Experimental Squid JiggingOff the Washington Coast
ROGER W. MERCER and MICHELE SUCY
Introduction
In the spring of 1981, the Northwestand Alaska Fisheries Center (NWAFC)of the National Marine Fisheries Servicewas contacted by Capta i n JerrySweeney of the salmon charter vesselTres Cher in regard to squid jigging as analternative to the declining salmon charter fishery off the Washington coast. Areview of existing literature on squidyielded several pieces of informationwhich indicated some potential for a nailsquid, Onychoteuthis borealijaponicus,or flying squid, Ommastrephes bartramii, fishery off the Washington coast.Marine mammal stomach content information (Kajimura et a!., 1980; Fis-
Roger W. Mercer is with the Resource Assessment and Conservation Engineering Division,Northwest and Alaska Fisheries Center, NMFS,NOAA, 7600 Sand Point Way .E., Seattle, WA98115. Michele Bucy is with the Soil SamplingService, Inc., 5815 Meridian Ave. N., Puyallup,WA 98371.
ABSTRACT-In the spring of 1981, theResource Assessment and Conservation Engineering Division oj the NMFS Northwestand Alaska Fisheries Center loaned twosquid jigging machines to Captain JerrySweeney oj the fishing vessel Tres Cher.These were used along with four of his ownmachines Jor experimental squid fishing offthe Washington coast. This experimentalfishing was prompted by reports of possiblecommercial quantities oj nail squid,Onychoteuthis borealijaponicus, and flyingsquid, Ommastrephes bartramii, in thenortheastern north Pacific Ocean. Fishinglocations were selected based on northernfur seal, Callorhinus ursinu , stomach content data which indicated either or bothspecies oj squid might be found over depthsgreater than 200 m at the head ofsubmarine
56
cus, 1982) indicated that nail squidmight be found along the Washingtoncontinental shelf at the head of submarine canyons. Experimental squidfishing conducted off the coast of BritishColumbia during 1980 (Bernard, 1981)resulted in catches of flying squid andnail squid, and reports from Japan (Okutani, 1977) indicated that both specieswere taken commercially by Japanesevessels for domestic markets.
In light of this information, a decisionwas made to conduct experimental squidfishing off Washington during the summer months of 1981. Two Japanese SanparI squid jigging machines belongingto the NWAFC were loaned to CaptainSweeney for comparison with his ownSwedish Kemers Atlanter machines during the planned experimental squid jig-
I Mention of trade names does not imply endorsement by the National Marine Fisheries Service, NOAA
canyons. Nocturnal squid jigging operations were conducted as an adjunct to daylight jigging for black rockfish, Sebastesmelanops, or trullinEdor albacore. Thunnusalalunga. The Tres Cher was olllfitted withtuna trolling gew; fish jig/?ing machines,and squid jigging machines.
A total of1,261 squids were caughl during21 nights of jigging Fom 10 May to 14 September 1981. Yivo of the squid caught wereflying sqwd and the rest were nail squid.About half of the squid cau!?ht were measured and examined for /?ender and sexualmaturity. Squid were not captured in commercial quantities during these experiments, but it is felt that commercial quantities oj nail squids miglll be available ofJthe Washin/?ton coast during periods whencoastal upwelling occurs.
ging trips. These machines weremounted on the Tres Cher at its berth inTacoma, Wash. The vessel was thenmoved to Westport, Wash., in early Mayto begin squid fishing experiments.
This paper documents this experimental squid fishing and, especially, describes in detail what was learned regarding jigging of oceanic squids.
Methods and Materials
The Tres Cher is a 17.1 m (56-foot),twin screw salmon charter vessel powered by two Volvo-Penta TMD-120300-horsepower diesel engines. AnIsuZll diesel electrical generator provides 20 kW of 60 Hz electrical power ateither 230 or 115 volts. Initially, tworecording depth sounders were used tosearch for squid schools. These were aMorrow JMF-15IG system used with a50 kHz transducer and a Si-tex HE-32Esystem with a 200 kHz transducer. AJRC/JFV-516 color recorder was installed in mid-August and slaved to theMorrow 50 kHz system. Navigationalequipment included a Raytheon Pathfinder 2800 radar, and a Morrow Loran Csystem which included an LCA-3450receiver, a CS-3450 steering computer,and an XYP 4000 plotter.
