Of Seasonal Distribution and Abundance of Fishes and Decapod Crustaceans in the Cooper River and Charleston Harbor, S.C., Prior to Diversion

NOAA Technical Report NMFS SSRF-782 A Five-Year Study · of Seasonal Distribution and Abundance of Fishes and Decapod Crustaceans in the Cooper River and Charleston Harbor, S.C., Prior to Diversion

E. l. Wenner, w. P. Coon III, M. H. Shealy, Jr., and P. A. Sandifer

July 1984

u.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service NOAA TECHNICAL REPORTS

National Marine Fisheries Service, Special Scientific Report-Fisheries

Thc major responsibiltlies of the National Marine hshCflcs Servin' (NMFS) arc to monitor and iLS~" the abundance and growaphic dillribulion of tlshery resources, to understand and prellici tluctuall,'ns in Ihe Quant it}' "nd distflbullon 01 these re",urccs, and 10 eSlabh.h levels for optimum ute or the resources. N\lFS is also charged \\Ith Ihe developmc", and Impiementalio n of poliCies lor managm~ natIOnal f"hmg ground. • , dc'clopmcnr and enforcement of domestic fishs.,ies rcgul ali o ns, survcll l"lIcc ,)r forel~1I IishlllF o rr lInnell SlatC\ coa.\tal wate", and 'he developmenl and enforcement of international fi shery agreem,'n[s anJ r"hcies. N\lFS al,,' """ts the rlshlr'~ illtl",,,\' thr(]u~h market'"~ servlCC and economic analys" programs, and mongqc iMUrance and vessel ('~) n stru ('ti ()n :-uP"ldil'''. II ,..: nl lel' {-' , analy/t" .... a nd rllbli ... hc~ 'itatl\{il" on v3riotJ\ pha.Ci("\ nl thr Indu,,,y The S r~(ial S(il~ l1Iifi( RCT','n-- h,hcriL· .... "ent.", v,J. \ l'\tahll'.hl'd in 1'i4'J. The ,l'fir''' l'l.lrrIC' repOrl' on $:Icnliru..: m\(~,\tigalion' that document 10nl·tCTm ('ontinuint! rri)~ram ... ~ '.r f\.;'\1F~, tH intl'rhi\l' ... ~:i cntlril' rl'rH)rt .. $n \ludlC'\ I'll rcqrll'lt.'d \(or<: , The report' may d('al with applied '"hery problem\. Th~ \C'riet is

abl) u,\,.'d ..1:- ,1 Illt.'dliJIll fl)f Ihl.' l'uhlh '~ HI ~ 'n (t f hlbh~)~rarhil' ''' 'll a "pCUalll l'J "l·ienlifil.' nalure :'1 U.'\-\ Tech nl,·,,1 Rc'p ", rts 'J~1fS SS RI a,e :I\adahlc IrLT In I\lnlled nurnhcrs 10 ~t)\anmenlal ,,~enliC\. bo,h I'edcral and Slate. Th9 arc aho a'ailabl~ in 1'.\l' h31l~\: f ... 'r l)jb:~ "'l 'll' :1 lifi ~ ' and (t:\":hnl (~ 1 r Uplh.:Jlll\"'" In Ihe marllll' ... l·ll'nl·e .... Indl\ltJual lllpIC \ rnd\ he tlhlamrd ,'rom DR22, U\Cr SC'rvl(,C" Bran(h. Environ mental S"':I t.' n((' III f\)rI1lJ[ 1<...lll ('CIlIa, '\JOAA, Ri)l' k \ Ilk, MD ~I)X~2 , RCl'l.' lll SS~ r· ... afC

":2 . L~lJ l f mc:nh,!J':n. Nh'I'110({flJ !li.llronu,. rUf " C .... l·lIll· f",hl'r\ ( ';,u,:h. fi ... t L Il~· "'J ,~ l'lh ... lhk mJ.na~l'mCnl prc)("rdurc\ for tncrc:a.\IOB production of lOCke ilC \\' ;:y, anJ J~(, :1i1d "'!,' l' l\) mrl '~ ltllHl, 1'}tW.-:' 1. B\ \\ll1l ~ l!n H 'idil1!"ql "11m .. ,, s",ol1 s 'n Iht' '-aknek RI\cr ""em, 8mtol Bay, Ala,ka. By Robert

\ I ~ HI.:I ' I ~-:-8, Iii - S r ,. I I ~ , I ~ uok' .... I II" anJ WIIIl:.111 J .\1c'kll. ..\pfli l'Il~. 111 + 9 p . . 4 fig,., II tabla.

7 ~J, khth ~, )rbn"'!l'n \·\)!llpl·. ... it illll anJ rbllkll.)1l \1" IU n)l'" Ir,llll Illi:tIld l · l,j .. I. 1I -lJ I "'".1P( I If ~JO,", .. fdh, / .Jaral/thode, t-amnchQ{ica. from d~relict pou. \\~Hcrl i'd' "~ju[ hc a:-!c rn -\!J"~~L Apr d- ,'\il.WI'Tllhn J",I7~. }h <.. l l ,~·q(! k \LII! 'I.HI \\ tll,.tln Ifl~h 'tnJ Donald [) W,,,lund \la)' 1919, 111 + II p., S fip., a"d Bn :,,' I ,,'in!, '\ 1' 6 ! I<)- ~ . lit • II r .. I fi~ , ~ 1,lrk, i .l~ k· .

-.:-1 ,'·''''.\;vi .l\C' J C·: J:i1:' In' l~ n\J",','Il' Il\llll h'rs ,oi 's'Ct't'",,"n .. 1 ,tnJ ,.,' ...... \~ I h .. l iH \ \\1 I til' I i'ht'f\ ...en d "' urnm;Jr~ $JfJ\II(\ of the' \OCkr-yt \.aJmon. ( ·n(,r , :,tl t'i ... ',,· :'.(~ ~ .HIJ b$~lt(T '" In Lh(' SI :\nJrl'\\ 13;i\ .~ qr~ m , l · ll~rl(,: \;,1. ;1I1d ;tJ!,I ' mrh' " ,'hIJ' '1,-rAJ . rUI" 1(> 'hl' t hl~nl' l.akes, ."laska, IR88-19~6. By MidI; c '. ':': I~ ... ·n,L.. !.l: c': ", !'r,1 B \ DI..)\ !c F SUlhl'tlJnJ \1.1 ', 14- -':, i\ ' ,2 ,1 I~ , .11 I j) : " d~cr , \U~U ' 1 l'I " . 1\ ' If, P , I < rl~ s .. " ,abies. f l ~" i I .;\;- :,>

: .'t'l '\ h',llIrh.:aJ .tnJ JC' ·':flrll\"C .1I,:I,:ount of P.1":lfic ({)35t anadromow s.abnoI ...·l' .3 ··, · ' 1· ' ~-I \I~ I. I[I '- ', \,lIc r· 1":lTI rCr;Hl; I I..' :r,.:I.J" i n the l.ul! ,, ! \ 1. 1' lll ,lf~ d I 'f l rL'arm'o! lJldllp: ... . tnJ ~1 "umman ld !hl'lr rrica'\.(''i.i h~ regIOn. 196()..76. By R l , II ~ ,jr t=( ' ''' lL :k ; '..Jt-,,; B \ (' I;1rt:'n\:~' \\ [)~J\! '" \1;-\\ IY-:-',)\ . J \\ "hk Jll.I K.,Mer! I "muh "cr,cll1~r I'P'I. 1\ + 40 p. , I~ fig, ., 2S tabt :+ ,{r.~ , '"

-.1 - \I ",,'rnS'lIls , 'd rda~I\' s1.)lrhln, [SI",,

L\r' .;lld ~t-'k r.:i lhYl he f nll) ~ r,lr ' h \ll' ... c..' r\JIII_11l '" I r(lrn : ~ ,: \,.\1f ..... \1 ·\R :\j) -.1 ~ hlc", ·nn'c· ntJi b.l, clIflCS tn Lc"'~ Island 'Xlund. 19"2-73. 8) R. N . IU

~hT i ' ! (1!'rl'nur:1! P r('p.tlll !~1r J ~ -~ 13', Sll'\('n )o.,: (" ',' k, H,lr .: ,!~ " l ',l\!:[1 ', .\ [) fr:un, . JI,J A F D'''.,ler. Des-cmber I'n9, t\ + JI p .. 40 fill'" 61abl

- .1~ i:l' Hlc'I11 · .... :l1cr te",perature trend, II1lhe \I,ddle AllamK B'ght dunng spr ~2~. \ t'rth ai ... ·~·....r l l"l" ('! 'l'l1lim\'nlpl~ Int.·an tl'mrl.·r,iiurc...· i 'n thl' ..... ~tn .... ran"I ...... 1·' ""J aulul11l1. IWW· "6 Bv Clarence W Da'1>. D~em~r 1972. 1\i • \3 p., H t.)[!-..)Iu!u f ~\ l! t(' : I iI. ~ m <'\pcIlJJr-lt: [lJ! h~ t h t.rm~-.~ r ~l rh ~)b ... t..T\ a! i,"n .... .I un,' IlfM, II ~ ' , tj table ... . Dc.:"mber l~--I }1, J F T SJUt . L L. Eb"", D. K. -'let J,n. anci C L. 1l,',n"I\ ,. ,:~t llU 3 f~ lY- C', Ii ; , .15 r . -+ ;'jg .... , I table

"·10 . FSlS,d L' ( [;fleel1 north"''''1 Allanoc ~ad,form fishes. By Richard "':2 ,,;'. Rc.' !t':t:ih."t'''' ;lH' ttlto' Hld c..· nt:t'I;,,·;! {\(' iI ,) 1 nl.1r1nt.' In\l·rtc...~br al e ., on !he ';'t)lIlhern Lan~ lOn and Ra\ E . Bo .. man . February 1980. i, .. 23 r., 3 figs., II lables

.-\[lantl~ .... I)::1:-! 'It 'he Lnl tt:'J "'13.!t>. By R",.: hard L O"H\J .;" ArnI19"'l.!. i\ p 3~ r , "41 DI""bullon of gammariJcan Amphipoda (CrUSlacea) in the Middle . -:"30, 'S urfa,,'C' \..'ir ~ ul3llL'ln In (he nl.)rthw!?'''l Gulf l)r \te,ico as d educC'J from lantlC BI~ht region . By Js'hn J Dickinson, Roland L. Wigle)', Richard D, B Jrirt r0tt le, By R " b ~ rr F. T~mrle and Js,11I' A. -'Ian in. :\'Iay 197<1. IiI ~ 13 p o, deur. ,II1J Su,an Bro"'n ·L e~er . o..,ober 1980. i, + 46 p .. 26 figs., 52 lab ~ fi~, .. .j table ,

'4~ . Waler struclure at Ocean Weather Slation V, nonhwestem PacifIC Ocr ~.11. AnnOt3teJ nlbllOgraph\' and subJe(1 ",de, 0n the shonnose siurgeon. ACI 1966-71. 8y D. :\1. Husby and G. R. Seckel. October 1980, 18 figs .. 4 tabl penser arenrOSi rW.'l. B, James G. Hoff. April 1979, iii + 1(0 p .

