Library

National Wetlands Research Center

U. S. Fish and Wildltfe Service

Biological Report 82(11 .lOl)

July 1989

TR EL-82-4

Species Profiles: Life Histories and

Environmental Requirements of Coastal Fishes

and Invertebrates (Pacific Northwest)

ENGLISH SOLE

QL

155

.S63

no. 82-

11.101

PACIFIC

OCEAN

Fish and Wildlife Service

Coastal Ecology Group

Waterways ExDeriment Station

U.S. Department of the Interior U.S. Army Corps of Engineers

Biological Report 82( 11.101)

TR EL-82-4

July 1989

Species Profiles: Life Histories and Environmental Requirements

of Coastal Fishes and Invertebrates (Pacific Northwest)

ENGLISH SOLE

Dennis R. Lassuy

Oregon Cooperative Fishery Research Unit

Department of Fisheries and Wildlife

Oregon State University

104 Nash Hall

Corvallis, OR 97331-3803

Project Officer

David Moran

U.S. Fish and Wildlife Service

National Wetlands Research Center

1010 Gause Boulevard

Slidell, LA 70458

Performed for

Coastal Ecology Group

Waterways Experiment Station

U.S. Army Corps of Engineers

Vicksburg, MS 39180

and

U.S. Department of the Interior

Fish and Wildlife Service

Research and Development

National Wetlands Research Center

Washington, DC 20240
L

This series should be referenced as follows:

U.S. Fish and Wildlife Service. 1983-19 Species profiles: life histories

and environmental requirements of coastx.fishes and invertebrates. U.S. Fish

Wildl. Serv. Biol. Rep. 82(11). U.S. Army Corps of Engineers, TR EL-82-4.

This profile should be cited as follows:

Lassuy, D. R. 1989. Species profiles: life histories and environmental

requirements of coastal fishes and invertebrates (Pacific Northwest) --

English sole. U.S. Fish Wildl. Serv. Biol. Rep. 82(11.101). U.S. Army Corps

of Engineers, TR EL-82-4. 17 pp.
PREFACE

This species profile is one of a series on coastal aquatic organisms,

principally fish, of sport, commercial, or ecological importance. The profiles

are designed to provide coastal managers, engineers, and biologists with a brief

comprehensive sketch of the biological characteristics and environmental

requirements of the species and to describe how populations of the species may be

expected to react to environmental changes caused by coastal development. Each

profile has sections on taxonomy, life history, ecological role, environmental

requirements, and economic importance, if applicable. A three-ring binder is

used for this series so that new profiles can be added as they are prepared.

This project is jointly planned and financed by the U.S. Army Corps of Engineers

and the U.S. Fish and Wildlife Service.

Suggestions or questions regarding this report should be directed to one of

the following addresses.

Information Transfer Specialist

National Wetlands Research Center

U.S. Fish and Wildlife Service

NASA-Slide11 Computer Complex

1010 Gause Boulevard

Slidell, LA 70458

or

U.S. Army Engineer Waterways Experiment Station

Attention: WESER-C

Post Office Box 631

Vicksburg, MS 39180

iii
CONVERSION TABLE

Multiply !Y To Obtain

millimeters (mm) 0.03937 inches

centimeters (cm) 0.3937 inches

meters (m) 3.281 feet

meters (m) 0.5468 fathoms

kilometers (km) 0.6214 statute miles

kilometers (km) 0.5396 nautical miles

square meters (m*) 10.76 square feet

square kilometers (km*) 0.3861 square miles

hectares (ha) 2.471 acres

liters (1) 0.2642

cubic meters (m3) 35.31

cubic meters (m3) 0.0008110

milligrams (mg) 0.00003527

grams (9) 0.03527

kilograms (kg) 2.205

metric tons (t) 2205.0

metric tons (t) 1.102

gallons

cubic feet

acre-feet

ounces

ounces

pounds

pounds

short tons

kilocalories (kcal) 3.968 British thermal units

Celsius degrees ("C) 1.8(=X) + 32 Fahrenheit degrees

inches

inches

feet (ft.)

fathoms

statute miles (mi)

nautical miles (nmi)

U.S. Customary to Metric

25.40

2.54

0.3048

1.829

1.609

1.852

millimeters

centimeters

meters

meters

kilometers

kilometers

square feet (ft*) 0.0929 square meters

square miles (mi*) 2.590 square kilometers

acres 0.4047 hectares

gallons (gal) 3.785 liters

cubic feet (ft3) 0.02831 cubic meters

acre-feet 1233.0 cubic meters

ounces (oz)

ounces (oz)

pounds (lb)

pounds (lb)

short tons (ton)

British thermal units (Btu)

Fahrenheit degrees (OF)

28350.0

28.35

0.4536

0.00045

0.9072

0.2520

0.5556 (OF

iv

milligrams

grams

kilograms

metric tons

metric tons

32)

kilocalories

Celsius degrees

Metric to U.S. Customary
CONTENTS

PREFACE

CONVERSION iA;Li

ACKNOWLEDGMENTS

.............................

.............................

.............................

NOMENCLATURE/TAXONOMY/RANGE

MORPHOLOGY/IDENTIFICATION AIDJ : : : : : : : : : : : : : : : : : : : : : :

REASONS FOR INCLUSION IN SERIES .....................

LIFE HISTORY ...............................

Spawning and Larvae ..........................

Postlarvae and Juveniles ........................

Adults .................................

GROWTH ..................................

MORTALITY

MOVEMENT AN; ;;TkI;S' : ....................................................

DISEASE AND PARASITES ..........................

THE FISHERY

ECOLOGICAL ROLE* : : : : : : : : : : : : : : : : : : : : : : : : : : : : :

ENVIRONMENTAL REQUIREMENTS ........................

Temperature ..............................

Salinity ................................

Temperature/Salinity Interaction ....................

OtherEnvironmentalFactors ......................

AREAS OF CONCERN .............................

LITERATURE CITED .............................

Page

iii

iv

vi

1

1

3

;

4

5

5

7

7

:

IO"

::

11

::

13

.

V
ACKNOWLEDGMENTS

I am particularly grateful to Beth Deimling, Dr. Ellen Pikitch, and

Dr. William Pearcy for their help in assembling the information for this review.

I am indebted as well to Adrian Hunter for her patience with an ever-defective

word processor and to several Washington, Oregon, California, and British

Colunbia universities and agencies for their speedy responses to information

requests. William Barss (Oregon Department of Fish and Wildlife), Gordon Kruse

(Alaska Department of Fish and Game), and Ellen Pikitch (University of

Washington) reviewed the manuscript.

v i
Figure 1. English sole (from Hart 1973).

ENGLISH SOLE

NOMENCLATURE/TAXONOMY/RANGE

Scientific name . . . Parophrys vetulus

(Girard)

Common name . . . . . . . . . . . . English sole

(Figure 1)

Other names . . . . . . . . . . This species is

known in Canada as the lemon sole

and has been called the point sole

(for its pointed head) in California. It is believed that specimens

that had been previouslv placed in

the species Isbpsetta ;'schyra are

actually hybrids of P. vetulus and

Platichthys stellatus (m73).