Lighting equipment consisted of three1,000-watt incandescent lamps placednear the jigging machines on the portquarter of the vessel. In addition to theincandescent lamps, two pairs of 3,000and 1,500-watt quartz halogen floodlights were positioned on the mast facingforward and aft, respectively.
Surface water temperature was measured with a bucket cast thermometer.Subsurface temperatures were measuredto a depth of 30.5 m using a Heathkit
Marine Fisheries Review
Thermospot thermometer. Thermospottemperatures were indicated inFahrenheit and converted to Celsius.Corrections were applied to the Thermospot values per calibration checksagainst the bucket cast thermometer. National Weather Service sea surface thermal analyses were obtained on a weeklybasis and used to help locate areas ofcoastal upwelling.
Fishing gear used for squid includedsport rods (hand jigging), two JapaneseSanpar Models 76-2 and 7-2 squid jigging machines (Fig. 1, 2), and oneSwedish Kemers Atlanter cod jiggingmachine rigged with an adapter drum forsquid jigging. Usually only one jiggingmachine was operated at a time. Dipnets with 45.7 cm diameter and 4.6 maluminum handles were also used to capture squids near the surface. A 50 fathomlong by 4 fathom deep gill net of 50.5mm (21J4-inch) stretched mesh was deployed off the bow during several earlytrips as a combination drogue and sampling tool.
The selection of fishing locations wasbased on a study (Fiscus, 1982) ofstomach contents of northern fur seals,Callorhinus ursinus, which indicatedthat either or both species of squid mightbe found over depths greater than 200 mat the head of submarine canyons. Siteselection each evening depended uponsea surface temperature, presence andconcentration of seabirds such as petrelsand shearwaters, presence of floatingjellyfish, Velella velella, and density ofany scattering layer detected by either ofthe sounders. Thermal boundaries weresought as indicators of boundary andstrong thermoclinal conditions often associated with oceanic squid species(Okutani, 1977; Naito et aI., 1977b).Generally, albacore, Thunnus alalunga,
Figure 1.-The automatic jiggingmachine used aboard the fishingvessel Tres Cher in 1981 offWashington. Moveable drumspokes allow adjustment of drumeccentricity and effective diameter.
80lb 140kgltestmonofilamentnylon line
.......- 2 - 6 kg weights
Swivel---"'"
Figure 2.-Gear arrangement found most successful during experimental squidjigging aboard the Tres Cher in 1981 off Washington.
July-Augusl-Seplember /983. 45(7-8-9) 57
Figure 3.- Lighting arrangement found to be most effective for nail squidduring the Tres Cher jigging experiments in 1981 off Washington.
Table 1.-Station and catch data including water temperature and lunar phase for experimental fishing stations of thefishing vessel Tres Cher in 1981 off WaShington.