743 . Average densilY index for walleye pollock, Th~ragra cha/cogamma, in : 32. A ss e ~" men! l) f the i\()nh\\t'st Atlantic mackerel. Scomber scombrus. s to~k . Bering Sea. 8)' loh-lee low and Ikuo Ikeda. November 1980, iii + II fll Emo,,' D . .-\nd erson . Arril 1919. 1\ + 1J p .. 9 tlgs .. 15 lables. 3 figs., 9 tables. NOAA Technical Report NMFS SSRF-782

A Five-Year Study of Seasonal Distribution and Abundance of Fishes and Decapod Crustaceans in the Cooper River and Charleston Harbor, S.C., Prior to Diversion

E. L. Wenner, W. P. Coon III, M. H. Shealy, Jr., and P. A. Sandifer

July 1984

u.S. DEPARTMENT OF COMMERCE Malcolm Baldrige, Secretary National Oceanic and Atmospheric Administration John V. Bryne, Administrator National Marine Fisheries Service

William G. Gordon, Assistant Adminstrator of Fisheries The National Marine Fisheries Service (NMFS) does not approve, recommend or endorse any proprietary product or proprietary material mentioned in this publication. No reference shall be made to NMFS, or to this publication fur nished by NMFS, in any advertising or sales promotion which would indicate or imply that NMFS approves, recommends or endorses any proprietary product or proprietary material mentioned herein, or which has as its purpose an intent to cause directly or indirectly the advertised product to be used or purchased because of this NMFS publication. CONTENTS

~ ...... , ...... 1 llllboda and maIaiaIa ...... ) DaIa coIIec:tion ...... ) DaIa analysis ••.•...•..• ...... J -....u ...... 4 Pbysic:oc:bemical parameters ...... 4 Community composition and richness ...... 4 Temporal and spatial distributions ...... 10 SI~IIIf~ /QIICft}/QIUS ...... 10 AnchOtl milch/iii ...... II M/cropolonills ulldu/Qtus ...... II Brrvoort;Q Iyf'tlllnus ...... II u;oslomus )CQnlhurus ...... II Symphurus p/Qgiuso ...... II Boirdi~IIQ chrysouf'tl ...... II Cyno.scion regQ/is ...... I~ Urophycis regia...... I~ Trinectes macu/atus ...... I~ Pena~ setiferus ...... I~ Pen~ a:.t«us...... J' XiphopenQ~us kroyeri ...... 1 , Callinectes SlIpidus ...... 1, Biomass estimates ...... 1, Discussion ...... 14 .cknowledgments ...... 1~

Uterature cited ...... 1 ~

I. Locations of six sampling stations in the Charleston Harbor-Cooper Ri\'er estuarine ~y\lrnl. S.( .. dUf\n~ : he ~ " \(u,h from February 1973 to December 1977 ...... ,...... " 2. Two-way coincidence tables of constancy :md fidelity. comparing SpecIes ~iaIlOn\ among \am.,iml! ,tall"n, 111 (h(' Cooper River-Charleston ~arbor estuarine system for fall. winter. spring. and summer coll('\;'lIon\. IY'7~· ~~ ~ ~ 3. Abundance of 10 major nsh species collected monthly in the channel of the Cooper RI\er·CharleshlO !t;alt'<..r estlWlIlC system, 1973-77 ...... II' 4. Annual variation in the transformed mean number of individuals of 10 major fish Specie. .:olk\.'c:\.Im Ihe ( (1o., r>ct' t(1\('! Charleston Harbor estuarine system. 1973-77 ...... I I 5. Abundance of four major species of decapod crustaceans coU('\.1cd in the channel of Ihe ( '{x)per RI\er·(h.ules(Iln Ilou bor estuarine system, 1973-77 ...... I : 6. Annual variation in the transformed mean number of individuals of four major decapod .:ru'I~C'all \pc'\.lC"\ "'"C'\.IC'\J III the Cooper River-Charleston Harbor estuarine system. 1973-77 . I I

T ....

l. Averqe water temperatures and salinities in the Charleston Harbor-Cooper RJ\er estual1~ \)"\trnl. S ( . I y~) ~. .. 2. Tocal numbers and tocal wciahts of ftsh species coUccted 1973-77 in tht- Cooper RJ\er-{'h£rlnlon Hvt-.,., C"JU.arlllC' systan, S.C ...... 1. Tocal numbers and tocal wciahts of decapod crustAcean species ~'"Olkctcd 1973-7'7 In Iht- Cooper RJ\n·<.lwlnlr>n H.art1o.>f estuarine system, S.c...... ~ 4.. Averqe numbers of species of fashes and decapod cruslacearu ~-oUccted 1973· Ii at UatJOru III (ht- loorn RI\t'T OwIeston Harbor estuarine system. S.c...... t> 5. Averqe numbers of individual ftsh and do~ crustacearu roUectcd 197)· Ii at UAlIOfU III Iht- (l.'Opn Ill\er OwIeston Harbor estuarine system, S.c...... t> 6. Species JI'OUPS formed from seasonal duster analyses of fashes and crustacearu ~-o&cted IIItht- Cooper Ill\n· <. hattnalXl Harbor estuarine system. 197J.. 77 ...... 1. AverIIIC ...... biomaa and density of fashes aDd decapod Cf1'Slecam coIecscd at .ullOm III Iht- <. ooper Ill\n · CbutaIoD Harbor aluarine systaD, S.c., 197J.. n ...... J)

iii A Five-Year Study of Seasonal Distribution and Abundance of Fishes and Decapod Crustaceans in the Cooper River and Charleston Harbor, S.C., Prior to Diversion

E. L. WENNER, W. P. COON III, M. H. SHEALY, Jr., and P. A. SANDIFER I

ABSTRACT

Fluctuations in the distribution and abundance of fIShes and decapod crustaceans collected by a 6 m otter trawl net from the Cooper River-Charleston Harbor estuarine system (Soutb Carolina, USA) were examined over a S·year sampling period. A total of 101 fisb species and 41 decapod crustacean species were collected. Species richness was greatest at stations nearest the harbor moutb. Annual fluctuations in species abundance were apparently related to low bottom-water temperatures whicb affected year-class strength. Ten species accounted for - 90% of the total number and - 71"7. of tbe total biomass of fin fisbes collected in tbe estuary: Sle/lijer lanceo/alus, Anchoa milchilli, Micropogonias undu/atus, . Brevoorlia Iyrannus, Leioslomus xanlhurus, Symphurus p/agiusa, Bairdiella chrysoura, Cynoscion rega/is, Urophycis regia, and Trinecles maculalus. The decapod crustaceans Penaeus selijerus, P. azlecus, Xiphopenaeus kroyeri, and Callinecles sapidus dominated tbe fin flSbes in abundance but not biomass. They composed - 96"7. by number and - 97"7. by weight of the lotal decapod fauna. The biomass of fishes from this study is lower than values reported for other estuaries along tbe Atlantic coast of tbe United States. The Cooper River-Charleston Harbor estuarine system, an important nursery area for fishes and decapod crustaceans, is characterized by gradual cbanges in faunal assemblages and considerable overlap in spatial dis tributional patterns of resident and transient species. Numerically dominant species of fisb and decapod crusta ceans form assemblages which are spatially and temporally ubiquitous. Resident estuarine species and slenohaline marine species are more restricted in their distribution.

INTRODUCTION The proposed rediversion probably will produce significant changes in estuarine habitat as well as in populations of estu arine organisms, such as fishes and decapod crustaceans. To Charleston Harbor and its tributary, the Cooper River, have assess possible effects of rediversion on population structure, been subjected to greatly increased man-made alterations since spawning success, and distribution of these organisms, it is 1942. Prior to that time, the Cooper River was a relatively necessary to determine species composition, abundance, and small coastal plains stream with a watershed of 1.86 million distribution prior to the perturbation. This paper describes km'. After construction of Pinopolis Dam across the upper fluctuations in these parameters over a 5-yr period for fishes watershed of the Cooper River and creation of Lake Moultrie, and decapod crustaceans in the Cooper River-Charleston input of freshwater to the Cooper River increased, resulting in Harbor estuarine system. inundation of marshes and abandoned rice fields. Increased freshwater flow into Charleston Harbor decreased salinity (Zetler 1953) and formed density currents with a predominant upstream bottom flow throughout most of the lower 18 km of the harbor. As a consequence, sediments were trapped within the harbor and shoaling increased considerably (U.S. Army STUDY AREA Corps of Engineers'). In turn, the shoaling has caused an increase in dredging costs and depletion of available disposal The Cooper River is classified as a mixohaline system, in sites within the harbor. Because of this situation, the Army which the salt wedge extends along the bottom to Big Island Corps of Engineers will redivert water flow in 1983 from Lake (Station C(02) and bottom salinities decrease from about % Moultrie into the Santee River system to effect a reduction of 27 0 at Cummings Point (Station J(03) to freshwater at the flow into the Cooper River. Tee (Station COOl) (Mathews and Shealy 1978) (Fig. I). Charleston Harbor is a stratified or salt-wedge estuary with saltwater intrusion primarily a function of the tidal range and the amount of freshwater released by the Santee-Cooper Dam. A salinity differential between top and bottom strata of the 'Marine Resources Research Institute, South Carolina Wildlife & Marine harbor causes the bottom flow currents to predominate over Resources Department. P.O. Box 12559. Charleston. SC 29412. the bottom ebb currents, with the result that upstream move 'U.S. Army Corps of Engineers. 1975. Final Environmental Statement: ment of the bottom currents within the saline region of the Cooper River Rediversion Project, Charleston Harbor. S.C.! U.S. Army Corps of Engineers. Charleston District Office. Charleston. SC 29403. 201 p. harbor forms a sediment trap (South Carolina Wildlife and ~~ 1 ct. 320 45 0 32°, 1\C 'v~~ ~1

Figure 1. - Locations of six sampling SUtiODS in IbeCbarleston Harbor - Cooper Riveresluary, S.C., during"e S-yrsludy from February 197310 December 1977