Class . . . . . . . . . . . . . . . . . . Osteichthyes

Order . . . . . . . . . . . . . . Pleuronectiformes

Family . . . . . . . . . . . . . . . . Pleuronectidae

Geographic range: English sole are

known from Sebastian Vizcaino Bay,

Baja California, Mexico (lat.

28“ 30' N, long. 115" 00' W) to

Unimak Island, Alaska (lat. 54'30'

N, long. 164" W) and occur in

commercial quantities from Santa

Barbara, California, to northern

Hecate Strait, British Columbia

(Alderdice and Forrester 1968).

Depth distribution is from .the

surfline to 550 m (Hart 1973) but it

is uncommon at depths greater than

146 m (Demory et al. 1976; Barss et

al. 1977). Commercial abundances

occur between 37 m and 126 m

(Forrester 1969a). Alderdice and

Forrester (1968) suggested that the

influence of water temperature on

egg viability may limit the boundaries of commercially exploitable

populations as well as the boundaries of qeoqraphic distribution.

The distribution of P.. vetulus in

the Pacific Northwe %Zi$Zi is

shown in Figure 2.

MORPHOLOGY/IDENTIFICATION AIDS

Body elongate, much compressed,

dextral

Head slet%?

on the right side).

with bluntly pointed

snout. M;uth terminal, small,

asymmetrical, with narrow gape; jaws

and teeth strongest on blind side.

1
lnternatiorial North Pacific

Fisheries Clommission

_\VANCOUVER,“hw\

4

SEATTLE

d

ND

WASHINGTON

KILOMETERS

OREGON

CALIFORNIA

- I

Figure 2. Distribution of the English sole in the Pacific Northwest Region.

2
Maxillary extends to forward part of

lower eye. Eyes large, upper somewhat

posterior to lower, entering profile.

Interorbital space narrow, ridge high.

Dorsal with one spine and 72 to 92

rays, originates above middle of upper

eye; anal, 54 to 72 rays, exposed

spine before fin'; pelvic, 6 rays,

thoracic; pectorals tend to be

pointed; caudal imperfectly truncate.

Scales imbricated, cycloid anteriorly,

ctenoid posteriorly. Lateral line, 89

to 105 scales, slightly decurved then

straight, dorsal branch long, close to

dorsal fin, extends to point over

pectoral fin. Color, uniform brown to

yellow-brown on eyed side; pale yellow

to white on blind side, tinged with

reddish brown, particularly on head.

Young variously colored gray to brown,

minutely spotted, often with sandy

appearance on eyed surface (see

Misitano 1976 for photos); often with

two yellow lines on blind side at

bases of dorsal and anal fins. Total

length (TL) to 57 cm in females, 47 cm

in males.

Distinguished from other flatfishes by a combination of pointed

head, long dorsal branch of lateral

line, and smooth anterior/rough

posterior scale pattern. The above

description was abstracted almost

entirely from Clemens and Wilby (1961)

and Hart (1973).

REASONS FOR INCLUSION IN SERIES

Barss (1976) wrote that among

flatfishes coastwide, the catch of

English sole was exceeded only by that

of the Dover sole and sometimes the

Petrale sole. Annual coastwide

landings (from California to British

Columbia, round weight) averaged 5,141

metric tons (t) from 1971 to 1980 with

a peak of 6,680 t in 1976 (Lynde 1986).

As in many coastal marine fishes, the

juveniles of P. vetulus depend on

shallow, nearshcre habitats as nursery

grounds. Ketchen (1956), in fact,

attributed the scarcity of English

sole in northern British Columbia to a

lack of suitable nursery grounds.

During early spring and summer,

juvenile English sole are the most

abundant flatfish in many Pacific

coastal embayments and estuaries

(Yoklavich 1982). Barss (1976)

suggested that English sole could

benefit from protected nursery areas.

My own favorite 'reason for

inclusionn was stated by Clemens and

Wilby (1961): "This is the choicest

of the small flatfishes, having a very

delicate flavor . . . .”

LIFE HISTORY

Spawning and Larvae

The spawning of English sole has

not been directly observed. All

suggested spawning locations and times

are inferred from the spatial and

temporal distribution of either turgid

or spent females or the egg and larval

stages. The site of spawning is said

to be over sand and sand-mud bottoms

at depths of 60-110 m (Ketchen 1956;

Barss 1976; Hewitt 1980). Spawning

is usually most intense during winter

(December to February), but is known

to occur in all seasons; peaks vary

from September to April (Laroche and

Richardson 1979; Kruse and Tyler 1983).

Individual English sole may spawn in

more than 1 year, but probably do not

spawn serially within a given season

(Harry 1959; Kruse 1981).

There is no apparent latitudinal

trend in the time of spawning (Laroche

and Richardson 1979). However, Kruse

and Tyler (1983) were able to develop

a simulation model that explained most

of the variation in observed spawning

season. Their model was constructed

from three relations between temperature and aspects of reproduction:

(1) rate of gonadal development is

inversely related to summer bottom

temperature, (2) spawning is inhibited

at temperatures below 7.8' C, and

(3) spawning is delayed by rapid

increase in bottom temperature.

3
Although English sole spawn

demersally, their eggs are buoyant in

full-strength seawater. Reported egg

diameter varies from 0.89 to 1.05 mm

(Budd 1940; Orsi 1968). Hatching time

varies from 3.5 to 12 days and depends

on both temperature and salinity

(Alderdice and Forrester 1968; Orsi

1968). Orsi (1968) provided a

detailed description of the embryology

of the English sole that included a

series of photos and illustrations of

the egg and early larval stages. He

noted that newly hatched larvae are

2.8-2.9 mm TL and grow to 4.6 mm

during the 9-10 days (at 10.6 "C) of

yolk-sac absorption. Orsi also noted

that in the absence of food, the last

surviving larvae died at 14 days.

The larvae of English sole are

pelagic and depend on favorable

current patterns for transport to

suitable nearshore nursery areas. The

duration of this pelagic larval stage

is generally cited as 6-10 weeks

(Ketchen 1956; Laroche et al. 1982).

Transformation to asymmetrical

morphology and settlement to a

demersal existence coincide as the

larvae reach 18-22 mm TL, at 60 to 120

days of age (Laroche and Richardson

1979; Rosenberg and Laroche 1982).

Postlarvae and Juveniles

English sole settling periods

vary widely even at the same location. Krygier and Pearcy (1986)

reported the capture of metamorphosing

sole in Yaquina Bay, Oregon, from

November through July; the month of

maximum density varied from November

to May. This protracted period of

benthic recruitment may reflect the

variability in the spawning season

(Kruse and Tyler 1983).

