Synopsis of Biological Data on Pacific Ocean Perch, Sebastodes Alutus

Home , Menhaden, Pacific ocean perch, Sablefish, Sebastes

A UNITEU STATES OEPARTMENT OF COMMERCE P iB U C F\TION f VES. DEPARÏ1ENT OF COMMERCE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

NATIONAL MARINE FISHERIES SERVICE

SYNOPSIS OF BIOLOGICAL DATA ON ACIFIC OCEAN PERCH Sebastodes alulus

FAO Fisheriès Synopsis No. 79 NMFS/S 79 SAST - Pacific ocean perch - L78 (01) ,007,09

Circular 347 NÒTE Until October 2, 1970, the Nationa' Maiirie Fisheries Service, Department of Commerce, was the Bureau ofComrnerèial Fisheries, De- partmeñt of the Interior.Throughout the body of this report, which was prepared for printing before October 2, the older term is used. UNITED STATES DLI LiWNT OG COkfïICE Maurice H. Stans, Secretary NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

NATIONAL MARINE FISHERIES SERVICE Philip M. Roedel, Director

Synopsis of BioogicaIDataon Ocean Perch, Sebastodes alu fus

By RICHARD L. MAJOR and HERBERT H. SHIPPEN

FAO Species Synopsis No. 79

Circular 347

Washington, D.C. December 1970 CONTENTS Page Introduction 1 iIdentity 1 1.1Nomenclature 1 1.2Taxonomy 1 1.3Morphology 4 2Distribution 4 2.1Tota' area 4 2.2Differential distribution 5 2.3Determinants of distribution 7 2.4Hybridization 7 3Bionomics and life history 7 3.1Reproductíon 7 3.2Preadult phase 10 3.3Adult phase li 3.4Nutrition and growth 12 3.5Behavior 14 4 Population 18 4.1Strutture 18 4.2Abundance and density 21 4.3Natality and recruitment 21 4.4Mortality and morbidity 22 4.5Dynamics of the population as a whole 22 4,6The population in the community and the ecosystem 22 5 Fishing 24 5.1Fishing equipment 24 5.2Fishing areas 27 5.3Fishing seasons 29 5.4Fishing operations and results 31 6 Protection and management 32 6.1Regulatory (legislative) measures 32 Acknowledgment 33 Literature cited 33

111 Synopsis of Biological Data on Pacific Ocean Perch, Sebastodes alutus

By RICHARD L. MAJOR and HERBERT H. SHIPPEN, Fishery Biologists National Marine Fisheries Service Biological Laboratory Seattle, Washington 98102

ABSTRACT This synopsis has information on the taxonomy, life history, population structure, and harvesting of a species that is being intensively fished and studied by the United States, Canada, the U.S.S.R., and Japan.This synopsis includes data from scientific papers either printed in English or translated from Japanese and Russian into English.

INTRODUCTION 1.12Synonymy The Fisheries Biology Branch of FAO has Sebastichthys alutus Gilbert (1890) formed a "Synopsis Association," composed of fishery agencies willing to contribute to the Acutomentum alutus Eigenmann and Beeson preparation of synopses on fishes and other (1893) aquatic organisms of commercial value. Sev- eral organizations, including the BCF (Bureau Acutomentum alutum Eigenmann and Beeson of Commercial Fisheries), have agreed to col- (1895) laborate with FAO in this undertaking. Under Sebastes alutus Matsubara (1943) this agreement, BCF has assigned the preparation of synopses on various economically 1.2Taxonomy important species to a number of its labora- tories.These synopses will be published in 1.21Affinities the BCF Circular series and will follow the Suprageneric format prescribed by H. Rosa, Jr. (1965). Phylum Chordata The primary purpose of the synopses is Class Teleostomi to make existing information readily available Order Percif ormes to fishery scientists according to a standard Family Scorpaenidae pattern, which will draw attention to gaps in Generic knowledge. The synopses will guide scientists Sebastodes Gill (1861) who investigate these or other species and provide a basis for the comparative study of Genotype: fishery resources. Sebastes paucispinis Ayres (1854a)

1 IDENTITY The generic concept used here is that of Cramer (1895:589-590): 1.1Nomenclature "Body and head somewhat compressed; 1.11Valid name head large, 22/5to 32/3 in length of Sebastodes alutus (Gilbert), Cramer (1895). body; depth 21/4 to 33/4 in length of

i body; mouth moderate or large, with apparently been synonymized with another the jaws equal or the lower more or less species and is not Sebastodes rosaceus [Jordan projecting; the maxillary reaching mid- and Gilbert, 1882].)Ayres retained the re- dle of eye or beyond, sometimes beyond maining species in the genus Sebastes.Gill posterior edge of orbit, its length from (1864) divided the rockfish species into four 13/4 to 3 in length of head;teeth in genera:Sebastodes, Sebastichthys, Se basto- villiform bands on jaws, vomer, and mus, and Sebastosomus.Jordan and Gilbert palatines.Head more or less evenly (1880) retained Sebastodes as a separate genus scaled, without dermal flaps;interor- but placed the remaining species in the genus bital space convex or concave, widening Sebastichthys. Jordan and Gilbert (1882) pro- markedly with age; cranial ridges more posed that all species belonged in the single or less developed, one or more of the genus Sebastodes.Jordan (1887) again re- following pairs always present, usually verted to two generaSebastodes and Sebast- ending in spines:preocular, supraoc- ichthys. Eigenmann and Beeson(1893) ular, postocular, tympanic, coronal, par- revised the rockfishes into eight genera:Se- ietal and nuchal. Five preopercular and bastodes, Sebastichthys, Sebastomus, Se basto- two opercularspines;one to three somus, Acutomentum, Acutospina, Primospina, spines on the suprascapula.Suborbital and Pteropodus. Cramer (1895) consolidated stay moderate, usually not reaching pre- all species into the single genus Sebastodes Gill, opercle.Gill-rakers various, very long 1861.Jordan, Evermann, and Clark (1930) and slender to very short.Scales mod- listed 14 genera:Sebastodes, Sebastichthys, erate or small, mostly ctenoid, 35 to 100 Sebastomus, Sebastosomus, A cutomentum, Acu- transverse series.Dorsal fin continu- tospina,Pteropodus,Rosicola,Eose bastes, ous, emarginate, its formula XIII-12 to Hispaniscus, Zalopyr, Emmelas, Sebastopyr, 16. Anal fin III, 5 to 9.Pectorals well and Sebastocarus. Matsubara (1943) claimed developed, the base broad or narrow, that the reasons for separating the genera the lower rays undivided. Caudal slight- Sebastodes and Sebastes are insufficient and ly rounded, truncate or slightly forked; that all species assigned to Sebastodes belong soft parts of vertical fins more or less in the genus Se bastes.In the present synopsis scaly.Pyloric coeca 6 to 11. Vertebrae Sebastodes is treated as a separate genus con- 12 + 15.Species of varied, often bril- taining the 54 species listed in table 1. liant colors, mostly red.Sexes colored alike." Specific Hitz (1965) extended the dorsal fin formula The type specimen is Sebastichthys alutus to XIII, rarely XI, XII, or XIV-11 to 18. Gilbert(1890)from south of Santa Cruz The species in the genus Sebastodes have Island, Calif. The following species diagnosis previously been assigned to as many as 14 for adult specimens is quoted from Phillips genera.Richardson(1844), Ayres (1854b, (1957: 78). 1859), and Girard (1854a, 1854b, 1856) de- "Body colorLight red including fins; scribed several species of rockflshes from the a dark oliveaceous area on back under Pacific Coast of North America and placed soft dorsal, and a smaller dark area on them all in the genus Sebastes (rockfish is the caudal peduncle; some light olive stip- common name for fish in the genus Sebastodes). pling on sides.Mouth and gill cavities Gill (1861) proposed the genus Sebastodes for Mouth mainly pink, but with some Sebastes paucispinis of Ayres, and Gill (1862) duskiness; gill cavity pink, with consi- placed all other Pacific Coast rockfishes in a derable black blotching in adults.Per- new genus Sebastichthys.Ayres (1862) ac- itoneumGray with black dots or black. cepted the genus Sebastodes but redefined it Top of head, at mid-orbitsSlightly con- to include ovalis, flavidus, melanops, and ro- vex to flat.Spines on top of headNas- saceus.(Note:This early-day rosaceus has al,preocular, supraocular, postocular,

2 Table 1.-Species in the genus Sebastodes weak. Lower marginof suborbital I.Sebastodes aleutianus 28.S. maliger bone-Two small, sharply triangular 2.S. alutus 29.S. melanops spines, or rounded lobes present.Low- 3.S. atrovirens 30.5. melanostomus er posterior edge of gill cover-Spines 4.5. auriculatus 31.S. miniatus 5. 5. aurora 32.5. mystinus present.Symphyseal knob-A prom- 6.S. brevispisiis 33.5. nebulosus inent, pointed, forward-projecting knob 7.S. carnatus 34.5. nigrocinctus is present. 8.5. caurinus 35.S. ovalis Raised patch of teeth on 9.S. chiorostictus 36.5. paucispinis tip of lower jaw-A strongly raised IO. S. chrysomelas 37.5. phillipsi patch of teeth present; not completely Il.S. ciliatus 38.5. pinsliger included by snout when jaws are closed. 12. 5. cossstellatus 39.S. polyspinis 13.S. cranieri 40.S. proriger End of maxillary-Under mid-orbit or 14.5. dalli 41.5. rastrelliger rear of pupil.Maxillaries-Covered 15.5. diploproa 42.S. reedi with scales.Mandibles-Covered with 16.5. elongatus 43.5. rhodochioris 17.5. emphaeus 44.S. rosaceus scales.Branchiostegals-With scales. 18.S. entomelas 45.S. ruberrimus Ends of pectoral and ventral fins-Tips 19.5. eos 46.5. rubrivinctus of pectorals extend to tips of ventrals, 20.S, flavidus 47.5. saxicola 21.5. gilli 48.5. semicinctus or slightly beyond, sometimes reaching 22.S. goodei 49.5. serranoides anus.Second anal fin spine-Usually 23.S. helvomocufatus SO. 5. serriceps twice as thick as third, occasionally only 24.5. hophinsi 51.5. uonbrosus 25.5. jordani 52.5. vexillaris slightly thicker.Tip of second fails to 26.S. levis 53.5. wulsoni reach tip of third by about one-sixth 27.S. ,nacdonaldi 54.5. zacentrus oforbit width(spinesdepressed). tympanic and parietals usually present, Spinous dorsal fin membrane-Moder- but small and weak (a tympanic or su- ately incised.Posterior profile of caudal praocular spine may be absent occasion- fin-Strongly indented.Terminal profile of anal fin-Nearly vertical, or with ally). Coronal and nuchal spines absent. slight posterior slant." Parietal ridges-Low and thin.The fivepreopercular spines-Moderately Sebastodes alutus(fig. 1) can be differ- strong, sharp, usually radially-directed entiated from the closely related species Se- but sometimes with upper two directed bastodes crameri and Sebastodes reedi by the backward. The two opercular spines- color of the mouth, which is red in alutus and Moderately strong, thin and sharp, the has blotches of black and pink in crameri, and upper-most usually longer.Supraclei- blotches of black and yellow in 'reedi (Westr- thral and cleithral spines-Strong to heim and Tsuyuki, 1967). Phillips (1957) and

Figure 1.-Sebastodes alut'u.s (Gilbert).Photograph furnished by Washington State Department of Fisheries.

3 Hitz (1965) published keys for the identifica- 1.33Protein specificity tion of species in the genus Sebastodes, Electrophoretic separation of hemoglobins 1.22Taxonomie status in starch gel media shows distinct differences This is a morpho-species, and it is polytypic, between the Sebastodes species alutus, crameri, reedi, and zacentrus.Hemoglobin patterns 1.23Subspecies remain consistent intraspecifically;variant forms appear in crameri and reecli (Westrheim Barsukov (1964) suggested that Sebastodes and Tsuyuki, 1967). alutits be divided into two subspecies: (1) the American S. a. alutus (Gilbert) distributed from California northward through the Gulf 2 DISTRIBUTION of Alaska to the Komandorskiy Islands and (2) the Asian S. a. paueispinosus (Matsubara) 2.1Total area distributed from Honshu Island into the Bering Pacific ocean perch live along the eastern Sea and eastward perhaps as far as Bristol and northern rim of the Pacific Ocean from Bay. The ranges of these two subspecies over- La Jolla, Calif. (FAO marine area INE), to lap in the region of the Aleutian and Koman- the Komandorskiy and Kurile Islands and in dorskiy Islands.Barsukov recognized, how- the Bering Sea (FAO marine area INW-see ever, that this division was provisional and that the problem needed further study. Table 2.-Proportional measurements (11 specimens) 1.24Standard common names, ver- and meristic counts (15 specimens) from Pacific nacular names. ocean perch, 33 to 45 cm. long, taken off California (Phillips, 1957;data in brackets from Barsukov, United States and Canada-Pacific ocean 1964) perch Frequency of Frequency U.S.S.R.-Tikhookeanskii morskoi okun measurement into of orbit Measurement width into Japan-Arasuka menuke Standard Head measure- length length ment 1.3Morphology Length of head 2.6. 2.8 Depth of body at origin of ventral fin 2.8- 3.4 l.l_l.2 2.8-3.5 1.31External morphology Depth of body at origin of anal fin.. 3.7- 4.6 1.4-1.6 2.1-2.7 Length of base of anal fin 6.1- 7.1 2.4-2.6 1.4-1.6 Length of snout 10.0-11.3 3.8-4.2 OLI .0 Phillips (1957) derived a series of propor- Width of orbit 9.3-10.1 3.4-3.8 tional body measurements from 11 adult speci- Width of interorbital space --4.6-4.9 0.7-0.8 Width of suborbital bone --0.1-0.2 mens and meristic counts from 15 specimens Length of upper jaw 5.6- 6.2 2.1-2.3 1.6-1.8 all taken off California (table 2).Barsukov Amount that lower jaw projects .. --0.2-0.4 (1964) extended some of the meristic counts Thickness of body 1.4-1.7 Width of base of pectoral fin --0.8-0.9 presented by Phillips; his findings are shown Longest pectoral fin ray 3.6- 4.1 1.3-1.5 2.4-2.8 Longest ventral fin ray --1.8-2.0 1.8-2.1 in brackets in table 2.Barsukov did not, how- Length of ventral fin spine --2.9-3.4 1.0-1.2 ever, present proportional measurements for Length offirst anal fin spine 0.4-0.6 Length of second anal fin spine 8.3-10.8 3.5-4.2 0.9-1 .0 comparison with those by Phillips.He ex- Length of third anal fin spine 0.9-1.1 plained that his specimens, most of which were Longest anal fin ray 5.9- 6.6 2.3-2.4 1.5-1.6 Longest dorsal fin spine 7.9- 8.9 2.9-3.4 1.1-1.2 smaller than the California specimens used by Longest dorsal fin ray 6.7- 7.8 2.5-2.9 1.2-1.5 Phillips, exhibited erratic size-related varia- Least depth of caudal peduncle .. . 10.6-12.3 4.1-4.5 0.8-1.1 Ventral length of caudal pcduncle . --1.8-2.0 1.8-1.9 bility, which made it impossible to predict the Dorsal length of caudal peduncle 2.5-2.8 1.3-1.5 proportional measurements for specimens lar- Posterior of anus to origin of anal fin 0.3-0.6 ger than the ones available to him-and made Longest raker on firstgill arch. 0.40.6 it impossible, therefore, to compare the pro- Number of rays in dorsal fin 14 or IS (rarely 16 or 17) Number of rays in anal fin 8 or 9 [6-9] portional measurements of fish from the var- Number of rays in each pectoral fin 18 (otcasionally 17) (15-19] ious areas. Unbranchcd rays in each pectoral fin 8 (occasionally 6, 7, or 9) [5-10] Number of rakers on first gill arch 33-38 [3340] 1.32Cytomorphology Number of pores in lateral line 44-sl [44-53] Diagonal rows of ocales below No information lateral line 49-55

