King Mackerel, Scomberomorus cavalla, Mark- Recapture Studies Off Florida's East Coast
Item Type article
Authors Schaefer, H. Charles; Fable, Jr. , William A.
Download date 04/10/2021 08:14:11
Link to Item http://hdl.handle.net/1834/26474 King Mackerel, Scomberomorus caval/a, Mark-Recapture Studies Off Florida's East Coast
H. CHARLES SCHAEFER and WILLIAM A. FABLE, JR.
Introduction reproductive capacity causing stock re Panama City Laboratory, began a co ductions and declining recruitment operative mark-recapture study on king King mackerel, Scomberomorus cav (Godcharles I). King mackerel have mackerel to determine movements in alla, is a coastal, pelagic scombrid been jointly managed by the South At both the Gulf of Mexico and along the found off the U.S. Atlantic and Gulf of lantic and Gulf of Mexico Fishery Man Atlantic coast. Subsequently, biologists Mexico coasts. This species has histori agement Councils since the implemen from both agencies tagged king mack cally contributed to commercial and tation of the Coastal Pelagic Fishery erel (17,042 releases, 1,171 returns) recreational catches throughout its Management Plan (CPFMP) in 1983. from 1975 through 1979 (Sutherland range in the southeastern United States. The maximum sustainable yield (MSY) and Fable, 1980; Sutter et aI., 1991; Commercial exploitation intensified for the U.S. king mackerel resource is Williams and Godcharles3). Results there in the 1960's with the introduc currently estimated at 26.2 million from this study indicated that the spe tion of large power-assisted gillnet pounds (NMFS2). cies consisted of at least two migratory boats and spotter aircraft. By the late The recreational fishery for king groups (stocks). Ranges of the two 1970's and early 1980's, increased de mackerel grew in importance as the stocks basically coincided with the Gulf mand for king mackerel had exceeded commercial fishery thrived. Moe (1963) of Mexico and the Atlantic Ocean off stated that in the early 1960's, king the southeast U.S. coast, with some mackerel was the species most desired mixing of the stocks off southeastern by anglers fishing from private boats, Florida during winter months. H. Charles Schaefer is with the Statistics Office, and was the staple catch of Florida's These conclusions were the primary Coastal Resources Division, Southeast Fisheries Science Center, National Marine Fisheries Ser charterboat fleet. In 1990-91, king basis for the division of the Gulf of vice, NOAA, 19100 S.E. Federal Hwy., Tequesta, mackerel was one of the three most Mexico (Gulf) and Atlantic king mack FL 33469. William A. Fable, Jr., is with the highly targeted species by recreational erel stocks, as defined by Amendment Panama City Laboratory, Southeast Fisheries Science Center, National Marine Fisheries Ser anglers along the southern U.S. Atlan 1 to the CPFMP (Gulf of Mexico and vice, NOAA, 3500 Delwood Beach Road, tic coast (NMFS, 1992). In recent years, South Atlantic Fishery Management Panama City, FL 32408. estimated king mackerel recreational Councils, 1985). Variable stock bound catches have exceeded reported com aries are used as part of the manage merciallandings in both the Atlantic and ment strategy. The Gulf group is sepa ABSTRACT-King mackerel, Scomber omorus cavalla, were tagged and released Gulf of Mexico (Fig. I). rated from the Atlantic group I April from eastern Florida between 1985 and In 1975, the Florida Department of 31 October at the Collier/Monroe 1993. Recapture trends from these studies Natural Resources (FDNR), now the County line in southwest Florida and 1 indicate an increase in tag returns from ar Florida Department of Environmental November-31 March at the Flagler/ eas north ofthe release sites, along with a decrease in recaptures from coastal waters Protection (FDEP), and the National Volusia County line in northeast Florida in the Florida Keys and Gulf of Mexico, Marine Fisheries Service (NMFS) (Fig. 2). The area between the Collier/ since earlier king mackerel tagging studies Monroe County line and the Flagler/ completed in the late 1970's. The data in Volusia County line in Florida is con dicate that eastern Florida waters may maintain resident king mackerel. Cyclical 1 Godcharles, M. F. 1993. Synoptic history of sidered to be a mixing area for the Gulf Federal management of king and Spanish mack and Atlantic migratory groups and is tag return patterns were noted along east erel and other coastal migratory pelagic species in ern Florida and in North Carolina. The pro the Gulf of Mexico and South Atlantic. Southeast referred to within this text as the "mix portion ofmixing ofpresently defined king Regional Office, National Marine Fisheries Service, mackerel stocks along eastern Florida may NOAA, St. Petersburg, Fla. Unpubl. rep., 8 p. vary yearly. Comparison of king mackerel 2NMFS. 1994.1994 report of the mackerel stock 3 Williams, R. 0., and M. F. Godcharles. 1984. tags show internal anchor tags to have a assessment panel. Southeast Fish. Sci. Cent., King mackerel tagging and stock assessment. Fla. higher percentage of return and lower per Natl. Mar. Fish. Serv., NOAA, Contrib. MIA-93/ Dep. Nat. Resour., Project 2-341-R, Completion centage oftag loss than dorsal dart tags. 94-42,27 p. rep. (unpub!.), 45 p.