Although it had been concluded in

the past that estuaries alone serve as

nursery areas for juvenile English

sole (Demory 1971; Olson and Pratt

1973), new evidence suggests that

shallow, open coastal waters may also

hw

provide juvenile rearing habitat

(LaRouche and Holton 1979;

1982; Krygier and

Rosy;r$g

Pearcy

Demory et al. (1973) listed ten Orego;

estuaries occupied by juvenile English

sole. Postlarval settlement occurs

both in estuaries and along sandbottomed open coastlines, primarily at

depths of less than 16 m (Laroche and

Holton 1979; Krygier and Pearcy 1986).

Growth rate of post-settlement, O-age

English sole is comparable in

estuaries and open coastal sites

(Rosenberg 1982; Krygier and Pearcy

1986). The number of juveniles at

open-coast sites, however, decreases

sharply after initial settlement. It

is not yet known to what extent this

decrease is due to the migration of

newly settled English sole from the

open coast to estuaries (Krygier and

Pearcy 1986) or to differential

mortality.

Alternate hypotheses, both based

in optimal foraging theory, have been

presented to explain the distribution

of postlarval and juvenile English

sole within estuaries. Yoklavich

(1982) suggested that the influence of

temperature on growth rate may limit

the distribution of juveniles to the

cooler, deeper channels in more

southern bays but favor a wider use of

intertidal habitats in northern bays

and estuaries. Toole (1980) proposed

that the distribution of young English

sole in Humboldt Bay could be explained as a combined response to

predator and competition avoidance as

well as optimal prey size availability.

Given the scope of the hypotheses,

both may be correct.

Juveniles move to progressively

deeper waters with growth, and leave

the nursery areas at 140-150 mm TL

(Misitano 1976; Sopher 1974, as cited

in Toole 1980). This emigration from

the estuaries generally occurs from

August through November (Pearcy and

Myers 1973; Yoklavich 1982). Again,

several alternative cues to emigration

have been proposed, such as temperature by Yoklavich (1982) and niche

4
‘)L

,i

shift and competition avoidance by

Toole (1980). Westrheim (1955)

suggested that "perhaps less than 5%

remain in the bay through the winter

and presumably emigrate in the late

winter or early spring of their second

year."

Adults

Adult English sole are almost

entirely absent from coastal bays and

estuaries (Westrheim 1955; Misitano

1976), and are generally restricted to

offshore sand or sand-mud substrates

(Demory et al. 1976; Barss et al. 1977;

Demory 1984). The depths at which

they are most abundant vary from about

20-70 m in summer to 40-130 m in

winter (Jow 1969; Barss 1976). This

results from a seasonal bathymetric

migration which is usually associated

with a contranatant (against the

current) movement to and more passive

movement with the current when

returning from deeper-water spawning

y;;;;d;) (Ketchen 1956; Forrester

, l

Male English sole mature at 2-3

years of age and females at 3-4 years

of age (Ketchen 1956; Van Cleve and

El-Sayed 1969). Harry (1959) reported

that 50% of the males were mature at

about 22 cm TL, and 50% of the females

at 31 cm TL. A review by Gunderson and

Dygert (1988) lists the age of 50%

maturity for females as 4 years, and

the average female length at 50%

maturity in an unexploited population

as 388 nun. Harry (1959) reported that

the number of eggs per female ranged

from 327,600 for a 30-cm fish to over

1.5 million for a 43-cm fish. On the

basis of Harry's data, Demory (1984)

calculated the following equation:

F = -1,875,906 t 75,377 L

where: F = fecundity (number of ova)

L = total length (cm).

GROWTH

Rosenberg and Laroche (1982)

detailed the growth pattern of larval,

metamorphosing, and early O-age

English sole. There was a period of

reduced growth rate during metamorphosis between 60 and 120 days of age

and 18 to 22 mm standard length (SL).

After growth was resumed, the newly

recruited benthic specimens had

reached about 34 mm SL at an age of

200 days (= 0.15 mm/day).

Rosenberg (1982) calculated a

growth rate of 0.28 mm SL/day for

English sole 140-480 days old.

Krygier and Pearcy (1986) calculated a

growth rate of 0.37-0.40 mm SL/day for

fish of a similar size range at the

same sites (Yaquina Bay and Moolach

Beach, Oregon) and the same years

(1978-79). Rosenberg's calculation

was based on otolith aging techniques,

and Krygier and Pearcy's on modal

progressions of length-frequency data.

Both reports, as well as that of

Laroche et al. (1982), discussed the

possible errors of each technique.

Krygier and Pearcy (1986) also

estimated that average daily growth of

fish of this age group was greatest

(0.46-0.49 mm) in late spring to early

fall, and much lower in winter

(0.26-0.32 mm).

English sole have been reported

to attain 130-160 mm TL by the end of

the first year of life (Van Cleve and

El-Sayed 1969; Westrheim 1955; Smith

and Nitsos 1969). Yoklavich (1982)

compared the relative growth rates of

laboratory-reared O-age (72-114 mm SL)

and "age class II” (156-188 mm SL)

P. vetulus. For trials run at 13 “C,

YYge7JTiT grew at a rate of 1.9% and

age II fish at 0.8% body weight per

day. Gross conversion efficiency,

(total growth/total ration) in terms

of both dry weight and calories, was

greatly reduced for age II fish (12.1%

and 17.8%, respectively) from

efficiencies of age 0 fish (26.8% and

34.5%, respectively).

5
Growth rates of males and females

are similar during the first 2 years

(Barss 1976), but females grow faster

thereafter. Van Cleve and El-Sayed

(1969), who provided a broad re;A;;i;,'

several growth studies of

sole, included a listing of von

Bertalanffy growth equation constants

from their own and other studies.

Although the relation of length to

weight was not markedly different in

males and females (Figure 3), a plot

of length at age (Figure 9) clearly

demonstrated their different growth

rates, particularly adults.

Maximum total length and ?ge is 57 cm

and 17 years for females, 49 cm and

15 years for males (Forrester 1969a).

7 .

TOI& Length (mm)

figure 3. Length-weight relationship

for Parophyrys vetulus ; redrawn from

Holland 1969).

4

3

3

2

*

!2

5

?

9

1

C

7-r.. . . _ _

0(

*‘c+-

Female

\/"

/

1

Male

a I . *

I

2 4 6 6 16 12 14 1

Age (yeara)

Figure 4. Length-age for English sole;

redrawn from Van Cleve and El-Sayed

1969).

Kreuz et al. (1982) reported a

March through September growing season

for adult English sole, growthG;;if;

most rapid in May and June.

rates between their study locations

(Astoria and Coos Bay, Oregon) did not

differ but did vary significantly

among years. Fluctuations in annual

growth increments were negatively

correlated with a continental shelf

temperature index (which increased

with increasing temperature) for peak

growth months and growth appeared to

be related to long-term trends in

upwelling. They also concluded that

growth "does not seem to be associated

with stock density." The relationship

of growth and maturation in English

sole may have changed in recent years

6
(Ellen Pikitch, Department of

Fisheries and Wildlife, Oregon State

University, Corvallis; pers. comm.),

such that sexual maturity is now

reached at a smaller size than was

reported by Harry (1959; see Life

History section).