4 50° 165°E. 800 165° 50° 135° 20°

ALAS 1< A

sp. 600 N :k ulf T"60° Bristol flock Pribilof SpeiiòeriJ\ Bering Seo:r, Is. Boy 'iok BRITISH Seo 'iïrikof I. omondorskiy Is. COLUMBIA: of 'Shumogin I. Dixon n!t mok I. 0k hots Hecote St: Queen Charlotta 5d Copo Co ; Voncouve ASH. 4504 45° Cope BIancó

La Jo ç 300 30° Figure 2.Distribution of Pacific ocean perch.

fig. 2).According to Alverson, Pruter, and Pacific ocean perch are Alaska coral; varieties Ronholt(1964),no fish of the genusSebastodes of deepwater starfish; and sea urchins (Al- appears to have penetrated the Bering Strait. verson and Westrheim,1961). If the Asiatic rockfishhypothesized by Barsu- kov (1964)to beSebastodes alutus paucis pin- 2.2Differential distribution osusare eventually shown to beSebastodes 2.21Larvae and juveniles alutusor a genuine subspecies, the range will extend southward to the Pacific Coast of Hon- Studies of the larvae of S.alutusand other shu Island, Japan.This synopsis is derived rockfishes are hampered by the inability of from scientific papers dealing with S.alutus investigators to identify larvaeto species. that inhabit the area from La Jolla,Calif., Aron (1958), for example, was unable to ident- to the Komandorskiy Islands and the central ify to species youngSebastodestaken up to Bering Sea.Information is lacking about the 480km. from shore in the Gulf of Alaska. Some stocks in the waters adjacent to the Kamchatka of these were larvae as small as 6 mm. Ahl- Peninsula and the Kurile Islands. strom (1965) reportedSebastodeslarvae to be abundant off California but was able to Pacific ocean perch are commonly found identify only S.paucispinis, iof at least 50 along the outer continental shelf and on the species that inhabit this region.Some ques- upper continental slope at depths of 150 to tion exists concerning the species identification 460m. They are usually near the 180-m. con- in the following reports that deal with the tour.The species is common in and along distribution of larval S.alutus: gullies, canyons, and submarine depressions of the upper continental slope.These areas Since the Pacific ocean perch is by far the characteristically have a gravel or rocky bot- dominant rockfish species caught in the Bering tom and frequently contain large boulders de- Sea and the Gulf of Alaska, Soviet scientists posited during glacial periods.Typical inver- have generally assumed that rockfish larvae tebrate animals taken in the trawl fishery for and juveniles taken there are S.alutus. Par-

5 aketsov (1963) found that ocean perch larvae taken during the summer several hundred kil- in the Bering Sea, after their birth in the ometers off the Oregon and Washington coasts. spring, are swept by a circular current from Most were 20 to 30 mm. long andwere pre- their area of birth(south and southeast of sumed to be progeny born during the preceding the Pribilof Islands) toward the shores of winter. Alaska and the Aleutian Islands.Lisovenko (1964) made an ichthyoplankton survey from Alverson and Westrheim (1961), combining Unirnak Island to the Strait of Juan de Fuca the preceding information with the knowledge during April to July 1963.He found free- that young S. alutus have been observed to swimming ocean perch larvae in the Gulf of "ball" at the surface, concluded that theyoung Alaska over the continental shelf and slope fish appear to lead a pelagic existence, dis- as far as 130 to 160 km. from shore.Greatest persed in offshore waters at considerable dis- concentrations were near the outer continental tances from the fishing banks. They further slope over depths of 180 to 700 rn.Lisovenko interpreted the regurgitation of livingyoung estimated the absolute abundance of ocean by albacore to mean that Pacificocean perch perch larvae in different areas off the coast of inhabit surface waters, at least during daylight. Alaska as follows: During the first year after birth young Area Total number of larvae ocean perch are plantonic, and their distribution is determined by the movement of the water Yakutat Peninsula 3,475 X 108 into which they were born.During their sec- Kodiak Island 1,933 x 108 ond year, however, young S. alutus takeup Shumagin Islands 761 X 108 life near the ocean bottom (Paraketsov, 1963). Unimak Island 233 X 108 Here they remain in waters from 125 to 150 m. The full significance of the estimates is difficult deep until they reach the age of sexual ma- to interpret because Lisovenko did not report turity.Schools of juvenile perch are usually the dimensions of the four areas.The esti- found over more shallow bottoms than are the mates appear to be dependent on density of adults, and consequently, the occurrence of larvae rather than on differences in the di- immature perch in the commercial catch is mensions of the areasmaximum larvae per small.Occasionally, however, the catch is com- rn.2 were 100 to 120 in the Yakutat area, 40 posed entirely of small fish (Moiseev and Par- to 50 in the Kodiak area, 20 to 30 in the Shurn- aketsov, 1961; Paraketsov, 1963). agin area, and 10 to 15 in the Unirnak area. Westrheim (1965', 1966a', 196Gb') rarely Ocean perch larvae appear in late April and found juvenile fish at depths greater than 250 May over the entire Gulf of Alaska in waters m. off Washington, Oregon, and British Colum- over bottom depths of 200 to 250 rn.Lisovenko bia.Juveniles were often mixed with adults, found them until early June in the western area however, indicating that the segregation of of his survey and as late as mid-July in the eastern part of the region. Westrheim, S. J. 1965. Catch rates and size The problem of identification that plagues composition of Pacific ocean perch (Sebastodes alu tus) the study of rockfish larvae also applies to the caught in the eastern North Pacific Ocean by the G. B. Reed, July to September, 1963-64.Fish. Res. Bd. juveniles.No key is available for juvenile Can., Biol.Sta., Nanaimo, B.C., Manuscr. Rep. Ser. rockfish; until the fish are about 20 cm. long, (Bio!.) 812, 23 pp.[Processed.] 21966a. Catch rates,sizecomposition, and sex they cannot be identified with certainty. Here ratio of Pacific ocean perch (Sebastodes alutus) caught again, a question exists about the accuracy of in the eastern North Pacific Ocean (Cape Spencer, Alaska, to Cape Blanco, Oregon) by the G. B. Reed, the species identification in the following re- August-September 1965.Fish. Res. Bd. Can., Biol. ports about juvenile S. alutus: Sta., Nanaimo, B.C., Manuscr. Rep. Series (Bio!.) 867, 28 pp.[Processed.] Powell and Hildebrand (1950) and Powell, 1966b. Catch rates, size composition, and sex ratio of Pacific ocean perch (Sebastodes alutus) caught in Alverson, and Livingstone (1952)reported the eastern North Pacific Ocean by the G. B. Reed, large numbers of S. alutus 20 to 50 mm. long January-March, 1963-65.Fish. Res. Bd. Can., Bio!. Sta., Nanaimo, B.C., Manuscr. Rep. Series (Bio!.) 869, in stomachs of albacore, Thunnus alalunga, 17 pp.[Processed.]

6 mature and immature fish reported by Moiseev 40- FISHING DEPTH and Paraketsov (1961) in the Bering Sea is X u 50- lOOm. f- not a universal characteristic. 30- 00- ISO m. 150-200m. Kibesaki (1965) stated that American and ou- 200-250 m. w 20- Japanese commercial fishermen rarely capture (0 juvenile ocean perch between 15 and 20 cm. z 'o- long, and almost never take fish less than 15 cr cm. long. He attributed this scarcity of small w o fish to either the mesh size of the nets, which 1416IB 2022242628303234363840 42 44 permits small fish to pass through, or to a BODY LENGTH (CM.) difference in habitat. Figure 3.Body lengths of Pacificocean perch taken in Lyubimova (1964) demonstrated a relation the Gulf of Alaska at Various depths (fromLyubimova, between body length and vertical distribution 1964). of fish(fig.3);smaller fish are generally taken in shallower water.Westrheim (see remain above the layer ofoxygen deficiency, footnotes 1, 2, and 3) reported similar findings. and maximum depth of concentrationsvaries 2.22Adults from 350 m. in summer to 420m. in winter. She also reported that 4.0° to 6.5°C. is the Moiseev and Paraketsov (1961) reported temperature range acceptable to adultperch. that from January to May in the Bering Sea, Young perch (14-26 cm.)may be found at low- the densest concentrations of ocean perch are er temperatures (2.5°-3.5° C.). in Bristol Bay and just south of the Pribilof Islands.During the rest of the year the con- 2.4Hybridization centrations extend into the central Bering Sea No information as far north as lat. 590 N. Lyubimova (1963, 1965) reported that the 3 BIONOMICS AND LIFE HISTORY Gulf of Alaska population is concentrated near Unimak Pass from May to September but that 3.1Reproduction the fish are also around Kodiak and Chirikof 3.11Sexuality Islands and in the northern Gulf of Alaska near the region of the Yakutat Peninsula dur- Pacific ocean perch are heterosexual and ing the rest of the year. without apparent sexual dimorphism. 2.3Determinants of distribution o Relative abundance of Pacific ocean perch loO varies widely within the total range of the species.Their preference for gullies and can- 200 yons has already been described (section 2.1). 300 We have also mentioned the relation between 400 size and bathymetric distribution (smaller fish are in shallower water).Other factors that 500 apparently influence distribution are the avail- 600 ability of the preferred food items (section 700 3.42), the state of maturity as it affects migration (3.51), oxygen content of the water, J F M A MJ J A SON D and temperature of the water.Lyubimova MONTH (1965) related the vertical distribution ofcon- Figure 4.The Vertical distribution of Pacific ocean perch centrations of perch in the Gulf of Alaska over in the Gulf of Alaska relative to the layer of oxygen deficiency. Numbers i and 2 indicate the upper and the course of a year to the layer ofoxygen lower limitsof the perch distribution (adapted from deficiency(fig. 4).Rockfish concentrations Lyubimova, 1965).

7 3.12Maturity To understand the development of the opposing Paraketsov (1963) reported that in the points of view, it is necessary to begin with Bering Sea females mature at 6 to 7 years and the work of Sorokii (1961) with Sebastes at a length of 22 to 25 cm. Lyubimova (1965) rnarinusthe closely related redfish in the found that in the Gulf of Alaska 8 percent of Atlantic Ocean.Sorokin, apparently working the male perch matured in their fourth year rith samples from the Barents and Norwegian and all had matured by their eighth year; 19 Seas, claimed that fertilization did not occur percent of the females matured in their fifth until 6 months after the male inseminated the year, and practically all were mature by age 8- female. Westrheim (1958)noted that nearly all Paraketsov (1963) stated that for S. alutus females captured by Oregon trawlers off the in the Bering Sea, mating and fertilization coasts of Washington and Oregon were mature. take place simultaneously and noted that this These fish were 26 to 48 cm. long and from was in contrast with S. marinus. 6 years to more than 21 years old.4 Lyubimova (1963) reported, on the other After comparing length-fecundity curves hand, that for S. alutus in the Gulf of Alaska, from the west coast of North America, the considerable time passes in the maturation of Bering Sea, and Gulf of Alaska, Lisovenko the egg before the moment of fertilization (1965) concluded that Gulf of Alaska fish at- by spermatozoa stored in the ovary. According tain sexual maturity earlier than do those from to Lyubimova (1965), mating is followed by other areas. a period of egg maturation lasting 3 to 4 months after which the eggs are fertilized by sper- 3.13Mating matozoa preserved within the ovary. Mating has not been observed, but the de- Sorokin (1967), who examined the gonads position of spermatozoa by the males into the from 8 male and 12 female ocean perch cap- bodies of the females (section 3.14) strongly tured in the Gulf of Alaska, found that mass suggests that mating (copulation) is by pairs. maturation of the testes and mass mating occur Whether ocean perch are monogamous, poly- in September and October and that most of gamous, or promiscuous is not known. the females have been impregnated by No- vember. He stated conditionally that the fe- Paraketsov (1963) reported January and males matured, ovulated, and were fertilized February as the mating period for ocean perch in October and November.In other words, in the Bering Sea and noted a 1:1 sex ratio there is little or no delay between mating and at time of mating; Lyubimova (1963) found fertilization. that Gulf of Alaska fish mated from September through November. 3.15Gonads 3.14Fertilization Westerheim (1958) determined the length- fecundity relation for 13 female S. alutus taken The Pacific ocean perch is an ovoviviparous off the coasts of Washington and Oregon (fig. species;i.e., eggs are fertilized internally and 5).Observed values ranged from 31,000 eggs are retained within the ovary during incu- for a 324-mm. (8-year-old) fish to 305,000 for bation. a 436-mm. (21-year-old) fish.The fecundity Whether fertilization occurs at mating or relation is expressed by the following formula: at a considerably later time ìs not clearly under- F = (4.8556 x 10-15)L6.33454 stood and has given rise to contradictory views. where F is thousands of yolked eggs and L is Since his 1958 study and his 1961 paper with the fork length in millimeters. Alverson (Alverson and Westrheim, 1961), Westrheim has determined (personal communication, June 1968) According to Paraketsov (1963), the aver- that 1 year should be added to the ages presented in age number of emergent larvae of Pacific ocean those two papers. We have made these corrections in this synopsis. perch in the Bering Sea was 80,000 to 150,000,