56(3), 1994 13 10 Gulf migratory group. fishing year (July·June) ( Recreational Commercial
FLS Jupiter. , I 85/86 B6I87 87/88 88/89 89/90 90/91 91/92 92/93 Boynton. t Figure I.-Estimated catches of king mackerel from the Gulf and Atlantic stocks by fishing year (FY). Source: 25°48'N NMFS (1994). (Nov.· Mar.) Dade 25 °20.4' N Monroe ing zone." For management purposes, / the commercial sector of the Gulf group .. -- FLK is partitioned into the eastern (Florida) and western (Alabama to Texas) zones. Annual quota allocations and bag lim its are enforced for each migratory Figure 2.-NMFS tagging locations (shaded), variable Atlantic/Gulf stock boundaries, and subareas used to partition Florida tag returns. group in accordance with the fishing year (FY). The Gulf group FY is de fined as 1 July-30 June and the Atlan tic group FY as 1 April-31 March. FDEP tagging. The tagging methods return address or phone number printed In 1983, the NMFS began additional and techniques for procurement of fish on the streamer. IA and SLA tags also scientific mark-recapture work to fur follow the original procedures devel included the tag number printed on the ther evaluate movement patterns of king oped during the FDEP study. Although disk portion. mackerel within Gulf of Mexico and only internal anchor (IA) tags were used During all of the tagging studies de Atlantic waters. Since then, tagging for the earlier FDEP tagging (Sutter et scribed, commercial handline fishermen studies have been conducted off Mex aI., 1991), the NMFS has experimented were contracted to catch king mackerel ico, Texas, Louisiana, northwest and with four different types of king mack for tagging. These fishermen were com eastern Florida, and North Carolina. erel tags from 1985 through 1993 (Fig. pensated for successfully tagged and The primary objective of tagging along 3). Single red or orange plastic IA tags, released fish based on the total weight Florida's east coast was to better under similar to those used during the FDEP of marked releases during each trip, as stand mixing patterns of king mackerel study, were used during 1985-88. Or calculated using a weight to length con from the eastern Gulf group and the ange shrink-lock internal anchor (SLA) version table. Although this method of Atlantic group. This paper summarizes tags were tested along with IA tags dur procurement proved costly, large num the current results of the NMFS mark ing winter 1989-90 tagging. Yellow bers of relatively unharmed fish were recapture work from 1985 through 1993 double-barb dorsal dart tags (DD92) usually available for tagging, and accu along eastern Florida. were used in combination with IA and rate information on releases could be SLA tags during 1991-92 tagging. The obtained by NMFS personnel (Fable, Methods following winter (1992-93), a new ver 1990). For continuity, earlier king mackerel sion of the dorsal dart tag (DD93) was King mackerel were caught using tagging studies (1975-79) by the state tested along with IA tags. All tags in commercial troll gear. Fish were imme of Florida and NMFS are referred to as cluded an identification number and diately unhooked aboard the vessel and 14 Marine Fisheries Review Initially, to publicize the king mack erel tagging program and to reward an glers for returning tags, posters and news releases were circulated, and a $10 reward was offered for each returned Shrink·lock anchor (SLA) tag. In 1986, to help increase the tag returns, an annual $1,000 drawing, sponsored by NMFS, was added to the !ll reward program. In 1991, the individual 81F====:J;m:JmmlIlJ~== reward was increased to $20 per fish. !!i Release and recapture data for the Internal