MinimumSta· Location Temperature (OC)
Catch (no.) fishln9lion Taken time LunarNo. Date Lat. N Long. W Time Surface 100 ~ Total on ji9s (min.) phase
1 5-10 48"02.4 125°16.6 2155 10.0 6.75-11 4r54.7 125°10.8 0400 6.7 0 0 365 1/4
2 5-11 47"26.0 125'09.7 2000 9.4 835-12 47°21.4 125'09.9 0430 89 8.3 6 510 1/4
3 6-13 46°527 124°56.3 2350 13.66-14 46°47.9 124°53.6 0540 14.5 8 4 350 1/4
4 6-25 47'02.5 124"37.5 0040 15.3 0 0 30 3/45 6-29 46°59.0 125°11.1 2100 15.3
6-30 46°551 125'09.8 0530 15.5 97 510 New6 7-2 47'00.9 125°11.6 1800 14.8
7-3 46°52.8 125°10.9 0430 14.8 105' 2 630 New7 7-11 46°360 125'00.9 2200 16.1
7-12 46"331 125'03.9 0500 15.9 111 6 420 1/48 7-16 4rOO.0 125'00.0 2030 15.8 17 0 180 Full9 7-17 47'00.5 125"08.7 0023 15.6 4 0 45 Full
10 7-17 46°54.5 124°599 0200 15.0 0 0 75 Full11 7-17 46°53.3 124°47.9 0400 14.2 0 0 40 Full12 7-28 46"35.2 125°07.5 2245 16.8
7-29 46"33.6 125°15.9 0300 12.5 2 0 255 New13 7-29 46°13.8 126"01.5 2214 16.8 2 0 60 New14 7-30 46"348 124°46.2 2300 16.5
7-31 46"31.7 124°431 0300 16.4 13 0 240 New15 8-1 46"207 125°129 2200 15.8
8-2 46°19.8 125°13.5 0430 15.5 10.0 305 105 390 New16 8-2 46°18.5 125"08.9 2145 15.8 9.4
8-2 46'18.5 125"08.9 2230 15.8 41 10 45 New17 8-3 47"21.2 124°54.5 2130 15.6 7.2
8-4 4r16.9 124°55.3 0600 14.8 239 154 510 New18 8-6 47"18.3 125°004 2345 150
8-7 47"07.6 124°48.9 0530 13.5 0 0 345 1/419 8-27 47°22.3 124°56.5 2045 15.7 66
8-28 47'121 124°555 0610 14.5 194 194 565 New20 8-28 47"203 124°58.2 1900 15.4 7.7
8-29 4r184 124°59.5 0200 154 106 106 420 New21 9-13 47194 125°00.0 1925 14.3 82
9-14 4715.5 124°57.7 0315 14.3 11 11 470 Full
l Two Ommastrephes bartramli Included
fishing was conducted during daylighthours along the blue-water edge (thermal boundary) so the vessel was usuallyclose to good "squid water" at sunset. Ifa scattering layer was detectable by thesounders, an area of peak target strengthfor the Si-tex 200 kHz sounder was generally chosen for a starting place.
After an initial jigging site wasselected, the vessel would lay to andawait sunset. If winds were above 10knots, a drogue was deployed from thebow of the vessel to prevent excessiverolling motion. A 50-fathom (50.5 mmmesh) gill net was initially used for adrogue but was replaced later in thesummer by a 6 m diameter parachutedrogue. Rate and direction of drift weremonitored using the Loran C and XYplotter. After sundown, quartz-halogenfloodlights and incandescent lights wereturned on to attract squid and jiggingmachines were started. Placement of thelamps in relation to jigging machines(Fig. 3) was in accordance with thatfound successful in other squid jigfisheries (Bernard, 1980; Ogura andNasumi, 1976). Behavior of the scattering layer was monitored on echo sounders, and the presence of squid or bait fishat the surface was noted. Hand jiggingwas often conducted in conjunction withautomatic jigging to help attract squid tothe boat and to determine what type ofjigging motion might be most effective.Rate of drop and retrieval and pauseinterval on the jigging machines wereadjusted to coincide as closely as possible to that found successful by hand jigging. Quartz-halogen floodlights wereturned off periodically to help concentrate squid under the incandescentlamps. If no squid were observed in thefirst hour or two, the gear was brought inand the vessel would search for a moreproductive site using the sounders to detect a heavier scattering layer. Sharklines were frequently deployed in an attempt to catch any sharks which mightbe attracted to the boat before they couldfoul the jigging gear. Squid jigging operations were secured at dawn.