8 Table 3.Spawning areas and time of spawning for S. alutus

Area Water Spawning season temperature Reference

Bering Sea (south and soatheast of the Pribilof Islands) March-May 3.8-4.2 Paraketsov (1963) Gulf of Alaska (north) March-April Lyubimova (1963) Gulf of Alaska (south) May-June Lyubimova (1963) Coastal waters off southwest Vancouver Island, British Columbia March Westrheim, Hurling, and Davenport (1968)' Coastal Waters off Washington-Oregon January-March 6.0-8.0 Snytko (1968) Westrheim,S.J., W. R. Hurling, and D. Davenport. 1968.Preliminaryreporton maturity, apawning season, and larval identification ofrock- fishes(Sebastodes)collected off British Columbia in 1967.Fish. Res. Bd.Can.,BiolSta., Nanaimo, B.C., Manuscr. Rep.Ser.(Biol.) 951,22pp. but fecundity varied from 30,000 to 350,000, F = (2.2 x 10-4)L5.3 and F = 2.075P1.56 both quantities depending on the length of the female.The number of larvae releasedis where L is length in centimeters, P is fish usually fewer than the number of eggs. weight in grams, and F is number of eggs. Lisovenko noted that the fecundity of S. alutus Lisovenko (1965) said that the fecundity increases less with length in the Gulf of Alaska of S. alutus in the Gulf of Alaska ranged from population than in other populations that have 2,000 to 69,000 eggs.Fecundity-length and been studied. fecundity-weight relations for the Gulf of Alaska population were described by the follow- 3.16Spawning° ing formulas: Pacific ocean perch spawn once a year; table 3 summarizes areas and time of spawning. On the main Bering Sea spawning grounds 350 (south and southeast of the Pribilof Islands), individual spawning schools consist of females with larvae at equal stages of development 300 (Paraketsov, 1963).Although the spawning season of the species extends from March to May, the spawning of a particular school is completed within 3 to 3½ hours.Paraketsov (I) (D observed that the first spawning is later in the (D w northern spawning grounds than in the south- CD 200 ern regions. o-J >- Area Time of first spawning u- o Lat 54°30'-55°10' March t,CI, Lat. 55°30'-56°30' April Lat. 56°30'-57°00' May North of lat. 58°30' No spawning reported Moiseev and Paraketsov (1961) described spawning; that is, the release of larvae by the female ocean perch in the Bering Sea as it was observed in a series of echograms obtained on April 17, 1960. The activities occurred over bottom depths of 390 to 400 m. What the o authors assumed to be spawning females were 300 400 500 FORK LENGTH (MM.) concentrated in a layer 25 to 30 m. off the bot- Figure 5.Relation of fecundity to length in Pacific ocean perch.Dots indicate observed values, and numerals ° Spawning, as used here, refers to the release of indicate age of each fish (adapted from Westrheim, 1958). larvae.

9 tom.A massive liberation of the larvae began at twilight (1730 hours) and was visible on the echogram as a foglike trace above the concentration of adult females.During the ensuing 1.5 to 2 hours, the number of larvae increased and ascended to 125 to 150 m. off the bottom.By 2010 hours an accumulation of larvae was recorded in a layer between 120 and 175 m. off the bottom. These observations were substantiated by catches of ocean perch larvae in egg nets. 3.17Eggs and sperm Sorokin (1967) examined the gonads of 8 males and 12 females taken in the Gulf of Alaska, July 23 to August 15, 1960.Histo- logical examination showed that both males and females were at varying stages of development.Spermatogonia in different phases of mitotic division predominated in the testes of one group of males, spermatids and sperma- Figure 6.Diagrammatic sketches of larval Pacific ocean tozoids were being formed in the testes of perch.(a) Lisovenko, 1964;(b) DeLacy et al., 1964; another group, and spermatozoids had formed and (c) Westrheim et al.(see footnote 1, table 3). in most of the cysts of the testes and had begun to flow into the lumina of the seminiferous described by Lisovenko (1964); DeLacy, Hitz, canals of the third group. and Dryfoos (1964);and Westrheim et al. Females with the most developed ovaries (footnote 1, table 3).DeLacy et al. differ- had maturing oocytes enclosed in two-layered entiated 13 species of rockfish by melanophore follicleswith well-developed envelopes and patterns, and Westrheim et al. differentiated zona radiata in the process of formation. The 6 species.The latter authors noted, however, second group included females whose ovaries that their specimens of S. alutus did not have were composed mainly of oocytes in which the multiple rows of melanophores on the ven- cytoplasm yolk had begun to form, building tral surface present in the specimens of DeLacy up at the peripheral zone of the oocytes in the et al.They also noted that the ventral row form of granules.A third group included stopped short of the anus by at least four myo- fishes whose ovarian oocytes were in the two- tomes, whereas DeLacy et al. reported that layered follicle stage;lipoid inclusions were the ventral row stopped short by two myotomes. scattered throughout the ooplasm, but the larg- Length of larvae at the time of emergence est were in the nuclear zone.Yolk formation has been reported as 6 to 8 mm. by Paraketsov apparently had not yet begun, or was in an (1963), 5 to 8 mm. by Lisovenko (1964), and incipient stage. The peripheral zone had bluish 6.1 mm (average) by Westerheim et al. (foot- granular formations. note 1, table 3). 3.2Preadult phase No information is available about the ad- 3.21Embryonic phase vanced larval or postlarval stages. No data. 3.23Juvenile phase Little is known about the pelagic and ben- 3.22 Larval phase thic phases of juvenile ocean perch.Powell The melanophore patterns of larvae ex- and Hildebrand (1950) reported that pelagic truded from adult females (fig. 6) have been forms have blue backs, silvery sides, and a

10 purple blotch on the operculum.Paraketsov 3.34Predators (1963) found that before the fish move to the Thompson (1915) reported S. alutus as one bottom in their second year, the principal food of the important constituents in the diet of items are planktonic crustaceans.After they halibut,Hippo giossusstenole pis. Tomilin pass to the bottom, the basic food changes pro- (1957) reported that rockfish Sebastodes spp. gressively from Euphausiidae to Pandalidae. were found in stomachs of 3 of 110 sperm Section 2.22 describes the distribution of ju- whales, Physeter catodon, captured in the veniles. Kurile Island region. 3.3Adult phase The junior author has observed adult S. alutus in the stomachs of large sablefish, Ano- 3.31Longevity pio poma fimbria, taken off the coast of Oregon. Pacific ocean perch are slow gTowing and 3.35Parasites, diseases, injuries, have a long life span. Westrheim (1958) found and abnormalities that the males, although they grow faster than females, have a shorter life span. He estimated Parasites of S. alutus are listed in table 4. maximum age to be 30 years for males and Wilkes (1957), who examined S. alutus speci- Paraketsov (1963) reported mens caught off Oregon for presence and in- 35 for females. cìdence of parasitic copepods, found seven spe- a 29-year-old fish from the Bering Sea. cies and identified sixfour of which were 3.32Hardiness listed as probable new species (table 4). Re- gions of infestation included gill filaments, eye No information. muscles, stomach, pyloric caeca, intestine, vis- 3.33Competitors ceral cavity, and gut wall. Although direct information islacking, Liston, Peters, and Stern (1960) found that many species probably compete with the Pacific the parasitic trematodes, Prosorhynchus spp. ocean perch,since its principal foodseu- and Porrocaecum decipiens, and an unidenti- phausiids, small crustaceans, and shrimpare fled copepod of rockfishes cause considerable the favorites of many species. economic loss in the fishing industry.These

Table 4.Parasites of Sebastodes alutus

Type of parasite Reference Platyhelmisathes: Cestodes: Bothriaceplsalusscorpii Afverson and Westrheim (1961) Bothrioceplsa1stapp.(larval) Arai (1969) Unidentified (two larval types in plerocercoid stages) Alverson and Westrheim (1961) Trematodes: Lepidapedoss spp. Alverson and Westrheim (1961) Megalocotyle tritssba Alveraon and Weatrheïm (1961) Podocotyle spp.(immature) Arai (1969) Porrocaecum decipiens Litton, Peters, and Stern (1960) Prosorlsyssc/sosspp. Alveraon and Weatrheim (1961); Liston et al. (1960) blemathelminthes: Nematodes: Two unidentified species (one in larval form) Alversonand Westrheim (1961) Inisakis spp.(larval) Arai (1969) Arthropsda: Copepodn Chondrocantlssss pingais Wilson Wilkes (1957) Choadrorant/ssss app. (probable new species) Wilkes (1957) Clavellopsi.s app.(tentative new species) Wilkes (1957) Colobomatus app.(probable new species) Wilkes (1957) Haemobaplsestheragrae Yamaguti Wilkes (1957) Penirulus spp.(probable new species) Wilkes (1957)

11 parasites are not known to be harmful to man, mature perch almost wholly abstain from feed- but their presence in fillets is esthetically ob- ing.Perch captured during the winter are jectionable.In 1958, incidence of parasitiza- leaner than those taken during the foraging tion for S. alutus was the highest (39 percent) period and their quality is inferior (Lyubimova, in the area of Hecate Strait, British Columbia; 1965).Figure 8 shows the percentages of moderate (21 percent) in the area from Cape full stomachs over the course of a year.The Cook, Vancouver Island, to the Columbia River; large increase in the percentage of full stom- and lowest (15 percent) in the area from the achs from May through September, indicates Columbia River to Cape Blanco, Oreg.The the high intensity of feeding during this per- corresponding percentages in 1959 were 45, 44, iod (Lyubimova, 1963).Immature fish feed and 27 (Liston and Hitz, 1961). year-round.Moiseev and Paraketsov (1961) reported that in the Bering Sea, 65 percent Liston et al. (1960) mentioned two theories of the nonexploded stomachs examined in May- for the greater abundance of the major para- September were full.Of the nonexploded site, Prosorhynchus, in the northern than in stomachs collected from fish accumulated on the southern area:(1) abundance of the parasite varies inversely with the intensity of the spawning grounds, 98 percent were empty. fishing, and (2) there is a geographical limit They concluded that S. alutus do not feed during the prespawning period.Snytko (1968) on the parasite or on one of its hosts. reported that in the Vancouver Island-Oregon Abnormalities region, perch feed from spring to late autumn. So-called blemishes, resembling a kernel of Skalkin (1964) showed that intensity of unpolished rice in size and appearance and feeding is not constant during the 24-hour per- occurring in muscles of Pacific ocean perch, iod.In specimens collected from 0800 hours were identified as aberrant cartilaginous tis- until 2000 hours on June 21, 1960, at depths sues (Liston et al., 1960).More than half from 140 to 150 m., the intensity of feeding of the fillets examined by Liston and Hitz was greatest at noon, least in the morning, and (1961) contained blemishes, but the aberrancy at an intermediate level in the evening. He is harmless and does not affect edibility. noted a different pattern in specimens collected 3.4Nutrition and growth from below 200 m.; with these, the greatest intensity of feeding occurred in the morning, 3.41Feeding declined during the day, and increased again Because of the inaccessibility of the natural in the evening but not to the level of the morn- habitat of the adult Pacific ocean perch to ob- ing.Skalkin suggested that the changes might servation and the (so far)insurmountable be related to the availability of food organisms. difficulties in bringing viable specimens to the surface for aquarium study, reports on the 3.42Food feeding of S. alutus are generally based upon The food of the Pacific ocean perch is not examination of the stomachs of dead specimens. different from that of many other groundfishes. Lyubimova (1963) reported that the study of Paraketsov (1963) reported that pelagic ju- the feeding habits of S. alutus is hindered by venile ocean perch fed on planktonic crusta- the "explosion" of the stomachs when the fish ceans, whereas benthic juveniles ate euphau- are brought to the surface. She noted, however, suds and pandalids.Moiseev and Paraketsov that the Gulf of Alaska population forages in (1961) found that the composition of the the summer (May-September) near Unimak stomach contents of Pacific ocean perch was Island.This area has high biological produc- 75 percent crustaceans (euphausiids and pan- tivity associated with the mixing of Bering Sea dalids), 15 percent squids, and 6 to 7 percent and Pacific Ocean water. Secondary foraging fish.Skalkin (1964) listed food items of Pa- areas lie just southwest of the Shumagin Is- cific ocean perch in the Bering Sea (table 5) lands, east of Kodiak Island, and southwest of and reported that immature fish feed mostly Portlock Bank (fig. 7).Lyubimova contended on calanoids, whereas mature fish feed mainly that during the rest of the year (October-April) on euphausiids.

12 1700 w. 160° 150° 1400

60° N.

550

500 Figure 7.Distribution of Pacific oceanperch in the Gulf of Alaska during theprincipal feeding period (from Lyubimova, 1965).

