Catch Rates and Si7.e of White Shrimp Caught by Cast Nets With DilfeTent Mesll Sizes By J. David Whitaker 1am~ E. J mkiti Lawrence B. DeLancey South Carolina Marine Resources Ctiiler Tedin;cal Report mo.her 77 South CardI:na WlldUrr: and Marine Raourws Department ?tb.rine Resourat DiWsion omce or Jlsbe.rles Manapmmt CrustKellll 'Ma:nqanmt Pnll Table of Contents T1ab.le of ean-tm.ts ........ •• •t•• ....... ...... ......... ·*"· 1•••• •lli• ii·~· ii'"'''""' t11t-•+• •••-11• •lfi• .. § ·~ LI.a, iof' Tabla. •. ••••••••••••••••••••••••••• • 111 • •ti • 111i iti!i iio-1-til 1!1-141-1-t!I !!fol I I llfll l!llW l!!t-l~!l 1! 11411-t! !ll ii Lia 1of :lil,p::.re:s .................... ......, . ....... ....... .,. i•. •i ••• iiii ilii ••• iii i iii itf 11!1 ••• tiit-iit>i iii iii l~.on .......... ,. ..........................................-. ...... * ••., .,.. .. .... •• • ••.• •• 1 ~ illld Ml!C:bild$.~. ,•• •••,. ..................................., ............ •lWI ••• •• ••••••• 2 Resull., ....................... n• ....... .,••• ., ••• ., ••• .,•• • .,•• • .,... .-.. • .,.,• ••• .-........... or 4 ~- .. ........ •1•• •it:• ••••• •m::-•!I!• ........ •m:•lel• ••••• -.w.-.!11•-. ... "'. •111 •i!i ......... i'lt-i<ii • •i-Witi •i'i"«i-wiil 7 ~d1tlons....,. ......................... ..... ..... __. •••• ••l•• • . ........ ..., . .. ..... .... ........ ... ... 15 A.ck:now~, !! •!!I•, ...................., . ...................................... •••1•• ••• ..... lfi Utentu:n Cit.ed ~· l 11!!! Iii!!!!.,·~ · ...... ~--·*Ill! pl9l-• •• • r.m• . ..... ..... ...... ....... •mi • •••• ••• ••• •t:m• •• • 17 . List of 1Tables J. CatCh ·data obsel'l'ed rOI" ~ m ' s.miirii.i.ii!'•••••••tt••········,.·· 4 l. Mean numbet and standUd deviation of white shrimp obsel'ved per set or nlnf' alStl fo_r ea:dii llil!Sh liu................... ..... ti• • .., ................ 11• •••••••• 11• ••• •1t1• •••191 . ·~.. 5 3. Total atdl ~ u weigbt imd number or whole shrimp per po&md ror lath !Id {9 Cil5b). •• •.. ••• •• ••• • •• .. • •• 8 4. By-Gtdl collNttd by each par (or the entire study. Siz~ range5· are sbc>wn u arapacie. 't'ldlh (crab), mande lm,gtb (squid), and total l~n&tfi (6nfi$h). • If .... &!t'a IHI a+.~ f il 6 fol fi-t I ...... e ... •• e ,. ..... ... 11..-e 11• e•e ••a•• a1' a aa a•a a• a •a a 11 ii List of Figur-es l . 1Stu:d)i i1e in .Alb.le)' RI. u ... •+• •· ••••••••·• •.+i••· •• ,.11, , ...... ... ....,., .... •• • •• .... •• J 2~ Fr«Jvency or OttUnen~ ror catch nrb!ll (oumfltt pell' cut) ef bite •hrtmp ,obffrved for different mesh sms ..••••.........•m... ......... ... 6 3. While shrimp .slu cllstributions for tbrtt· mah mes. De yerticaJ~ daSbed lfute se~ usable be) unusable shrimps ..•• on ••n • ••• ' 4. Averqe l~nlfh of ~ &hrimp ror dift'ermt mesh sizes u 1~ for ea.ch mmplln1 date,... .............,, • •••• •••••••• fl .............. 