2 3 ~e Resources Department ). Extended periods of high recorded size measurements for all species numbering s 50 dver flow in the Cooper River frequently dilute water in specimens per tow. At stations where the trawl captured Charleston Harbor and even in the vicinity of the harbor larger numbers of organisms, we subsampled the catch as 1I1000th (U .S. Army Corps of Engineers, footnote 2). follows: If ~ 50 to·s250 individuals were collected, a minimum .Coastal marshes cover approximately 20,230 ha in the entire of 50 randomly selected specimens was measured; if > 250 to ~:harleston Harbor system. Of the total marsh area, salt s 500 individuals were caught, a minimum of 20% was narshes compose about 48%, while freshwater marshes cover measured; when > 500 were caught, a minimum of 10"70 was Ipproximately 36"70, brackish marshes make up 6"70, and measured. mpoundment areas cover 10"70 (Tiner 1977). The marshes of : le Cooper River reflect strong freshwater inflow, dominated Data Analysis :y bulrushes (Scirpus sp.), cattail (Typha sp.), and giant cord The degree of similarity among collections and among !rass, Spartina cynosuroides. Smooth cordgrass, Spartina species was determined using normal and inverse cluster anal ,Iternif/ora, dominates the low salt-marsh habitats and is yses, employing the Bray-Curtis similarity coefficient and nixed with black needlerush, Juncus roemerianus, in up "flexible sorting strategy" with the cluster intensity coeffi itream locations where salinity transitions occur (South cient, p, set at the now standard value of - 0.25 (Lance and ::arolina Wildlife and Marine Resources Department, foot- Williams 1967; Williams 1971; Stephenson et al. 1972; 10te 3). Clifford and Stephenson 1975). Species which occurred in only one or two collections during a sampling period and col METHODS AND MATERIALS lections which contained only one species were eliminated from the analyses. Abundances were logarithmically trans Data Collection formed (log,o[x + 1] where x is the number of individuals for a given species) in order to lessen the tendency of extremely abun dant species to dominate the similarity matrix (Clifford and We sampled six fixed stations in the channel of the Cooper Stephenson 1975). River-Charleston Harbor system (Fig. 1): COOl (The Tee») C002 Two dendrograms were generated for each season: 1) A :Big Island), c003 (North Charleston), C004 (Mouth of Cooper dendrogram which indicated association of all sites by season River), JOOl(Charleston Harbor), and J003 (Cummings Point). during the 5-yr sampling period based on faunal similarity, :ita'tions extended in a transect from the harbor mouth inland to and 2) a dendrogram which indicated association of all species :l~ve permanent freshwater. Each station was sampled once a collected each season during the 5-yr sampling period based on month during the 5 yr from February 1973 through December the abundance of species at sites where they were collected. 1977, with the following exceptions: COOl was sampled only dur Nodal analysis (Williams and Lambert 1961; Lambert and ing 1973 and January 1974 and was discontinued because of un Williams 1962) was subsequently used to examine species irawlable bottom; a new station, JOO 1, was established in January group and station coincidences based on patterns of constancy 1975. In addition, J003 was not sampled until May 1973. and fidelity (Boesch 1977). All collections were made with a 6 m (20-ft) semiballoon An index of abundance (Musick and McEachran 1972; ,tter trawl of 2.5 cm (I-in) stretch mesh. This net is particu Elliott 1977) was used to compare numbers and weights of arly selective toward capture of juvenile fishes and is less selected dominant species and is expressed as: :ffective in collection of older, larger fish and highly mobile Jecapod crustaceans. Twenty-minute tows were made against IN Index of abundance = - ~ log '0 (x + 1) ]ood tide during daylight hours at a speed of 1.3 mls (2.5 kn), Nl 'esulting in a coverage of 1.5 ± 0.4 kmltow. Bottom-water samples were collected 0.5 m above the bot where x = no. or weight of individuals of a given species in a :om with Van Dorn bottles at each station prior to trawling. chosen frame and N = no. of collections in that time Water temperature was read from stem thermometers frame mounted within the Van Dorn bottles. Salinity was measured We determined biomass and density estimates for fishes and in the laboratory with a Beckman RS7B induction salinometer. decapod crustaceans from computations of area swept by our Dissolved oxygen was determined by the Winkler-Carpenter trawl gear. Estimates of area swept (a) were determined by method (Strickland and Parsons 1968). Turbidity was deter the following equation given by Klima': mined with a Hach Model 2100A turbidimeter. Winter sam pling encompassed January-March; spring sampling April a = KM(0.6H) June; summer July-September; and fall October-December. 10,000 m 21ha Specimens collected were either processed in the field or pre served in 10"70 Formalin and returned to the laboratory for where K is speed in meters per hour, M is time in hours fished, identification, counting, weighing (nearest 0.1 g), and mea and H is headrope length in meters. The constant 0.6 desig suring (total length for fishes; carapace width for crabs, mea nates an effective swath of about 600/0 of the headrope length sured as distance between tips of lateral spines; and total as used by Roe (1969) and established by Wathne (1959). The length for shrimp from tip of rostrum to tip of telson). We area swept by our 6 m otter trawl was estimated by this method to be 0.54 haltow.

'South Carolina Wildlife and Marine Resources Department. 1972. A study of the Charleston Harbor estuary with special reference to deposition of dredged 'Klima. E. F. 1976. A review of the fishery resources in the western central sediments. Unpubl. manuscr.. unpaginated. Office of Marine Conservation. Atlantic. WECAF Studies No.3. FAO No. 32975-76. 77 p. Available from Management and Services. P.O. Box 12559. Charleston. SC 29412. UNIPUB.l180AvenueoftheAmericas. New York. NY 10036.

3 RESULTS perature ranges, along with relative abundance of all SJJCdIa collected, are available upon request from the authors. Tr.n Physicochemical Parameters species accounted for 90070 of the total number and 71 'It of die total biomass of fishes collected in this estuarine system: Sta Bottom-water temperatures were very similar among all sta drum, Stellifer /anceo/atus; bay anchovy, Anchoa mitchil1i; tions with mean temperatures lowest but most variable in Feb Atlantic croaker, Micropogonias undulatus; Atlantic ruary and warmest in July, August, and September. Yearly menhaden, Brevoortia tyrannus; spot, Leiostomus xanthurus; average temperatures were lowest in 1976 and 1977 (Table 1). blackcheek tonguefish, Symphurus plagiusa; silver perch, Salinities measured monthly were highly variable at all sta Bairdiella chrysoura; weakfish,Cynoscion regalis; spotted tions; nonetheless, average salinities were sufficiently different hake, Urophycis regia; and hogchoker, Trinectes maculatus. between stations (Table 1) to justify classification of sites ac Stellifer lanceolatus was the most abundant fish collected each cording to the Venice system (Anonymous 1958). Station year of the study, except in 1977 when Brevoortia tyrannus COOl was classified as limnetic because salinity did not was most abundant. exceed 0.5% 0 throughout the year it was sampled. Salinities at During the 5-yr sampling period, we collected 44 decapod stations COO2 and COO3 ranged from 0.4 to 18.0% 0, and crustacean species (Table 3). Decapods dominated the fIShes these stations were characterized as limnetic-mesohaline. We numerically but not in biomass. The numerical dominance was classified station COO4 as limnetic-polyhaline based on the due to large numbers of white shrimp, Penaeus setiferus, col lected in the Cooper River-Charleston Harbor system, This salinity range of 0.67-26.2%0. Stations JOOI (7.5-27.7% 0 ) and JOO3 (19.4-33.3%0) had the highest salinities and were species constituted 83% of the total number and 69% of the classified as mesopolyhaline and polyeuhaline, respectively. total biomass of decapod crustaceans. Penaeus setiferus was Average salinity varied also with season, being lowest in spring numerically dominant during each of the 5 yr of our study, and highest in fall (Table I). except in 1977 when P. aztecus was most abundant. These two A verage dissolved oxygen concentrations were greatest at all penaeid shrimps, together with seabob, Xiphopenaeus kroyeri, stations in January and February and lowest in summer. No and blue crab, Callinectes sapidus, composed about 96'70 by relation was apparent between dissolved oxygen concentra number and 97% by weight of total decapod fauna collected tions and station or depth. The lowest average concentration from the Cooper River-Charleston Harbor estuarine system. measured in the Cooper River was 4.9 mg/1. Average numbers of species collected were greatest in 1976 Although we did not specifically determine sediment char at the higher salinity stations COO4, JOO3, and JOOI (Table 4), acteristics for our fixed stations in the Cooper River-Charles whereas species richness decreased along the transect of sta ton Harbor system, Mathews and Shealy (1978) reported the tions upriver. Mean numbers of individuals were greatest at general bottom type to be as follows: COOl (hard-mud), COO2 the higher salinity stations (C004, JOO3, J(01). In addition, (sand), COO3 (shell and sand), COO4 (mud-shell-sand), JOOI more individuals were collected in 1975-76 than in 1973-74 and (mud and sand), and JOO3 (shell and mud). 1977 (Table 5). The fewest individuals were collected in 1977, probably because of prolonged periods of extremely low water temperatures during January and February 1977_ Table I.-Average water temperaiUres and salinities in the Charles Normal classification analysis showed that collections were ton Harbor-Cooper Rher estuarine system, S.c., 1973-77. not distinctly grouped according to their location along the Environmental factors salinity gradient. During all seasons, collections from stations Avg. temp. Avg. salinity classified as limnetic and! or mesohaline were faunistically ( OC) (% 0) Parameters least similar to those from high-salinity sites, but overlap oc Year (all stations) curred in classification of collections in the mesopolyhaline 1973 22.1 12.0 and polyeuhaline range. Because groups broadly overlapped 1974 20.2 14.1 1975 21.1 14.5 by stations and were not clearly separated by cluster analysis 1976 19.9 15 .7 according to salinity regimes within the estuary, we compared 1977 19.8 15 .7 collections from our fixed stations, rather than site groups as Station (all years, 1973-77) determined from cluster analysis, with the species groups listed J003 20.9 27.6 JOOI 20.7 19.2 in Table 6. In this way, seasonal comparisons among stations COO4 19.8 12.6 were facilitated by direct cross-referencing against the species C003 20.9 5.4 assemblages at each station. C002 20.5 1.8 During all seasons, collections from higher salinity stations COOl 18.6 0.07 Season (all stations, 1973-77) JOO3 and JOOI were characterized by stenohaline marine Fall 19.1 15.6 species. These included black sea bass, Centropristis striata; Winter 11.7 14.5 searobins (Prionotus spp.); striped cusk-eel, Ophidion Spring 21.7 13.7 marginatum; lady crab, Ovalipes ocel/atus; seabob, Summer 28.4 14.9 Xiphopenaeus kroyeri; swimming crabs (Portunus spp.); and hermit crabs, Pagurus /ongicarpus and C/ibanarius viltatus. In fall, stenohaline marine species (Group B) displayed only Community Composition and Richness moderate to low constancy and fidelity for collections at stations JOO3 and lOOt (Fig. 2), while in winter, many of the A total of 101 species of fishes was collected from the same species and other marine transient species were still Cooper River-Charleston Harbor system during the 1973-1977 infrequently encountered but highly faithful to collections sampling period (Table 2). Length, bottom salinity, and tem- from station JOO3 (Fig. 2). Stenohaline marine species, which