Captured squid were measured,sexed, and examined for sexual maturitywhen they were to be sold dressed.When whole squid were to be delivered,only measurements of dorsal mantle
58
length were obtained. Whole andcleaned squid were held on ice for up to 3
,,\\,\
Jigs enterwater atedge ofshadow/zone
days in stackable, self-draining, plastictubs(102 x 61 x 30cm) before delivery.
Marine Fisheries Review
Table 2.-00rsal mantle length (OML) of male and female nail squid, Onychoteuthis boreafijaponicus, capturedduring experimental jigging all the Washington coast in 1981.
Sexes combined Males Females
Sta· No. Mean No. Mean No. Meantion exam- DML exam- DML exam- DML
Dale no. Ined (mm) S.D. lned (mm) S.D. ined (mm) SD
5110·5/11 1 05/11·5/12 2 2 235 226
3 92 3.06/13-6/14 3 8 180 33.06/29-6/30 5 977/12·7113 6 102 139 3907/11-7/12 7 70 145 286 31 139 21.4 39 151 34.47/16-7117' 8
9 17 134 8 132 1371011
7/30-7131 14 13 191 6 193 7 1888/1-8/12 15 78 131 26.1 46 132 26.2 32 130 26.08/3-8/4 17 84 164 23.4 53 162 230 31 166 24.28/27·8128 19 193 176 216 128 174 20.7 65 182 23.39/13-9114 21 21 176 453
1Four different stations fished during one night. Catch from all stations combined.
12 7.----,;
1240 W
480 N
47' N
Wil/apaaav
ColumbiaRiver
WASHINGTONSTATE
117
~AstoriaCanyon
•16
15
"13.
1260 W
Figure 4.-Location and stationnumber of sampJ ing sites of the Tres
Cher during 1981 squid jiggingexperiments off Washington.
Results
Experimental squid jigging was conducted during 21 nights between 10 Mayand 14 September 1981. Fishing locations (Fig. 4) were primarily at the headof submarine canyons in depths that exceeded 200 fathoms (366 m). A total of1,261 squid were captured during theexperimental fishing period (Table 1).With the exception of two flying squidtaken on 2 July, the catch consisted entirely of nail squid. Catch rates wereinitially poor but improved as jiggingexpertise was acquired and water temperatures increased. Of the 1,259 nailsquid captured, 595 were taken on automatic jigging machines and 664 weredip netted. No squid were captured in thegill net. Maximum catch rates of 30pounds per machine per night were experienced later in the summer.
In addition to collecting informationon the best conditions for jigging squid,biological data, such as dorsal mantlelength (DML), gender, and sexualmaturity, were obtained from some ofthe captured specimens.
A total of 687 nail squid and the 2flying squid were examined. All weremeasured and 455 nail squid and I flyingsquid were sexed. The flying squid measured 404 mm DML and appeared to bean immature female. Data for the nailsquid are presented in Table 2. None ofthe squid examined were sexually mature, but early signs of maturation(Murata and Ishii, 1977) were evident inmale nail squids taken in early Augustand in one female nail squid taken on 13September.
Julv-A/lg/lsl-Seplernber /983. 45(7-8-9) 59
Several methods of processing squidfor market were tested. Some squid weregutted and iced, others were iced in theround (whole). In both cases, a ratio ofone part squid to one part ice was used.In-the-round nail squid were held iced intubs for up to 3 days with no detectableloss of quality.
Discussion
Although large numbers of nail squidwere attracted to the Iights of the vesselon several occasions, it was difficult totempt them into attacking the jigs. Several factors including sea state, light intensity and placement, jig shade, jiggi ngmotion, sea temperature, and lunarphase were found to affect the catch ratesignificantly.
