MFR PAPER 1095 Paul Struhsa ker and Donald C. Aasted are on the staff of the Southwest Fis heries Cen te r, National Marine Fisheries Deepwater Shri mp Trapping in Service, NOAA, Honolulu, HI the Hawaiian Islands 96812.
moderate numbers with th e trawls PAUL STRUHSAKER and DONALD C. AASTED between 150 and 400 fathoms (275 and 730 m). However. the initial in ABSTRACT-The results of preliminary deepwater shrimp trapping sur vestigations indicated that trappi ng. veys in the Ha waiian Islands consisting of 82 sets involving totals of 306 rather than trawling. was perhaps a traps and 3,960 h of fishing time in the 75 to 450-fathom ( 135-825 m) more effecti ve method for capturing depth range are discussed. A variety of traps, bait containers, and baits th ese latter species. were tested. Attempts to capture the penaeid shrimp, Penaeus marginatus, larke (1972) conducted trappIng in substantial numbers were unsuccessful. More success was experienced urveys during 1969 and 1970 at sev in trapping the caridean shrimps Heterocarpus ensifer and H. laevigatus. era l locales off the Hawaiian island of For these species, it was found that traps covered with burlap cloth out Oahu. The sampling gear consi ted of fished uncovered traps by factors of 2.5 to 10. H. ensifer was found to be everal trap type . but all were un most abundant in depths of 200-250 fathoms (365-455 m) where catches covered traps constructed of 0.5-inch with optimum trap and bait combinations ranged from 15 to 63 pounds (6.8 ( 13-mm) mesh wire screens. This wo rk to 28.6 kg) per trap for sets of less than 24 h duration. Seventy traps set provided data on the biology and overnIght during spring 1973 off the south coast of Oahu produced a total depth distributIon of H . en.liji-r a nd of 1,015 pounds (460 kg) for an average of 14 .5 pounds (6.6 kg) per trap. H . l{/ e\'i~(/llI\ and indicated tha t H . The larger H. laevigatus was found to be most abundant in depths of ensiler mi ght be present in sufficient 240-375 fathoms (440-685 mY , where catches ranged up to 34 .8 pounds quantities to support a commercial (15.8 kg) for 4 traps. It is speculated that the various species of Heterocar fishery. pus represent an unexploited world resource of considerable magnitude. Further trapping trial were inter mittently conducted by M FS during amenable to harvest by shrimp trawls 197 1-73 at various localities in the INTRODUCTION in depths of 60-125 fathoms ( 110- H awaiian Islands. These trials were During 1967 and 1968 the National 230 m)1 (Yoshida. 1972: Struhsaker. of a preliminary nature. and various Marine FIsheries Service (NMFS) de Yoshida. and Shomura2 ). Two species combinations of trap. bait containers. voted four cruises of the RY Town of caridean shrimps. H elerocllrp1l1 a nd baits were utilized . Most of the send Crolll\\ ell to demersal resource el/liji-r Milne-Edwards and H . lael'igll data were obtained during fall 1972 surveys in the Hawaiian Islands. The IllS Bate (Fig. I), were a lso taken in and it became apparent at this time primary ampling gear utili zed were that burlap-covered traps were more shrimp trawls. although a few shrimp effective in capturing H . ensiler than trap stations were effected. These sur .~ Metric eq uivalents are approxim ate. were uncovered traps. Attempts to - Struhsaker. P., H.O. YoshIda. and R.S. veys demonstrated that the penaeid Shomura. Exploratory shrimp trawling in th e trap P . lIlarginllllls in sub tantial num shrimp. PenllellS IIllIrginallis Randall. H awaii an Islands. unpubl. ms .. Southwest Fisheri es Center. Honolulu Laboratory. ber were unsuccessful. Fol low-up was available in modest amounts and Honolulu. HI 96812. cruises with more extensive trapping
FIgure 1.-A tr8lh specimen ot Heterocarpus ensi'er (A, lelt) about 115 mm total length . Note ocellus on the sIde ot the cephatothorax ("head" ) and the strong backwar dly projecting spines on the th ird and fourth segments of the abdomen ( " tall" ) . A tresh specimen ot Heterocarpus laevlgatus (right, B) about 175 mm total length.