4 Table 2.-Total numbers and total weights of fish species collected 1913-77 io the Cooper Rive.r- Charleston Harbor estuarioe system, S.C. Species are listed in order of abundance, aod data are RS!S!le.d over the 5:Ir ,a!eling eerlod. Number Weight 52·cies Total Total (kgl Stellife7' ZanceoZatus 22,932 33.33 167.882 18.90 Anch"" mitchilli 9,203 13.38 15.957 1.80 Mic7'Opogonias unduZatu. 7,862 11.43 108.374 12.20 B.,.evoo.,.tia tymnnus 4,848 7.05 82.699 9.31 Lfliostomus · mnthuMis 4,228 6.15 56.200 6.33 SymphU"U8 plagiu8a 3,053 4.44 41.633 4.69 Bai7'dielZa ch"Y8OU7'a 3,006 4.37 83.849 9.44 Cynoscion .,.egalis 2,578 3.75 33.005 3.72 Y7'ophyci8 7'egia 2,250 3.27 30.091 3.39 TM.nsctss 1PI2CutatuB 1,996 2.90 15.108 1.70 IctaluMLs oatus 1,931 2.81 40.623 4.57 Do.,.os01m. petenense 1,060 1.54 5.374 0.60 .4loBa aestivalis 513 0.75 1.809 0.20 HsnticiJ"'7'huB l1mBnc.anus 310 0.45 5.057 0.57 OpSCUlUS tau 282 0.41 38.124 4.29 Parotich thy. dentatu8 250 0.36 9.805 1.10 Psp7'ilus alepidotus 239 0.35 2.730 0.31 Parotichthys lethostignn 215 0.31 39.568 4.45 Pep.,.ilu6 t.,.uzcanthu8 184 0.27 1.730 0.19 ChloJl08Comb""'8 cJt~8U"""6 132 0.19 0.493 0.06 Opi8thonenn ogU num 128 0.19 0.763 0.09 S't1"OPUB C.,.OS80tUB 126 0.18 0.842 0.09 Ictalu",B ptmctatus 124 0.18 1.763 0.20 Prionotu6 tnbuluB 108 0.16 0.268 0.03 4nchoa hepsetus 103 0.15 0.818 0.09 Pomatomus saltatm 91 0.13 2.306 0.26 4nguilZa 7'ostmta 74 0.11 9.959 1.12 Cent"op7'isHs phitadelphica 70 0.10 2.945 0.33 Citha7'ichthys epitopterus 63 0.09 0.345 0.04 Chaetodipte"U8 fabe7' 56 0.08 0.617 0.07 Scophthalmus aqu08uS 54 0.08 0.484 0.05 Ictalu""s nebulo8us 53 0.08 2.557 0.29 Aloea sapidissirtrl. 50 0.07 1.149 0.13 Ancylopsetta quad7'ocelZata 43 0.06 0.709 0.08 TM..chiu1'U.B leptuJ'IUs 41 0.06 1.690 0.19 Selene vomeJl 40 0.06 0.377 0.04 p.,.ionotus evolana 32 0.05 0.216 0.02 A1'ius felia 32 0.05 2.788 0.31 U7'ophycis {lo"ido.na 29 0.04 0.978 0.11 8YP60blenniu8 hentai 29 0.04 0.236 0.03 HOJlone sa..rat i l is 23 0.03 0.154 0.02 Ophidion ""7'ginatum 22 0.03 0.433 0.05 Ictalu7'U8 fl.n"catus 22 0.03 0.530 0.06 Setene Betapinnis 21 0.03 0.096 0.01 Cynoecion nebulosuB 21 0.03 1.037 0.12 Lagodon momboides 19 0.03 0.692 0.08 Caranx hippos 18 0.03 0.321 0.04 CS7ItJlopJlistis st~ta 15 0.02 0.437 0.05 UJlophyciB Ba7"l.li 12 0.02 0.203 0.02 DQ..8ya.ti8 sabina 12 0.02 11.731 1.32 Pog(J71ia.s e.,.omis 12 0.02 5.000 0.56 Euci7lO8tomus ap. II 0.02 0.107 0.01 Lepi60stllUS OSSQUS 10 0.01 17.662 1.99 A toea msdioe7"'is 9 0.01 0.011 0.01 Gobiesoz St1'UmDSUB 9 0.01 0.044 0.01 ::iccJfT/lJer-omo1'l.HJ lm.Culatus 0.01 0.214 0.02 Lutjanus (!JIiseus 9 0.01 0.107 o. ( ~ l Euc.iooetomus ay.genteus 7 0.01 0.062 0.01 PM..anot~s Bp. 7 0.01 0.022 0.01 ProionotUB eaJlolinus 7 0.01 0.019 0.01 HBnidia menidia 6 0.01 0.025 0.01 Prionotus sci tulus 5 0.01 0.038 0.01 Monaeanthus kispidus 5 0.01 0.009 0. 01 Al'"chosa7"gUB P7"obatocepha1.uB 5 0.01 0.156 0.02 Cynoscion nothus 5 0.01 0.035 0.01 La1"imus fasciatus 4 0.01 0.027 0.01 AstJloscopus y-!T'f'08cum 4 0.01 0.030 0.01 Mugil CUl'"B1m 4 0.01 0.078 0.01 Cyp-,.inus ea1'pio 4 0.01 18.883 2.13 SynoduB fo.tens 4 0.01 0.187 0.02 B.,.evoOJltia smithi 3 0.01 1.297 0,[5 Acipsnse7' oZY7'hynchuB 3 0.01 13.835 1.56 Bagroe m1"inus 3 0.01 0.041 0.01 Chilomycteru8 antilZa7'Um 3 0.01 0.006 0.01 Gobionenu8 Bhufeldti 3 0.01 0.006 0.01 Symphu'f"U8 civitatus 3 0.01 0.026 0.01 SphOS1'Oides nueulatu8 3 0.01 0.133 0.01 PeJlOO flavescens 0.01 0.024 0.01 LCUJocephalus 1.aevigatus 0.01 0.106 0.01 "'"gil CephalU8 0.01 0.028 0.01 Gobione.llu8 boleo6orm 0.01 0.006 0.01 Hyp80blenniu6 i011.thae 0.01 0.009 0.01 I ctalu7'Us platyeephaluB 0.01 0.335 0.04 Rhinoptera bonasus 0.01 D01'0601Tl1. cepedianum 0.01 0.035 0.01 Lepomis punetatu8 0.01 0.030 0.01 Elops SaUl"UB 0.01 0,[26 0.01 HOJlone amel"icana 0.01 0.010 0.01 Mycte.,.oper>ea mic7"olepis 0.01 0.073 0.01 Cymu.,.a mi.c7'U7"Q. 0.01 0.177 0.02 Raja egZante7'i.a 0.01 0.671 0.08 Ca.,.chaminus plumbeus 0.01 1.046 0.12 Lepomis au7"itu8 0.01 0.008 0.01 Ic.talu'/"U.s natalia 0.01 0.009 0.01 Ictalu7"Us meta.s 0.01 0.058 0.01 Eleot.,.is pisonis 0.01 0.018 0.01 Gobionellus hastatu8 0.01 0.003 0.01 Sphymena guachancho 0.01 0.001 0.01 Sciaenops ocellatus 0.01 0.004 0.01 MenticiM'hus littomlie 0.01 0.028 0.01 Enneacanthus gloM-oeue 0.01 0.001 0.01

'OTA!. 68.796 888.409

5 Table 3.--Total numbers and total weights of decapod crustacean species cbllected 1973-77 1n the Cooper River-charleston Harbor estuarine system, S.C. Species are listed in order of abundance, and data are pooled over the 5:vr sampling period. Number Wdlht Species Total % Total (M) Penaeus setiferus 80,121 82.62 492.927 69.20 Penaeus a.atecus 8,053 8.30 56.757 7.97 Xiphopenaeus k1'oyeroi 2,657 2.74 4.928 0.69 Callinectes sapidus 1,914 1.97 137.936 19.36 Callinectes similis 1,438 1.48 11.029 1.55 Trachypenaeus const1'ictus 721 0.74 0.912 0.13 Palaemonetes vulgarois 388 0.40 0.199 0.03 P01'tunus spinimunus 243 0.25 2.308 0.32 Pagu1'us longica1'pus 215 0.22 0.182 0.03 P1'otunus gibbesii 193 0.20 0.420 0.06 Ovalipes stephensoni 191 0.20 0.646 0.09 Penaeus auora rum 177 0.18 1.256 0.18 Panopeus he1'bstii 133 0.14 0.358 0.05 Rh ith1'opanopeus ha~isii 82 0.08 0.045 0.01 Pa laemonetes pugio 82 0.08 0.047 0.01 Clibana1'ius vittatus 77 0.08 0.054 0.01 Ovalipes ocellatus 69 0.07 0.426 0.06 Mac1'obrachium ohione 47 0.05 0.165 0.02 Pagu1'Us pollicarois 25 0.03 0.086 0.01 Palaemonetes sp.* 24 0.02 0.014 <0.01 Neopanope sayi 20 0.02 0.019 <0.01 Cance1' i1'1'oratus 19 0.02 0.248 0.03 Alpheus n01'manni 11 0.01 0.003 <0.01 Menippe me1'cena1'ia 10 0.01 1.066 0.15 Libinia emunginata 10 0.01 0.077 0.01 Libinia dubia 7 0.01 0.019 <0.01 Hexapanopeus angustif1'ons 7 0.01 0.020 <0.01 AlpheuB hete1'ochaelis 6 0 . 01 0 . 009 <0.01 Palaemonetes inte1'medius 5 0.01 0.003 <0.01 Sicyo~ia laevigata 5 0.01 0.005 <0.01 Panopeus occidentalis 5 0.01 0.005 <0.01 Dortunus sp. * 5 0.01 EU1'ypanopeus dep1'essus 4 <0.01 0.004 <0.01 Callinectes 01'natus 2 <0.01 0.082 0.01 Exhippolysmata oplopho1'oides 3 <0.01 0.004 <0.01 Lysmata ~u1'demunni <0.01 0.002 <0.01 Sicyonia b1'evi1'OBt1'is <0.01 0.004 <0.01 Hepatus epheliticus <0.01 0.060 0.01 Micropanope so. <0.01 0.001 <0.01 Libinia sp. * <0 .01 0.001 <0.01 Xanthidae* <0.01 Penaeus sp. * <0.01 0.001 <0.01 P1'ooombarus claT'ki <0.01 0.006 <0.01 Callinectes SD.* <0.01 0.001 <0.01

TOTAL 712,330

*Field identification or damaged specimen(s).

Table 4.-Average numbers of species of fishes and decapod crustaceans col- Table 5.-Avenge numbers 01 individual fIsb ud decapod c~ coIected lected 1973-77 at stations in the Cooper River-Charleston Harbor estuarine 1973-77 at stations in tbe Cooper River-CbarlestoD Harbor esturiH 1YIl-. system, S.c. Numbers in parentheses = standard error of the mean; n = number S.C. Numbers in parentbeses = studanl error 01 the _; n=aumber 01 of samples per year. samples per year.

Average numbers of species/station Grand Average numbers of individuals/slalion Grand Year COOl C002 C003 COO4 )003 )001 Mean Year COOl c002 c003 COO4 )003 JOOI Mean 1973 4 6 10 13 12 10 1973 21 355 867 1,195 456 718 (0.81) (1.05) (0.89) (1.56) (2.35) (6.70) (218.97) (429.07) (473.38) (146.88) n= 1\ n = 11 n= 12 n= 11 n=8 n= 11 n= 11 n= 11 n=1I n=8 1974 2 6 9 15 15 11 1974 2 158 541 533 619 463 (0.81) (1.23) (2.04 (2 .14) (45.92) (209.96) (94.50) (ISO.18) n=1 n= 12 n= 12 n= 12 n= 12 n=1 n=12 n=12 n=12 n=12 1975 6 11 12 15 16 12 1975 80 554 519 1,233 1,467 771 (0.94) (1.53) (1.41) (2 .12) (\.79) (47.58) (369.91) (123.91) (355.84) (346.78) n= 12 n= I2 n=12 n= 12 n= 12 n= 12 n=12 n=12 n=12 1976 8 12 18 18 i6 14 1976 319 715 1,018 688 922 732 (0.78) (\ .40) (1.46) (1.44) (1.66) (136.55) (397.20) (198.60) (149.82) (225. SO) n= 12 n=12 n=12 n=12 n=12 n=12 n=12 n=12 n=12 n=12 1977 9 12 12 13 19 13 1977 206 263 171 299 503 288 (0.75) (1.38) (1.79) (1.77) (1.27) (65.88) (90.67) (48.07) (119.31) (191.41) n=12 n=12 n=12 n=12 n=12 n=12 n=12 n=12 n=12 n=12 Grand mean 223.6 588 687 .2 659 964

6 Table 6.--Species groups formed from sessonal cluster analyses of fishes and decspod crustaceans collected in the Cooper B1ver-Charlsston Harbor estuarine system. S.C •• 1973-77. FALL WINTER SPRING SUMMER