10 5. Relatioosb1p ~ &vent# Jtn_gth of wbi.Ce lhrimp mbD in die 3/8-ln. gear for udl, 5let. and number ot shrimp caught by that par sbtnirn u • perttntqe or total catdl (peJ' set.) ro_r all gea:n mm.M.Iiecl19i i lf • • • • • • • • • • • •f t+I ii•• ••••••••••• l t l+4 •*• •• • •• •• • • ittfof I+••••• l4 iii Introduction l\maeid hriwp ha\'t beeq shrimp baldng, hmttlOrdl) has au b}' aast net In C08.Slal hie tmploJed f« numJ years in W8lerS al U. United Sbta: for South Carolina, a hat: oruy bemme pneratiQlg~ The rast ,cut nm popular AMUlly ('lbeiUDK,. 1988; 'WHtl blmd-lewn wit.II coUm twine Wmtz and ~"' 1.9D), Totall and later witlb D)'lnl'i. The.w mts naeatioml ad:cb or mr1mp 1n 1'H't osuallJ mmt:ruded of a U'73 ·wa1 ectimated W be about minJmal mesh me of about l!l~. 0.:53 mlllioo lb. (0..U mlfilon k&) 1 (ll.7-PUD) lfua:N IQSb. SmaDt.r (bl:a.U oro or· about 9.Sll pen:mt or mem mes required iudJ more 1fle c:mnmen:la'I b'IHIJ-caulbt ~an-.I d, llif.O)J e- t'_ --~ PrlMe- Jandinp 1(Cupb and McKem:le;. namJyi' (lllCtoTJ-mosb'ucted1 197.41~ ~ver 1 alkbn of white mQDolil•,.,. neUi ha,.i~ betome shrimp., &nacm Rtifmu. during 1JJ.e more commonly used nd+ the baking lalOllS have hem These netit CUJi Mi mMS procfoced computed to be ab!Mlt l .161 million In 1llmmt 11n1 she and are much Ibo. (0.53 miWon kl) (bead!l..on) lln ]IS.I npmslw lhlln the hand-RWD 1987, .75 mlllJon lb.. (0.34 miOiGa nets. Tboqb J/2..i:IJ. me.di nm kC} in 1988. &Del 0.80 million lb. an mm.man, lbr JIB-In~ (91.5-mm) (~ mllllo_n q)i.n D!Sl ~ 1quan mesh net has !become YHJ USS; Wala and Hen11, 1989; R. 'popular In atdtin& shrimp to be Low, llft'S· mmm.)i. White sbrim-J mmumed or. used as fishing bait. Uqbt by baiting in 1987 and Relltiveb little ' ~ ar-. 19.U :llDCOullted for m a.iimated :lllftllable OD shrimp :size Oil" atdJ. 29 ag_d. n pel"ttllt, rtip«ti\ltfJ' I Of ntes for cast iDeU of dlfferent die totd tu.nest of whJte sbrimp. m ma. Wmdwud (1989) The dramatic mtteue m lhrimp eamlned this In ,coastal, ~ addli by baiting lo lmban waters. but mm w01fl ha not been 1dom wh1icb llan ~ tli1idition&Dy ln Somh Carolina.. The on'Jy dosed to 1COJ111Derdal rrawlln,I., llw camparah'le data for 8oufb camed «uarD amoq manapn Cunllu wrN mllededl In a slud:y and enW-Onmmta.fistt,,, Tbqb of different m• siu!s mband manap:f'5, beUe.Te that recruiftnent ~ (M~ and WhhBlftr, 1overflstdq will not O!i:mJ' under 1980). cunut l.evtls al eaon. :mdl laws. Though die practke of tbe nste, ot raoun:e sboufd be atlndin& lhrimp wkh half and avd.cted. Tbeilinl (1981) reported ban~ wflh cast Dell ~nned di.t 13.8 peremt of die :dlrimp haiUn in 1987 used J/8-in. mesh die lcadl line. Sevenll meshes in nds, and mmt ol die remainder eatb net wen measvried1 .and littl~ ~ JJJ2-iD. m~ lfidS. In the ¥.ariahlllty WU found. 