anchor (IA) described studies (10,285 releases, 546 returns) were compiled from the NMFS ~§§§§§5::Jj]RE~W~AR![O]RFJOOOOOi2!Ei2===:::::JP~H§EON[E~800-;E4!2137]'39!B36c:::::::::Jd:=::::::J Panama City Laboratory tagging records and the NMFS Cooperative Dorsal dart (0093) Gamefish Tagging Program database. Six separate tagging experiments, con ducted by the NMFS from 1985 through 1993, are described here. Table 1 lists Dorsal dart (0092) the locations, dates, and release num bers during each experiment. No tag ging was performed during winter 1990-91. The number of fish released Figure 3.-Types of king mackerel tags used by NMFS during 1985-93. during these studies (10,285) is com parable to the number released in east ern Florida during the 1970's FDEP study (10,120). To describe movement patterns, re leases were grouped into three spatial/ temporal regions. Recaptures were grouped into the geographical location of recovery, taking into account the present management strategy. Returns from outside of Florida were partitioned into the state of recapture. Due to its expansive coast line and the high pro portion of returns, Florida was divided into four subareas: Collier/Monroe County line to Alabama (FLW), Collier/ Monroe County line to DadelMonroe Figure 4.-Placement of internal anchor (IA and SLA) tags (A) and dorsal dart (0092 and 0093) tags (B). County line (FLK), Dade/Monroe County line to FlaglerNolusia County line (FLS), and FlaglerNolusia County line to Florida/Georgia border (FLN) placed ventral side up in a V-shaped beside the dorsal fin into the muscula (Fig. 2). trough. Prior to 1991, IA tags were in ture using a short-handled insertion Recaptures were also grouped ac serted with forceps into the abdominal needle. Immediately after tagging and cording to the ocean of recovery, using cavity through a 6-10 mm slit made measurement, presumed healthy fish the Gulf of Mexico and Atlantic Ocean, with a scalpel. During 1991-92 and were released over the side of the boat. as defined by the Supreme Court deci 1992-93 tagging, IA and SLA tags were Information recorded for each released sion, United States v. Florida, October inserted using a stainless steel insertion fish included tag numbers, fork length, term 1975. No adjustments were made tool designed by the NMFS Panama month-day-year, latitude-longitude, and for possible factors affecting tag return City Laboratory. With both methods, the condition of fish. Release information rates. Temporal relationships were de disk portion of the tag remained inside was ultimately entered into a release and scribed by grouping recaptures by sea the abdominal cavity, and the plastic recapture database, currently managed son and area of recapture in relation to streamer protruded externally (Fig. 4). by the NMFS Cooperative Gamefish time of freedom. Seasons are divided Double-barbed dart tags were inserted Tagging Program, Miami. as 3-month periods: winter is defined 56(3),1994 15 as December, January, and February; market, was not included for movement during the 1985-86 and 1987 studies spring as March, April, and May; sum analysis. (Table 1). Fish tagged during winter in mer as June, July, and August; and fall southeast Florida (1988-93) averaged Results as September, October, and November. largest at the beginning of the winter One recapture from the 1987 tagging The mean fork length (FL) varied for for each study. Length frequency histo study, returned from a New York fish each study with the largest fish tagged grams, comparing percentages of re leases to recaptures (5 cm grouping) show that a larger percentage of fish Table 1.