Group A Group A Group A Group A

Cattinectss sapidus Sicyonia laeviuata SteZZifer lanceolatuB Leiostomus ~nthU1'UB Symphurus ptauiusa Libinia dubia 'Penaeu8 Betife1'Us Mic~opogonias unduZatus Cyn06cion ~suatis Muuit cu~sma Upophycis pegia CynoBcion ~euatis Bai~distta ch~sou~ Neopanops sayi Tmchypenaeus conBt~ctus PenaeuB aatecus Anchoa mitchitti Atphsu8 no~nni CaZZinectes simiZiB Anchoa mitchiZZi Ststtifs~ lancsotatus Libinia sma~ginata Bpevoo~tia tymnnuB Penaeus setife1'UB PS1'lilSUS sstiferus ~ionotus 8cituZus Pep~iZus tpiacanthus CaZZinectuB 8imiZis ~onOtu8 svolans MicropogoniaB unduZatus TmchypenaeuB conBt~ictus Group B LeioBtomus ~nthu1'Us SteZZife~ lanceolatuB Group B Anchoa mitchiZZi Hypsobtennius hentai CaZZinectes sapidus Group B Ophidion ma~i1'liltum Cent~op~istis st~ta Symphupus pZagiusa ~onotus t~butus Upophycis fZopidana TPinectes macuZatus Pagupus Zongica~us Psnasus du07'a~m Centpop~istis phiZadeZphica Poptunus gibbesii Ovalipes ocsllatus CaZZinectes 8imiZis Group B Po~tunus spinimanus Ponunus spinimanus Xiphopenaeus krooye~ Ophidion ma~ginatum Paguru8 tonuica~us Po~tunus gibbesii Opsanus tau Pagupus poZZica~iB CZiba1'lil~U8 vittatus Portunus spinimanus FamZichthys dentatuB OvaZipes oceZlatus Catlinecte8 8imiZis Tmchypenaeus constPictus Penaeus aztecuB Msntici~u8 ame~canus Gobieso~ 8t1'UmoSUS CynoBcion ~egaZiB Group C ~chype1'lilsu8 const~ctus Ovatipes ocsZZatus PamZichthY8 ZethoBtigma Ponunus uibbssii Menippe me~cena~a BairdieZZa ch~80ura APiU8 fetis Xiphope1'lilSU8 k~oys~ Pagu1'Us potZica~s PaZaemonetes vuZgaPiB Cent~opPistis phiZadeZphica PaUU1'US tonuica~us CithaPichthys spiZopte1'Us Group C Mentici~hus ame~canus Group C CZibanarius vittatus Cancep ir~omtus Etpopus CP0880tu8 Anchoa hsp8etus Pamtichthys dentatus AncyZopBetta quad~oceZZata ChZo~oscomb1'US ch~s~s CZibanaPius vittatus Group D SeZene setapinni8 Group C PaguPUB ZonuicaPpu8 Pep~itus alepidotus FPionotUB t~ibuZus PaZaemonete8 puuio Opisthonema oUZinum Anchoa mitchiZZi PenaeUB duomPUm PaZaemonetes vuZgaPis Dasyatis 8abina Brevoonia tymnnus FPionotuB ca~oZinus PamZichthYB Zethostigma A~U8 fetis Mic~opogonias unduZatus PamZichthYB dentatus Rhith~opanopeus ha~~sii BairdieZla ch~sou~a Group D 0pBanuB tau Chaetodipte1'Us fabe~ Dorosoma petenense CaZZinectes sapidus Pe1'lilSU8 aatecu8 Penasus setifePUB Dasyatis Babina Symphupus pZagiusa SteZZifep ZanceoZatuB CentroppiBti8 stpiata Trinecte8 macuZatuB Group D Leiostomus ~nthuPUB APiUB feZis BaipdieZZa chpy8ou~a SymphU1'UB pZagiusa CithaPichthys spiZoptepus B~evooptia tymnnus Gobie80~ 8t1'Umosus CaZtinectes sapidus Cyn06cion nsbuZ08US PamZichthys Zethostigma Group E Group E Selene vome~ Upophycis pegia Pomatomus 8aZtat~~ Anchoa hepsetus PepriZus aZepidotu8 Group D OvaZipes oceZZatus ChZoroBcombPUS Ch~y8UPUS Group E TPichiupus ZeptU1'U8 Opisthonema ogZinum Et~opus CT08S0tUB Anchoa hepsetus Pataemonetes VUZgz~8 Cynoscion ~egaZis Group F SeZene setapinnis Eucinostomus a~gentsu8 HypsobZennius hentzi PaZaemonete8 puuio ScophthaZmu8 aquosus Doposoma petenense Group F Ca~= hippos PaZaemonetes pugio PPionotus evoZanB AZosa aestivaZis Lagodon rhomboides Rhithropanopeu8 haPPiBii SeZene vomer Do~osoma petenense PPionOtU8 tribuZu8 PaZaemonete8 pugio T~ichiuPU8 Zeptupus Lutjanus ~iseus At08a aestivatis Pomatomus 8aZtatpix Pomatomus saZtatp~ Menidia menidia AZosa ae8tivaZi8 Panopeus he~bstii Group F Ctibana~us vittatus LepiBosteuB 08Beus FPionotus t~ibuZus AtoBa sapidissima AZOBa sapidiBBima PenaeUB duompum Pa~Zichthys Zethostigma AncyZop8etta quadpoceZZata Upophycis fZoPidana Menticir~hus amePicanus AnguiZla ~ostmta AnguiZZa postmta ChaetodiptePUB fabe~ IctaZu1'Us fu~catus Group E Panopeus occidentaZis Neopanope sayi Eucinostomus sp. ScophthaZmus aqUOSUB Leiostomus ~nthu1'Us Penaeu8 aztecuB FPionotuB sp. Group G T~nectes maculatu8 Palaemonetes intepmediuB IctaZu1'Us catus Rhithpopanopeus ha~Pisii Group G Do~osoma petenense Et~opus C~OS80tus Pogonias cromis AZosa aestivaZis Cent~op~isti8 phiZadeZphica A~ch08argus ppobatocephatuB IctaZupus punctatus Morone saxatiZis Pa~Zichthys dentatus Panopeus he~bstii Mac~obmchium ohione PepriZus t~canthus Opsanus tau Cynoscion nebutosuB IctaZupus catus Scomberomopus macuZatus Menidia menidia PaZaemoneteB vuZgapis Rhithpopanopeus happisii Mic~opouonias undulatU8 Opsanus tau Group H Macpobrachium ohione B~evoo~tia tymnnus IctaZuNs catuB Group F Ophidion ma~ginatum Pagu~uB poZZica~is IctaZupus punctatu8 OvaZipeB BtephenBoni IctaZupus nebuZosus Poptunus spinimanus AnguiZZa rostmta Portunus gibbeBii Mac~obmchium ohione Mentici~uB ame~canuB Perca fZavescens Mo~one s~tiZiB Lepisosteus 08seus AZpheus heterochaeZiB IctaZupus catus T~inectes macuZatus Acipenser o~~hynchuB IctaZuPU8 pZatycephaZus

7 .~

FALL STATIONS C004 ..------A .------8 '------C t.===== ~ f--~- '------F

1 I 1 -06 -02 04 08 0 _207VERY HIGH _201l W SIMILARITY mIll >O!l HIGH 0<0.1 VERY lOW

(/) ~~03MOOERATE W U W .------A Q.. .------8 (/) L-----C ~------D~~~~~~~.. ~;;;;~ .----- E ~--_b"1'TTTlIDllW.llllJL\rrmnlTTT1rTf"...... WJ.L....., '------F

I I I -r-----, -10 - 06 -02 04 08 _) 3 HIGH SIMILARITY mIl 21 lOW c:JI ) 2 MODERATE 0<1 vERY lOW

WINTER STATIONS

r------Ar---~r_--~----~----_r---__; '------B .------C flilll.llW.4J.U.LJJ.If== .------0 en '--_____ E f----+-...... "t---- ...... """""-t------i Q.. => '------F o rl---,,----TI-~,r- 0:'10 -06 - 02 02 (!) SIMILARITY _207 vERY HIGH 020 I LOW fiII)05HIGH 0<0 I VERY lOW en UJ mJ20 3 MODERATE

(,) UJ r-----A Q.. en '------8 .------C r------0 1ItHtttt'~\!#+i>it_--_ttifflttttttttt---___1

'------E~--_+--_+------f..... L------FL-__L-~~~~~~ ~~ I I I I -10 -06 -0.2 02 SIMILARITY _23 HIGH lIIIJ2'lOW _22 MOOERAT£ 0< IVERY LOW

Fljturt 1.-'flI.• >- ...., '''(llncidHl~ ta~ of ronstaJM:~-and ~. wb.1dI rom~ species IIS\!IOdadoas --. sam.... stIIdNs.dIe Cooper ~ IIartIor r....,. winm. spring. ud sumlMt' roIedkIns, 1973-77, 15ft T.bIe 6 r.... species aroaP ... 8 SPRING STATIONS

,....---- A ...------1 '-----8 ';::::====L------F ~ ~ en L------~~i]ijE~~~~===~~~ CL CONSTANCY :J ...-,---.-, --,-, ----r, ~,--',--',r-'r--'ll o -1 .0 -0.6 -0.2 04 0 .8 _~0 . 7VERY H'GH fEllJ ~O . , LOW a:: SIMILARITY (!) ITIIIl20.5HIGH O

SUMMER STATIONS

en CL :J I I I I I CONSTANCY -0.6 - 0 .2 0.4 0 .8 o _1.0.7VERY HIGH fJiD20.1 LOW ~ SIMILARITY [lill1.0.5HIGH 0<0.1 VERY LOW en m~0 . 3MODERATE o"" J003 JOOI C003 C004 C002-COOI ...------A WIl!!!II!!!! ""CL '------8 en ,....-----C ,....---- D ...-----E '----- F 11111111111111

'------G t· > .'.

I I I I FIDELITY -0.6 -0.2 0.4 0.8 _1.3 HIGH mn~ILOW SIMILARITY _~2 MODERATE 0 < I VERY LOW

9 were restricted in spring to collections at higher salinity stations sistently present in cotiections from stations Joo3, Joot, but displayed only moderate to low constancy there, composed COO4, and c003. assemblages C, D, E, and H (Fig. 2). Species in these groups Other assemblages defined by our analysis included species included fourspot flounder, Ancylopsetta quadroce/lata; tolerant of a wide salinity range and not restricted to any sta searobins (Prionotus spp.); black sea bass, Centropristis tion location, but generally of low density. Included in these striata; lady crabs, Ovalipes ocel/atus and O. stephensoni; groups were anadromous species, Alosa aestivalis and A. Atlantic cutlassfish, Trichiurus lepturus; and striped cusk-eel, sapidissima; the American eel, Anguilla rostrata; and the Ophidion marginatum. Many of the same species composed caridean shrimps, Palaemonetes pugio and P. vulgaris. groups B and C from our cluster analysis of summer data and were restricted but infrequently encountered at collections from stations 1003 and 1001 (Fig. 2). Temporal and Spatial Distributions The only species restricted to samples from the lowest salin ity stations (COOl, c002) formed group G in spring (Fig. 2). Patterns of distribution for the most abundant species of However, the resident estuarine species, letalurus punctatus, fishes at each station for each month of collection are shown I. catus, and Macrobrachium ohione, which composed this in Figure 3, and fluctuations in their abundance over the S-yr g;oup displayed only moderate constancy for collections from sampling period are shown in Figure 4. Length-frequency plots these low-salinity stations. which were generated for selected species are not shown but Ubiquitous species were present during all seasons in the are available from the authors upon request. Cooper River-Charleston Harbor estuarine system. These species included the numerically dominant fishes and decapod Stellifer lanceolatus, Star drum.-Star drum were most crustaceans. Although their penetration extended as far up abundant at higher salinity stations COO4, Jool, and JOO3, river as stations C002-C001, species in these assemblages were whereas catches were negligible at stations farther upriver generally most constant in collections from stations 1003, (COOl, C(02) (Fig. 3A). This species displayed seasonality in 1001, and COO4. In the fall, members of groups A and F were its abundance, with most individuals collected October encountered at all stations; but only members of group A were through May. Catches of S. lanceolatus also underwent con consistently collected, as denoted by their very high constancy, siderable annual variation and were greatest during the years at collections from stations 1003, 1001, COO4, and C003 (Fig. 1974-76 (Fig. 4A). Length-frequency polygons for star drum 2). In our analysis of winter collections, only members of over the 5-yr sampling period suggested a consistent influx of group C were eurytopic in station location. Species in this small fish ( < 80 mm TL) into the population during summer group were consistently represented in collections at stations with recruitment continuing into fall. Frequencies of these 1003, 1001, and COO4, but they were not restricted to these small fish were lower during winter and spring. Our results are stations (Fig. 2). Members of group A in spring were generally consistent with those of Welsh and Breder (1923), Dahlberg found at all sites but were most consistently encountered at and Odum (1970), and Shealy et al. (1974), who also noted stations 1003,1001, and COO4 (Fig. 2). Our analysis of summer that recruitment of young fish first occurred during summer data showed that euryhaline species of Group A were con- after late-spring and early-summer soawninll.