MORTALITY

Mortality in English sole, as in

nearly all fishes, is greatest during

early life-history stages. Several

researchers have correlated year-class

strength with the extent and time of

spawning and the successful benthic

recruitment of pelagic egg and larval

stages (Ketchen 1956; Hayman and Tyler

1980; Kruse 1984). Sources of

mortality for eggs, larvae, and newly

recruited juveniles include adverse

temperature and salinity conditions

(Alderdice and Forrester 1968),

predation (Rosenberg 1982), adverse

ocean advection (Kruse 1984), and

absence of prey for larvae (Gadomski

and Boehlert 1984).

Reported annual mortality rates

for older fish are based largely on

data from catches in experimental and

commercial trawls. Mortality varies

widely with sex, age, and the degree

of exploitation. Average annual

mortality may be as high as 50%-75% in

highly exploited stocks (Ketchen 1947,

as cited in Holland 1969; Menasveta

1958). Ketchen reportedly estimated

annual natural mortalities in an

unexploited population as 30% for

females, and 38% for males. A

coastwide rate of annual natural

mortality of 23% was reported by the

Pacific Fishery Management Council

(1982). Barss (1976) reported a

different pattern from exploited

stocks off the Oregon coast, where

mortality was higher in females (36%)

than in males (32%). He suggested

that the difference was due to the

higher susceptibility of the larger

females to commercial fishing

pressure. An even more complicated

picture was presented by Holland

(1969). His investigations in Puget

Sound showed a greater mortality for

females (36%) than males (33%) from

the third to fifth years of life at

one site, but the reverse

(males = 38%-50%, females = 27%-48%)

for 8- to lo-year-old fish at a second

site. Golden et al. (1986) used a

value of 26% average annual fishing

mortality to reconstruct stock sizes

off the Oregon coast. They also

estimated age-specific mortality

values for fish from 3 to 13 years of

age.

In a study of 20 different species

of fish that included copper rockfish

(Gunderson and Dygert 1988), the

instantaneous natural mortality rates

were positively correlated with the

gonadosomatic index (GSI), expressed as

gonad weight + bodyweight. It may be

possible for this index to predict the

natural mortality rate for a fishery

management model of English sole. Note

that Gunderson and Dygert estimated GSI

as 0.18 for this species.

MOVEMENT AND STOCKS

Knowledge of the discreteness of

populations is integral to the management of any species. Except for brief

mention by Clemens and Wilby (1961)

that English sole "move about freely,"

most authors have concluded that

movement is largely restricted to

seasonal spawning migrations (previously discussed) in geographically

segregated stocks (Ketchen 1956; Jow

1969; Pattie 1969; Barss 1976). There

may, however, be a small but highly

migratory fraction in many stocks, as

reports on most tagging studies have

mentioned at least one or a f$w longdistance recoveries. Migration rates

have been as high as 4 mi/day (Hart

1973) and tag recovery distances as

great as 700 mi (Clemens and Wilby

1961).

Major spawning populations within

the Pacific Northwest region have been

identified from Puget Sound (Holland

7
1969), the northern Washington coast

(Pattie 1969), the central Oregon

coast (Barss 1976), and two stocks in

northern and central California that

are segregated roughly in the vicinity

of Eureka (Jow 1969). There is some

indication of mixing near the

prescribed boundaries of several

stocks, as well as evidence of

multiple substocks within the major

;;;;;;ngs (Holland 1969; Forrester

Day (1976) concluded on the

basis *of tagging and recapture data

that English sole in Puget Sound

demonstrated "pronounced homing" and

suggested that individuals may be

territorial. However, I have found no

record of behavioral observations to

substantiate the possibility of

territoriality.

DISEASE AND PARASITES

Olson (1978) reported on extensive

studies of host-parasite relations in

juvenile and adult English sole along

the Oregon coast. The presence and

intensity of infections were related

to the habitats in which the fish were

collected; infection was a more

serious factor in habitats with higher

temperature. A total of 29 species of

parasites were identified. At

temperatures above 15 “C, juveniles

are apparently more susceptible to a

microsporidial infection capable of

causing mortality. Angel1 et al.

(1975) determined that an epizootic

skin tumor disease was a significant

cause of mortality in a Puget Sound

population of juvenile English sole.

A myxosporidean disease that

causes a "milky" appearance to develop

in the flesh of some adult English

sole renders the fish unmarketable. A

'wormy" appearance presents a similar

marketing problem when adults are

infected with the nematode Philometra

americana (Holland 1969; Barss 1976)

Although no mention was made of thei;

effect on the health of the fish,

neither of these conditions is harmful

to human consumers.

THE FISHERY

The English sole has been an

important species in California trawl

fisheries since the late 1880's (Jow

1969) and a major contributor to both

the Washington and Oregon trawl

fisheries (Pattie 1969; Barss 1976).

Landings in both the U.S. and Canadian

fisheries increased during the years

immediately after World War II

(Ketchen 1956; Jow 1969). In U.S.

waters, however, the catch declined

somewhat with the rise in prominence

of the Dover sole (Jow 1969). Both

Dover and English soles are used in

the filet of sole trade.

Females comprise over 90% of

English sole landings (Kruse 1984;

Golden et al. 1986). Many mature

males, because of their smaller size

(see section on Growth), are apparently discarded at sea (Barss 1976). In

1959-79, in Pacific Marine Fisheries

Commission (PMFC) Area 3A, age-classes

4-7 averaged nearly 80% of the total

landings by weight (Kruse 1984).

Average weight of females for this

area and period was 0.45 kg (Kruse

1984).

The total weight of English sole

landed during the years 1966-85 in

International North Pacific Fishery

Commission (INPFC) Columbia area and

PMFC Area 3B combined averaged nearly

1,300 t (Golden et al. 1986). However,

only one of the last 5 years of this

period has produced landings in excess

of 1,000 t. A similar pattern of

decline is seen in estimated biomass

in these same areas. Golden et al.

(1986) compared survey (catch, effort,

and catchability) and virtual population analyssoil; (VP!) estimates of

English biomass. They

"tentatively concluded" that VPA

estimates, which were much lower than

survey estimates (e.g., 1985, VPA =

3,030-3,572 t; survey = 5,634 t) were

the better of the two.

Unfortunately, this leaves open

the possibility that past estimates

8
were too high or that a significant

amount of catch is unaccountable

because of nondirected multispecific

fisheries. Parental stock may have

been reduced to a level at which

fishing mortality adversely affects

recruitment. If so, management

options for stock rehabilitation

(e.g., trip limits, area closures,

mesh-size regulation) are limited due

to this multispecific nature of the

catch. English sole represent only 7%

of the total catch for all Oregon

trawl fisheries in which they are

taken (Golden et al. 1986). Alternative means of explaining recent

declines in recruitment based on

environmental factors (Ketchen 1956;

Hayman and Tyler 1980; Kruse 1984)

have apparently not been applied to

recent oceanographic data (Golden et

al. 1986). Growth of age I fish was

shown to be negatively correlated with

density of the age-1 cohort and with

bottom temperature. Both factors

should be considered in models of

English sole stocks (Peterman and

Bradford 1987). A recent model of

population dynamics of English sole off

Washington and Oregon achieved best

results when it incorporated the

following: (1) the effect of ocean

temperatures on time of spawning, egg

hatching success, and fish growth; (2)

density-dependent larval mortality; (3)

age-dependent mortality of fish (4

years old; and (4) density-dependent

growth of age 1 fish (Peterman et al.