24 pandalld "hnmr" In the \ I~IOII\ 01 trar\ ("- ..:""I..:r. Illhlll ( o ll ap\lbl..: n.lund \hnmp Ir..lr' (/lg 4) were aha te,ted to a Ilmll..:d dcgru.: Th e~ are 14 Inch..:, (3(-, cml high . 24 In che (60 cml In diameter al th..: I\lp. 34 In c h c~ (X6 cm) In diam..:t..:r at the bott om and ha,e \hallcl\.\ tunn..:l" l..:..Id in g to four entrance" The \I...:h bi ng con~i.,t, of I 25 -Inch (~I - mm l stretc hed mc.,h n~ Ion . Finall y. an expenmental collap"l bk "tent trap" (Figs. 5. 6. and 7) wa, teskJ on one occasion. Each 01 the three frame mal.. ing up the hottom. side. a nd li d of the trap mea~ure, 2X4 feet (60x 120 cm) and I" en cia ed with 0.5-i nch wire mesh "creen . The three frame are joined with ~pllt Figure 2.- A covered square trap. This trap type links of a size th at permit folding of F,gure 4 - A coil pllble I hrlmp p OI produced the best catches 01 H ele,oca,pus th e frames and are covered with a ensifer. "..:1\ ,If 12-1 4 h Th si ngle piece of burlap. A bridle attach were ,u'r"nded n"ar t h~ tri als scheduled fo r 1973 we re ca n ed to the corners of the lid runs trar cell ed . through the outside corners of the E-ach trap ba I bottom frame (Fig . 6) . When clo\ed. GEAR AND SAMPLING EFFORT bndle of () 2"-II1c.h th e li d is secured with a rubber strap Gear a nd S-hooks. The triangu lar end T he "squa re tra p" (in reference to frames a re attached to the bottom of its squa re cros -secti on) produced th e the trap by split links a nd have two half- lin ks welded on the leg articulat best catches of H elerocar p lis. It mea sures 2X2X 4 feet (60x60x 120 in g with the side frame (Fig 7) . The tunnels are constructed With 1.5-lnch cm) (Fi g. 21. The frame is constructed of the trap 1,lndl n (38-mm) mesh ( tretched) n)- Ion web of ~8- in c h ( IO- mm) di ameter steel ,et It \\a, al 0 th ba r a nd i encl osed with 0.5-in ch bi ng and are secured to entrance n ngs 3 inches (75 mm) in diameter T he squa re mes h galvani zed wire screen . out through the t: tunnels are held in place by a rubber The sides. top. a nd botto m are th en Ing bad, 1 he rrlJ strap and S-hook (Fig. 6) . covered with burlap. The tunnels (one center f,lr dtt dc.h Several bai t containers were teoted at each end) are also constructed with Itne fh c ground the screen (but are uncovered ) and Containers constructed of O.5-lnch taper to approximately 3-in ch (75 -mm) mes h screen measuri ng about 4 X 4 X 6 di a meter openings about one-third th e inc hes (lOX lOX 15 cm) were gen di sta nce in from each end Covered erall) superior to plastiC containers and uncovered traps of si mil a r con of the ame size perforated With 025- struction . but enclosed wi th I-i nc h inch (6-mm) holes or bait wrapped In (25 -mm) (bar-to-ba r) he:\.agonal wire cheese cloth . F rom I to 2 pounds creeni ng were also tested . (0.5-1 kg) of bait were ~ufticlent for " Flat traps" (Fig. 3). can tructed ~imil a r l y to the qua re traps. but mea- uring I X 2 X 4 fee t (30X60X 120 cm). we re utilized Ill OS t oft en in the shal lower depth sun eyed . It was fe lt th at the lowe r ramp angles of the tun nel m igh t pro\ e to be more effeclI \ e in capturing P. IIwrgill 15 on the order of 50-150 fathoms (90- longl i ne floats or a more elaborate northern MaUl , and th e west coast of 275 m) greater than the depth of water buoy consisting of an I H- foot (5-m) the 1\land of Hawaii off Kawaih ae. being fis hed. A chain weight is fl ag and li ght stafl o f 2.5-ln ch (64-mm) Dunng spnng 197\, 21 set~ were snapped onto the buoy line about di ameter condUit piping which fits made oil the south coast of Oahu With 25-50 fathoms (45-90 m) below the into a weighted fr ame which 1\ fl oated our gear by personnel of the Hawaii end of the last section to a sure that with a large Inn er tube. The~e buoy~ Institute of Manne BIOl ogy (H