'We 1..9B9 shli'lmp baftln.l llshery ~ about. diKioffrH1 bowe'Vff'11 ddd l<lmti 4-5 petCerit or the shrimpnt liD tb:t­ lmmds of Detlil ....,. be • · much a Benlbn 8laJ used 112-tn. Oil' Ill in.. lllqer tbM ~hat ii ·1m1rtoed 1ulet ~h nets. In Che on die mMI.. The dlsnepaney In Charlson rarea. about .20 perunl labels and ,lldual mesh shes DUlJ' of'tlle shrimpen used 112-in. cw be related to nets. bdn.1 produced laqer mesh (R. Low. pe:n. lby fOftip muufidui'en dud tomnL). !P~ nm In metric Sb.el, and Tht primary objedDa •Of then label diem In Eq,tlsh unib.. Chis stvd)" We.il"f CO ~ the• Samp~g was mndud:edl .reJ:atlve 1mtcb rates llDd .size or the .Athley River afJaut 7-8 ml • brimp cop.t with east nm of 1(U-ll km) hm the mouth of dm".eft:ni mah sizes: en-er bait and Cilarlestm l:lubor (lil1.l)_. 1'be m determidt! if there :i.I ~ polmi.lal sampling area was di¥lded Into !loa of miall, unusaMe shrimp n~ blocks, and duee po'les were •hkh iJiie ca.upt with smaD-meib set In am or three Ta11daml'­ cue. nm. diosen blocb 10D each 111111plin1 trip. Bait hlll!I, In the r-onn or equal pam or fts'b 1(mmfladai) Materials, .and Methods meal and hdtttld&I mud Wllnl 5-6 • (1%7 - 1:52 mm) In dillllKUI'. Bills were nattemd ilO A 'Uddmeu M~h *:a (s:quue) ot about 2 In. r(:SI mmJ before nmnioed in this ltudy 1"en 311-­ ~ df!ililoC·~ on .,...,.. IL-... - . ~.. ~·M:'Y .__ Y!ll: uvwvmit :in. (9.S mm), 112--ln. 1fll.7 mm)., usually ·In about :2 ft. (0.6 m)". (15.9-mm) ~ The JJ~ and !/I-in.. xad lOatk!n 1(di5tance ·from th!!· in~ and l/2-in ~ b nm wen lbiuik) WU dtpendeiit upon ltqe purdlaed r.rom LOmll nUU Jtares or Ute tide. A. dngJe 'ball ... and die 5/8-i.JI. 111esb nee. wu p1aced about 2---3 ft. (O.ti "' ' ·' 111!) ~ from :a 1r.atalog suppl1 l!rom a IDlll'kin.I pale. Ball wat home+ Nets were liPlde of deposited Oaut. 15 to 2-0 min. monafilammt Dddn1, and am before 1Ullld~ Sunpllna ~ had • ntdiul of • ft. (l.8 Iii)~ Tbt about JO mm. after ~ lint bait -..Otll S/8-blt. mt!Cb lid. rlhal baD bad been dropped. 1()m wuld be -.ea bac1 a radius· of nmdom(J-«leded n.et. wu used to tet,en 'ft.., nqlliliq mD' to r.-rmove amplll· dlrtt dHTertllll bdlbd pa11:1 • foal Gt~ ad 1'Nttam in ~ blod;. One cast WU rnadtJ recorded. A tUlal 10f 54 cam was at eecb pole in ll!3l:h hlodt, and lbe made each ni&bt with 18 cuU of · p~ was repeated two more 1tadl Dft.. Six sampba trips WHe timn (tGtaJ of l'1 am) OJmplC«hia mAde lbmirem 23 AqJult ad U ane set. A S«Ond !d of samlJllng SepteQJber· 1..989. A tobll of 3l4 WU corullxted beginniq 30 fDig, 'r.asts was made durllll ·the study. after the laA ·pole of'~ Orst .set St••i:stb.1 analysa MllJ!l.trcl wu Ample4. Net order was qaln of Kruskal·Wallls tab (after the randomly auigned for lbe MCGnd data were ~ llil1bl! naa- m or samples. umber of shrimp 11ormal on tolal wfl&b1, mean and b1-adm ft recorded tor n.m;gbett and mean length of each cast. A.t CGmpteticm or am shrimp ro.r eKh let co uctJ1aiD II set, JO nmdlamly-selected shrimp ~pfftn.-nt (P ~ 0.115) dllfel'elKlel hm eacb par wHt mamttcl ror emed amoaa.the dine mm toc.i lenllfli 1111d total weilht for all liza. shrimp awlht by ach net wu - 4- Results than i 001 llluimp per cut, 1he 112- ln.