One of the most important conditionsfor catching squid was placement andintensity of artificial lights. High lightoutput all around the boat attracted themost squid, but too much direct light onjig lines reduced the catch significantly.Three 1,000 watt incandescent lightswere rigged with directable shades assuggested in Ogura and Nasumi (1976)and focused over the gunwale to strikethe water at an approximate 45° angle(Fig. 3). This arrangement of the incandescent lights permitted the jig lines toenter the water at the edge of the shadedzone resulting in an improved catch rate.Further improvements in catch were obtained by turning off the quartz-halogenfloodlight that illuminated the port quarter of the vessel where the jiggingmachines were located and by intermittently turning all quartz-halogen floodlights on and off. By this method, thesquid could be attracted to the vessel andthen concentrated under the incandescent lamps in the area of the jiggingmachines. The squid seemed to preferremaining in the shadow area under thevessel until they sighted a jig or prey inthe lighted area, at which time theyrushed out to attack.
Because of the importance of 1ightintensity to squid jigging, lunar phasehas a pronounced effect upon the successof fishing operations (Arnold, 1979;Bernard, 1981). When the moon was fulland the sky clear, very few squid wereattracted by our lights and, conversely,
60
the best catch rates were experienced onthe darkest nights.
Sea temperature was measured carefully both at the surface and at a depth ofapproximately 30 m in an effort to locatetemperature conditions similar to thosewhere nail squid were found in thenorthwestern Pacific (Naito et aI.,1977b). Squid were encountered andtaken by jigs in greatest abundance inareas where the surface temperature exceeded 15°C. The best jigging successoccurred on 28 August in an area wherethe surface temperature was 15.rC andthe temperature measured at 30 m depthwas 6.6°C. Although this seems to indicate that nail squid may not be caught onjigs in surface waters below 15°C, theseincreased catch rates may relate more toimprovement in jigging and lightingtechnique than water temperature. Nailsquid are taken by jigs successfully inthe western north Pacific in surfacewater temperatures of 11°-13°C (Murataet aI., 1976).
Several colors and sizes of jigs andjigging motions were tested to determinethe best combination. Catch rates did notseem dependent on the color of the jigsbut, when few squid were around theboat, the lighter shaded jigs such aswhite, yellow, and clear were taken preferentially. When squid were plentifularound the boat and the catch rate wasup, all colors and shades worked equallywell. Size of the jigs also seemed to havelittle effect on the catch rate. Small squidwere willing to attack jigs that were almost as large as themselves.
Jigging motion turned out to be veryimportant in catching squid. The bestmotion varied in different locations andat different times. Hand jigging forsquid was the quickest way to determinewhat the best motion and depth settingsmight be on any particular occasion. Retrieval rate of the automatic jiggingmachines could be adjusted by rheostator reducing the drum diameter; jiggingmotion was achieved by moving thedrum spokes to various positions tochange the eccentricity of the drum (Fig.I). A motion that worked well duringAugust was achieved by adjusting thedrums to maximum eccentricity andslowing the average retrieval rate to 51 mper minute with a I-second pause for
about every 4 m of line retrieved. Thisretrieval rate was considerably slowerthan the 70-75 m per minute found successful in other jig fisheries (Suzuki,1963; Igarashi et aI., 1968). It was foundbest to lower the jigs only as deep asnecessary to attract the squid becausetangles in the lines increased as moreline was let out. It was not generallynecessary to lower the bottom of the jigstring deeper than 40 m. Although manysquid followed the jigs up from thedepths, almost all squid caught were observed to attack the jig just before itcleared the water during retrieval.
Sea state and wind conditions directlyaffected jigging success. Ideal conditions were calm seas and little wind.When wind velocity exceeded JO knots aparachute drogue was deployed from thebow to minimize rolling motion andprevent an excessive drift rate. Rollingmotion disturbed the motion of the jiglines causing occasional tangles and significantly reducing the catch rate. Although tangling could be minimized bychanging to heavier weights (3-6 kg) onthe jig lines, a sustained wind velocityexceeding 25 knots prevented successfuljigging operations from the Tres Cher.