fMB J the polypropylene line does not float remain ed at the surface even In areas utlllLlng the I V Vallalll M£IId Dunng at the ea surface. The set I retneved where the currents approached 3 ugust 1971, 9 set'i we re made WI th with a line-hauling power blocI-..: th e I-..n ots. A 4-fathom (7-m) pi I-..up line the R V Dal It/ ICIrr l ()rt/()1I In th e 100-fathom seCllons are stowed di with a small float IS att ached to the l eeward Isl ands of the Hawaiian rectly into their containers as the line buoy . rch lpelago nl.!ar ecker hland, comes aboard. french f- ngate Shoal , l. aysan Isl and, Because of the buoyancy of the Distribution of Sampling Effort and Plonl.!l.!r BanI-.. polypropylene line, minimal flotation Because the trappl ng I.!xperi ments £-rom March 1<:171 to Augu\t 1971, for the marl-..er buoy IS required. Our werl.! IIltersper<,ed With other ves<,el 82 exploratory shnmp trapping \et~ buoys consisted of either simple bam actiVit ies, most \eh 'Were made at InvolVing totals of 306 traps and about boo pole with two or three pia tiC du I-.. and retneved at da'Wn Ho'Wever. 3,960 h of fishing lime 'Were elfected 'We do havc a fe'W data for daytime In "anou areas of the Ha'Walian h sets We trapped n a vanet) of bot lands. The dlstnbutlOn of sampling tom t)pe\, aVOiding onl) steepl) slop effort by depth 'Was as follo'Ws 75-11() Ing areas and rough-bottom grounds fathoms (135-23'i m). 24 ets, 130-200 'Where thc traps might have been fathoms (23'i-365 m), 2 sets, 200-300 \nagged fathoms (365-'i50 m), 47 ets, 100-400 fathoms (550-710 m). 7 sct~. 400-4'i0 RESULTS fathoms (730- 25 m), 2 \ets Most Trapping for ampllllg effort 'W e\pended III depths of 75-130 fathoms and 200-300 fa Penaeus marginatus thoms 'Where P. IlI1Irs.:illllllll and H ttempt to trap P. IIll1rs.:llIlIIlIl III I! III I./er , r~pecllvel), are mo t abun sub tanllal number 'Were unsucces - dant ful. but the sampling effort .... as of a Most of the trappl ng effort f r P very prellmlnar) nature fter gen l11a(s.:lllllIlII tool-.. place III the Pail 10 erally negall\.e result obtained dunng Channel where thl pecle I most spnng 197 I. e\pen ment 'Wllh capll\. e abundant ( truh al-..er et ai, unpubl hnmp 'Were conducted at the IF m .). The deeper depth range ex Ke'Walo Ba In faci llt] R pon e of plored with the R TOlIlHl!lld Crol11- the hn mp 'Wa noted dunng hours of Figure S.-A collapalble tent trap ready 'or II I! II were off th e north coa t of Oahu. li ght and darkne to baited a nd un 'Iahlng. the north edge of Pengulll Bank, ff bai ted flat trap (a ll uncovered) eq ulp- Figure 6.-A tent trap with ralud lid. Figure 7.-A collapsed tent trap . The end 'ramea 'old outward, over the bottom panel. 26 ped with a variety of entrances. Rathe r surprisingly, there were no majo r differences in the catch rates between the various combinations of the trap types and baits tested. These results were proba bl y confused by a bnorma l temperature and light conditions. A l though adult P. lI1arginallls appear to be negatively phototactic (Struh saker et al" unpubl. ms.), best capture results were obtained by suspending a li ght over an unbaited tra p . This resulted in all of the available shrimp (18-20) in a test ta nk 24 feet (7 01) in diameter entering the trap within 15-20 minutes . Further field trials conducted dur ing fa ll 1972 were inco nclu ive. aside from determining that flat traps out fished square traps on the a me string. Traps containing a deep-sea di ving Figure 8.