1987). A management model would

further need to incorporate long-term

changes in growth schedules indicated

by recent evidence (Peterman et al.

1987).

ECOLOGICAL ROLE

Gadomski and Boehlert (1984)

found in their study off the Oregon

coast that "the diet of P. vetulus

larvae is very specific; appendicularians (Oikopleura spp.) comprised 97%

of the total number of food items

consumed" when their peak abundances

coincided. In that portion of the

study when peaks did not coincide,

appendicularians were still the

primary food item (66%), but the diet

also included "other food sources such

as tintinnids, invertebrate eggs, and

nauplii." These authors suggested

that such apparent dependence on a

specific prey 'may result in significant food-related mortality" in years

when larval and appendicularian peak

abundances do not coincide. Hogue and

Carey (1982), who examined the guts of

40 metamorphosing larvae (16-18 mn SL),

found no evidence of feeding. This

lack of feeding may help explain the

occurrence of a “growth plateau"

during metamorphosis (see section on

Growth).

Both Hogue and Carey (1982) and

Toole (1980) found that harpacticoid

copepods were a major food source of

early O-age English sole. Hogue and

Carey (1982) found that other small

prey such as polychaete palps and

juvenile bivalves were also important

dietary items. After measuring the

mouth size of specimens of 30 mm (SL),

they concluded that prey of greater

than 2 mm in any dimension were too

large to be consumed. Both studies

described a feeding transition within

O-age sole -- Hogue and Carey (1982)

at 35 mm SL and Toole (1980) at 50-65

mm TL. This size range coincides very

nearly with the change to "adult"

morphology (Toole 1980).

Juvenile English sole are

apparently opportunistic and generalist benthic feeders, with selection

only at the level of major taxonomic

groups of prey (Toole 1980). Within

prey groups, the extent of dietary

inclusion varies with local seasonal

prey abundance (Collins 1978; Toole

1980; Hogue and Carey 1982). The most

commonly mentioned prey items include

polychaetes, amphipods, cumaceans, and

bivalve siphons. Hogue and Carey

(1982) described two patterns of

feeding behavior in laboratory-held

juveniles -- the first a sort of sitand-wait strategy with occasional

lunges at surface prey, and the second

9
a more active disturbance of the upper

few millimeters of sediment and

subsequent feeding on fleeing prey.

In this same study, data on die1

change in gut fullness suggested that

juvenile English sole are primarily

diurnal feeders.

Hulberg and Oliver (1979) who

analyzed the taxonomic and "ecolo&cal"

composition of the diets of adult

English sole ( X = 228 mm SL) and

speckled sanddab (137 mm) from

Monterey Bay, found considerable

taxonomic overlap in their diets.

However, behavioral and microhabitat

differences among prey species and in

feeding behavior of the two flatfishes

suggested a clear trophic separation.

The English sole fed primarily

on shallow-burrowing, surface-active

prey, but was apparently capable of

digging into the sediment to capture

deeper-burrowing prey as well. The

sanddab limited its feeding primarily

to hyperbenthic and pelagic prey. A

detailed taxonomic and numerical

description of the diet of large

(230-450 mm TL) English sole and four

other flatfishes from off the Oregon

coast was presented by Kravitz et al.

(1976). For the single day on which

fish were collected, the diet of

P. vetulus was the most diverse.

Again, amphipods, polychaetes, and

cumaceans were commonly consumed.

Like the juveniles, adult English sole

feed opportunistically on a wide

variety of benthic invertebrates, such

as polychaetes, shrimp, and small

molluscs and crabs (Clemens and Wilby

1961). The polychaetes Caoitella spp.

are locally abundant in disturbed

areas. In these areas, Engl ish sole

exhibit significant numerical and size

selection of this food. Frequency of

Capitella spp. and median size were

usually significantly greater in the

fish than in the environment (Becker

and Chew 1987). Feeding on this

polychaete peaked at night, whereas

adult English sole do not usually feed

then (Becker and Chew 1987). Benthic

assemblages dominated by pioneer

species such as Caoitellg spp. may have

comparatively high productivity and

hence be an enhanced food source. It

has not been established, however, that

enhanced populations of a small number

of species of prey will provide a

healthy, balanced diet (Becker and Chew

1987).

Pelagic larvae are subject to

heavy predation by appendicularians

(Kruse 1984). Toole (1980) noted a

lack of predators in the intertidal

areas used most heavily by juveniles,

but found a small English sole in the

gut of a juvenile lingcod (Ophiodon

elongatus) that was caught in a nearby

estuarlne channel. Other potential

predators in these channels were rockfish, croakers, and sharks. Rosenberg

(1982) suggested that a greater

abundance of "large fish" represented

a more substantial threat of predation

in the open ocean than in estuarine

waters. Roffe and Mate (1984) found

that P. vetulus constituted about 5%

of thedimacific harbor seals in

the Rogue River, Oregon. Seabirds

(e.g., cormorants and pigeon guillemots) may also prey on juvenile sole.

ENVIRONMENTAL REQUIREMENTS

Temperature

Ames et al. (1978) determined an

upper lethal temperature limit (50%

survival) for P. vetulus of 26.1 OC.

Juveniles of Essthan119 mm were

more susceptible than intermediatesized fish. Yoklavich (1982) found a

significant reduction in juvenile

growth rate at 17.5 'C. Reduced

relative growth rate was due to a

decline in daily ration rather than

in conversion efficiency. Yoklavich

further related high temperatures t0

the distribution of juveniles within

estuaries as well as their time of

emigration from estuaries, particularly at the southern margin of their

geographic range.

Lower lethal temperature limits

have been addressed primarily for the

10
eggs of English sole. Ketchen (1956)

observed complete mortality and no

development past first cleavage at

3.8 'C. At 7 "C, eggs proceeded

through several stages of development,

but all died before hatching.

Alderdice and Forrester (1968)

observed complete mortality of eggs at

20 'C, but were able to attain a 50%

hatching success at 4 "C. A 90% total

hatch was estimated to occur in the

temperature range of 7-11 'C. These

authors concluded that temperature may

limit abundance at the northern and

southern boundaries of the range of

commercial exploitation by lowering

egg viability, and may be lethal to

eggs near the boundaries of geographic

distribution. Kruse (1984) used their

temperature-hatch success relation and

found it consistent with Oregon

temperatures and year-class strengths.

Temperature has a marked influence

on development time (Alderdice and

Forrester 1968). Hatching occurred in

only 3.5 days at 12 "C, but required

11.8 days at 4 'C. A similar slowing

in the development of larval English

sole at low temperatures is central to

the explanation given by Ketchen

(1956) for an observed inverse relationship between sea surface temperature and year-class strength. It has

also been suggested that oceanic

temperature during the pre-spawning

period influences year-class strength

(Hayman and Tyler 1980; Kruse 1984).