Another unexpected problem significantly affecting jigging success wasinterference from blue sharks, Prionaceglauca, which were also attracted by theIights of the vessel. By striki ng at orbecoming entangled in the jig strings, ashark could break off part or all of a30-jig string which could prove costly interms of time and gear lost. Shark lineswere deployed fore and aft on the vesselin an attempt to intercept blue sharksbefore they could damage the jigginggear. Later communication with aJapanese squid jigging expert
2revealed
that sharks are a common problem insquid jigging and that no better methodthan rigging shark lines has been discovered.
In addition to learning how to locateand catch squids, some biological datawere collected: DML, gender, and an
'Yutaka Ikeda, squid jigging consultant, TaitoSeiko Co. Ltd., Imaasa Building. No. 1-21,I-chome, Higashi-shimbashi, Minato-ku,Tokyo 105, Japan. Pel's. commun .. September1981
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100
50 l-. L- .L.- .l.- .1- ----I
May June July August September
Figure 5.-Dorsal mantle length frequency of nail squid taken in 1981 offWashington during experimental jigging aboard the Tres Cher.
indication of sexual maturity. The twoflying squid taken on 3 July had DML'sof 410 mm and 220 mrn. Mean dorsalmantle lengths for nail squid are presented in Figure 5 and in Table 2. Thereappeared to be an increase for one sizegroup of nail squid in mean DML from92 mm on II May to 176 mm on 28August (Fig. 5). This reflects a growthrate of approximately 2 cm DML permonth which compares well with thatreported from the northwestern Pacific(Naito et aI., 1977a; Murata and Ishii,1977).
The wide range of observed nail squidDML (Fig. 5) made modal length analysis for age and growth information verydifficult. Widely separated DML's arealso reported in nail squid from thewestern north Pacific and, apparently,reflect different age groups and highlyvariable growth rates (Naito et aI.,1977a; Murata and Ishii, 1977). Actual
Julv-A ugust-September /983, 45(7-8 -9)
values of mean DML were 80-100 mmsmaller than those reported from thewestern and central north Pacific duringthe same season (Naito et aI., 1977a;Murata et aI., 1976).
Although more length and maturityinformation, especially at different seasons of the year, is required to fullydefine age groups, growth, and spawning seasons, it was possible to drawsome preliminary conclusions from ourdata. A hypothetical growth curve forthe sampling period was drawn usingmodal DML for both sexes from stationswhere nail squid were measured. Squidfrom two jigging stations were excludedfrom the growth curve computation. Thelarger squid (235 mm average DML) thatwere caught on II May were representative of many more large squid whichwere observed around the boat but notcaptured; such numbers of large squidwere not observed again until 13 Sep-
tember. Consequently, we feel that theyprobably represented a different agegroup which either spawned and died ordeparted the area before the 13 June trip.The eight nail squid that were measuredfrom the 13 June trip were excluded because of the small sample size and poorcurve fit. The shape of the growth curvesuggests that nail squid caught duringthese experiments were probablyhatched during mid- to late winter 1981.
Some of the squid taken during theseexperiments were examined for sexualmaturity. Male nail squid (272) wereexamined for sperm packets whileaboard the vessel and 9 additional nailsquids (4 male, 5 female) were saved forlaboratory examination by Clifford Fiscus (scientific consultant, Brier, WA98036, August 1981). Sperm packetswere observed developing in males during late July, and one female (294 mmDML) which was taken on 13 September
6/
had nidamental glands which measured103 mm in length and were orange incolor. This coloration is reported to signify the onset of maturation (Murata eta!., 1976). Divergence in size of malesand females reported to occur duringsexual maturation of nail squids ( aitoet a!., 1977a; Murata and Ishii, 1977)was not observed in these squid.