-Summary of size distribution of king mackerel releases. were released than were recaptured in Tagging Study No. Mean Size range smaller size groupings «65 cm FL) (Fig. Years Months Location tagged FL(mm) S.E. FL(mm) 5). This is most evident in the histogram 1985-86 Dec., Jan. New Smyrna 891 872 109 540-1,180 developed from 1991-92 tagging. The largest percentage of returns oc 1987 April, May Jupiter 719 891 10.2 670-1,270 April. May Boynton 284 871 8.7 600-1,200 curred within the first year following Combined 1,003 885 9.7 600-1,270 release for all studies with decreasing 1988-89 Dec. Sebastian 599 879 7.9 525-1,450 returns during each year thereafter Jan.-March Ft. Pierce 1,228 731 7.5 460-1,175 March, April Boynton 216 729 7.4 510-980 (Table 2). The overall return rate from Combined 2,043 774 6.1 460-1,450 these studies is thus far 5.3%. Time at 1989-90 Dec. Sebastian 288 744 6.6 540-1,160 large varied from 0 to 2,261 days, aver Jan.-March Ft. Pierce 1,763 697 59 435-1,200 aging 360 days. Returns from the west April Boynton 3 630 12.9 570-690 Combined 2,054 703 60 435-1,200 ern zone of the Gulf of Mexico indi cated the farthest distance traveled away 1991-92 Dec., Jan .• March Sebastian 740 763 73 420-1,190 Feb. Ft. Pierce 638 672 8.0 480-1,120 from the point of release. All of the fish March Jupiter 838 613 7.9 410-1,130 Combined 2,216 680 6.2 410-1,190 recaptured in Texas (3) were estimated to have traveled over 2,000 km. The 1992-93 Dec.• Jan. Sebastian 296 854 69 560-1,370 Feb., March Jupiter 1,729 763 7.5 480-1,220 most distant Atlantic recapture (1,430 March Ft. Pierce 53 716 12.3 590-880 km) was recovered from Virginia Combined 2,078 775 7.1 480-1,370 Beach, Va. Interestingly, 37.9% (207) of all recaptures were recovered within 36.,-----.,--:-::-:-,------, 36.,------, 50 km of tagging with 37.2% (77) of 30 _Tegged these at large for more than 1 year. Of 26 1SSIAecaptured 26 the 248 fish recaptured more than 100 20 20 km away from the point of tagging, 16 16 63.3% were recovered from north of the 10 tagging location. There was no observed relation between size and distance trav 50 70 36,------, 36 -,------, eled. Due to spatial/temporal variations S.E. Florida 1 988-89 S.E. Florida 1 989-90 _Tagged 30 _Taggod 30 in tagging regions, recapture results of ~ R"cap tured fSSRecaptured 26 26 these studies are treated separately. Re C o ral area. 100 110 '20 36,------, 36,------...... , S.E. Florida 1 991 -92 S.E. Florida 1 992-93 30 30 _Tagged Table 2.-Number of recaptures per 12-month period ~R.capturBd following release. 26 26 20 20 Days from release to recapture Per- 16 16 Tagging 0- 366- 731- 1,096- 1,461-1.826- 2,191- cent period 365 730 1.095 1,460 1.825 2,190 2,555 return 10 10 1985-86 18 12 6 3 4.0 o o 1987 53 34 10 5 6 10.9 60 00 70 80 90 100 "0 120 60 00 70 80 90 100 110 120 1988-89 87 20 7 5 1 5.9 Fork length at tagging (cm) 1989-90 60 43 13 3 1 5.8 1991-92 35 8 4 2.1 1992-93 82 27 1 5.3 Figure 5.-Length frequency distribution of releases and returns from 1985-93 king mack Totals 335144 41 13 11 5.3 erel tagging (5 cm groupings). 16 Marine Fisheries Review Winter Tagging 1985-86, was returned from the Gulf ofMexico late spring to early fall. Recaptures from New Smyrna Beach Area in the fall off Panama City, Fla. Tem north of the FlaglerNolusia border (15) poral return patterns show the highest occurred in the spring and summer Most of the recaptures (38) from fish number of recaptures in southeast months. Recaptures within southeastern tagged during winter in the New Florida during spring for four consecu Florida occurred during all months of Smyrna Beach area (891 releases, 39 tive years following the tagging, as well the year, but were concentrated during