-A 123-pound (56-kg) catch 01 Helero ranged between 15 and 63 pound~ light captured shrimp on three occa carpus ensiler produced by lour traps. (6.8 and 28 .6 kg) per trap on o\cr sions when the other traps o n th e The performance of burlap-covered night sets. One of the better cat(hc~ string did not ta ke any shrimp (maxi and uncovered sq uare traps wi th 0 .5- made at this time was off the north mum single trap catch, five shrimp). inch mes h were directly compared on hore of Oahu in 240 fathoms (440 OJ) However, the best catch of nine eight occasio ns when strings of a lte r where 122 .7 pounds (55.8 kg) of If shrimp for a n overnight et was in a n nating trap types were set. The covered ellSlfer were taken with four square uncovered flat trap baited with fi nely traps always o utfis hed the uncovered traps baited wi th fish (Fig. 8, Tv,o ground fis h . Three sets of traps fished traps by factors of 2.5 to 10. covered traps accounted f( r O.h during dayli ght hours produced low Because most catches of H . ellsiler pounds (49.3 kg). while tv.o unco\ catches similar to night sets. were made at ni ght in deep water. it ered traps captured 14.4 pnurds ( 'i Clarke ( 1972) reported a best catch would seem that they are not differ kg) . of this species as 26 individua ls in entially entering th e covered traps to The best in gle catch of H. (I, f I eight traps in 60 fathoms ( 110 01 ) seek she lter. We agree with Bu tler was 63 pounds (286 kg, Ir()rr d t h off th e no rth coast of Oahu. We feel ( 1963) that possibly the covered traps baited. covered squarc trap d nn I that concerted trapping tri als for this are rendered more effecti ve in that the 24-h set in 225 fathoms {410 01 nl rth species might result in a viabl e fishing ba it scent i concentrated at the trap of Maui . Another covered squ",rc trup strategy that could produce catches of entrances. rather th an diffused through on this tring. baited \\ Ith ~ I commercia l valu e for sma ll vessels. the sides in additio n to the entrances produced 24 pounds (IO.q g. in the case of uncovered traps. Trapping for the rema in ing two cO\ereL q Five general types of bait were traps also baited With fish a d ~h Heterocarpus ensifer tested: fine ly ground fi sh , squid, produced only 1.5 and lOr During fall 1972 severa l types of shrimp (H . ellsiler) , and coarsely shop (0.7 and 0.5 kg). respe<..tl\cl T traps, bait containers, a nd baits were ped fish and shrimp . F ish a nd shrimp great d is pa rity in the catches Inul\.. j tested in various combinati ons o n set were superio r to squid a nd the coarse to us th at the latter two traps (\\hl"n of 4-6 traps per string. These pre ly chopped fish and shrimp outfished were positioned In the middle of thc liminary trials were not designed for the fi nely ground containers of th ese string) landed on end or v.ere rl" the results to be subjected to statisti cal species. This finely ground bait prob fi shing for some other reason evalu ation , but the main trends of the ably dispersed too rapidly. Bloody D uring spnng 1973. two o\ernlght effectiveness of the various trap com and oi ly fis hes such as skipjack tuna sets of SIX covered square traps on a binations in capturing H . ensiler were (KalslllVonlis pe/all1is) , boarfish (A 11 - string were made In 225 fathoms readily apparent . ligonia spp .) and A 1I/0plIS were (410 01) off the north coast of Oahu Square traps with 0.5-inch me h found to be superior to lizardfis hes to pro\ide shrimp for test marketing. wire screen were more effective than (Sy nodontidae), flatfishes (BothidaeL One string produced a total of 134 the other types tested . The catches of and smelt (Os meridae) . pounds (605 kg) of H. em!}£'/'. v.lth square traps with I-inch mesh wire Catch rates of H . ensiler obtained three traps baited with skipjack tuna screen were less, apparently owing to during fall 1972 were high ly variable accountIng for 10225 pounds (46.'\ escapement. Catches from the flat due to the variety of traps, containers. kg), and three traps baited \\ith v.hite traps and round traps were consistent and baits tested and the depth sam bait smelt (AlloslI1cru.\ elon~(/llI\) tak ly lower than for the square traps. pled . At this time the best catches ing 31.75 pound (1 4 .0 kg). The sec- 27 20,--,---,---,---,--,---,---,---,--.