3.43Growth rate Investigators have reported on the growth 30 rate of Pacific ocean perch from various areas 28- within the range of the species. w 24- In the Bering Sea, S. alutus attained an w average length of 31.5 cm. at 10 years of age °- 20- and 42 cm. at 20 years (fig. 9); the oldest fish, 29 years, was 48 cm. long (Paraketsov, 1963).Gritsenko (1963), also working with fish from the Bering Sea, found that linear growth was greatest during the first 5 to 7 D yeärs.The relative annual increase in length was similar for both males and females and MONTH declined from 54 percent initially to 10 per- Figure 8.Percentage of full stomachs in samples of cent in the 7th year; from the 8th year onward Pacific ocean perch taken each month in the Gulf the relative annual increment of growth did of Alaska (from Lyubimova, 1963). not exceed 10 percent, and toward the 16th to

13 50 Table 5.-Composition of food of Pacific ocean perch sampled in the Bering Sea (from Skalkin, 1964) Maximum 40 Maximum frequency Item weight of occurrence Percent Percent 30 Galanas cristatus V 86.4 100.0 o Calanus plome/aros V 85.6 100.0 Galanos glacialis V 30.0 72.0 Eucalanus bun gil V 4.7 28.7 Pareuchoeta fapsnica V 1.2 4.8 Thysanoessa longipes 100.0 100.0 Thysanoessa raschii 84.6 100.0 Thysanoessa inermis 98.6 100.0 Euphausia pacifica 2.1 7.2 Myaidae app. (3 speciea) 84.8 95.0 5.3 66.7 Themisto spp. i i i i i i i I I I 1nonyx nygax -- -- o Ariaphipodaspp. 3.6 38.1 0 2 4 68lO 12 14 16IS 20 22 24 Pandalidae spp. (2 species) 10,7 14.3 AGE (YEARS) Sagittaelegans 17.2 41.7 Beroe cucumis 6.7 11.1 Figure 9.-Growth of Pacific ocean perch in the Bering Polychaeta spp. larva Insignificant 8.3 Sea (Paraketsov, 1963). Cephalopoda spp. (2 species) 47.4 75.9 Clione Iimacina -- -- Gastropoda larva -- -- Oicopleura app. -- -- 3.44Metabolism Gorgonocephalus spp. Insignificant 5.0 Op/saura leptoctenia Insignificant 1.9 Macruridac app. fry 17.6 66.9 No information Scopelifarmea (luminous anchovy") 1.4 2.9 3.5Behavior 3.51Migrations andlocal move- 17th years this increment declined to about ments 2 percent. The extensive "migrations" described in Lyubimova (1964) found that in the Gulf this section are not based on tagging but pre- of Alaska, S. alutus grew 5.4 to 2.7 cm. per sumably on changes in distribution and abun- year during the first 5 or 6 years and then dance.Until supported by tagging studies, growth gradually decreased to 2.2 to 1.4 cm. the migrations reported here must be regarded per year. as hypothetical. Westrheim (1958) reported that S. alutus Moiseev and Paraketsov (1961) reported grows very slowly off Washington and Oregon, that from January to May in the Bering Sea, particularly after the 11th year.Maximum the densest concentrations of S. alutus are in length increment is in the first year for both Bristol Bay and in the spawning area just sexes; maximum weight increment is in the south of the Pribilof Islands.Depths in these sixth year for males and in the seventh year areas range from 340 to 420 m.Except for for females.Table 6 shows Bertalanify con- distinct daily vertical migrations, the schools stants calculated from the Pacific ocean perch are relatively immobile. From May to Sep- data. Westrheim (1958) depicted the age/length Table 6.-Bertalanffy constants calculated from Pacific and age/weight relations by sex as shown in ocean perch growth data obtained from the scale figures 10 to 13.He determined the length- method of growth analysis (adapted from Westrheim, weight relation as follows: 1958) Constants Females Males: W = (7.2510 x 10-9) L3.24960 [,,,,,,,,,_,,j t 1-14 1-14 Females: W = (1.5339 x 10-8)L3.11877 Los 403 mm. 432 mm. K 0.20 0.18 where W weight in pounds and L = fork Woa 0.93 kg. 1.15 kg. length in millimeters.Figure 14 shows these to .-0.71 year -1.09 years ta 30 years 35 years relations.

14 400 zF- LENGTH (n60 - -300-- L) z 50- o1- z z 40- -200 z 30- z o 20- \ LENGTH NCR EME NT -100 z z IO- (n o o Io 15 20 25 28 AGE (YEARS) Figure 10.Age-length relation for male Pacific ocean perch taken off Washington and Oregon, based on the Bertalanffy method of growth analysis.Dots indicate observed values obtained from the direct method of growth analysis (adapted from Westrheim, 1958). 500

-400

LENGTH -300 zo 50- (n E 40- -200 z 3o- o

20- LENGTH INCREMENT I00 = % z IO- (n / o o 5 Io IS 20 25 30 34 AGE (YEARS) Figure 11.Age-length relation for female Pacific ocean perch off Washington and Oregon, based on the Ber- talanify method of growth analysis.Dots indicate observed values obtained from the direct method of growth analysis (adapted from Westrheim, 1958).

(n C 2.0 z (.908)

a_(n (n ZE (n -Zi- zIO (n (n'--z Oz(n (n Z(n z =n. (n 1.0 0.20 (.454) - o(.090) Z(n -J (no 0.10 (.045) (n

o o o 5 IO IS 20 25 28 AGE (YEARS) Figure 12.Age-weight relation for male Pacific ocean perch off Washington and Oregon, based on the Ber- talanff y method of growth analysis (adapted from Westr- heim, 1958).

15 2.5 (1.14) o, o, o 2.0 (.908)5' o o, w o. z o - w o-z wo, z- - U) o z -zo C 1.0 0 (.454) 0.20 (.090) WEIGHT INCREMENT 0.10 5 (.045) /

0 o o 5 0 15 20 25 30 35 AGE (YEARS) Figure 13.Age-weight relation for female Pacific ocean perch off Washington and Oregon based on the Ber- talanify method of growth analysis (adapted from Westr-. heim, 1958).

MALES 5.0 5.0 (2.27) (2.27)

CI) wU) w 4.0 U) 4.0 (1.82)ow ((.82) z' oZF. z Cflw 3.0 z 3.0 (1.36) (1.36) 0.2o z z 2.0 U) 2.0 U) (.908) (.908) jijuo I.0 1.0 (.454) (.454)

o O 20 30 40 50 20 30 40 50 FORK LENGTH (CM.) FORK LENGTH (CM.) Figure 14.Length-weight relation for male and female Pacific ocean perch off Washington and Oregon.Solid dots indicate observed values from which each curve was calculated (from Westrheim, 1958). tember the fish make an intensive foraging mi- the Olyutorskiy Gulf (Paraketsov,1963). No gration to the central Bering Sea; from Sep- movement across the deep part of the Bering temberto January theyreturn.During Sea has been reported. migration the schools are in shallower water The observations of Lestev (1961) are not but at a greater range of depths(140-360 m.). in agreement with those of Moiseev and Para- Figure15shows the depth distribution in the Bering Sea in summer and winter. ketsov (1961).Lestev reported that in the Bering Sea, rockfishes (primarily Pacific ocean In the Bering Sea, S. alutus rarely forage perch) do not make long migrations;each north of lat. 590 N., and populations off the stock occupies one region, which it does not east coast of Kamchatka do not go north of leave.

16 No one has tagged and released Pacific SUMMER WINTER ocean perch, mainly because of the decom- pression problems encountered in bringing live loo ci fish to the surface. w Regarding vertical movement, Moiseev and 200 Paraketsov (1961) reported daily vertical migrations of ocean perch in the Bering Sea dur- 300 ing the prespawning period (January-April). I= The fish were near the bottom during the day o- and as much as 40 m. off the bottom during 0w 400 the night. Lestev (1961) found, however, that in the summer the vertical distribution and dimensions of the schools changed little during I I ( I 20 IO O IO 20 30 the course of a 24-hour day.During the day, PERCENTAGE 0F CATCH the schools become somewhat more dispersed Figure 15.Vertical distributionof Pacific ocean perch and their depth(top to bottom)increased. taken during summer and winter in the Bering Sea (from He also noted that trawl catch rates remained Paraketsov, 1963). the same at night as during the day; he spec- ulated that this similarity might be because Lyubimova (1963, 1965), who described the movements of Pacific ocean perch in the Gulf of Alaska, wrote that foraging occurs from May to September and that Unimak Pass SUMMER WINTER is the principal foraging area.During for- 955 aging, the schools are in water 150 to 250 m. deep, mostly 150 to 200 m. During the mating 183 period, the fish cease to feed; after mating, they form into schools of a single sex.Most 366 schools of females migrate into the north and northeast part of the Gulf of Alaskainto the Portlock, Kodiak, and Yakutat areas. Imma- u-, ture females also migrate to the northeastern (956 part of the Gulf of Alaska but not until De- w cember and January. Some schools of females w- 183 do not migrate, however, but stay near Unimak Pass.The schools of mature females, while in the northerly reaches of the Gulf of Alaska, are in water 234 to 450 m. deep. Males, too, migrate during the winter, mov- ing from the Unimak to the Chirikof and '957 Kodiak Island areas. Lyubimova (1963) noted 83 their gradual descent to greater depths.In summer they are at 150 to 185 m., in November at 234 to 300 m., and in February at 350 to 366 400 m. Alverson and Westrheim (1961) concluded that off Washington and Oregon S. alutus 30 20 IO O IO 2030 40 move into deeper water during the winter. PERCENTAGE OF CATCH Major catches in the summer are between 146 Figure 16.Vertical distribution of Pacffic ocean perch and 292 m.; whereas catches in the winter are taken in summer and winter by the Washington trawl usually between 276 and 366 m. (fig. 16). fleet, 1955-57 (from Alverson and Westrheim, 1961).

17 of the lack of complete darkness in the Bering 4 POPULATION Sea during the summer. 4.1Structure Alverson and Westrheim (1961) reported that trawl fishermen off the west coast of 4.11Sex ratio North America find that the morning drag Sex ratio, although it varies considerably yields the most ocean perch.Catches remain with time of year and from sample to sample, good in the late morning and afternoon but are probably is1:1.Moiseev and Paraketsov not as good as those made at daybreak. (1961) noted that the percentage of males in the schools of S. alutus in the Bering Sea grad- Schools of ocean perch in the Gulf of Alaska ually increases until July when the sexes be- migrate vertically each day during the feeding come about equal.According to Paraketsov period (Lyubimova, 1965).During daylight (1963), the sexes remain equal until February. the concentrations are distributed along the Spawning schools contain 98 to 99 percent fe- bottom; during the night they rise to a height males, but the males remain close by. of 20 to 50 m. off the sea floor.Skalkin (1964) Lyubimova (1963) found that Gulf of showed that this behavior is a function of Alaska fish also exhibited a 1: 1 sex ratio during feeding (section 3.41) and that nonfeeding the summer foraging season(May-Septem- schools do not perform vertical migrations. ber); however, by November the males pre- Lyubimova mentioned that Moiseev and Para- dominated in a ratio of 4: 1 because most fe- ketsov(1961) had described similar daily males had left for the more northerly spawning vertical migrations in the Bering Sea, but she areas. failed to take into account that the latter auth- Westrheim (1958) noted that males dom- ors were dealing with prespawning fish, which inate (60-82 percent) commercial landings in supposedly do not feed. Thus, if the hypothesis Oregon in February and March. He felt that that prespawning fish in the Bering Sea do not this male dominance occurred when females feed is true, then the distinct daily vertical moved to deeper water where they spawned. migrations described by Moiseev and Para- Females dominated the catches in September ketsov cannot be explained by the distribution (66 and 76 percent in 1951 and 1952, respec- of the food organisms. tively). 3.52Schooling Continuing his investigations, Westrheim (see footnotes 1, 2, 3) found that the sex ratio Lestev (1961) observed that in the Bering changed with depth in the winter (February Sea, Pacific ocean perch do not form large and March) but not noticeably so in the sum- accumulations but are indistinct, compact mer (July-September).In the winter, males schools. The maximum length of a school was predominated in the deeper waters, but in the 1,300 m. and the average length 300 to 500 m. summer the sexes were usually equally rep- Schools more than 30 m. across were not en- resented.These results were derived from countered.Schools were occasionally 60 to 80 samples taken in coastal waters from Oregon m. in depth, but 15 to 20 m. was more common. northward to Unalaska Island. Most schools were in contact with the bottom, 4.12Age composition and the base of the school was more dense than the top.In May and June, the schools were Striking differences in age composition be- usually 9 to 15 m. off the bottom, but occasion- tween regions are shown by samples of the commercial catches in the Bering Sea (fig. 17), ally they ascended to within 49 to 90 m. of the Gulf of Alaska (fig. 18), and off the coasts of surface in waters 140 to 465 m. deep. Washington and Oregon (fig. 19).The dom- 3.53Responses to stimulii inant ages are 13 and 14 years in the Bering Sea catches; 10 to 13 years in catches off the No information. coasts of Washington and Oregon; and 7 and

18 20 120

1960 Io T 80 li. 8 lO 12 14 16 18 20 20 oLi 20 1961 234 5678910111213145 GE (YEARS) Figure 18.Age composition of Pacific ocean perch in the o Fm, Gulf of Alaska (from Lyubimova, 1964). 8 IO12 14 16 18 20 20 400 N 1,768

1962 10

rV1 hi 8 IO12 14 16 18 20 AGE (YEARS) Figure 17.Age composition of Pacific ocean perch in the Bering Sea, 1960-62 (from Paraketsov, 1963). lOO

8 years in the Gulf of Alaska. Although some I of the differences may be attributable to dif- 5 lO 15 20 >21 ferent aging techniques, real differences prob- AGE (YEARS) ably exist.Westrheim (footnote 1)stated Figure 19.Age composition of Pacific ocean perch off that "small" fish from the Gulf of Alaska Washington and Oregon (adapted from Westrheim, 1958). turned out to be no younger than "large" fish from British Columbia. the Bering Sea showed the most suitable mesh Gear selectivity has a definite but unas- size to be 8- to 9-cm. mesh size in the forward sessed effect on the left sides of the age distri- part of the net and 3.0 to 3.5 cm. in the cod-end. bution curves of figures 17 to 19.North See also section 3.12 for information on age American fishermen use trawls of 8.9-cm. cod- at maturity and section 3.31 for maximum ob- end mesh size.Soviet fishermen(at least served age. those in the Gulf of Alaska and southward) are believed to use trawls of 7.6-cm. mesh with 4.13Size composition a 4.1-cm. mesh liner in the cod-end.Lestev The size compositions of samples taken from (1961) reported that fishing experiments in trawl fisheries in the Bering Sea, Gulf of

19 Alaska, and off the coasts of Washington and couver, B.C. (table 7).The mode of 36 cm. Oregon are shown in figures 20 to 22.The is similar to that for the Bering Sea and Wash- size composition of the fish from the Gulf of ington-Oregon samples. Westrhein (see foot- Alaska is unlike that of fish from either the notes 1, 2, 3) presented data obtained on re- Bering Sea or the Washington-Oregon area. search cruises in 1963-65 along the coast of For both sexes combined, Bering Sea fish have North America from Oregon to the Aleutian a mode at 37 to 39 cm. and the Washington- Islands.Although the length composition of Oregon fish at 35 cm.In contrast, the mode the catches varies considerably within areas, for Gulf of Alaska fish, as presented by Lyubi- moya (1964), is 25 to 29 cm.The Japanese° report that ocean perch taken in their Gulf of 300 Alaska trawl fishery during 1963-65 had a 31- cm. mode in each year. Female ocean perch were larger than males in samples from the Bering Sea (fig. 20) and the Washington-Oregon coast (fig. 21) but not in samples from the Gulf of Alaska (fig. 22). 200

Westrheim (see footnote 1) presented the o size composition of S. alutus landed in Van-

o ° Fisheries Agency of Japan.1966.Outline of the z Japanese bottomfish fisheries in the Gulf of Alaska for 1965.2 pp.[Processed.] lOO

300

o 25 30 35 40 45 50 I FORK LENGTH (CM.) u, Figure 21.Size composition of Pacific ocean perch off 200 Washington and Oregon.1 - both sexes, N = 1,779; 2 - males, N = 904; and 3 - females, N 875 (from Westrheim, 1958). w 2,200 2,000- 1,80 0- z 1,600- loO I 400- 1,200- 2 p00- 800- 600- 400- \-. 200- " -... o O 61i I i i 1416 (82022242628303234363840424446 28 3032 3436 384042444648 LENGTH (CM.) LENGTH (CM.) Figure 22.Size composition of Pacific ocean perch in Figure 20Size composition of Pacific ocean perch in the Gulf of Alaska.1 - both sexes, N = 9,737; 2 - males, the Bering Sea.i - both sexes, 2 - males, and 3 - fe- N 4,852; and 3 - females, N = 4,887 (from Lyubimova, males (from Paraketsov, 1963). 1964).