returns) were found along eastern as recurrent returns in North Carolina the winter in the Cape Canaveral to Fort Florida (Fig. 6, Table 3). One fish was in the fall for more than four years fol Pierce area and during May in the Jupi recovered from the Gulf of Mexico off lowing tagging (Table 4). Thirty percent ter to Palm Beach area. Fish tagged Louisiana in October 1987. All recov of returns (33) from this study were fish during mid-winter offFort Pierce showed eries from north of the tagging area oc at large for more than 1 year and recap the most movement, accounting for five curred summer through fall, while the tured within a 50 krn radius of release. of the seven Gulf returns and all of the majority of recoveries from south of the A comparison of these results to those five Atlantic returns north of Florida. tagging area were concentrated during of the FDEP study show a marked de Recaptures from 1989-90 tagging winter and spring months in southeast crease in the number (Fig. 9) show fewer Gulf of Mexico re Florida. Results indicate that this group of Gulf of Mexico and Florida Keys returns along with an turns (5) than from the previous study of fish may have been primarily resi dential (nonmigratory) off eastern increase in southeast U.S. Atlantic coast coupled with more returns from areas Florida. The lack of tagging within this returns (Table 6). north of the Volusia/Flagler border (29) (Table 3). Fish tagged in mid-winter off region during the FDEP study does not Winter Tagging 1988-93, Fort Pierce again showed the strongest allow comparison of these results to Southeast Florida those of 1970's tagging. tendency to move, providing all of the From 1988-93 the NMFS tagged Gulf of Mexico returns and 11 returns Spring Tagging 1987, 8,391 king mackerel in the same region from north of Florida. Returns from Jupiter Area in southeast Florida during four winters north of the tagging area were concen Recaptures from April and May tag (Table 1). Recaptures from 1988-89 trated from spring through fall. South ging in the Jupiter area (1,003 releases, tagging (2,043 releases, 121 returns) east Florida returns occurred year-round 109 returns) ranged along the Atlantic show extensive movements (Fig. 8). with the highest number during winter coast from Virginia to the Florida Keys Atlantic Ocean returns ranged from off the Cape Canaveral to Fort Pierce (Fig. 7). Outside of Florida, the major North Carolina to the Florida Keys. Gulf area. ity of the recoveries (19) were from of Mexico returns (7) ranged from west Movement, as indicated by the dis North Carolina in the fall. Only one tag ern Florida to Texas, and occurred in tribution of tag returns from 1991-92 Table 3.-Distrlbution 01 king mackerel tag returns. Tagging period Recapture 1985- 1988- 1989- 1991 1992 All location 1986 1987 1989 1990 1992 1993 years Virginia 2 N. Carolina 19 2 7 3 2 33 S. Carolina 2 2 6 2 13 Georgia 2 2 3 8 Florida1 FLN' 11 5 10 14 3 13 56 5 <:J 2/86 12/866/8771878/88 3 <) 11/87 12/87(2) FLS 27 74 94 84 38 88 405 5 <) 4/86 11/86 12/86(2)12/87 FLK 4 5 2 2 13 6 <) 4/86 1/87(3) 8190(2) 1 <) 8/88 FLW 4 4 9 5 <) 3/865/86(3)7/86 Alabama 2 Louisiana 2 Texas 2 3 Unknown Totals 39 109 121 120 47 110 546 Figure 6.-Location and month/year of tag returns from 1985-86 tagging 1 See Figure 1 and text for description of Florida subareas. in the New Smyrna Beach, Fla., area. 56(3), 1994 /7 tagging (2,216 releases, 47 returns), was to Miami, Fla. No tags were returned trends show northward movement in the restricted primarily to the Atlantic coast from the Florida Keys, but one tag was spring and summer of 1992 and recur (Fig. 10, Table 3). Tag recoveries ranged returned from the Gulf of Mexico off ring recaptures in southeast Florida the along the Atlantic coast from Virginia of Fort Morgan, Alabama. Recapture following two winters. 