---,---,--,---,---,---,--,---, ond string produced a total of I 18.5 He1erocorpus enslfer Ie pounds (53.9 kg), the three skipjack (NONOYIGEROUS N ,156 ) tuna baited traps producing 80.5 pounds (36.6 kg), while the three 16 whitebait smelt traps captured 38 I. .,j pounds (17.3 kg) . The tent trap was , also tested on this string (baited with 12 • 0°':'- skipjack tuna) and produced an addi ", , , " " 8 10 tional 12 .5 pounds (5.7 kg) . This was :'1 1' ' : " the single te t of thi trap type. and e inasmuch as a square trap is about " 2.1 times the volume of the tent trap. 6 " we feel that this design might even tually prove to be practical. During August 1973. six sets of 2 I 0 • .~ covered square trap baited with tuna ~',' were made in the 200-250 fathom ~ 55 60 65 70 75 eo e5 90 95 100 105 110 115 120 125 130 135 (365-460 01) depth range in the Lee TOTAL BODY LENGTH (mm I ward Islands. The results indicated Figure 9.-Length-weight curve for 156 non ovigerous Heferocarpus enslfer. that the peak abundance of H . ellSifer 20,---,---,---,------.------, may occur deeper there than in the trances occurrIng dUrIng the original Heterocarpus enslfer Ie main group of the Hawaiian Islands. constructIOn or after modification due (OVIGEROUS N' ge) Four traps produced totals of 46.5-50 to damage. 16 , , pounds (21.1-22.7 kg) at each of three These catches of H . em/fer with sets between 225 and 250 fathoms covered trap generall, exceeded those I. . " " I ~ °'0- (410 and 460 01) near ecker Island. experIenced by Clarke (1972) with 0- 0. 0.: r 12 D, .o'! A 6-h daytime set here in 200 fathoms uncovered traps outside Kaneohe Ba, (!) W • °i (365 01) with two traps produced only on the northeast coast of Oahu during ~ >- 10 0 10 indl\·ldual shrImp. Only 2-3 pounds ovember 1970. Catches there for 0 II) (0 9-1.4 kg) of H. ell.lifer were taken in nine quantitative ets in the 150- to ..J ~ two overnight sets of four traps in 250-fathom depth range varied from i? 6 205 and 215 fathoms (375 and 390 01) 0.6 to 11 .9 pounds (0.3 to 5.4 kg) near Laysan Island. per trap and averaged 4 .5 pounds Our covered square traps were (2.0 kg). At that time the be t catch tested in a more uniform and extensive obtained wa a respectable 96 pound manner dUrIng May 1973 by HIMB (43.6 kg) from eight traps fi hed in personnel when 19 overnight sets (of 200 fathoms (365 01). ?oo 105 110 115 120 125 130 135 TOTAL BODY LENGTH (mm I 21) were made in the 200-220 fathom We have taken H. ensifer in depths (365-415 01 ) depth range off the south ranging from 76 to 360 fathoms (137 Figure 10.-Length-weight curve for 98 ovigeroul Heterocarpus ensifer. coast of Oahu between Waikiki Beach to 660 01). Clarke (1972) took the and Sand Island. Four traps were species between 80 and 400 fathoms Clarke (1972) al 0 demonstrated fished to a string and were baited (146 and 730 01) but concluded that that the 150- to 250-fathom depth with a mixture of two species of smelt it is most abundant between 150 and range was the zone where the largest (primarily Thale/chthys pacificlls and, 250 fathoms (275 and 455 01). Our size-class of shrimp occurred. The to a lesser extent. Hypa m esils pretia results indicate a peak abundance be catches in greater and lesser depths .IllS). Catches varied from 2 to 34.9 tween 200 and 240 fathoms (365 and were comprised of a significantly pounds (0.9 to 15 .9 kg) per trap. 440 01), but we have few stations in greater portion of maller indi viduals. Total catch from 70 traps (complete depths between 150 and 200 fathoms We did not collect extensive lengt h data not available for six traps) was (275 and 365 01). Quite probably the frequency information. but estima about 1,0 15 pounds (461 kg) for an depths of peak abundance for H . ensi tions of the size composition of the average of 14 .5 pounds (6.6 kg) per f er vary locally according to varia catches also indicate that smaller trap . These data also reflect our i 01- tions in the temperature structure. shrimp are fo und above and below the pression that