20 Table 7.-Size compositionof Pacific ocean perch 4.22Changes in abundance landed in Vancouver from Queen Charlotte Sound, 19130-63 (modified from Westerheim, text footnote1) Studies of changes in abundance of Pacific

Year ocean perch have not been published, but un- Fork Total Size fish composition length 1960 1961 1962 1963 published evidence assembled by scientists of Cm. Number of fish Number Percent the United States and Soviet Union suggests 20 that abundance has declined markedly after in- 2 2 1 5 0.08 4 6 12 0.20 tensive fishing in certain parts of the Gulf of 6 5 14 36 60 0.98 Alaska and off the northwestern United States. 8 27 36 46 21 130 2.13 30 78 94 108 43 323 5.29 4.23Average density 2 l-35 135 183 108 561 9.18 4 230 223 352 337 1,142 18.69 No information. 6 252 262 428 379 1,321 21.62 8 204 191 304 344 1,043 17.07 40 184 118 170 260 732 11.98 4.24Changes in density 2 128 66 97 138 429 7.02 4 45 32 93 75 245 4.01 Lestev (1961), in describing the schooling 6 26 lo 30 24 9° 1.47 characteristics of S. alutus (sec. 3.52), noted 8 9 14 0.23 50 0.03 that a typical school was in contact with the 2 0.02 0.02 bottom and was denser at the base than at 4 the top.He also stated that in winter and Total no. of fish1 1,329 1,188 1,857 1,737 6,111 spring, when the fish gather in prespawning 1 Numbers sampled. aggregations, catches are larger and more consistent than in the summer, when the fish are feeding. his work generally corroborates previous information that the modal size is larger in the See also sections 2.2, 3.51. Washington-Oregon andBritishColumbia 4,3Natality and recruitment areas (34-42 cm.) than in the Gulf of Alaska (most commonly 30 cm.). 4.31Reproduction rate The 54-cm. specimen landed in Vancouver No information. from Queen Charlotte Sound in 1960 (table 7) 4.32Factors affecting reproduction appears to be the longest on record. Food supply, predation, parasitism, and 4.2Abundance and density physical factors of the environment undoubt- edly affect reproduction of the population, but 4.21Average abundance the extent is unknown. Alverson et al. (1964) derived estimates of 4.33Recruitment standing crop of S. alutus (table 8). According to Westrheim (1958), some 3- Table 8.-Estimated weights of standing crops of S. to6-year-old ocean perch appear in trawl alutus, by depth interval, in different regions; a catches taken by the U.S. fleet off Washington dash (-) indicates that no estimate was made be- and Oregon; appreciable numbers, however, cause of limited sampling effort, and a plus (+) indicates that the given weight is a minimal estimate are not captured until age 7.Alverson and (modified from Alverson et al., 1964) Westrheim (1961) concluded that full recruitment probably does not occur until the 12th Depth interval (m.) Region Total weight or 13th year. The age composition in the 2-90 91-180 18 1-420 J - Metric tons - - Bering Sea and the Gulf of Alaska (figs. 17 Washington-Oregon ... .- 3,175 46,266 49,441+ and 18) suggests that full recruitment occurs British Columbia and at about age 13 in the Bering Sea and at about Southeastern Alaska - - 249,476 1 333,393+ Gulf of Alaska 454. 83,461 40,823 124,738 age 8 in the Gulf of Alaska-at least with the Alaska Peninsula .... 0 6,803 13,154 19,957 gear that the Soviet fishermen were using at Bering Sea (Eastern). O + - - the time the samples were collected.Because Total sveight 454+ 177,354+ 349,719+ 527,529+ Estimated total. 8-year-old fish in the Gulf of Alaska are the

21 same size as age-6-year-old fish off Washing- fishery. He reasons that because of moderate ton-Oregon, we might assume that age-6 fish natural mortality and slow growth, the biomass are being fully recruited in the fishery initi- of a year class reaches its maximum relatively ated by the Soviet fleet off Washington-Oregon early (in the sixth year). Assuming that the in 1966. natural mortality is moderate at all levels of stock size and that recruitment would not be According to Pereyra,7 age-2 fish are har- adversely affected by reduced size of the par- vestable with the nets of smaller mesh size ent stock, Pereyra determined that physical used by the Soviet fishermen off Washington equilibrium yield would be obtained if the and Oregon. He calculated that 11,069 metric stocks were fished at an early age.The dy- tons of age-2 fish are recruited to this fishery namics of the Gulf of Alaska and Bering Sea annually. populations have not been similarly examined. See also sections 4.12, 4.13. 4.6The population in the community 4.4Mortality and morbidity and the ecosystem 4.41Mortality rates Alverson et al. (1964: 157-158) presented Westrheim (1958) estimated that the na- the following information concerning the role tural mortality was 32 percent off the coasts of S. alutus in the demersal fish community of Washington and Oregon.Pereyra(see of the northeastern Pacific Ocean: footnote 7) used the data from Westrheim "Pacific ocean perch was the dominant (1958) to calculate an age-specific fishing mor- form in the aggregate species catch tality rate of 0.10 for the fully recruited age throughout the arc of the northeastern groups (12 and older)of the Washington- Pacific Ocean from southern Oregon to Oregon population under conditions of the U.S. Unimak Pass at depths from 100 to 149 fishery.The rate (0.10)is the same under fathoms, and ranked among the top five conditions of the Soviet fishery, but it includes spécies in the 150- to 199-fathom depth fully recruited age groups 6 and older. zone."(See table 9) 4.42Factors causing or affecting The importance of S. alutus in the rock- mortality fish community is even more pronounced; Al- Predators are discussed in section3.34. verson et al. (1964: 94-96) state further: The total effect of predators on the population "Pacific ocean perch, the most important is unknown. single species of rockfish harvested in 4.43Factors affecting morbidity the north-eastern Pacific, dominated the rockfish catches on the other (sic) con- Parasites are discussed in section 3.35. tinental shelf and upper continental 4.44Relation of morbidity to mor- slope in the regions between southern tality rate Oregon and Unimak Pass.It was the dominant species contributing to the No information. rockfish catches in regions south of Cape 4.5 Dynamics of the population as a whole Spencer in depth zones from 50 to 299 fathoms, and in the Gulf and Peninsula Pereyra (see footnote 7)calculated the regions in depth zones between 1 and maximum equilibrium yield of the Washington- 199 fathoms. Oregon stock at 16,084 metric tons under conditions of the U.S. fishery and 24,381 metric "Its importance in the rockfish com- tons per year under conditions of the Soviet munity on the upper continental slope at depths from 100 to 149 fathoms Walter T. Pereyra, Deputy Director for Research, throughout the geographic area between Bureau of Commercial Fisheries Exploratory Fishing southern Oregon and Unimak Pass is in- and Gear Research Base, Seattle, Wash.Personal communication.January 1969. dicated by the fact that it accounted for

22 Table 9.The five most abundant demersal fish taken from the northeastern Pacific Ocean and their percentage of total catch by regions and depth Region Species l-90 m. Percentage Speciesintervals (adapted from91-181 Alverson,m. Pruter, and Ronholt, 1964) Percentage Fishing depth Species 182-273 m. Percentage Species 274-365 m. Percentage Species 366-547 m. Percentage Oregon-Washington MicrostomusMerlacciasAt/seresthes productas pacificas stornias 251315 AtheresthesIllicrostomas5. a/atas stomias pacificas 4714 9 S.ilnoplopMicrostomas orna pacificasfimbria alistas 142134 5.MicrostomasAusop/opoma alotas fimbriapacificas 371319 British-Colurnbia-soutlsrustern Alaska: ,ít/seresthesAnoplupornaClyptocepisalas ¡turniaS fimbria zachirus 19 4 S.SqaalasAnop/opoma alatas acasothias fimbria 47 38 S.AtheresthesMer/accias a/atas productas¡turnias 55 56 AtheresthesSebasto/obas ¡turnias opp. 4 5 S.Sqaalus brevispisoisalotasMicrustomas acantMas pacificas Il19 99 5.MicrostomussAtheresthes rabrivinctasTisera gro ¡turnias cha/copacìflcas grammas 15 457 5.Hydro/oMicrostomasAthereothes rabrivinctas gas stomiat pacificas co/hei 14 5 Gulf of Alaskas LepidopsettoPlatichthys stellatas biliuseata 1413 S.Atheresthes a/atas ¡turnias 3116 AtheresthesS. a/atas ¡turnias 2832 5.A theresthes ¡turnias a/atas 48 19 ACoryphaenoides theresthes ¡turnias (Fam.Macrouridae) 2432 Alaska Peninsula: RajaACadas upp.therestises macrocephalus st orn/as 1012 9 HippoCadasTisera glossoides grunsacrocephalas chalcogrammas elassodon 79 AnoplopomaHippoThera glossoides gro cha/cofimbria grarnrnas elassodosn 56 HippoglossasHippog/ossoidesMicrostomas pacificasstenolepis e/assodon 60 S.Assop/opomaMicros/ornas alotas fimbriapacificas 101118 LepidopsettaCadasHip poglossus macrocephalas bilnieata stenolepis 1929 CadasHippoAtheresthes glossoidesmacrocepha/as stomias elassodon Il19 9 HippoS.Atheresthes alistas g/ossoides stornias elassodon 194512 Assop/opomaTheragra.4 theresthes chalcograunrnas ¡turnias fimbria 64 12 6 C/yptocepha/asAtheresthesCcsryphaenoides stono/ai zachiras (Fam.Macrouridae) 4533 6 Bering Sea: HippoglossoidesAtheresthesLimanda ¡turnias05/sera elassudon 43 45 LepidopsettaThera gro chalcogrammasbilineata 7 7 C/yptocepha/asThera gro cha/co zachiras grammas 10 3 Hippog/ossoides5. a/atas ebassodoos 2 5 Sebastolubascf usoplopoma spp. fimbria 5 ° Inadequate sampling. PlatichthysHippoglossoidesLepidopsettaTisera gra stellatas bilioseatachalcugrammas elassodon 2613 4 77 to 98 percent of the total rockfish ing vessel and retrieved over the starboard catches.In waters between Cape Spen- side. cer and Unimak Pass it accounted for over 62 percent of the aggregate rock- Lestev (1964) reported that Russian fisher- fish catches made at depths between i men, after extensive testing of several types and 199 fathoms. In the Gulf and Pen- of trawls in the Bering Sea in 1960, concluded insula regions the percentage contribu- that herring trawis of the Polish or Kalinin- tion of Pacific ocean perch to the total grad types (fig. 24) were most successful for rockfish catch was considerably greater catching S. alutus. He found that because on the continental shelf than in more S.alutusare so often found over rough, coral southern waters.The increase in the bottom, it was necessary to rig the trawls as percentage importance of Pacific ocean lightly as possible.The corkline and leadline perch in the shallow portion of its depth should be rigged so that (1) the pressure of range in more northern waters is due in the net on the bottom will be as little as pos- part to a decline in the number of other sible, (2) the groundline scarcely touches the Sebastodesinhabiting the region.The Pacific ocean perch occurred in all in- bottom, and (3) the leadline moves above the side areas surveyed.However, it did bottom. not play as important a role in the rock- The nets used by fishermen of the U.S.S.R. fish catches in inside areas as in the for harvesting Pacific ocean perch are gener- comparable depth intervals in adjacent ally of lighter material and rigged fuller in offshore regions." the belly than trawls used by fishermen of Can- Lyubimova (1963) cited the work of V. I. ada and the United States (Alverson, 1967). Troinin, who noted that the distribution of The U.S.S.R. trawls have additional floats, and Pacific ocean perch in the Gulf of Alaska coin- droppers about 2 m. long with heavy weights cides with the distribution of humpback whales, Megaptera nodosa. The similarity in distri- Table 10.Details of a standard 400-mesh east coast bution is explained by the similarity in food: trawl used off the west coast of North America alutusfeed (adapted from Greenwood, 1958);' the trawl webbing both the humpback whale and S. can be of either light or heavy material on zooplanktonmainly Euphasiidae and Cal- Otter trawl anidae that live in depths of 150 to 200 m. in 400 mesh eastern type the area. Web material: Light weight: Wings, minare, belly 48 thread, 45%i mesh cotton webbing Intermediate 72 thread, 31/a" mesh Cotton webbing 5 FISHING Cod-end 96 thread, 31/,imesh Cotton webbing 5.1Fishing equipment Heavy weight: Wings, square, belly 60 thread, 4'/" meshCotton webbing Intermediate 84 thread, 3 '/a" meshcotton webbing 5.11Gear Cod-end 120 thread, 31/2" meshCotton webbing Ropes and lines: Bottom trawls of various types towed by Head rope 71 feet plus eyes, of %" 6x19 galvanized wire a variety of vessels are the only type of gear rope wrapped with 6-thread manila line. Footrope 94 feet pius eyes, of 6x24 galvanized wire used to catch significant quantities of ocean rope wrapped with 27-thread manila line. Breast lines 7 feet including eyes, of %" galvanized wire perch.According to Alverson (1959), trawls rope wrapped with 6-thread manilaline. Rib lines 8 each,of 27-thread manila line, one along used on the west coast of the United States each seam and one along top and bottom and Canada vary considerably in size and de- center,and one from the corners st each bosom on top and bottom running diag- sign, depending on the geographic area and onally to join side rib lines. national background of the fishermen.The Hanging of net: Head rope Wings hung 4 bars to 71/a" hangings. trawls are essentially the same, however, as Bosom hung 4 meshes to 514hangings. Footrope Lower bosom:4 meshes hung to 95,4 on those used in the world's major trawl fisheries. 21-threadmanila hangingline.9V," of the hanging line hung to 7" on footrope. Figure 23 and table 10 depict the details of Lower wing:4 bars hung to on 21- threadmanila hangingline. l01/, of the standard bottom trawl.These nets are hanging line hung to 71/,on the footrope. usually set directly over the stern of the fish- Nylon and polypropylene have almost replaced Cotton as the web fabric.