4 <) 6/87(3) 6/91 <) 9/87 12/87 4 <) 12/87 4/88 4/89 4/9' 10 <) 6/87(7) 12/87 5/88 5/89 1 <) 5/87(2) 6187(5) 7/87 8187(2) 5/88(3) 6/88 8/88 5/89 IB> <) 5/87(2) 6/87 5/88(9) 5/89(10) 4190(2) 5190(2) 5191(2) Ie> 8 <) 5/88(4) 5/8910/8912/894/91 1 <)8/91 1 '04/89 _4<) 4/88 11/881/91 3/92 Figure 7.-Location and month/year of tag returns from 1987 tag ging in the Jupiter, Fla., area. Table 4.-Number of returns from Jupiter 1987 tagging by recapture location, Table 5.-Number of returns from 1988-93 tagging in southeast Florida by recap· days at large, and season of recapture. ture location days at large and season of recapture. Recapture location 1 Recapture location 1 Release Release to Season Florida to Season Florida return of return of (days) recovery2 FLW FLK FLS FLN GA SC NC VA (days) recovery2 TX LA AL FLW FLK FLS FLN GA SC NC VA 0-365 Winter 3 0-365 Winter 1 51 Spring 12 Spring 2 3 121 4 1 1 Summer 19 2 Summer 3 1 20 21 3 3 4 Fall 1 12 Fall 19 1 1 1 366-730 Winter 366-730 Winter 2 15 1 1 Spring 22 Spring 1 25 3 3 1 Summer 2 2 2 Summer 2 17 9 2 Fall 2 Fall 8 2 3 731-1,095 Winter 1 731-1.095 Winter 6 Spring 7 Spring 9 Summer Summer 1 Fall Fall 4 1,096-1,460 Winter 1,096-1,460 Winter 1 Spring 3 Spring 4 Summer Summer Fall Fall >1,460 Winter >1,460 Winter 2 Spring 1 Spring Summer 2 Summer Fall Fall 1 States outside of Florida are abbreviated: see Figure 1 and text for description of , States outside of Florida are abbreviated; see Figure 1 and text for description of Florida Florida subareas. subarea. 2 Seasons are divided as 3-month periods (i.e. winter is Dec., Jan., Feb.). 2 Seasons are divided as 3-month periods (i.e., winter is Dec., Jan.. Feb.). 18 Marine Fisheries Review Recaptures from 1992-93 tagging counted for five of these seven returns turns) show distinct differences from (2,078 releases, 110 returns) are thus far and for the two returns from the Florida earlier FDEP tagging (Table 6). Will confined to the Atlantic coast (Fig. 11). Keys. No fish have yet been recaptured iams and Godcharles3 reported that mi Seven fish were recovered north of in the Gulf of Mexico, grating king mackerel tagged in the Florida during spring through fall. Fish Combined results from winter tag winter off southeast Florida moved prin tagged later in the winter in Jupiter ac- ging 1988-93 (8,391 tagged, 398 re- cipally into the Gulf of Mexico during the summer. More recent NMFS tag ging indicates that only 3.3% (13) of all recaptures occurred north of the CollierlMonroe County line in the Gulf of Mexico, while 18.1 % (72) were from north of the Vol usia/Flagler County line 1 <) 6/92 in the Atlantic. Returns from within the Florida mixing zone (313) occurred nearly exclusively within the Atlantic Ocean. One fish was recaptured from Gulf of Mexico waters near Summer land Key. Thus, only 3,5% (14) of re 1 Table 6.-Comparison of NMFS tagging to earlier FDEP tagging showing the number of releases in parentheses. Jupiter area S.E. Florida area (May-June tagging) (Dec.-April tagging) FDEP NMFS FDEP NMFS Recapture 1975-78 1987 1975-78 1988-93 location (2,674') (1,003') (6,500') (8,391') <)3/904/906/90 7190(3) 3/91(2) 7/91 Virginia 2 1 1 5 <) 6/90 4/91 7/91 8/91 6/93 N. Carolina 6 19 4 14 ¢ 9/916/92 S. Carolina 5 2 1 11 Georgia 1 2 1 15 Q 3J9~:~910';;~~~)(~)2;:~~~)(~~:~~~) ~~~~ ~~~) 12/92 6 9 0""7/91(3) 8/9112/91 1/92(2) 4/9211/9212/92 Florida' ~ 14 <)<~~~~~~)) ~)~~og}9~2~~~26~91j97~91(2) FLN 8 5 6 40 6 <) 2/903/90 5/91 4/925/923/93 FLS 146 74 436 304 9 <) 2/90(2) 3/90{2) 5/90 7/90 5/91 5/928194 FLK 30 4 45 9 ~ 4 <) 2/90(2)12190 10/91 , <) 1190 FLW 2 1 36 8 4 ¢ 1/90 3/90 9/90 7/91 Alabama 4 1 'I Louisiana 1 3 1 _ ~ <:) 7/90 4/92 Texas 5 16 3 Unknown --1 --1 1 Totals 207 109 553 398 1 Number of releases. Figure 9.