considerable variation In the main group of the Hawaiian depths of peak abundance. occurs between localities and depths Islands, bottom temperatures are about Clarke (1972) pointed out that H. and even between identical trap ar 14°C at 150 fa th oms (275 01) , 9.5 °C ensifer seems to exhibit protandrous rangements on the same string . This at 200 fathoms (365 01 ), and 8°C at hermaphroditism (sex change from is probably due to local variati on 250 fa thoms (455 01 ) .3 male to female with growth), but that in the abundance of H. ensifer and the situation seems to be more com varIatIon in placement of the bait 3 Unpublished data, Southwes t Fisheries Center, Nati onal Marine Fisheries Service, plex than for some of the commercial container and in the trap tunnel en- Honolulu, HI 96812. pandalid shrimps in that a large por- 28 tion of the males reach near-maximum of the total weight contributed by th e of about 240 to 37':.. lath 'm, (44 size without transforming and that tails of ovigerous and no no vl gerous 684 m) many small individuals (below egg individuals. both with and without The proportion of large and mall bearing size) are females. A large shell and eggs (Fig. II) . The majo rity in diV idual, of H . Itltl 1~(III1~ tdk.en 10 proportion of the larger females taken of ovigerous individuals have total the traps abo seems tll \ar: bct\\l:~n are ovigerous (gravid, or "berried") tail weights making up a bout 45-55 catches. bu t the pattern IS nlll yet throughout the year. Clarke (1972) percent of the total weight, whe reas clear Large indl\ Iuual, of thiS pecIc presented data that indicated that this the tail weights of most of the non attain lengths of 200-220 mm tntJI condition varied with depth and that ovigerous individuals were about 40- length . but me,t of the InUI\IUUJI the proportions may vary seasonally. 50 percent of the total weight (Fi g. compriSing the largest "ze-gr up The largest size-group of H. ensifer IIA and B). These data indicate that ra nge from 150 to 17':.. mm tlltal taken in our traps usually weighed the egg mass is about 5 -I 0 percent of length and average 8- I I InUI \ Idu Is about 35 to 45 individuals per pound the total body weight. With the shell per pou nd (heads on). (75 to 100/kg) with the heads on , and eggs removed, the tail muscle of although the largest indi vi duals taken both ovigerous and nonovigerous in run 28-30 per pound (62-66/kg). We dividuals make up about 25-35 percent FURTHER CONSIDERATIONS obtained total length (tip of rostrum of the total weight (Fig. IIC and D) . One problem encountered \\lth H. to tip of telson) and weight data for ensifer is cannibalism of d certain 156 nonovigerous H. ensifer (Fig. 9) percentage of the trappeu InUI\ IdUdl, Trapping for and 98 ovigerous females (Fig. 10). W e have no precise data on lhl\ phe Data were obtained from specimens Heterocarpus laevigatus nomenon. but rough estimates indicate frozen less than a month, thawed, H. ia egivaflls (Fig. I) is a large that as little as I percent to as mu..:h and damp-dried . The fitted exponen species of H elerocarpLis inhabiting a as 15 percent of all the InLlI\ldu I tial length-weight curve for the non deeper depth range than H . ensifer. in a trap may be affecteu Sublec,tl ovigerous individuals is: 10glQ W = Clarke (1972) collected this species Iy. it seemed that the highest at 0.0162 L - 0.8789, where W = total between 200 and 400 fathoms (365 of cannibalism occurred In s t weight in grams, and L = total length and 730 m), while we have obtained long durati on or In trap 'n .... hleh th in millimeters ; 1'2 = 0.972. The equa it in depths ranging from 235 to 450 bait su pply was exhausted I a tion for the ovigerous individuals is: fathoms (430 to 825 m). We have individuals are most ufte., Jftt. 10glO W = 0.0105 L - 0.1947, where rather limited coverage in the deeper and, if ovigerous. the eggs JftU r2 = 0.589, W = total weight in portion of this