24 BOTTOM SECTION TOP SECTION FOOTROPE 28.7 METERS HEADROPE 21.6 METERS

80m

4.5 meters 272m / SQUARE 207m -'/

m = mesh

57m 57m

INTERMEDI AT E

SOnSO coq-EN)

Figure 23.Dimensions of a standard 400-mesh eastern-type otter trawl used off the west coast of North America (Greenwood, 1958).See table 10 for details.

0 TOP BOTTOM 4 MESH N- T 4 MESH TO P BOTTOM H

68 MESH 26 MESH 34/32 N(O N 70 (t) 28 M. 72 MESH 55 MESH 1.6 M. 56 MESH 28 MESH 84 MESH 262 MESH 16M. 34/32-70 196 MESH 80 MESH27 MESH 74 MESH 070 34/24 -70 34/24-70 48 MESE 38M. 151 MESH 167 MESH 43 MESH 62 MESH 210 MESH -J 6O 'ILWJ!9 Ñ 34/24-50 34/24-50 0 187 MESH 53 MESH o.' w) 35 MESH 40 190 MESH 50 MESH 221 MESH 030 ISBMESHISOMESH.<, o Q22 205 MESH 04 «i 34/24-30 I45MESH" '' cs4 121 MESH 177 MESH 125 MESH c\i 34/24-20 ' 125 MESH 85 MESH / 52 MESHu

N EI s, Figure 24.Polish (I) and Kaliningrad (II) trawis used by U.S.S.R. fishermen in the Bering Sea (from Lestev, 1964).

25 attached are placed on the groundlines.This operation in figures 27 and 28. The nets fished arrangement allows the net to skim over the by the stern-ramp trawlers of Japan and the bottom.The vertical opening of the net is U.S.S.R. are probably larger versions of the about 8 to 10 m. (Lestev, 1961). standard bottom trawl.These nets are cast The Japanese use four basic fishing tech- and retrieved through a ramp in the stern of niques in the Bering Seathe Danish seine the vessel. method, bull trawling, sideset trawling, and North American and Japanese trawls are stern-ramp trawling (Alverson et al., 1964). of 8.9-cm. stretched mesh webbing. Nets used The Danish seine and its operation are depicted by fishermen of the Soviet Union are believed in figures 25 and 26 and the bull trawl and its to be of 4.1-cm. webbing in the cod-end.

70 40 I 85 70 30 40E-132 70, ISO 75 I SOT-82 mm

75 OOT-SZmm

75 75 75

FR 75 75

301 -52mm HL 5T_O2 mmj 75 NOT TOT

T TWINE SIZE 'E' 14 05m 'E'E 7.26m ME 0H S IZE

FO FOOTROPE

ML HEADLINE

Figure 25.Dimensions and construction characteristics of a Danish seine (from Tominaga, 1963).

Figure 26.Operation of Danish seine (from Bourgois, 1951).

26 T TWINE SIZE F. R. mm MESHSIZE HL.

HL HEADLINE

FR FOOTROPE

SL SIDELINE

Io EXTENSION WIiG

UPPER WING

LOWER WING

SOT -75 mm

150

42 33 SIDE PANEL

40 DODY

76 95 95 C OD END

OUTER NET 400 T-115 mm NOT DRAWN TO SCALE C OD E ND INNER NET 300T-92 mn Figure 27.Dimensions and construction characteristics of a typical Japanese bull trawl (from Tominaga, 1963).

Echosounders are used by fishermen of all Figure 30 shows types of vessels used by nations to locate schools of fish.Lestev(1961) the U.S.S.R. to trawl for Pacific ocean perch. reported that the Russians use echosounders Japan uses similar vessels.Unlike the United continuously in the search for Pacific ocean States and Canadian vessels, which usually fish perch to determine bottom relief, density of alone, Russian and Japanese vessels usuallyop- schools, and size of probable catch.Once a erate in fleets. A fishing fleet consists of fish- school is detected, its location is marked with a radio buoy.Conventional buoys are useless ing vessels, tankers, freezers, factory ships, and in the foggy Bering Sea. supply and service vessels. 5.12Boats 5.2 Fishing areas A wide variety of boats are used by Cana- Almost all the larger concentrations of S. dian and United States fishermen to trawl for alutus from Cape Blanco, Oreg., to the Koman- ocean perch.According to Alverson(1959) dorskiy Islands and the Bering Sea arenow the vessels most commonly used are converted being fished.Figure 31 shows major grounds, salmon seiners and halibut schooners which most of which were delineated by Alverson and average about 18 m. long (fig.29). Westrheim(1961)and Moiseev(1964).

27 Wind or Chain Curren t

Ground Chola Warp ro p e

4. 3.

Ground ro p e

---

(j1 Trawler B sends Its warp to A whIch nha cicles it to the ground rope Trawler B lays the warp; trawler A lays the ground rope Trawler A has cast its net and lays the portside ground rape, trawler B waits A has laid the porteide warp;the tow begins Towing the bulltrawl End of ths tow;fh e trawlers approach each other HaulingInthe net

Figure 28.Operation of a bull trawl (from Bourgois, 1951).

Trawling for Pacific ocean perch by United mai or catches were taken in summer between States and Canadian vessels (Alverson and 150 and 300 m. and in the winter between 275 Westrheim, 1961) has been carried out mainly and 400 m.Lestev (1961) found a similar at depths of 92 to 549 m.; however, the bulk distribution in the Bering Sea. of the catch is taken at depths of 146 to 366 m. Lestev(1964)fishedexperimentally at Depths for trawling vary with season and depths of 300 to 700 m., but it is not known area.In the Gulf of Alaska the most suitable if commercial fishermen have fished at these depths for commercial fishing for rockfish are between 180 and 350 m. in summer and 250 depths in the Bering Sea. and 420 m. in winter (Lyubimova, 1964). Al- Information is given elsewhere on areas of verson and Westrheim (1961) reported that greatest abundance (section 2.22),hydrograph-

28 i li ii ¡

A- Lw

s - - t'r- - - -- ___ :=;:::---= :::;;;; p- -=;:;::T±:_ -

Figure 29.Type of vessel used by North American fishermen to catch Pacific ocean perch.Length 15-30 m. (from Sundstrom, 1957). ical features associated with high abundance There is little agreement between author- (section 3.41), and changes in the location of ities as to the best time of year for the catching the fishery during its development (section of Pacific ocean perch.In the Bering Sea, 5.41). catches made during winter and spring were larger and more consistent than those made 5.3 Fishing seasons during summer (Lestev,1961). Lyubimova Fishing seasons for Pacific ocean perch are (1964)reported that in the western Gulf of not regulated by law but rather by weather Alaska near Unimak Pass, commercial catches and economic factors. Lestev(1961)reported were greatest from June to October.Westr- that extremely bad weather north of 570 N. heim (footnote3)found that Pacific ocean in the Bering Sea prevents fishing from No- perch were scarce in the northern and eastern vember through May.In areas to the south- parts of the Gulf of Alaska during winter. He ward fishing can be considered a year-round also reported that test fishing during the winter activity especially when carried out by the in Queen Charlotte Sound in1963-65yielded large ships used by the Japanese and U.S.S.R. few Pacific ocean perch in areas with a com- fishermen. During winter and spring the ma- mercial fishery during the summer, whereas ture fish move to deeper water so that the good catches were made in deeper waters off duration of the fishing season in a particular Vancouver Island during the entire year. area depends on the ability and willingness Differences in schooling and migratory be- of the fleets to pursue the fish into deeper havior seem to explain why catches may be waters and on the economic feasibility of such larger in some areas during certain seasons fishing. than at other times.

29 (a) (b)

Figure 30.Types of vessels used by the U.S.S.R. to harvest Pacific ocean perch:(c) stern-ramp trawler, length 84.5 m. (from Hitz, 1968). (a) side trawler, length 38-44 m., (b) side trawler, length 54.2 m., and (c) 70°E. 800 700 600 150° 400 30 ow.

60° 60°N.

55° 55°

GULF 0F ALASKA 500 500

450 450

400 40°

Figure 31.Locations of major fishing grounds for Pacific ocean perch (Alverson and Westrheim, 1961; Moiseev, 1964).

5.4Fishing operations and results In 1963 the U.S.S.R. fleet returned to the Gulf of Alaska and also began to fish for ocean 5.41Effort and intensity perch near the Aleutian Islands. About 135 me- Active commercial fishing for Pacific ocean dium trawlers and 12 stern-ramp trawlers were perch in the northwestern United States began fishing in the Gulf of Alaska in 1963 and about in 1946 (Alverson and Westrheim, 1961). Un- 5 stern-ramp trawlers in the Aleutian Island til that time, ocean perch were incidental in area.In 1964 about 150 U.S.S.R. vessels were catches of other fish. From 1946 to 1951, most in the Gulf of Alaska and about 20 near the boats fished off Oregon and Washington. After Aleutian Islands; in 1965 about 130 ships were 1951, however, the fishery expanded rapidly, in the Gulf and 20 near the Aleutians. The fleet moved as far south as Dixon Entrance in 1965. and soon trawlers were fishing from Oregon In [May] 1966, the Soviet perch fleet in the northward to Queen Charlotte Sound, British Gulf of Alaska reached a peak of 131 vessels. Columbia.Trawlers operating out of Wash- In February 1966, some of these vessels moved ington and Oregon ports have had the fishery south to British Columbia, fishing from Dixon almost exclusively to themselves, having taken Entrance to Queen Charlotte Sound; in early at least nine times the Canadian catch each year April, two stern-ramp trawlers and 23 side except 1958. trawlers began fishing for ocean perch off New- Alverson and Westrheim (1961) predicted port, Oreg. They remained there until catches that the waters off southeastern Alaska and the apparently dropped off in early May. In 1967, Aleutian Islands were potential grounds for the maximum size of the fleet in the Gulf of expanding the Pacific ocean perch fishery. Alaska was about 94 vessels. Up to 105 ves- Their prediction was quickly realized.The sels were operating off the coasts of British U.S.S.R., from an initial trawling effort in the Columbia, Washington, and Oregon. How Bering Sea in 1959 (30-40 trawlers), had by many were fishing for Pacific ocean perch is 1962 begun to harvest S. alutus ìn the Gulf not known. of Alaska. In June 1962 about 50 Soviet trawl- The Japanese have had massive trawling ers and 9 refrigerated ships moved from the operations in the Bering Sea since 1954, pri- Bering Sea into the Gulf of Alaska.Later in marily for pleuronectids, and only since 1960 1962, this fleet increased to about 70 vessels. have Pacific ocean perch appeared in their

31 catch reports.Although information on the amounts of Pacific ocean perch less than 25 number of ships and effort expended by Japan cm. in fork length.The Japanese use essen- on ocean perch in the Bering Sea is not avail- tially the same gear in the Gulf of Alaska. able. the catch statistics indicate that the ef- The Russian fishermen are believed to use 4.1- fort on ocean perch is minor in relation to the cm. webbing in the cod-end and thus take total Bering Sea effort.If we assume that the younger (smaller) fish if they are available catch per unit of effort has been relatively to the trawls. stable from year to year since 1960, we can interpret the increasing catches to mean in- 5.43Catches creasing effort. Table 11 gives catches of Pacific ocean Japanese fishing vessels first moved into perch for the North American nations (Canada the Gulf of Alaska in 1960.The size of the and the United States), the U.S.S.R., and fleet gradually increased to 13 vessels in 1965, Japan; section 4.5 discusses maximum equil- 6 of which were stern-ramp trawlers (see foot- ibrium yield. note 6). By 1965 Japanese vessels were fishing off the Washington and Oregon coasts. 6 PROTECTION AND MANAGEMENT To date no comprehensive catch-per-unit-of- 6.1Regulatory (legislative) measures effort data have been published for any of the major Pacific ocean perch fisheries, although 6.11Limitation or reduction of 'total several authors have reported information on catch the gross catch per hour. Alverson and Westr- heim (1961) found that the average catch per No limitations on total catch. hour for Washington-based trawlers for the late 1950's ranged from 0.36 to 0.91 metric Table 11.-Catches of S. alutus by year and nation, ton with a general increase towards the north- 1946-68 ern extremity of the fishing ground (Queen Year United States U.S.S.R.° and Canada1 j Japan3 Total Charlotte Sound, British Columbia). This j Metrictous trend, they cautioned, may have been influenced 1946 44 44 to some extent by greater efficiency of vessels 1947 74 74 1948 96 96 fishing the northern grounds.Alverson et al. 1949 474 474 (1964) presented information on average catch 1950 691 691 1951 842 842 per hour by depth for research vessels sampling 1952 2,918 2,918 in four areas-Washington-Oregon, British Co- 1953 2,792 2,792 1954 4,950 4,950 lumbia-southeastern Alaska, Gulf of Alaska, 1955 2,388 o 2,388 and Alaska Peninsula.The highest average 1956 3,703 3,801 7,504 1957 3,578 6,601 10,179 catch per hour was in the Washington-Oregon 1958 2,674 3,301 5,975 coastal areas (0.768 metric ton per hour). Av- 1959 4,018 1,400 5,418 1960 4,369 17,502 430 22,301 erage catch per unit of effort is probably higher 1961 5,773 20,603 13,077 39,453 in the Bering Sea and the Gulf of Alaska. Data 1962 8,317 61,610 13,622 83,549 1963 11,188 129,921 30,626 171,735 provided by Moiseev and Paraketsov (1961), 1964 9,962 275,746 58,613 344,321 Lestev (1961, 1964), and Lyubimova (1963, 1965 14,272 391,900 75,050 481,222 1966 12,325 247,900 110,984 371,209 1964, and 1965) suggest that the average catch 1967 16,180 162,000 101,788 279,968 per unit of effort was about 5 metric tons per 1968 12,610 98,494 121,468 232,572 hour, at least in the early years of the fisheries 1 Data for 1946:55 from Alverson and Westrheim (1961), and data for 1956-68 from Pacific Marine Fisheries Commission (1964-68). in those areas. 2 U.S.S.R.catchesincludesmallbut unknown quantitiesof other rockfishes. Data for195 5-64 from Food and Agricultural Organization of the United Nations (1956-65) and International Commission for the 5.42Selectivity Northwest AtlanticFisheries(1957-66). FAO statisticsfor U.S.S.R. ocean perch catches were foc the Atlantic and Pacific Oceano combined; ICNAF (Atlantic Ocean) catches svere subtracted from the FAO totals to yield the Pacific Ocean catches.Data for 1965 and 1966 from Inter- Washington, Oregon, and British Columbia national NorthPacific Fisheries Commission (1967) and for 1967 and 1968 from Herbert A. Larkins, Fishery Biologist, Bureau of Commercial trawlers are now using 8.9-cm. stretched mesh Fisheries Biological Laboratory,Seattle, Wash. (Personal communication, December I, 1969). webbing.This gear does not take significant Data from International North Pacific Fisheries Commission (1961-69).