-Location and month/year of tag returns from 1989-90 southeast Florida tagging. 2 See Figure 1 and text for description of Florida subareas. 56(3),1994 19 3 0 5/937/939/94 1 <> 7/92 2 <) 6/93 3/95 I'e> 10 <) 4/92(2) 5/92 8/9212/92(4) 1/943/94 Ie> 11 03/934/93(4) 8/93 3/94 7/9412/94(2) 1/95 Ie> <) 4/92 5/92 6/92(3) 1/93 4/93(2) [e> 20 0< ;j~;l~l :j~;~~l ;j~; ~j~; ~~~; 12/93 ¢ 1/92 6/92 8/92 [&> 24 0 3/93(6) 4/93( 13) 5/938/93 3/94 8/94 5/95 <) 4/92(2) 2/93 3/93 5/93(2) 02/933/93(8) 4/93(7) 1/942/943/942/95 4 <) 4/92 3/93{2) 4/94 o <) 3/92 12/92 <) 3/93 3/94 <) 3/928/92 4 <) 3/93(3) 5/94 <) 12/91 3/92 <) 3/93 5/93 7 --<2:1 <) 3/93 2/94 Figure IO.-Location and month/year of tag returns from 1991 Figure) I.-Location and month/year of tag returns from 1992 92 southeast Florida tagging. 93 southeast Florida tagging. also included the highest number from showed a pattern of repeated returns in all of the four tag combinations of SLA the Gulf of Mexico (8) and from the spring and summer. and IA tags tested (Table 8). Tag loss Atlantic north of Florida (16). Fall re was lower for SLA tags (16.0-22.5%) Tag Comparisons turns, the lowest of any season, were than IA tags (30.0%). During winter concentrated along the Atlantic coast During the first three tagging studies 1991-92 tagging, lA, SLA, and DD92 with the highest number of returns in (1985-86, 1987, 1988-89), all fish were tags showed varying return rates per southeast Florida. Temporal patterns single-tagged using IA tags (4.0-10.9% combination (0.5-5.3%). DD92 tags had show repeated returns in North Caro return). Results of 1989-90 tagging a higher calculated tag loss (50.0 lina in the summer and fall (Table 5). show that there were no appreciable dif 57.1 %) than SLA (0%) or IA tags Recaptures from northeast Florida also ferences in return rates (5.6-6.1 %) from (10.7%). Tagging in 1992-93, which involved testing a new type of dorsal dart tag (DD93) along with IA tags also, Table 7.-Number of returns from 1988-93 tagging in southeast Florida by recapture location and season and showed varying rates of return per com month of recovery. bination (0-7.1 %). DD93 tags showed Winter Spring Summer Fall a much higher tag loss (54.4%) than IA Recapture tags (12.3%). location Dec. Jan. Feb. Mar. April May June July Aug. Sepl. Del. Nov. Early recaptures from 1992-93 tag Virginia 1 ging provided a clue to problems asso N. Carolina 1 2 3 3 3 1 S. Carolina 2 1 1 1 1 2 ciated with the DD93 tag. Several Georgia 1 1 2 1 1 Florida double-tagged fish were recaptured FLN' 3 2 2 12 15 5 1 with both tags intact, but with a large FLS 45 16 14 46 76 37 11 12 16 10 2 19 FLK 1 2 1 3 2 open wound slanting posteriorly from FLW 2 3 the DD93 tag (Fig. 12). We believe that Louisiana Alabama 1 vibrations of the streamer against the Texas 2 - soft dorsal skin and tissue were progres Totals 45 19 16 51 84 44 28 38 31 18 5 19 sively creating a larger hole surround , See Figure 1 and text for description of Florida subareas. ing the tag. Constant motion of the fish 20 Marine Fisheries Review and streamer of the DD93 tag would Table S.