Salinity

I found no experimental information on the salinity tolerance of

juvenile or adult English sole.

However, Alderdice and Forrester

(1968), who investigated the effects

of salinity on hatching success,

reported that a 90% total hatch was

estimated to occur within a salinity

range of 17-34 ppt. The breadth of

this range led them to conclude that

"over the geographic range of the

species, salinity would appear to have

little influence on egg viability."

Temperature/Salinity Interaction

Alderdice and Forrester (1968)

found that the "interaction effect of

temperature and salinity on total

hatch is such that, with increases

(or decreases) in salinity, maximum

survival is maintained only with

coupled increases (or decreases) in

temperature." In their experiments, a

temperature change of 1 'C was roughly

equivalent (in effect on total hatch)

to a salinity change of 4 ppt. They

further concluded that optimum

conditions for survival "appeared to

be associated with salinities and

temperatures of 25-28 ppt and 8-9 'C."

Other Environmental Factors

All demersal life stages are

apparently associated with unconsolidated sediment substrates. Barss

(1976) observed that laboratory-held

juveniles bury themselves and concluded that they are thus limited to a

sand bottom. Adults have been collected almost entirely from sand or

sand-mud substrates (Barss 1976; Day

and Pearcy 1978), though Ketchen

(1956) reported that all English sole

spawning grounds in his study were

over "soft mud" bottoms.

I found no information on

experimentally determined dissolved

oxygen minima for juvenile or adult

English sole. However, Levings (1980)

caught decreasing numbers of English

sole from a British Columbia fjord

during a period in which dissolved

oxygen levels dropped to 1.0 mg/l.

After this point, P. vetulus was no

longer caught. fi was not known

whether this was due to emigration or

to mortality. Alderdice and Forrester

(1968) concluded that "oxygen is not

likely to be a critical factor" in the

survival of pelagic eggs and larvae.

Fairly extensive information about

the effects of contaminants on English

sole is available (Krahn et al. 1984;

Malins et al. 1984). Johnson et al.

(1988) report that exDosure to aromatic

1 1
hydrocarbons may interfere with ovarian

development.

AREAS OF CONCERN

Perhaps the most critical area of

concern in the biology of the English

sole is in developing an understanding

of recent declines in recruitment.

Such an effort would require the

verification of causal mechanisms

suggested by Ketchen (1956; on interaction of temperature and water

currents during the larval stage), by

Hayman and Tyler (1980; on prespawning temperature conditions), and

by Golden et al. (1986; on overexploitation of parent stock). A

clarification of population dynamics

(particularly mortality) in open

coastline versus estuarine nursery

areas is also needed. Of particular

concern to coastal development is the

possibility, particularly at the

southern margin of English sole

distribution, of thermal pollution

altering the suitability of existing

estuarine nursery areas.

1 2
Alderdice, D.F., and C.R. Forrester.

1968. Some effects of salinity and

temperature on early develooment and

survival of English sole (Pare hr s

vetulus). J. Fish. Res. Board -i&-

2573):495-521.

Ames, W.E., J.R. Hughes, and

G.F. Slusser. 1978. Upper lethal

water temperature levels for English

sole (Parophrys vetulus) and -rock

c

sole (Lepidopsetta bilineata) subjected to gradual thermal increases.

Northwest Sci. 52(3):285-291.

Angell, C. L., B. S. Miller, and

S.R. Wellings. 1975. Epizootiology

of tumors in a population of juvenile English sole

from Puget

J .

Soun~h%$~s

Fish. Res. BoaFd Can. 32(101

1723-1732.

Barss, W.H. 1976.

Oregon Dep.

The English sole.

Fish Wildl. Inf. Rep.

No. 76-l. 7 pp.

Barss, W. H., R. L. Demory, and

N. TenEyck. 1977. Marine resource

surveys on the continental shelf and

upper slope off Washington, 1975-76.

Commercial Fisheries Research and

Development Acts Completion Report.

Oregon Dep. Fish Wildl., Newport.

34 PP.

Becker, D.S., and K.K. Chew. 1987.

Predation on CaDitella spp. by smallmouthed pleuronectids in Puget Sound,

Washington, U.S.A. U.S. Natl. Mar.

Fish. Serv. Fish. Bull. 85:471-480.

LITERATURE CITED

Budd, P.L. 1940. Development of the

eggs and early larvae of six California fishes. Calif. Dep. Fish

Game Fish Bull. 56. 53 pp.

Clemens, W.A., and G.V. Wilby. 1961.

Fishes of the Pacific coast of

Canada. Fish. Res. Board Can. Bull.

No. 68. 368 pp.

Collins, P. 1978. Feeding and food

resources utilization of juvenile

English sole and speckled sanddab in

the central portion of Humboldt Bay,

California. M.S. Thesis. Humboldt

State University, Arcata, California. 151 pp.

Day, D.S. 1976. Homing behavior and

population stratification in central

Puget Sound English sole Paro hr s

vetulus. J. Fish. Res. B&

-282.

Day, D.S., and W.G. Pearcy. 1978.

Species associations of benthic

fishes on the continental shelf and

slope off Oregon. J. Fish. Res.

Board Can. 25:2665-2675.

Demory, R.L. 1971. Depth distribution of some small flatfishes off

the northern Oregon-southern Washington coast. Res. Rep. Fish. Comm.

Oreg. 3:44-48.

Demory, R.L. 1984. Progress report

on the status of the English sole in

the INPFC Columbia-Vancouver areas

in 1984. Commercial Fisheries Research and Development Acts Report.

Oregon Dep. Fish Wildl., Newport.

24 PP*

1 3
Demory, R. L., B . 0. Forsberg,

M.J. Hosie, and W.H. Barss. 1973.

Report of estuary surveys, JulyAugust 1972. Oregon Dep. Fish

Wildl. Internal Rep. GS-73-1. 15 pp.

Demory, R.L., M.J. Hosie, N. TenEyck,

and B.O. Forsberg. 1976. Resource

survey on the Oregon coast. Commercial Fisheries Research and Development Acts Completion Report. Oregon

Dep. Fish Wildl., Newport. 49 pp.

Forrester, C.R. 1969a. Life history

information some groundfish

species. Fis? Res. Board Can.

Tech. Rep. No. 105. 17 pp.

Forrester,

English

tagging

Pac. Mar

C.R. 1969b. Results of

ij;j&ishpq!g&,V;;;;U,;:

. Fish. Comm. Bull. 7:1-10.

Gadomski, D.M., and G.W. Boehlert.

1984. Feeding ecology of the pelagic larvae of English sole

vetulus and butter sole

isole is off the Oregon coast. Mar.

Ezil%og. Ser. 20:1-12.

Golden, J. T., R. L. Demory,

E.K. Pikitch, and W.H. Barss. 1986.