32 6.12Protection of portions of pop- H. R. MacMillan Lectures in Fisheries, ulation Univ.BritishColumbia,Inst.Fish., No regulations exist in North America for Vancouver, B.C., Canada, 190 pp. limitations of size or efficiency of gear or craft, ALVERSON, DAYTON L., and closed seasons, or sex or condition of fish. SIGURD J. WESTRHEIM. 1961. A review of the taxonomy and bi- Closed areasthe United States provides ology of the Pacific ocean perch and its some protection to fish resources by prohibiting fishery.Cons. Perma. Tnt. Explor. Mer., fishing by foreign vessels within 12 nautical Rapp. Proc.-Verb. 150: 12-27. miles of the coast.Canada similarly protects ARAI, HISAO P. the stocks adjacent to her coast, except that 1969.Preliminary report on the parasites United States fishermen fish in Queen Charlotte of certain marine fishes of British Co- Sound. lumbia.J. Fish. Res. Bd. Can. 26: 2319- Restrictions on use of fishin California, 2337. trawl-caught fish, including Pacific ocean perch, ARON, W. are taxed 5 cents per 45.4 kg. (100 pounds) 1958.Preliminary report of midwater if used for any purpose other than human trawling studies in the North Pacific consumption. Ocean. Univ. Wash., Seattle, Dep. Ocean- ogr., Tech. Rep. 58, 64 pp.[Processed.] AYRES, WILLIAM O. ACKNOWLEDGMENT 1854a.New species of Californian fishes. Paul T. Macy of the Seattle Biological Lab- Proc. Bost. Soc. Natur. Hist. 5: 94-103. oratory's Publications Unit made a significant 1854b.[New species of California fishes.] contribution to this synopsis.In checking the Proc. Calif. Acad. Sci. 1: 7-8. literature citations, he went far beyond the 1859. [New species of California fishes]. standard review and frequently called our at- Proc. Calif. Acad. Sci. 2: 25-32. tention to information that we previously had 1862.[New species of California fishes]. overlooked. Proc. Calif. Acad. Sci. 2: 207-218. BARSUKOV, V. V. LITERATURE CITED 1964.Vnutrividovaya izmenchivost' u AHLSTROM, ELBERT H. Tikhookeanskogo morskogo okunya (Se- 1965.Kinds and abundance of fishes in bctstodes alutus Gilbert).[Interspecies the California Current region based on variability of the Pacific ocean perch egg and larval surveys.Calif. Coop. (Sebastodes alutus Gilbert)]. In: Soviet Oceanic Fish. mv., Rep. 10: 31-52. fisheries investigations in the northeast- ALVERSON, DAYTON L. ern part of the Pacific Ocean, Part II 1959.Trends in trawling methods and (Sovetskie rybokhozyaistvennye issledo- gear on the west coast of the United vaniya y severo-vostochnoi chasti Tik- States.In: Humar Kristjonsson(ed- hogo okeana, vyp. II).Tr. Vses. Nauch.- itor), Modern fishing gear of the world, issled. Inst. Morsk. Ryb. Khoz. Okeanogr. pp. 317-320. Fishing News (Books) Ltd., 49 (Izv. Tikhookean. Nauch.-issled, Inst. London. Morsk. Ryb. Khoz. Okeanogr. 51):231- 1967. A study of demersal fishes and fisheries of the northeastern Pacific Ocean. 252. (Transi. pp. 241-267 in complete Ph.D. Thesis, Univ. Washington, Seattle, volume transi. avail. Clearinghouse Fed. 286 pp. (Typescript.) Sci.Tech.Inform.,Springfield,Va., ALVERSON, D. L., A. T. PRUTER, and TT 67-51204.) L. L. RONHOLT. BOURGOIS, FRANCOIS. 1964. A study of demersal fishes and fish- 1951.Japanese offshore trawling.U.S. eries of the northeastern Pacific Ocean. Fish Wiidl. Serv., Fish. Leafi. 389, 60 pp.

33 CRAMER, FRANK. GIRARD, CHARLES. 1895.On the cranial characters of the 1854a.Description of new fishes collected genus Sebastodes (rockfish). Proc. Calif. by Dr. A. L. Heermann, naturalist at- Acad. Sci., Ser. 2, 5(1): 573-610.(Re- tached to the survey of the Pacific Rail- printed, 1895, in Leland Stanford Jr. road route, under Lieutenant R. S. Wil- Univ. Pubi., Hopkins Seaside Lab., Con- liamson, U.S.A.Proc. Acad. Natur. Sci. trib. Biol. II.) Philadelphia 7:129-140. DELACY, ALLAN C., CHARLES R. RITZ, 1854b.Observations upon a collection of and ROBERT L. DRYFOOS. fishes made on the Pacific Coast of the 1964.Maturation, gestation, and birth of United States, by Lieut. W. P. Trow- rockfish (Sebastodes) from Washington bridge, U.S.A., for the museum of the and adjacent waters. Wash. Dep. Fish., Smithsonian Institutiop.Proc. Acad. Fish. Res. Pap. 2(3): 51-67. Natur. Sci. Philadelphia 7: 142-156. EIGENMANN, CARL H., and 1856.Contribution to the ichthyology of CHARLES H. BEESON. the western coast of the United States 1893.Preliminary note on the relation- from specimens in the museum of the ship of the species usually united under Smithsonian Institution.Proc. Acad. the generic name Sebastodes.Amer. Natur. Sci. Philadelphia 8:131-137. Natur. 27: 668-671. GREENWOOD, MELVIN R. 1895. A revision of the fishes of the sub- 1958.Bottom trawling explorations of family Sebastinae of the Pacific coast of southeastern Alaska, 1956-57.Commer. America. Proc. U.S. Nat. Mus. 17: 375- Fish. Rev. 20(12): 9-21. 407. GRITSENKO, O. F. FOOD AND AGRICULTURAL ORGANIZA- 1963.Vozrast i temp rosta Tikhookeans- TION OF THE UNITED NATIONS. kogo morskogo okunya Beringova morya 1956-65. Yearbook of fishery statistics (Age and growth rate of Pacific ocean (years 1955-1964), vols. 5-7, 9, 11, 12, perch in the Bering Sea).In:Soviet 14-16,18. Food Agr. Organ. United fisheries investigations in the northeast- Nations, Rome. (Various pagination.) ern Pacific Ocean, Part 1(Sovetskie GILBERT, CHARLES H. rybokhozyaistvennye issledovaniya y 1890.Scientific results of explorations by severo-vostochnoi chasti Tikhogo okeana, the U.S. Fish Commission steamer A iba- vyp. 1). Tr. Vses. Nauch.-issled.Inst. tross.No. 12. A preliminary report on Morsk. Ryb. Khoz. Okeanogr. 48 (Izv. the fishes collected by the steamer Alba- Tikhookean. Nauch.-issled. Inst. Morsk. tross on the Pacific coast of North Amer- Ryb. Khoz.Okeanogr. 50):313-316. ica during the year 1889, with descrip- (TransI. pp. 328-331 in complete vol. tions of twelve new genera and ninety- transi, avail.Clearinghouse Fed. Sci. two species.Proc. U.S. Nat. Mus. 13: Tech. Inform., Springfield, Va., as TT 49-126. 67-51203.) GILL, THEODORE. RITZ, CHARLES R. 1861.Notes on some genera of fishes of 1965.Field identification of the north- the western coast of North America. eastern Pacificrockfish(Sebastodes). Proc. Acad. Natur. Sci. Philadelphia 13: U.S. Fish Wildl. Serv., Circ. 203, 58 pp. 164-168. 1968.Catalogue of the Soviet fishing fleet. 1862. Note on some genera of fishes of Nat. Fish., Yearbook Issue 1968, 48 (13): Western North America.Proc. Acad. 9-19, 21-24. Natur. Sci. Philadelphia 14: 329-332. INTERNATIONAL COMMISSION FOR 1864.Critical remarks on the genera Se- THE NORTHWEST ATLANTIC bastes and Sebastodes of Ayres. Proc. FISHERIES. Acad. Natur. Sci. Philadelphia 16: 145- 1957-66.Statisticalbulletin[for years 147. 1955-1964J.Int. Comm. Northwest Atl.

34 Fish., Halifax, N.S., Canada.(Various Beringovom more (Technique of rock- pagination.) fish trawling in the Bering Sea).In: INTERNATIONAL NORTH PACIFIC Sovietfisheriesinvestigationsin the FISHERIES COMMISSION. northeastern Pacific Ocean, Part 3 (Soy- 1961-69.Proceedings of annual meetings etskie rybokhozyaistvennye issiedoyan- (1961-69).Int. N. Pac. Fish. Comm., iya y severo-vochostnoi chasti Tikhogo Vancouver,B.C.Canada. (Various okeana, vyp. 3).Tr. Vses. Nauch.-issied. pagination.) Inst. Morsk. Ryb. Khoz. Okeanogr. 53 JORDAN, DAVID STARR. (Izv.Tikhookean. Nauch.-issied.Inst. 1887. A catalogue of the fishes known to Morsk. Ryb. Khoz. Okeanogr. 52):213- inhabit the waters of North America, 221. (Transi. pp. 319-336 in complete north of the Tropic of Cancer, with notes vol. transi, avail. Clearinghouse Fed. Sci. on species discovered in 1883 and 1884. Tech. Inform., Springfield, Va., as TT U.S. Comm. Fish and Fish., Rep. Comm. 67-51205.) 1885: 789-973. LISOVENKO, L. A. JORDAN, DAVID STARR, 1964.Raspredelenie lichinok Tikhookean- BARTON WARREN EVERMANN, skogo morskogo okunya Sebastodes alutus and HOWARD WALTON CLARK. Gilbert y zalive Aiyaska [Distribution of 1930.Check list of the fishes and fishlike larval Pacific ocean perch (Sebastodes vertebrates of North and Middle America alutus G.) in the Gulf of Alaska].In: north of the northern boundary of Ven- Sovietfisheriesinvestigationsinthe ezuela and Colombia.U.S. Comm. Fish northeastern Pacific Ocean, Part 3 (So- and Fish., Rep. Comm. 1928, Pt. 2, 670 vetskie rybokhozyaistvennye issledova- pp.(Doc. #1055.) niya y severo-vostochnoi chasti Tikhogo JORDAN, DAVID STARR, and okeana, vyp. 3).Tr. Vses. Nauch.-issled. CHARLES H. GILBERT. Inst. Morsk. Ryb. Khoz. Okeanogr. 53 1880.Description of seven new species (Izv. Tikhookean. Nauch.-issled.Inst. of sebastoid fishes from the coast of Morsk. Ryb. Khoz. Okeanogr. 52): 223- California.Proc. U.S. Nat. Mus. 3: 287- 231. (Transi. pp. 217-225 in complete 298. volume transi. avail. Clearinghouse Fed. 1882.Synopsis of thefishes of North Sci. Tech. Inform., Springfield, Va., as America.U.S. Nat. Mus. Bull. 16, 1018 TT 67-51205.) pp. 1965.0 piodovitostiSebastodesalutus KIBESAKI, OSAMU. Gilbert zal. Alyaska (On the fecundity of 1965.Hokuyo no okeru teigyoshigen Sebastodes alutus Gilbert of the Gulf of (Demersal fish resources in the North Alaska).In:Soviet fisheries investi- Pacific).Nihon Suisan Shigen Hogo gations in the northeastern Pacific Ocean, Kyogikai, Suisan Kenkyu Soho (Japan Part 4 (Sovetskie rybokhozyaistvennye Fish. Resourc. Conserv. Ass., Fish. Res. issiedovaniya y severo-vostochnoi chasti Ser.)11, 45 pp. (Transi., 1966, Bur. Tikhogo okeana, vyp.4).Tr. Vses. Commer. Fish., Br. Foreign Fish., Wash- Nauch.-issied.Inst. Morsk. Ryb. Khoz. ington, D.C.) Okeanogr. 58 (Izv. Tikhookean. Nauch- LESTEV, A. V. issied. Inst. Morsk. Ryb. Khoz. Okeanogr. 1961.Tralovyi by okunya y Beringovom 53):171-178.(Transi. pp. 162-169 in more (The trawl fishery for rockfish in complete vol. transI, avail. Clearinghouse the Bering Sea).Moscow, Izd. Ryb. Fed. Sci. Tech. Inform., Springfield, Va., Khoz. (Tekhnika Rybolovstva Seriya), as TT 67-51206.) 26 pp.(Preliminary transi., Fish. Res. LISTON, JOHN, and CHARLES R. HITZ. Bd. Canada, Bioi. Sta., Nanaimo, B.C., 1961.Second survey of the occurrence of Transi. Ser. 439). parasites and blemishes in Pacific ocean 1964.Tekhnika tralovogo lova okunya y perch, Sebastodes alutus, May-June 1959.