C. Micropogonias A, Stel/iter /onceo/atus B. Anchoo milchilli undu/alus o.Srwoorlio Iyronnus E. Leioslomus Itanlhurus - N - N II) ~ _ II) o 0 000 000 o 0 000 000 ~ ~ § i ~ ~ u u (.) (,) (,) (.) , .., ,'0 0 0 ."0 .0

'0 '0"

,-0 ;0.-0 ."00

0 .-0 0 .-00, ."00

'0", '0", I?'}} :'00 _

'0-,

Figure 3.-~bundance, expressed as the antiloll of the tnmsfonned (log .. (x + 1)) mean number of individuals, of 10 major fish species collected monthly in tile dlaanel of tile Cooper River-Cbarleston Harbor estuarine system, 1973-"T7. Legend indicates four arbitrary levels of abundaDce, from rare or absent ("'1) to lIIIIldmum abuDdance (51-315).

10 Allchoa mitchHIi, Bay anchovy.-Anchoa milchilli were Br~voortitl lyrtlnnUs, Atlantic menhaden.-Allantic collected at aU stations in the Cooper River-Charleston Harbor menhaden were coUected at every 51ation ~ for COOl, the .,-em, except for the most limnetic station (COOl) (Fig. 3B). station farthest upriver (Fig. 3D). Menhaden displayed little Bay anchovy were most abundant at station JOOI. Monthly change in abundance by month but were most consistently pre- fluctuations in abundance indicated that little, if any, sea sent in November, Decanber, January, and June. Annual IOD8Iity was associated with catches of bay anchovy, but catches fluctuated moderately about the Jl'Uld mean and were c:atc:hes did undergo annual fluctuations, being highest during greatest in I m (Fig. 40). 1974-76 (Fig. 4B). Leiostomus XIInthurus. Spot.-Spot exhibited a distribu Micropogonias undulalus, Atlantic croaker.-Atlantic tional pattern similar to that of Atlantic croaker. being most croaker were collected at all stations in the Cooper River abundant at stations JOOI and J003 near the mouth. Spot Charleston Harbor system, but abundances were greatest also were most abundant during May·July (Fig. 3E). Annual from April through July at higher salinity stations, particularly catches of spot steadily increased over the 5-yr sampling period those located near the mouth (1001, J(03) (Fig. 3C). Annual (Fig. 4E). The average size of spot was greatest in fall and variation in catches of croaker was small, with little fluctua winter. Length-frequency distributions indicated that spring tion about the grand mean (Fig. 4C). Length-frequency dis and summer catches of spot were dominated by fishes in the tributions indicated that most estuarine croaker available to 60-80 mm size range. Our data support results of other studies our trawls were < 120 mm TL throughout the year. Al in South Carolina (Dawson 1958; Shealy el al. 1974). North though these smaller fish predominated in spring and summer Carolina (Hildebrand and Cable 1930). and the lower Chesa· catches, they were also present during other seasons, but in peake Bay (Hildebrand and Schroeder 1928; Chao and Musick fewer numbers. Newly recruited fish ( < 30 mm TL) generally 1977). which found that young-of-the-year spot fir\! entered appeared first in fall and continued to appear in the popula the estuary in April. tion during winter and spring. The continued presence of small croaker during spring in South Carolina may reflect the slow Symphurus plaRiusa. Blackcheek IOnguefi~h . -SymphuruJ growth of fish spawned in late winter or early spring (Chao plagiusa were most abundant in higher ~alinity areas of the and Musick 1977). By summer, few croaker <45 mm were Cooper River-Charleston Harhor system. although the \pecie

,..------l

A. 5,./li,., mllCH/""'. B. Anchotl mifcllilli C. Micropogonitn 12 undul",u.

&&.I (J.Z ---IlI-F=\- C ·eo O . Z ::). III C -- GIIA"O W(A" L o F. Sy",,",W"$ p/lIgi"MI )( 1.2 &&.I I . IO~ o Z ' ! 1"- -- ,. ~ I 1 -~

1 ~__,._ -__- .•~ "T - -- ~ L-1"'-i5-1Ti4--ri&---'':'~"~ n 74 ,., ,.. n 13 141t1 1e "" 13 14 1& 1e 11 YEAR

flpft ..-.u...... Uw ...... t.r + 1)1_ ...... , .... 1, ? oI ...... ~ .... C.... --.<~ ...... ___ .,.., 1ft).n.

II (Fig. 3G). Although silver perch were present in the Cooper were collected at the most seaward stations, with maximum River-Charleston Harbor system throughout the year, abundance occurring at the mouth of the estuary. Little abundance of the species was greatest from August through variation in annual catches of spotted hake was present in our January. Annual catches decreased in 1977 (Fig. 4G). The samples (Fig. 41). presence of silver perch throughout the year in estuaries of South Carolina (Shealy et al. 1974; Wenner et al. 1982) differs T,inecles maculalus, Hogchoker.-Trinec:les macu/alUl from the seasonal pattern observed in Chesapeake Bay. Chao were collected sometime during the year at every station in the and Musick (\977) noted that most silver perch leave the York Cooper River-Charleston Harbor system. Hogchoker were River estuary of Virginia by November. They collected no most consistently abundant at stations upriver (C002 and silver perch from January to March and suggested that the C(03) and displayed no apparent seasonality in abundance year-round presence of the species in estuaries south of Chesa (Fig. 3J). Annual catches of hogchoker increased over the ~-yr peake Bay may be due to the higher salinity or temperature of ~ampling period and were greatest in 1976 and 1977 (Fig. 4J). those waters.

Cynoscion regalis. Weakfish.-Weakfish wen: collected at Penaeus setiferos. White shrimp.-Catches of white shrimp ae stations except COOl and were most abundant during sum were \easonal with most individuals occurring late summer mer (Fig. 3H). Annual catches were fairly C'onstant with little through fall. White shrimp were also most numerous at the variation about the grand mean (Fig. 4H). The average length downriver stations (Fig. 5A). length-frequency distributions of weakfish did not differ markedly hy season. but length indicated that young-of-the-year white shrimp were present in frequency distributions showed that the modal length for the Cooper River-Charleston Harbor system during summer spring catches was usually smaller than for other \ea\OIl\. and fall. 1\lost \hrimp wllecled during th~ seasons were < 80 Thi ~ reduction in size is probably caused by incTeasing mm Tt. except in 1977 when a few shrimp > 120 mm TL numbers of young-of-t he-year weakfish. newly recruited from were colle(led in summer and fall. The absence of young the May-August spawning period (Lunz and Sch\\artz 1970). of-the-year shrimp in 1977 is also reflected in the annual catch data for thaI year when a marked decrease in abundance of Uroph.l ·cis regia. Spotted hake.-Spotted hake di ' played the white shrimp o(curred (Fig. 6A). Modal lengths of white most seasonality in its distribution and abundan-:e. being shrimp generally in(reased during spring to > 100 mm Tl. collected from February to !\\ay only (Fig. 31). Their absence The larger size of shrimp during spring is attributable to from South Carolina estuaries during the rest of the year is ~horeward migration of large shrimp from offshore waters attributed to offshore migration to deeper water during (Williams 1955) or to the growth of overwintering shrimp to warmer months (Hildebrand and Cable 1938). Spotted hake \ubadult size (Bishop and Shealy 1977).

A. Penaeus setiferus 8. Penaeus aztecus

N If) If) N If) -:> u u u U -:> -:> I I 71 f----tv......

I 0 f----fo;i...... ,., 9f----tv~ " 0 '0 0 8f---f---"-- tooo'oo ~ 7r--r~~~~~~~ 6r--r~f-.r"-..-j;-..-"--oi,.-"-.J;;--~ [ 00' 0 CC'.: 5 '0 0 ' 0'0 CJ)4r--r~1---'-+';;'..j-"":,,:.i ~ ~r-~-+--~~~~ ~Ir-~-+""--"-~~...o.."l"",",,,,, Z o C Xip!1openaeus ~ kroyeri O. Co//inectes sopidus

12r-~-+--r-~-4~ 000°0°)0°0°00.;)0 I 1r--+__ 1- __r-~ __ ~oTo ~o 00 000 000 000 000 000 0 l0r--r~r-~~--~UY 0 0 00 °00 0 0 0 ~ r--+--1---F-0 ~o-+-__-j.o.-°..!!. o...

1r--r~r--+--+--+-~ I'1gI1ft S.-AbwlClance. e~ as tile .... of tile 1nIIIIf_ 6r--r--lr--+--+--+-~ 0 00 0 00 0 00 !d (log .. (x + 1)1 mean number of iDdIvid.. II NdI !UIioII NdI

° Donlh. of four major species of decapod mIIt8CaIIS coIecIed ill 5r--r-r--+--+--+-~ ° 0 0 0 4r--+-_r--+--+__ +- ____ 000 0 0 0 0 :be thannel of Ihe Cooper R1ver-Olalteslnn IbrtIor estuMiH 00 00 0 0 0 0 I)'ltem, 1!I7J.77. illdkales fou 1IlIIIInrJ!neII 01 alia ~r-~-+--r--+--+~ 0 0 Leand 0°0 0 0 0 0°0 0 0 0 0 WKe, from rare or ....1 (.1) to ...... ~ I r--r~--+-~--~~ 00 00 """"'0 :101·1,340).

12 " ,,

these estuaries during winter is probably due to gear bias for A. Penaeus sefiferus B. Penaeus azfectlS larger-sized shrimp (Wenner et aI. 1982). 1.6 1.4 Xiphopenaeus kroyeri, Seabob.-Seabob were limited to 1.2 higher salinity areas of the estuary during fall and winter 1.0 (Fig. SC). Annual catches were low, and no seabob were col lected in 1973 and 1977 (Fig. 6C). Although X. kroyeri occurs .80 L&J in the lower portion of estuaries, it is most commonly encoun 0 Z tered in the near offshore coastal zone (Gunter 19S0). ct 0 z Callinecles sapidus, Blue crab.-Blue crab were collected ::> throughout the Cooper River-Charleston Harbor system, but CO occurred year-round only at stations COO4 and 1001 (Fig. ct -- GRAND MEAN SD). Crab were also least abundant at stations upriver. Annual catches increased over the S-yr sampling period except for a LL. C. Xiphopenaeus O. Callinecfes sapidus o 1.6 kroyeri slight decline in 1977 (Fig. 6D). Size-frequency distributions of blue crab covered a wide range of sizes from 10 to 100 mm X 1.4 carapace width with small crab ( < 60 mm CW) present during L&J o 1.2 all seasons. Average sizes of blue crab were generally larger in Z spring and summer.

___ L:_ Biomass Estimates 7-G.M. - .20 Biomass and density for fishes were greatest at higher salin ity stations 1001 and COO4 during winter and spring (Table 7). 73 74 75 76 77 73 74 75 76 77 Increased values during these time periods were coincident YEAR with the increased dominance of catches by Stelli/er lanceola Ius, Brevoortia Iyrannus, and Micropogonias undulatus. Decapod biomass and density were greatest at station 1001 in Charleston Harbor and during fall and summer for all stations Figure 6. - Annual variation in tbe transformed Ilog,o (x + 1») mean number of individuals of four major decapod crustacean species coUected in tbe Cooper combined. These seasonal peaks coincided with periods when River-Cbarleston Harbor estuarine system, 1973-77. young-of-the-year shrimp became vulnerable to our trawl gear. Our mean total biomass and density estimates for all seasons Penaeus aztecus, Brown shrimp.-Brown shrimp were and stations sampled in the Cooper River-Charleston Harbor highly seasonal in their occurrence within the Cooper River system over the S-yr study period were: Charleston Harbor estuarine system. They were collected May Biomass (kg/ha) Density (no'/ha) to September and were most abundant during lune and luly at Fishes 6.04 471 higher salinity stations (Fig. SB) . Annual catch rates were Decapods 4.98 678 variable and highest in 1974 and 1976 (Fig. 6B). luvenile brown shrimp entered the estuary in spring, remained through These estimates are comparable to those obtained by Wenner the summer, and were almost totally absent from fall and et aI. (1982) for estuarine portions of the Santee River system winter collections. This seasonal abundance pattern has also of South Carolina and by Shealy et al. (1974) for estuarine been noted in other South Carolina estuaries (Bishop and portions of the Cooper River-Charleston Harbor and Edisto Shealy 1977), although the absence of brown shrimp from River systems.