Although some signs of maturationwere detectable in the nail squid takenduring late August and early September,other signs such as size difference inmales and females and the attainment ofspawning size (300-370 mm DML), asreported by Naito et a!. ([977a) andMurata and Ishii (1977) were not. Forthese reasons, we believe that the growthand maturation of our squid were probably 1-2 months behind the squid described by Murata and Ishii (1977); and,according to the hypothetical growthcurve (Fig. 5), the nail squid taken offWashington probably would only reach amaximum size of 250-280 mm DML atspawning. Spawning for these squidwould probably occur from early tomid-winter and subsequent hatchingfrom mid- to late winter. Also, there mayhave been several age groups present offWashington during our investigations:One age group of nail squid representedby the large size group (235 mm meanDML) taken in early May, a secondgroup represented by most of our catchfrom May to September, and a thirdgroup represented by many small (approximately 50 mm DML) squid observed on 13 September.
62
The effect of ocean currents and related migratory behavior of nail squidoff the Washington coast should bestudied. It is possible that nail squid migrate in a northerly direction past Washington to spawn in the north Pacific; thismigration, if it occurs, would be similarto those reported for squid of the westernnorth Pacific (Naito et aI., 1977b).
Acknowledgments
The authors would like to thank Captain Jerry Sweeney for providing thefishing vessel Tres Cher without whichthese experiments would not have beenpossible. We also wish to thank CaptainSweeney, Captain Conrad Selfords,Mathew Sweeney, and Mike Bucy fortheir enthusiastic assistance in the pursuit of squid. Special thanks to CliffordFiscus for his able assistance in identifying and determining sexual maturity ofsquid caught.
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biology and fisheries. U.K Minis!. Agric.Fish. Food, Dir. Fish Res., LoweslOft Lab.Leafl. 48, 37 p.
Bernard, F R. 1980. Preliminary report on thepotential commercial squid of British Columbia. Can. Tech. Rep. Fish. Aqua!. Sci. 942,51 pp.
1981 Canadian west coast flyingsquid experimental fishery. Can. Ind. Rep.Fish. Aqua!. Sci 122, 23 p.
Fiscus, C. H. 1982. Predation by marine mammals on squids of the eastern north PacificOcean a~d the Beri ng Sea. Mar. Fish. Rev.44(2):1-10.
Igarashi, S .. T. Mikami, and K. Kobayashi.1968. Studies on fishing gear. II. An auto-
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niv. 18(4):357-364.Kajimura, H., C. H. Fiscus, and R. K. Stroud.
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____ , , and H. Araya. 1976.The distribution of oceanic squids, Ommas/rephes banramii. Onycho/ell/his borealijapolliclis. Gona/opsis borealis and Todarodes pacijiclls in the Pacific Ocean offnortheastern Japan. Bull. Hokkaido Reg.Fish. Res. Lab. 41:1-29.
Naito, M., K. Murakami, and T. Kobayashi.1977a. Growth and food habit of oceanicsquids (OmmaS/rephes banramii.Ollycho/euthis borealijaponiclis. Berry/ell/hismagis/er, and GonalOpsis borealis) in thewestern Subarctic Pacific Region. Res. Ins!.North Pac. Fish., Fac. Fish. Hokkaido Univ.,CO!ltrib. 91 :339-351.
____, . N. Naka-yama, and J. Ogasawara. 1977b. Distributionand migration of oceanic squids (Ommas/rephes bar/ramii. Onycho/ell/his borealijaponiclIs. Berry/ell/his magister and GonalOpSis borealis) in the western subarctic Pacificregion. Res. Ins!. North Pac. Fish. Fac. Fish.I-Iokkaido Univ.. Contrib. 90:321-337.
Ogura, M., and T. asumi. 1976. Fishing lampsand light attraction for squid jigging. Fish.Rep. FAO, 170 (Suppl. 1):93-98.
Okutani, T. 1977. Stock assessment ofcephalopod resources fished by Japan. FAOFish. Tech. Pap. 173, 62 p.
Suzuki, T. 1963. Studies on the relationshipbetween current boundary zones in waters tothe southeast of I-Iokkaido and migration ofthe squid, Ommas/rephes s/oani pacijiclis(Steenstrup). Mem. Fac. Fish. HokkaidoUniv.II(2):75-153.
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