35 U.S. Fish Wildi. Serv., Spec. Sci. Rep. Tikhogo okeana, vyp.4).Tr. Vses. Fish. 383, 6 pp. Nauch.-issled. Inst. Morsk. Ryb. Khoz. LISTON, JOHN, JOHN PETERS, and Okeanogr. 58 (Izv. Tikhookean. Nauch.- JOSEPH A. STERN. issled. Inst. Morsk. Ryb. Khoz. Okeanogr. 1960.Parasites in summer-caught Pacific 53): 95-120. (TransI. pp. 85-111 in rockfishes.U.S. Fish Wildi. Serv., Spec. complete vol. transI, avail. Clearinghouse Sci. Rep. Fish. 352, 10 pp. Fed. Sci. Tech. Inform., Springfield, Va., LYUBIMOVA, T. G. as TT 67-51206.) 1963.Osnovnye cherty biologii i raspredel- MATSUBARA, KIYOMATSU. eniya Tikhookeanskogo morskogo okunya 1943.Studies on the scorpaenoid fishes of (SebastodesalutusGilbert)y zalive Japan: Anatomy, phylogeny, and taxon- Alyaska [Some essential features of the omy.Trans. Sigenkagaku Kenkyusyo 1 biology and distribution of Pacific ocean and 2, 486 pp. perch (Sebastodes alutus Gilbert) in the MOISEEV, P. A. Gulf of Alaska].In:Soviet fisheries 1964.Nekotorye itogi issledovanii Bering- investigationsin northeasternPacific ovomorskoi nauchno-promyslovoi ekspe- Ocean, Part i (Sovetskie rybokhozyaist- ditsii (Some results of investigations car- vennye issledovaniya y severo-vostochnoi ried out by the Bering Sea research chasti Tikhogo okeana, vyp.1).Tr. expedition).In:Soviet Fisheries In- Vses. Nauch.-issled.Inst. Morsk. Ryb. vestigations in the northeastern part of Khoz.Okeanogr.48 ( Izv.Tihookean. the PacificOcean, Part 3(Sovetskie Nauch.-issled.Inst. Morsk. Ryb. Khoz. rybokhozyaistvennye issledovaniya y Okeanogr. 50):293-303.(TransI. pp. severo-vostochnoi chasti Tikhogo okeana, 308-318 in complete vol. transl. avail. vyp. 3).Tr. Vses. Nauch.-issled.Inst. Clearinghouse Fed. Sci. Tech. Inform., Morsk. Ryb. Khoz. Okeanogr. 53 (Izv. Springfield, Va. as TT 67-51203.) Tikhookean. Nauch.-issled, Inst. Morsk. 1964.Biologicheskaya kharakteristika Ryb. Khoz. Okeanogr. 52): 7-29. (TransI. stada morskogo okunya Sebastodes alutus pp. 1-21 in complete vol. transl. avail. G. zaliva Alyaska (Biological character- Clearinghouse Fed. Sci. Tech. Inform., istics of the Pacific redfish in the Gulf Springfield, Va., as TT 67-51205.) of Alaska).In:Soviet fisheries inves- MOISEEV, P. A., and I. A. PARAKETSOV. tigationsinthe northeasternPacific 1961.Nekotorye dannye ob ekologii mor- Ocean, Part 3 (Sovetskie rybokhozyaist- skikh ershei (sem. Scorpaenidae) sever- vennye issledovaniya y severo-vostochnoi noi chasti Tikhogo okeana [Information chasti Tikhogo okeana, vyp. 3).Tr. on the ecology of rockfishes (family Scor- Vses. Nauch.-issled. Inst. Morsk. Ryb. paenidae) of the northern part of the Khoz. Okeanogr. 53(Izv. Tikhookean. Pacific Ocean]. Vop. Ikhtiol. Vol. 1, No. Nauch.-issled. Inst. Morsk. Ryb. Khoz. 1 (18): 39-45. (Preliminary transl. Fish. Okeanogr. 52): 213-221.(TransI. pp. Res. Bd. Can., Biol. Sta., Nanaimo, B.C., 208-216 in complete vol. transI,avail. FRB Transi. Ser. 358.) Clearinghouse Fed. Sci. Tech. Inform., PACIFIC MARINE FISHERIES Springfield, Va., as TT 67-51205.) COMMISSION. 1965.Osnovnye etapy zhiznennogo tsikla 1964-68.Data series:bottom or trawl morskogo okunya Sebastodes alutus Gil- fish.Pac. Mar. Fish. Comm., Portland, bert y zal. Alyaska [The main stages of Oreg.[Various pagination.] the life cycle of Pacific ocean perch (Se- PARAKETSOV, I. A. bastodes alutus Gilbert) in the Gulf of 1963.0 biologii Sebastodes alutus Bering- Alaska].In: Soviet fisheries investiga- ova morya (On the biology of Sebastodes tions in the northeastern Pacific Ocean, alutus in the Bering Sea).In:Soviet Part 4 (Sovetskie rybokhozyaistvennye fisheries investigations in northeastern issledovaniya y severo-vostochnoi chasti Pacific Ocean, Part i(Sovetskie rybo-

36 khozyaistvennye issledovaniya y severo- field, Va., as TT 67-51204.) vostochnoi chasti Tikhogo okeana, vyp. SNYTKO, V. A. 1).Tr. Vses. Nauch.-issied. Inst. Morsk. 1968.Tikhookeanskii okun' y Vankuvers- Ryb. Khoz. Okeanogr. 48 (Izv. Tikhook- ko-Oregonskom raione(Pacificocean ean.Nauch.-issled.Inst. Morsk. Ryb. perch in the Vancouver [Island]- Oregon Khoz. Okeanogr. 50): 305-312.In Rus- region).Ryb. Khoz. 44(10): 9. sian.(Transi. pp. 319-327 in complete SOROKIN, V. P. voL transi.avail.Clearinghouse Fed. 1961.The redfish; gametogenesis and mi- Sci. Tech. Inform., Springfield, Va., as grations of the Sebctstes marinus (L.) TT 67-51203.) and Sebastes mentalla Travin. Cons. PHILLIPS, JULIUS B. Perma. mt. Explor. Mer., Rapp. Proc.- 1957. A review of the rockfishes of Cal- Verb. 150: 245-250. ifornia (Family Scorpaenidae).Calif. 1967.Nekotorie svedeniya o gametogeneze Dep. Fish Game, Fish Bull. 104, 158 pp. ipolovykhtsiklakhTikhookeanskikh POWELL, DONALD E., skorpenid (Some data on gametogenesis DAYTON L. ALVERSON, and and sexual cycles of the Pacific Ocean ROBERT LIVINGSTONE, JR. Scorpaenids). Tr. Polyar. Nauch.-issled. 1952.North Pacific albacore tuna explor- Inst. Morsk. Ryb. Khoz. Okeanogr. 20: ation, 1950. U.S. Fish WildI. Serv., Fish. 304-315. (Transi., 1968, Fish. Res. Bd. Leafi. 402, 56 pp. Can., Biol. Sta., St. Johns, Nfld., Transi. POWELL, DONALD E., and Ser. 1137.) HENRY A. HILDEBRAND. SUNDSTROM, GUSTAF T. 1950.Albacore tuna exploration in Alask- 1957.Commercial fishing vessels and gear. an and adjacent waters, 1949.U.S. Fish U.S. Fish Wildi. Serv., Circ. 48, 48 pp. Wildl. Serv., Fish. Leafi. 376, 33 pp. THOMPSON, WILLIAM F. RICHARDSON, (SIR) JOHN. 1915. A new fish of the genus Sebastodes 1844.Ichthyology.In: R. B. Hinds (ed- from British Columbia, with notes on itor), The zoology of the voyage of H. others. Brit.Columbia, Rep. Comm. M. S. "Sulphur," under the command of Fish. 1914: 120-122. Captain Sir Edward Belcher, during the TOMILIN, A. G. years 1836-42, pp. 51-150.London. 1957.Kitoobraznye.Zveri SSSR ipri- ROSA, H., JR. lezhashchikh stran, Tom 9(Cetaceans. 1965.Preparation of synopses on the bi- Mammals of the U.S.S.R. and adjacent ology of species of living aquatic organ- countries, Vol.9).Izd. Akad. Nauk isms. Food Agr. Organ. United Nations, SSSR, Moscow, 756 pp.(Transi, avail. FAO Fish.Synopsis 1, Rev. 1, 75 pp. Clearinghouse Fed. Sci. Tech. Inform., [Processed.] Springfield, Va., as TT 65-50086.) SKALKIN, V. A. TOMINAGA, HIROSHI. 1964.Pitanie morskikh okunei y Bering- 1963.Mothership fleets, their methods and ovom more (The feeding of ocean perch fishing gear.In:Modern fishing gear in the Bering Sea).In:Soviet fisheries of the world 2, pp. 423-428.Fishing investigations in the northeastern Pacific News (Books) Ltd., London. Ocean, Part 2 (Sovetskie rybokhozyaist- WESTRHEIM, SIGURD JERGEN. vennye issledovaniya y severo-vostochnoi 1958.On the biology of Pacificocean chasti Tikhogo okeana, vyp. 2). Tr. Vses. perch Sebastodes alutus (Gilbert).M.S. Nauch.-issled. Inst. Morsk. Ryb. Khoz. Thesis, Univ. of Washington, Seattle, 106 Okeanogr. 49 (Izv. Tikhookean. Nauch.- pp.[Typescript.] issled. Inst. Morsk. Ryb. Khoz. Okeanogr. WESTRHEIM, S. J., and H. TSUYUKI. 51):151-166. (Transi. pp. 159-174 in 1967.Sebastodes reedi, a new scorpaenid complete vol.transl.avail.Clearing- fish in the northeast Pacific Ocean.J. house Fed. Sci. Tech. Inform., Spring- Fish. Res. Bd. Can. 24: 1945-1954.

37 WILKES, S. N. 1957.The parasitic copepods of the long- jawed rockfish, Sebastodes alutus(Gil- bert).M.S. Thesis, Oregon State Col- lege, Corvallis, 28pp.[Typescript.] MS.2O35 GPO 997-680

38 YNOPSES OF FISHERIES 3IOLOGICAL DATA This is mìe o, u series of documents issued by FAO, CSIRO and TJSFWS concerning species and stocks of amial je olganisins of present or potential economic interest.The primary purpose of this series is to make existing ¡ fcnmat inn readily available to fIshery scientists aecording to a standard pattern, and byso doing alsoto draw attention to gaps in knowledge.Itis hoped that synopses in this series will be useful to other scbntists initiating investigations of the species concerned or of related ones, as a means of exchange of knowledge among those already working on the species, and as the basis for comparative study of fisheries sources.The- willlie brought up to date from time to time as farther information becomes available tier as revisions of the entire document or their specific chapters. lìe relevant series of documents are: FAO I'islìeries Syuotsis No. FR/S I replaeiiwr, ai, ...rom :Li.03 FAO Fisheries Biology Synops FE/S CSIRO Pisiieries Synopsis No. I)FO/S and T$SFWS FAO Fisheries Synopsis No. BCF/S Synopses in finse series are compiled according' to a standard outline described in Fib/Si Rev. 1 (1905) FAO CSITiO anti USFWS aie working to secure the co-operation o-f other organizationsand of individuai ..i.-ntists in qualifying synopses on species about which they have knowledge, and welcome offers of help in tlui task. A dditious and CorreCtions in synopses already issuedvill also he most welcome.Comments including suggestions foi' the espansion oC tIte outline anti requests for information should be addressedto the co-ordinatcirs and editors of the issuing organizations: FAO: Fishery Resources 1.)ivision Mai'ine Biology and Environment Branc Food :i nd Agricul tare Organization 01' the United Nations Via dello Terme di Caracalla 00100 Rouie, Italy CSIRO: en A. \\Triolit cientific Editor '1RO Division of Fisheries and Ice Box 21 Cronulla, N.S.W. 2230 Australia Thomas A. \lanar Chief, Scientific Publications Unit National L\l arino Fisheries Service Bldg. 67, Naval Support Activity Seau le. Washington 98.115, U.S.A. Svnoosis û f biological data on the Norway pout Trisopterus esma-ri anuary 1968 ilev.I (Nilesont 1855 .l"ri/816 Synopsis of biological data on the bream A bra rias broma (L.) 'ebruary 1968 FRm/S3-1 Synopsis of biological data on he blue whiting i1-licrnmesistius poutassou. uiy 1968 Rev. 1. (Risso)IS [0 I'Rm/S37 Synopsis of biological data on the Malayan anchovy Stolephorus pseucloheer- April 1968 il, bus H :trdtnherg 19:33 1'lIn/S38 Svi apsis of biological data on.1 seepS yllum nodoso-nt. (Linnaeus) Le Jolis August 1968 1' Rm,'S39 Synopsis of biological data on .11oìwst routa lotíssimu,n Wittrock in Japanese August 1968 cultivation BC I Synopsis of the biological data on the Pacific mackerel, Scoinl,&r japonicus February 1969 lloutturn (Northeast Pacific) BCF'.'S.il Synopsis of' biological data on the chum salmon, Oneorlqjnchus Iceta March 1970 (Walhaum) 1792 BCF, S42 Synopsis of biological data on the Atlantic menhaden, Brei.'oortiu tyì'annu.s November 1969 FRi. S00 Re, i Synopsis of biological data on the pike Eso.r w'ins (Linnaeus) 1758 I\lay 1909 FErn 'Sf3 Synopsis of biological data on the anchoveta Cetcng-roulis mystice tus October 19 fiunther, 186G J) FO 'SO Synopsis of biological data on the tiger prawn Penacus esculentus July 1969 llaswill, 1879 F' ll.!S:5 Synopsis of biological data on West African croakers Psc-odotolithns typos, November 1969 Ro-.t e eqo lesin od P. clon go tus F'Rni 'S78 Synopsis of biological data on smelt Osmoerns ei.erlanus (Linnaeus) 1758 December 1909 FRi '48i) Synopsis of' biological dieta on the eel il ngiiilla anguilla (Linnaeus) 1758 April 1970 i)I'O S4 Synopsis of biological cinta on the rainbow prawn Pa-ro penaeopsis scuiptilis May 1970 I)F'O/S5 Synopsis of biological data on the school prawn il-Jeta penacus macleayi May 1970 UNITED STATES DEPARTMENT OF COMMERCE NATIONAL OCEANIC & ATMOSPHERIC ADMINISTRATION NATIONAL MARRIE FISHERIES SERVICE SCIENTIFIC PUBLICATIONS UNIT BLDG'S7, NAVAL SUPPORT ACTWITY SEATTLE, WASHINGTON 98115 POSTAGE AND FEES PAID US. DEPARTMENT OF COMMERCE OFFICIAL BUSINESS

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