Table 7.-Average seasonal biomass (kg/ha) and density (no.lha) of fishes and decapod crustaceans collected at stations in the Cooper River-Charleston Harbor estuarine system, S.c., 1973-77.

Average biomass and density/ station Grand C002 c003 0104 1001 1003 mean Season kg/ha no.lha kg/ha no.lha kg/ha no.lkg kg/ha no.lha kg/ ha no.lha kg/ ha no.lha Fishes Fall 3.62 166 2.63 202 7.55 592 11.03 542 4.30 888 5.37 472 Winter 3.53 175 3.78 258 16.48 621 14.52 976 6.52 558 8.60 480 Spring 1.75 428 5.25 242 13 .94 763 11.99 1,071 6.06 636 7.45 589 Summer 0.86 97 2.44 289 2.49 252 5.30 602 4.59 593 2.95 346

Oecapods Fall 1.57 521 6.71 1,122 9.35 1,380 15.60 1,993 6.68 915 7.31 1,116 Winter 0.05 8 0.22 17 0.77 143 2.03 314 6.40 931 1.74 260 Spring 0.06 10 0.53 58 5. 10 376 17.80 1,270 2.27 287 4.26 339 Summer 0.90 221 12.20 2,078 5.26 928 12.10 1,288 3.18 338 6.28 943

13 DISCUSSION diversity and richness. Weinstein et al. (1980) noted that in creased predation pressure probably enhanced species divmity The Cooper River-Charleston Harbor estuarine system is in downstream marsh areas of the Cape Fear River, N.C., by characterized as mixohaline with gradual changes in faunal preventing dominant competitors from monopolizing the assemblages. The most striking differences in species composi major food and space resource. An alternative explanation is tion occurred between those stations located at or near the that enough food may be present in the lower reaches of the mouth of the estuary and those located far upriver. The fish river to support a high diversity of species. Euryhaline species and decapod crustacean species assemblages associated with such as the sciaenids were numerically dominant in the Cooper these two areas were primarily composed of stenohaline River-Charleston Harbor system and were most abundant at marine species and low-salinity resident estuarine species, downriver stations. Juvenile sciaenids feed opportunistically respectively. Nevertheless, euryhaline species, which extended on a variety of infaunal and demersal species (Chao and from the mouth of the estuary into brackish waters, were Musick 1977). Their successful coexistence in higher salinity the dominant faunal component throughout the estuary as a areas with stenohaline marine and other estuarine species may whole. Except for a few freshwater species, resident estuarine be attributed to utilization of food resources from different species (e .g., TrineCles macu/alus, Anchoa milchi"i, levels of the water column and to the abundant food resources Pa/aemoneles pugio, lcla/urus catus) were found throughout of the estuarine system. In this case. food would not be a tht system, their distributions often overlapping with those of limiting resource and intrafamilial or interspecific competition specJ\~s derived from the marine environment. This distribu would not be as important a factor (Chao and Musick 1977). tional pattern is similar to that described by Weinstein et al. Temporal distributional patterns were another important (1980) who noted considerable overlap in di stributional pat aspect of the fish and decapod community of the Cooper terns of resident fishes and stenohaline marine transients in River-Charleston Harbor system. Temporal changes in species the Cape Fear Riyer, N.C. associations and abundance were related primarily to fluctua The obseryed overlapping spatial distributional patterns of tions in abiotic variables. Bottom-water temperature in the resident and transient fishes and decapod crustaceans can channel of the estuarine system exerted a substantial influence be related to salinity regimes within the estuary and to the on the abundance of species collected. The most noticeable physiologICal tolerances of component estuarine species to decreases in abundance of fishes and decapods coincided with these regimes. In comparison with estuaries of the Middle annual minimum temperatures. especially those experienced .-\tlantic states, such as Chesapeake Bay, South Carolina during the extremely harsh winter of 1977. These seasonal estuaries are narrower, deeper, and shorter in length (Mathews trends in abundance were especially evident for the sciaenid and Shealy 1978). The physiography of estuaries (Pritchard fishes and penaeid shrimps. For those species which may over 1954), in addition to other factors such as runoff, tidal action, winter in the estuary. such as Micropogonias undulatus and and current \elocity (Mathews and Shealy 1978), affect verti Penaeus spp. , extremely low winter temperatures can destroy cal mixing and, consequently, determine salinity regimes as an entire year-class (Massmann 1971; Farmer et aI. 1977). well. The combined effect of these factors in South Carolina Thus. temperature-related mortalities. as well as emigration of estuaries is a compression of the isohalines, with resultant juveniles, probably contributed to the low abundance and overlap in the distributional patterns of many estuarine spe biomass observed at that time. Similar explanations were cies. Ultimately, however, it is the physiological tolerances of suggested by Weinstein (1979) for decreased abundance of component estuarine species which really determine their Penaeus spp. in the Cape Fear River. N.C. distribution. The spatial limits of freshwater species are main Seasonal differences in species assemblages reflected tained through physiological constraints, while other resident changes in abundance as well as exclusion of some species estuarine species are able to tolerate a wider range of salinity from the estuary during part of the year. However, most spe and apparently are not limited by competition and predation cies remained in the estuary throughout the year, while their to the lower reaches of the estuary (Weinstein et al. 1980). abundances changed seasonally. Nevertheless, while faunal af Physiological tolerances are also important in determining the finities varied throughout the year, as indicated by cluster upestuary limits of species which are numerically dominant in analysis, the species composition of the estuarine system as a the Cooper River-Charleston Harbor system. For the most whole was not altered appreciably. Temporal fluctuations in pan, these species were unable to penetrate into areas where abundance appear to be a means through which more species the isohalines were ~0.5 % o and were generally most abun are able to utilize the estuary simultaneously by a reduction in dant at stations in the mesopolyhaline zone. densities and competition for food and space. The overlapping spatial distributions of many resident The importance of abiotic factors in determining the distri estuarine, stenohaline marine, and numerically dominant butional patterns of estuarine biota has elicited concern about euryhaline species in the Cooper River-Charleston Harbor the effects of rediversion on the integrity of species assem system are reflected in the greater species richness and abun blages and, more importantly, on interspecific balance (Shealy dance of individuals at stations in the mesopolyhaline zone. and Bishop 1979). A restriction of freshwater inflow will prob Assemblages at these stations were comparatively diverse, ably cause salinities to be higher and, consequently, modify consisting of some resident estuarine and euryhaline species the existing salinity gradient. Additional consequences of a de and many stenohaline marine species. Seasonal peaks in spe crease in flow rate might include a decrease in nutrient and cies diversity are largely attributable to those stenohaline detritus influx, lowering of the water table, reduction in water marine transients which occur sporadically in low densities turbidity, alteration of estuarine circulation, and reduction in throughout the lower reaches of the Cooper River-Charleston the ability of organisms to withstand stresses of normal Harbor system. Biological interactions such as predation and drought periods (Heald 1970; Keiser and Aldrich 1976). These competition for space and food can also contribute to species alterations. should they occur in the Cooper River-Charleston 14 Harbor estuary. will undoubtedly affect the suitability of the ACKNOWLEDGMENTS estlW'Y as a nurseryground. A reduction of freshwater inflow will eventually increase the We are grateful to all persons who assisted in collection (If homeohalinity of this estuarine system. A displacement of the specimens and data in the field, especially J. Miglarese, R. c;urrent mesopolyhaline zone further upstream will affect the Richter, and J. Bishop. We thank T. D. Mathews and K. H. distribution and abundance of larval and juvenile fishes and Austin for analysis of water samples; K. Swanson for prepara :,hrimps. Upestuary marshes are critical areas for early devel tion of figures; N. Kopacka for assistance with computer pre· I)pmental stages of fishes and shellfish (Weinstein 1979). The gramming; and B. J. Ashby and L. Hodges for typing and nflow of freshwater. which currently inundates marshes and retyping the manuscript. The field study and manuscript ben tibandoned rice fields in the Cooper River-Charleston Harbor efited from comments by our colleagues: E. B. Joseph, V. G. estuarine system is more important in maintaining upestuary Burrell, Jr., G. R. Sedberry, and C. Bearden. marsh habitat suitable for fishes and decapod crustaceans. After The data were collected and automated by financial support rediversion. much of this habitat, currently subject to overflow, from the Coastal Plains Regional Commission (Contract .viii no longer be available as a nursery due to lowered water 10340031) as part of the Estuarine Survey Program of the levels and higher salinities (U.S. Army Corps of Engineers South Carolina Marine Resources Center and were analyzed footnote 2). A substantial reduction in nursery habitat could and published through funding from NOAA Office of Sea tiffect the entire estuarine foodweb. Estuarine salt marshes are Grant (Grant 00140-93027). highly productive, being dominated by cordgrass (Spartina) which ultimately provides a source of food to organisms in the estuarine system (Massmann 1971). Thus, the nursery functions LITERATURE CITED of estuaries are closely related to the viability of plant commu ANONYMOUS. nities. Alteration of areas which supply much plant detritus 1958. Symposium on the classification of brackish waters. The Venice sys may lower the numbers of detritus-algae consumers which, in tem for the classification of marine waters according to salinity. Oikos turn, will eventually limit subsequent trophic levels. This may 9:311-312. be particularly troubling from an economic point of view be BEARDEN, C. M. 1964. Distribution and abundance of Atlantic croaker, Micropogon un cause the abundance of commercially valuable penaeid shrimp dulatus, in South Carolina. Contrib. Bears Bluff Lab. 40, 23 p. is directly related to the absolute area and type of estuarine BISHOP, J. M., and M. H. SHEALY, Jr. intertidal vegetation (Turner 1977). 1977. Biological observations on commercial penaeid shrimps caught by bot tom trawl in South Carolina estuaries-February 1973-January 1975. The habitat of stenohaline marine species may not be af S.c. Mar. Resour. Cent. Tech. Rep. 25, 97 p. fected deleteriously by rediversion. In fact, these species will BOESCH, D. F. 1977. Application of numerical classification in ecological investigations probably penetrate even farther upriver than they currently of water pollution. Va. Inst. Mar. Sci. Spec. Sci. Rep. 77, 125 p. do. Because numbers of species and individuals of fishes and CHAO, L. N., and J. A. MUSICK. decapod crustaceans are now higher in more saline reaches of 1977. Life history, feeding habits, and functional morphology of juvenile the river, species diversity of areas in the Cooper River sciaenid fishes in the York River estuary, Virginia. Fish. Bull., U.S. 75:657-702. Charleston Harbor which are currently lower in salinity could CLIFFORD, H. T., and W. STEPHENSON. be increased by rediversion. Increases in diversity probably will 1975. An introduction to numerical classification. Acad. Press, N.Y .• be attributed to higher numbers of stenohaline marine species 229 p. rather than euryhaline or resident estuarine species; however, DAHLBERG. M. D., and E. P. ODUM. 1970. Annual cycles of species occurrence, abundance, and diversity in many estuarine species, whether resident or transient, are liv Georgia estuarine fish populations. Am. Mid!. Nat. 83:382-392. ing near the limit of their physiological tolerance of tempera DAWSON, C. E. ture or salinity, so further alteration of the environment may 1958. Study of the biology and life history of the spot. Leioslomus xan- exclude some species permanently (Odum 1970). Ihurus Lacepi:de, with special reference to South Carolina. Contrib. Bears Bluff Lab. 28, 48 p. In addition to changes in diversity, the species assemblages ELLIOTT, J. M. 1977. Some methods for the statistical analysis of samples of benthic in as we have defined them by station location will probably be vertebrates. 2nd ed. Freshwater Bio!. Assoc., Sci. Pub!. 25. 160 p. altered following rediversion. Whether this alteration will en ENRIGHT, J. T. tail a mere shifting of assemblages upriver or the introduction 1976. Climate and population regulation: The biogeographer's dilemm::.. of completely different groupings of species will depend on the Oecologia (Ber!.) 24:295-310. effects of rediversion on competition and predation. Food re FARMER, C. H .• Ill. C. W. BOARDMAN, and J. D. WHITAKER. 1977 . The South Carolina shrimp fishery. S. C. Wild!. Mar. Resour. sources can be limiting in estuaries (Lasker 1975; Houde 1978; Div .• Educ. Rep. 8. 49 p. Laurence 1977). If habitat is lessened and the opportunity for GUNTER, G. spatial segregation becomes minimal, then seasonality and 1950. Seasonal population changes and distributions as related to salinity. other forms of temporal segregation may be the only means of of certain invertebrates of the Texas coast. including commercial shrimp. reducing competition among species with similar food require Pub!. Inst. Mar. Sci., Univ. Tex. 1(2):7-51. HANSEN, D. J. ments (Weinstein 1979). Seasonality, which includes differ 1969. Food, gtcwth, migration. reproduction. and abundance of pinfish. ences in spawning periods as well as density-independent fac Lagodon rhomboides, and Atlantic croaker. Micropogon undulatus. near tors such as temperature, dissolved oxygen, and nutrient Pensacola, Florida, 1963-65. Fish. Bull., U.S. 68:135-146. inputs, may mitigate any changes in competition or predation HEALD, E. J. 1970. The everglades estuary: An example of seriously reduced inflow of (Enright 1976) precipitated by man-made perturbations. In freshwater. Trans. Am. Fish. Soc. 99:847-848. turn, the adverse effects of rediversion on the estuarine biota HILDEBRAND, S. F., and L. E. CABLE. may be neither drastic nor irreversible, although this remains 1930. Development and life history of fourteen teleostean fIShes at Beau to be seen. fort, N.C. Bull. U.S. Bur. Fish. 46:383-488. 15 1938. Further notes on the development and life history of some teleosts at SHEALY, M. H., Jr., and J. M. BISHOP. Beaufort, N.C. Bull. U.S. Bur. Fish. 48 :505-642. 1979. Hydrographic and biological studies in relation to Cooper liver HILDEBRAND, S. F., and W. C. SCHROEDER. low-flow conditions prior to river rediversion. In Cooper River Con 1928. Fishes of Chesapeake Bay. Bull. U.S. Bur. Fish. 43(1), 366 p. trolled Low-Flow Study, p. 139-178. S.C. Water Resour. Comm. Rep. HOUDE, E. D. 131. 1978 . Critical food concentrations for larvae of three species of subtropi SHEALY, M. H., Jr., J. V. MIGLARESE, and E. B. JOSEPH. cal marine fishes. Bull. Mar. Sci. 28:395-411. 1974. Bottom fishes of South Carolina estuaries-relative abundance, sea KEISER, R. K., Jr., and D. V. ALDRICH. sonal distribution, and length-frequency relationships. S.C. Mar. 1976. Salinity preference of postlarval brown and white shrimp (Penaeus Resour. Cent., Tech. Rep. 6, 189 p. aztecus and P. setiferus) in gradient tanks. Texas A & M Sea Grant STEPHENSON, W., W. T. WILLIAMS,. and S. D. COOK. Pub I. TAMU-75-208, 260 p. 1972. Computer analyses of Petersen's original data on bottom commu LAMBERT, J. M. , and W. T. WILLIAMS. nities. Ecol. Monogr. 42:387-415. 1962. Multivariate methods in plant ecology. IV. Nodal Analysis. J. STRICKLAND, J. D. H., and T. R. PARSONS. Ecol. 50:775-802. 1968. A practical handbook of seawater analysis. Fish. Res. Board Can., LANCE, G. N., and W. T. WILLIAMS. Bull. 167, 311 p. 1967 . A general theory of classificatory sorting strategies. I. Hierarchical TINER, R. W., Jr. systems. Com put. J. (Lond.) 9:373-380. 1977 . An inventory of South Carolina's coastal marshes. S.C. Mar. LASKER, R. Resour. Cent., Tech. Rep. 23, 33 p. 1975. Field criteria for survival of anchovy larvae: The relation between TURNER, R. E. inshore chlorophyll maximum layers and successful first feeding. Fish. 1977 . Intertidal vegetation and commercial yields of penaeid shrimp. Bull., U.S. 73:453-462. Trans. Am. Fish. Soc. 106:411-416. LAURENCE, G. C. WATHNE, F. 1977. A bioenergetic model for the analysis of feeding and survival poten 1959. Observations on trawl-door spread and a discussion of influencing tial of winter flounder, Pseudopleuronectes american us, larvae during the factors. Commer. Fish. Rev. 21(10):7-15. period from hatching to metamorphosis. Fish. Bull., U.S. 75:529-546. WEINSTEIN, M. P. LUNZ, G. R. , and F. J. SCHWARTZ. 1979. Shallow marsh habitats as primary nurseries for fishes and shellfISh, 1970. Analysis of eighteen year trawl captures of seatrout (Cynoscion sp.: Cape Fear River, North Carolina. Fish. Bull., U.S. 77:339-357. Sciaenidae) from South Carolina. Contrib. Bears Bluff Lab. 53, 29 p. WEINSTEIN, M. P., S. L. WEISS, and M. F. WALTERS. MASSMANN, W. H. 1980. Multiple determinants of community structure in shallow marsh 1971. The significance of an estuary on the biology of aquatic organisms habitats, Cape Fear River Estuary, North Carolina, U.S.A. Mar. BioI. of the Middle Atlantic Region. In P. A. Douglas and R. H. Stroud (edi (Berl.) 58:227-243. tors). A symposium on the biological significance of estuaries, p. 96-109. WELSH, W. W., and C. M. BREDER, Jr. Sport Fish. Inst. Publ., Wash., D.C. 1923. Contributions to life histories of Sciaenidae of the eastern United MATHEWS, T. D., and M. H. SHEALY, Jr. States Coast. Bull. U.S. Bur. Fish. 39:141-201. 1978. Hydrography of South Carolina estuaries, with emphasis on the WENNER, E. L., M. H. SHEALY, Jr., and P . A. SANDIFER. North and South Edisto and Cooper Rivers. S.c. Mar. Resour. Cent. 1982. A profile of the fish and decapod crustacean community in a South Tech. Rep. 30, 148 p. MUSICK, J. A. , and J. D. McEACHRAN. Carolina estuarine system prior to flow alteration. U.S. Dep. Commer., 1972. Autumn and winter occurrence of decapod crustaceans in Chesa NOAA Tech. Rep. NMFS SSRF-757, 17 p. peake Bight , U.S.A. Crustaceana 22 :190-200 WILLIAMS, A. B. ODUM, W. E. 1955 . A contribution to the life histories of commercial shrimps (Penae 1970. Insidious alteration of the estuarine environment. Trans. Am. idae) in North Carolina. Bull. Mar. Sci. Gulf Caribb. 5:116-146. Fish. Soc. 99:836-847. WILLIAMS, W. T. PRITCHARD, D. W. 1971. Principles of clustering. Annu. Rev. Ecol. Syst. 2:303-326. 1954. A study of the salt balance in a coastal plain estuary. J. Mar. Res. WILLIAMS, W. T., and J. M. LAMBERT. 13 :133-:44. 1961. Multivariate methods in plant ecology. III. Inverse association - ROE. R. B. analysis. J. Ecol. 49:717-729. 1969. Distribution of royal-red shrimp, Hymenopenaeus robustus, on ZETLER, B. D. three potential commercial grounds off the southeastern United States. 1953 . Some effects of the diversion of the Santee River on the waters of Fish. Ind. Res. 5:161-174. Charleston Harbor. Trans. Am. Geophys. Union 34:729-732.