Results of virtual population

analysis of English sole in the

INPFC Columbia - Vancouver areas

(draft final report). U.S. Natl.

Mar. Fish. Serv. Project No.

l-180-R2.

Gunderson, D.R., and P.H. Dygert.

1988. Reproductive effort as a

predictor of natural mortality rate.

J. Cons. Cons. Int. Explor. Mer

44:200-209.

Harry, G.Y. 1959. Time of spawning,

length at maturity and fecundity of

the Enqlish, petrale, and Dover

soles (Parophrys- vetulus, Eopsetta

jordani, and Microstomus

respectively). l-h C

Res. Briefs 7(1):5!13:

Hart, J.L. 1973. Pacific fishes of

Canada. Fish. Res. Board Can. Bull.

180. 740 pp.

Hayman, R.A., and A.V. Tyler. 1980.

Environment and cohort strength of

Dover sole and English sole. Trans.

Am. Fish. Sot. 109(1):54-70.

Hewitt, G.R. 1980. Seasonal changes

in English sole distribution: an

analysis of the inshore trawl

fishery off Oregon. M.S. Thesis.

Oregon State University, Corvallis.

59 PP.

Hogue, E.W., and A.G. Carey, Jr.

1982. Feeding ecology of O-age

flatfishes at a nursery ground on

the Oregon coast. U.S. Natl. Mar.

Fish. Serv. Bull. 80:555-565.

Holland, G.A. 1969. Age, growth, and

mortality of races of Enqlish sole

(Parophrys vetulus) in Puget Sound,

Washington. Pac. Mar. Comm. Bull.

(7):35-50.

Hulberg, L.W., and J.S. Oliver. 1979.

Prey availability and the diets of

;._ czz-oy;uri;g Jflatfish. Pages

C.S. Simesad,' eis.

Lipovsky and

Gutshop '78,

fish food habits studies: proceedings of the Second Pacific Northwest

Technical Workshop. Washington Sea

Grant Pub. WSG-WO-79-1.

Johnson, L.L., E. Casillas, T.K.

Collier, B.B. McCain, and V.

Varanasi. 1988. Contaminant effects

on ovarian development in English

sole, Parophrvs vetulus, from Puget

Sound, Washington, U.S.A. Can. J.

Fish. Aquat. Sci. 45:2133-2146.

Jow, T. 1969. Results of English

sole tagging off California. Bull.

Pac. Mar. Fish. Comm. 7:15-33.

Ketchen, K.S. 1947. The age, growth,

and mortality of the lemon sole

vi’ ’

14 e
M.A. Thesis. University of British

Columbia, Vancouver. 63 pp.

Ketchen, K.S. 1956. Factors influencing the survival of the lemon

sole (Paro hr s vetulus) in Hecate

Strait,&i&CiZ%iEZZ. J. Fish.

Res.BoardCan. 13:647-694.

Krahn, M.M., M.S. Myers, D.G. Burrows,

and D.C. Malins. 1984. Determination of metabolites of xenobiotics

in the bile of fish from polluted

waterways. Xenobiotica 14(8):

633-646.

Kravitz, M. J., W .G. Pearcy, and

M.P. Guin. 1976. Food of five

species of co-occurring flatfishes

on Oregon's continental shelf.

U.S. Natl. Mar. Fish. Serv. Fish.

Bull. 74:984-990.

Kreuz, K.F., A.V. Tyler, G.H. Kruse,

and R.L. Demory. 1982. Variation

in growth of Dover soles and English

soles

Iit.

related to upwelling.

Trans. Fish. sot. 111(Z):

180-l 92.

Kruse, G. H. 1981. Relationship

between shelf temperature, coastal

sea level, the coastal upwelling

index, and English sole (Parophrys

vetulus) spawning activity off

Dregon. M.S. Thesis. Oregon State

University, Corvallis. 68 pp.

Kruse, G.H. 1984. A simulation model

of English sole (Paro hr s vetulus)

recruitment mechanisms. --Vii.--

sertation. Oregon State University,

Corvallis. 103 pp.

Kruse G.H., and A.V. Tyler.

Simuiation of

1983.

temperature and

upwelling effects on English sole

(Parophrys vetulus) spawning

season. Can. J. kish. Aquat. Sci.

40(2):230-237.

Krygier, E.E., and W.G. Pearcy. 1986.

The role of estuarine and offshore

nursery areas for young English sole

Fish. Bull. 84:119-132.

Laroche, J.L., and S.L. Richardson.

1979. Winter - spring abundance of

larval English

vetulus,

sole, [arophrys

between the Colum ia River

andpe Blanco, Oregon, during

1972-75 with notes on occurrences of

3 other pleuronectids. Estuarine

Coastal Mar. Sci. 8(5):455-476.

Laroche, J.L., S.L. Richardson, and

A. A. Rosenberq. 1982. Aqe and

growth of a pleironectid

vetulus, during the

period in Oregon coastal waters.

U.S. Natl. Mar; Fish. Serv. Fish.

Bull. 80:93-104.

Laroche, W.A., and R.L. Holton., 1979.

Occurrence of O-age English sole,

Parophrys vetulus, along the Oregon

coast: an open coast nursery area?

Northwest Sci. 53(2):94-96.

Levings, C. 0. 1980. Demersal and

benthic communities in Howe Sound

Basin and their responses

dissolved oxygen deficiency. CaiY

Tech. Rep. Fish. Aquat. Sci.

951:1-27.

Lynde, M. 1986. The historical

annotated landings (HAL) database:

documentation of annual harvest of

groundfish from the Northeast

Pacific and. eastern Bering Sea from

1956 to 1980. NOAA Tech. Memo.

FMFS F/NWC-103. 196 pp.

Malins, D.C., M.S. Myers, W. McLeod,

and W.T. Roubal. 1984. Organic

free radicals in liver microsomes in

English sole, Parophrys vetulus,

containinq liver lesions. Second

International Symposium on Responses

of Marine Organisms to Pollutants,

Woods Hole, MA, 27 April 1983.

Mar. Environ. Res. 14(1-4):537.

Menasveta, 0. 1958. Migration and

fishing mortality of English sole

15
(Parophrys vetulus) in Saratoga

Passage and adjacent waters.

M. S. Thesis. University of

Washington, Seattle. 84 pp.

Misitano, D. 1976. Size and stage of

development of larval English sole,

Parophrys vetulus, at time of entry

into Humboldt Bay. Calif. Fish Game

62(1):93-98. -

Olson, R.E. 1978.

the English sole,

in Oregon, USA.

13:237-248.

Parasitology of

Parophrys vetulus,

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Olson, R.E., and

Parasites as ind ~-

I . Pratt. 1973.

icators of English

102:405-411.

Orsi, J. 1968. The embryology of the

English sole,

Calif. Fish Game

Pacific Fishery Management Council.

1982. Final fishery management plan

and supplemental environmental

impact statement for the Washington,

Oregon, and California groundfish

fishery. Portland, Oregon. 330 pp.

Pattie, B.H. 1969. Dispersal of Enslish-sole, Parophrys vetulus, tagged

off the Washington coast in 1956.