depth range, but several merets are remond hrst Th grams, and L = total length in milli catches indicate that this species can viscera, and. finally. the tUI meters. be taken in sufficient quantities to ture are attacked ThiS rcs..Jit We also determined the percentage support a commercial fishery. Our problem of sorting thE. u initial catches with uncovered traps partiall y devoured Indi'dduul 20 were not encouraging, and were simi contaminate the c,ate" ( lar to those experienced by Clarke cannibali zed and smJI shr 10 (1972) where yields were usually on most easily effected in the order of 1.5 pounds or less per seawater . trap. We poi nt out that the trap Some of the better catches of H . these preliminary tnals c,;ol\ ia e l'igaills we obtained with covered usage, and certainly do nl t traps are as follows. South coast of what may become the optimu i 1 Oahu: 18 pounds (8.2 kg), three traps, and construction. Probably ., !] ~ 1::': " ~ 246 fathoms (450 m); 10 .6 pounds tainer u tilizing the princIple, (4.8 kg) , two traps, 255 fathoms (465 covered trap \\ ith a long taper d u m) . North coast of Oahu: 11.1 pounds nel would be suitable. 1he me hilt: I ~r~" ' I I ,:•• ~ : 1 (5.0 kg), two traps during a 4-h day of the tunnel should be Inl.:rc ... d t time set, 285 fathoms (520 m). Kawai about 0.75 Inc'h ((9 ml'11 to pemllt hae, Hawaii: 7 pounds (3 .2 kg), two escapement of m II hnmp P Ibl} traps, 238 fathoms (435 m). Leewa rd a trap \\ IIh ;1P entmpc'e on one end Islands: 15 pounds (6.8 kg). four traps, and a flat creen on the other end ~r O,"·~' 320 fathoms (585 m ). Pioneer Bank, \\ould permit e "apement d m II lL 134.8 pounds (15 .7 kg). four traps. indj\ Iduals dunng h uhng of the trap 360 fathoms (660 m), French Frigate thu redu';lng the am unt of nmg ~ ~ ~ c ~ ~ ~ 00 PERCENT Shoal; 7 pounds (3 .2 kg). four traps, on the fJ hermen' part and Flgu,e 11 .-Helerocarpus ensifer. Weight 01 tail 440 fathoms (8 05 ml. Pioneer Bank mg the premature hant: t with .hell a. pe,cent 01 total weight: A. Ovlge, ou. lemale. ; B. Nonovlge,ou. Individual • . Weight Although the data are rather frag shnmp. 01 tall without .hell al pe,cent 01 total weight: mentary, it woul d appear that thiS The tU11 meat of tht' t\\ pt: I C. Ovlge,ou. lemale.; D. Nonovlge,ou. individ ual • . species is most abundant In depth' of H elero( arplls tend to bre d \\n 29 rapldl) '" hen the hrimp are improper cisely d etermined. but pro babl y ex ACKNOWLEDGMENTS I) chilled aboard the ve el. T he ceeds 1.000 km2 . ~hrim p mu t be immediate ly placed It wo uld seem tha t H . ensiJer, a n We tha nk William Van Heukelem In cru hed Ice o r chilled seawater. a lmost entire ly cosmopolitan pecies fo r providing catch data obtained with Thi~ '" III pro VI de an acceptable prod occurring fro m H awa ii to the western the FV Va/hllH Maid and Bernard uct fo r up to a bout 3 day afte r central A tl a ntic. is about as a bundant Ito for the photograph of the traps. captu re W e fo und that cooking the in other parts of its range as in H awaii . Thomas A . Clarke and Lael L. Ron shrimp nght after capture re ulted in In the western A tla ntic. expl o ratory ho lt made pertinent comment on the chilled shelf life of 3 to 4 days. O ne trawl catches by the M FS we re o f ma nuscript. Richard B. Roe provided test of Immediate freezi ng of raw the same magnitude as we re those in ex plo ratory trawling data for the west ~hrimp In a bn ne solutio n at a bou t H awaiian waters.4 Limited trapping ern central Atlantic. The illustrations - 20° resu lt ed In a n acceptable near G ua m in the weste rn Pacific 5 are by Tamotsu Nakata. product A fter freezing. the sh ri mp have produced catch es similar to tho e "'ere placed In a conventio na l freezer reported he re. and tested at Intervals over a 2-week. Using data presented by Moiseev L1TERATU RE CITED penod Ver} li ttle a lt was ta ken up ( 1969). it was calculated that the Butler, T. H. 1963. An improved prawn b) the shrimp and the product did 200- to I,OOO- m depth zone o f the trap. Fish. Res . Board Can., Bi oI. Stn., not seem to dete n ora te during the wo rld continental a nd insul ar slo pes Nanaimo, C irc. 67, 7 p. C larke, T. A. 1972 . Exploration for deep bnef te t peri od . in regions whe re species of Herero benthic fis h and crustacean re ources in Care m u t be taken not to overcook H awai i. U ni v. Hawaii , H awai i Ins!. Mar. carpus may occur has a tota l a rea of Bi oI. T ech . Rep . 