16 Guidelines for Contributors

~ENTS OF MANUSCRIPT Literature cited. In text as: Smith and Jones (1977) or (Smith and Jones 1977); if more than one author, list according to age. Give the title (as concise as possible) of the paper years (e.g., Smith 1936; Jones et al 1975; Doe 1977). All pa e author's name, and footnote the author's affiliation, pers referred to in the text should be listed alphabetically by g address, and ZIP code. the senior author's surname under the heading "Literature Cited"; only the author's surname and initials are required in nts. Contains the text headings and abbreviated figure the author line. The author is responsible for the accuracy of .s and table headings. Dots should follow each entry and the literature citations. Abbreviations of names of periodicals lUmbers should be omitted. and serials should conform to Biological Abstracts List ofSer ials with Title Abbreviations. Format, see a recent Technical lct. Not to exceed one double-spaced page. Footnotes Report . .erature citations do not belong in the abstract. Abbreviations and symbols. Common ones, such as mm , m, See also Form of the Manuscript below. Follow the g, ml, mg, °C (for Celsius), 070, 0/00, etc., should be used. Ab Iovernment Printing Office Style Manual, 1973 edition. breviate units of measures only when used with numerals; lames, follow the American Fisheries Society Special periods are rarely used in these abbreviations. But periods are :ation No. 12, A List of Common and Scientific Names used in et al., vs., e.g., i.e., Wash . (WA is used only with ZIP Ites from the United States and Canada, fourth edition, code), etc. Abbreviations are acceptable in tables and figures Use short, brief, informative headings in place of where there is lack of space. erials and Methods ... Measurements. Should be given in metric unit s. Other equi ·ootnotes. Type on a separate sheet from the text. For valent units may be given in parentheses. )lished or some processed material, give author, year, f manuscript, number of pages, and where it is filed y and its location. FORM OF THE MANUSCRIPT

nal communications. Cite name in text and footnote. Original of the manuscript should be typed double-spaced on 1 footnote: John 1. Jones, Fishery Biologist, Scripps In white bond paper. Triple space above headings. Send good d u on of Oceanography, La 10lla, CA 92037, pers. com- plicated copies of manuscript rather than carbon copies. The 21 May 1977. sequence of the material should be:

es. Should be self-explanatory, not requiring reference FIRST PAGE : text. All figures should be cited consecutively in the text CONTENTS heir placement, where first mentioned, indicated in the ABSTRACT and margin of the manuscript page. Photographs and TEXT rawings should be of "professional" quality-clear and LITERATURE CITED .ced, and can be reduced to 42 pices for page width or to TEXT FOOTNOTES ;as for a single-column width, but no more than 57 picas APPENDIX Photographs and line drawings should be printed on TABLES (provide headings, including "Table" and Arab ic y paper-sharply focused, good contrast. Label each numeral, e.g., Table 1.-, Table 2.-, etc.) ~. DO NOT SEND original figures to the Scientific Edi · LIST OF FIGURE LEGENDS (entire legend , inclu ding -IMFS Scientific Publications Office will request these if "Figure" and Arabic numeral, e.g. , Figure 1.- , Figure are needed. 2.-, etc.) FIGURES es. Each table should start on a separate page and Id be self-explanatory, not requiring reference to the text. lings should be short but amply descriptive. Use only ADDITIONAL INFORMATION :ontal rules. Number table footnotes consecutively across 'age from left to right in Arabic numerals; and to avoid Send ribbon copy and two duplicated copies of the manuscri pt usion with powers, place them to the left of the numerals. to: ~ original tables are typed in our format and are clean and Ie, these tables will be reproduced as they are. In the text Dr. William 1. Richards, Scientific Editor lbles should be cited consecutively and their placement, Southeast Fisheries Center Miami Laboratory 'e first mentioned, indicated in the left-hand margin of the National Marine Fisheries Service, NOAA uscript page. 75 Virginia Beach Drive Miami, FL 33149 nowledgments. Place at the end of text. Give credit only lose who gave exceptional contributions and not to those Copies. Fifty copies will be supplied to the senior author and se contributions are part of their normal duties. 100 to his organization free of charge.