Pac. Mar. Fish. Comm. Bull. 7:11-14.

Pearcy, W.G., and S.S. Myers. 1973.

Larval fishes of Yaquina Bay,

Oregon: a nursery ground for marine

fishes? U.S. Natl. Mar. Fish. Serv.

Fish. Bull. 72(1):201-213.

Peterman, R.M., and M.J. Bradford.

1987. Density-dependent growth of

age I English sole, Parophrvs

vetulus, in Oregon and Washington

coastal waters, U.S.A. Can. J. Fish.

Aquat. Sci. 44:48-53.

Peterman, R.M., M.J. Bradford, and G.H.

Kruse. 1987. Simulation model of

English sole, &roDhrvS yetulur,

population dynamics in Washington and

Oregon, U.S.A., coastal waters. Can.

J. Fish. Aquat. Sci. 44:1870-1878.

Roffe, T.J., and B.R. Mate. 1984.

Abundance and feeding habits Of

pinnipeds in the Rogue River,

Oregon. J. Wildl. Manage. 48(4):

1262-1274.

Rosenberg, A. A. 1982. Growth of

juvenile English sole, Parophrys

vetulus, in estuarine and open

coastal nursery grounds. U.S. Natl.

Mar. Fish. Serv. Fish. Bull.

80:245-252.

Rosenberg, A.A., and J.L. Laroche.

1982. Growth during metamorphosis

of English sole, vetulus.

U.S.

Parophrys

Natl. Mar. Fish. Serv. Fish.

Bull. 80:150-153.

Smith, J.G., and R.J. Nitsos. 1969.

Age and growth studies of English

sole, Paro hr s vetulus, in Monterey

Bay, &a. Pac. Mar. Fish.

Comm. Bull. 7:73-79.

Sopher, T.L. 1974. A trawl survey of

the fishes of Arcata Bay, California.

M.S. Thesis. Humboldt State University, Arcata, California. 103 pp.

Tooler C. L. 1980. Intertidal

recruitment and feeding in relation

to optimal utilization of nursery

areas bv iuvenile Enqlish sole

Van Cleve, R., and S.Z. El-Sayed.

1969. Age, growth, and productivity

of an English sole (Parophrys

vetulus) population in Puget Sound,

Washington. Pac. Mar. Fish. Comm.

Bull. 7:51-71.

Westrheim, S.J. 1955. Size composition, qrowth, and seasonal abundance

of juvenile English sole (Paro hr s

vetulus) in Yaquina Bay.---kk

i%iiK%egon Res. Briefs 6:4-9.

.

1 6
Yoklavich, Il. 1982. Growth, food

consumption, and conversion effiin G.M. Caillet and C.A. Simenstad,

3s. Gutshop '81: fish food habit

ciency of juvenile Engltsh sole,

(Parophrys vetulus). Pages 97-105

studies. Washington Sea Grant Publ.

WSG-WO-82-2.

1 7
;

1272 -101

?EPORT DOCUMENTATION 1. ‘-‘R: No. 2. 3. Recipient’s Accession No.

PAGE Biological Report 82(11.101)*

. Title and Subtitle S. Rwo~ Date

species Profiles: Life Histories and Environmental Requirements of July 1989

Coastal Fishes and Invertebrates (Pacific Northwest)-- English Sole c

Authoris)

Dennis R. Lassuy

0. P*r(OtTdng OrSanization Rapt. N(

. PwforminS Orwnizatlon Name and Address 10. Pmiact/Task/Worh Unit No.

Oregon Cooperative Fishery Research Unit

Oregon State University, 104 Nash Hall II. Contract(C) or Grant(G) No.

Corvallis, OR 97331-3803 (0

- - -~- (G)

2. Spwroring Or#anizatlon Name and Address

U.S. Department of the Interior U.S. Army Corps of Engineers ’

Fish and Wildlife Service Waterways Experiment Station

National Wetlands Research Center P.O. Box 631

Washington, DC 20240 Vicksburg, MS 39180

::

I

IS. Supplementary Notes

* U.S. Army Corps of Engineers TR EL-82-4

.& Abrtnct (Limit: 200 words)

Species profiles are literature summaries of the taxonomy, morphology, distribution, life

history, ecological role, and environmental requirements of coastal aquatic species. The:

are prepared to assist coastal managers, engineers, and biologists in the gathering of

information pertinent to coastal development activities. The English sole is a major

contributor to Pacific Northwest trawl fisheries and is used extensively in the filet-ofsole trade. Spawning is usually most intense during winter, but occurs in all seas&is.

Temperature conditions before spawning and during the egg and larval stages are critical

to subsequent year-class strength. Hatching success is apparently greatest at salinitie!

and temperatures of 25-28 ppt and 8-9 "C. Postlarvae settle in open-coast and estuarine

areas. Densities of rearing juveniles are highest in lower estuaries. Growth may be

inhibited at temperatures above 17.5 "C. Emigration from nursery areas to deeper, sandbottomed offshore areas occurs during late summer and fall. Juveniles and adults feed on

a wide variety of benthic invertebrates. Female English sole grow faster and mature late]

(3-4 years) than males (2-3 years). Females are more susceptible to capture in the multi,

species trawl fisheries that typify Pacific Northwest ground fishing. A better understanding of the relation between oceanic conditions and early life-history stages, the

avoidance of estuarine thermal pollution, and the protection of remaining coastal nursery

areas are important to the maintenance of English sole abundance.

17. Document Analysis a. Dacripton

Estuaries Temperature

Flatfishes Depth

Fisheries Sediments

Salinity Feeding habits

b. Id.rRlfl~n/Op.n-Ended Twmr

Life cycles

Growth

Oxygen

Animal migrations

English Sole

Parophrys vetulus

Environmental requirements

;

c. COSATI Field/Group

S. Availability Stat0ma-d

Unlimited release

19. Security Class (This Report)

Unclassified

20. Security Class (This Pace)

Unclassified

21. No. of Paa*%

17

tz. pric*

;.. ANSI-239.18) “r,l”nrU l”“l Lr- I-’

(F.xm.rly NTIS-W

oepartment of Comm*rc*
As the Nation’s principal conservation agency, the Department of

the Interior has responsibility for most of our nationally owned

public lands and natural resources. This includes fostering the

wisest use of our land and water resources, protecting our fish

and wildlife, preserving the environmental and cultural values of our

national parks and historical places, and providing for the enjoyment of life through outdoor recreation. The Department assesses

our energy and mineral resources and works to assure that their

development is in the best interests of all our people. The Department also has a major responsibility for American Indian reservation

communities and for people who live in island territories under U.S.

administration.

DEPARTMENT OF THE INTERIOR

FISH AND WILDLIFE SERVICE

US. .

TAKE PRIDE w

-.

w

in America

UNITED STATES

DEPARTMENT OF THE INTERIOR

FISH AND WILDLIFE SERVICE

National Wetlands Research Center

NASA-Slide11 Computer Complex

1010 Gause Boulevard

Slidell. LA 70458