29: 1- 18. these specie. BOi ling time o f 2-4 about 5 millio n km2 . W e assume that Gulland, J. A. (editor). 197 1. The fi sh re sources of th e ocean. Fish. News (Books) . min are adequate for the frozen H . the area of the 200-600 m d epth ra nge Ltd., Surrey, 255 p. ('/l\;/er. The tail meat can be he ll ed is about ha lf this: 2.5 millio n km2 . H ancock, D. A., and G. Henriquez. 1968. Stock assessment in the shrimp ( H el ero easil) for other methods o f prepa ra Assu ming tha t 10 pe rcent of this a rea ca rpus r eed i) fi shery of C hile. In M. . tion by bnefh thawing in running is fi shable and suppo rts concentra ti o ns Mistakidis (editor), Proceedings of th e World Scientific Conference on th e Bi ol '" ater or atter a ~O-sec bl anch . of h rimp, we have a potentia l fi shing ogy and Culture of Shrimps and Prawns The onl) present comme rcial fi h area of a pproximately 250,000 km2 . If held in Mexico C ity, Mexico, 12-21 June 1967. FAO Fish. Rep. 57, 2:443-465. en for a specie o f Hererocarpu.1 yields o n the o rder of 1-10 metric Kessler, D. W. 1969. Test-tank studies of 2 shrimp-pot effi ciency . Fish. Ind. Res. (f{. reC'dr Bahamonde) ex i ts pri marily tons/km are reali stic, then it seems 5: 15 1- 160. off (hill.', and to a lesser extent. Peru . probable that H . ensiJe ,. a nd othe r Moiseev, P. A. 1969. Bi ologicheski e resursy Mirovogo okeana (The living resources of In thiS hlghl) productive regio n o f members of this genus repre ent a n th e world ocean). Izd atel 'stvo "Pishche up\\elling, a tra",1 fi hery p roduce unexplo ited resource of considera bl e vaya Promyshl ennost" Moskva. (Trans lated by I rael Program Sci. Transl., 1971 , dhout 10,000 metric tons annua ll y magnitude . 334 p. ; avail abl e U.S. Dep. Commer., Natl. IHancod: and Hennquez. 1968). It Tec h. Inf. Serv., Springfield, V A, as TT 4 Data fr om Pascagoula Fish ery Products 7 1-50026) . has been e ... timated that the tota l avail Tec hnology Laboratory, Pascagoula, MS Yoshida, H. O. 1972. Exploratory bottom ..tblc grounds are about 1.600 km2 in 39567. trawling in H awaii an waters. Indo-Pac . S L. G . Eldri dge, University of G u am, Fish . Counc., Proc., 13 Sess., Sect. 3:255 - extent and that production coul d reach Agana, Guam 969 10. Pers. comm. 26 1. "lwut 2() ,O OO metric tons annuall y ((,ulland, 197 I) ThiS indicates a n annu,tl production of about 12.5 MFR Paper 1095. From Marine Fisheries Review, Vol. 36, No . la, l metnc tlln /k.m October 1974. Cop ies of this paper, in limited numbers, are avail In Ha\\..tll. It appears tha t the abu n able from 083, Te chnical Information Division, Environmental dance llf II. ('/IIi!i'r i~ greatl y under SCience Informatio n Cen ter, NOAA , Wash ington, DC 20235. stlmdted h\ sampling with 4 I-foot hnmp tr .. m!s Our ma"\ lmu m catc h rdte Illr thl\ peLies was 240 k. g/k.m 2 althllugh mn,t <.dtc.:hes "'ere les than II) pen:ent III thiS It IS perhaps be t ..tt pr~ ent III not speculate o n the are.1 eflectlvel) lished b) a Sin gle hnll1p (rdp. hut rather point l)Ut aga in th .. t Ir.lp' are a much more effiC ient me.ln (II h,ln cs t Inc H. ell\l It r 1n 11.1\\.111 W~ feel th,1I ..In ..Innu;1 \ leld I I llr 2 metne l on'/"m~ lo r ' Ha "',111,111 \\,llef d,le n,)t 'eem like an unrC,1 f),lhlc ("'llIll .. lte The t )tal area f the pllillum depth r.mge fl) r H 1/\1 If 111 Ih Ill .. III 'r,lup ,)1 the lid'" 111.111 I I.Hld h.1 Ihlt heen pre- 30