 4.75 2.27 16 105 5905.25 2001 6 Pacific cod 3 Walleye pollock 31.82 6.92 16 105 39529.5 2001 6 Skates 1 Bairdi Tanner crab 0.8 0.78 28 168 1120.17 2001 6 Skates 1 Gadidae 3.3 2.11 28 168 4643.78 2001 6 Skates 1 Offal 2.34 1.7 28 168 3283.96 2001 6 Skates 1 Opilio snow crab 2.24 2.02 28 168 3153.32 2001 6 Skates 1 Pleuronectidae 0.48 0.42 28 168 672.83 2001 6 Skates 1 Unid. Chionoecetes 9.5 4.33 28 168 13351.2 

2001 6 Skates 1 Walleye pollock 41.51 7.37 28 168 58365.68 2001 6 Walleye pollock 3 Gadidae 1.04 0.78 30 276 14513.93 2001 6 Walleye pollock 3 Walleye pollock 2.49 2.49 30 276 34779.67 2001 6 Walleye pollock 4 Walleye pollock 4.61 3.53 27 158 15695.59 

230
RECENT TECHNICAL MEMORANDUMS


Copies of this and other NOAA Technical Memorandums are available from the 

National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22167 

(web site: www.ntis.gov). Paper and microfiche copies vary in price. 

AFSC157 JOHNSON, S. W., A. DARCIE NEFF, and J. F. THEDINGA. 2005. An atlas on the distribution and habitat 

of common fishes in shallow nearshore waters of southeastern Alaska, 89 p. NTIS number pending. 

156 HOFF, G. R., and L. L. BRITT. 2005. Results of the 2004 Eastern Bering Sea upper continental slope 

survey of groundfish and invertebrate resources, 276 p. NTIS number pending. 

155 YANG, M-S., K. AYDIN, A. GRIEG, G. LANG, and P. LIVINGSTON. 2005. Historical review of capelin 

(Mallotus villosus) consumption in the Gulf of Alaska and Eastern Bering Sea, 89 p. NTIS No. PB2005­

110464. 

154 HOLLAND D. S. 2005. Economic analysis of protection of essential fish habitat in Alaskan fisheries: An 

analysis of research needs, 35 p. NTIS No. PB2005-110129. 

153 FRITZ, L. W., and C. STINCHCOMB. 2005. Aerial, ship, and land-based surveys of Steller sea lions 

(Eumetopias jubatus) in the western stock in Alaska, June and July 2003 and 2004, 56 p. NTIS number 

PB2005-108287. 

152 AMES, R. T., G. H. WILLIAMS, and S. M. FITZGERALD. 2005. Using digital video monitoring systems 

in fisheries: Application for monitoring compliance of seabird avoidance devices and seabird mortality in 

Pacific halibut longline fisheries, 93 p. NTIS No. PB2005-107312. 

151 TESTA, J. W. (editor). 2005. Fur seal investigations, 2002-2003, 72 p. NTIS No. PB2005-104811. 

150 GULLAND, F. M. D., H. PÉREZ-CORTÉS M., J. URBÁN R., L. ROJAS-BRACHO, G. YLITALO, J. WEIR, 

S. A. NORMAN, M. M. MUTO, D. J. RUGH, C. KREUDER, and T. ROWLES. 2005. Eastern North Pacific 

gray whale (Eschrichtius robustus) unusual mortality event, 1999-2000: A compilation, 33 p. NTIS No. 

PB2005-105795. 

149 RUGH, D. J., K. E. W. SHELDEN, C. L. SIMS, B. A. MAHONEY, B. K. SMITH, L. K. LITZKY, and R. C. 

HOBBS. 2005. Aerial surveys of belugas in Cook Inlet, Alaska, June 2001, 2002, 2003, and 2004, 71 p. 

NTIS No. PB2005-103921. 

148 EILER, J. H., T. R. SPENCER, J. J. PELLA, M. M. MASUDA, and R. R. HOLDER. 2004. Distribution and 

movement patterns of chinook salmon returning to the Yukon River basin in 2000-2002, 99 p. NTIS No. 

PB2005-100707. 

147 MCELDERRY, H., J. SCHRADER, D. MCCULLOUGH, J. ILLINGWORTH, S. FITZGERALD, and S. 

DAVIS. 2004. Electronic monitoring of seabird interactions with trawl third-wire cables on trawl vessels ­

a pilot study, 39 p. NTIS No. PB2005-100243. 

146 WING, B. L., and D. R. BARNARD. 2004. A field guide to Alaskan corals, 67 p. NTIS No. PB2005-100429. 

145 RUGH, D. J., B. A. MAHONEY, and B. K. SMITH. 2004. Aerial surveys of beulga whales in Cook Inlet, 

Alaska, between June 2001 and June 2002, 26 p. NTIS No. PB2004-106479. 

144 ANGLISS, R. A., and K. L. LODGE. 2004. Alaska marine mammal stock assessments, 2003, 224 p. 

NTIS No. PB2005-100248. 

143 ZENGER, H. H. JR. 2004. Data report: 2002 Aleutian Islands bottom trawl survey, 247 p. NTIS No. 

PB2004-105068.