-Summary information on king mackerel releases by tag type showing percentage of tag loss in parentheses. probably not allow such a wound to heal Release Return before the tag fell out. Supporting this Tagging Tag Mean theory, several other double-tagged fish period combinations No. FL(mm) N % Tags not recovered were recaptured with the DD93 tag 1985-86 11A 891 872 39 4.0 missing and a gaping wound where it 1987 llA 1.003 885 109 10.9 had been inserted. These experiments indicate a higher 1988-89 llA 2.043 774 121 5.9 tag loss from both DD92 and DD93 tags 1989-90 llA 33 636 2 6.1 1 SLA 510 697 31 6.1 than either SLA or IA tags. Double 1 IA + 1 SLA 675 698 40 5.9 12 IA(30.0%) 9 SLA(22.5%) tagged fish with one dorsal dart tag and 2 SLA 836 714 47 5.6 15 SLA(16.0%) one internal anchor tag also showed a 1991-92 llA 287 673 2 0.1 lower percentage of return than those 1 SLA 188 690 10 5.3 10092 197 616 1 05 fish single- or double-tagged using only 1 SLA + 1 0092 387 661 6 1.6 3 0092(50.0%) internal anchor tags, especially for 1 IA + 1 0092 1.157 698 28 2.4 3 IA(10.7%) 16 0092(57.1 %) smaller fish «700 mm FL). 1992-93 llA 749 745 53 7.1 10093 28 740 Discussion 1 IA + 10093 1.301 793 57 4.4 7 IA(12.3%) 31 0093(54.4%) The actual mechanisms of king mackerel migration are not well known. The highly pelagic nature of this spe cies is evidenced by the range of recap tures from these studies (from Texas to Virginia). Recaptures from the Gulf of Mexico suggest that there has been at least limited migration from southeast Florida, beyond the Collier/Monroe County line, to both the eastern (9 re turns) and western (6 returns) zones of the Gulf of Mexico. The percentage of cross mixing of king mackerel popula tions (i.e. fish that are spawned in the At lantic Ocean and later travel to the Gulf of Mexico) has yet to be documented. Important factors such as differential fishing mortality rates, variable tag re porting rates, fishery closures, and changes in fishing patterns have not been weighted for in this study. Differ ences in reporting rates of tagged fish most likely occur between different lo calities and among different resource users. The familiarity of fishermen in southeast Florida with the NMFS tag ging program has undoubtedly co"ntrib uted to the high return rate recorded there. Florida's east coast also supports intensive year-round king mackerel fishing, unlike certain areas in the Gulf Figure 12.-King mackerel recaptured 60 days following tagging, showing a large wound of Mexico and north of Florida. The surrounding the dorsal DD93 tag. implementation of the CPFMP in 1983 did not affect the recoveries from ear lier FDEP tagging, but has undoubtedly Gulf migratory group king mackerel Gulf of Mexico. Due to the complexity affected tag recoveries since the onset were closed for varying periods in the of interactions affecting tag returns and of recent NMFS tagging. winter and spring, thereby eliminating the relatively large area encompassed From 1987 through 1993 the com tag recoveries which would have oc by these studies, no adjustments were mercial and recreational fisheries for curred both within south Florida and the attempted for these differences or their 56(3), 1994 21 effects on results of this research. All were released in the Atlantic and recap eastern Florida group, which moves sea results and conclusions within this text tured in the Gulf of Mexico, along with sonally along the Florida east coast. are based solely on the most current seventeen fish that were tagged in the Winter tagging studies showed year NMFS return data. Gulf of Mexico and recaptured in the round recaptures within southeast Sutter et al. (1991) estimated that sea Atlantic. This low transfer of tagged fish Florida with a larger percentage occur sonal overlap between the Gulf and At between these two areas, as indicated ring during summer months. Sutter et lantic stocks off southeastern Florida in by recaptures, concurs with the results al. (1991) also noted indications of a the late 1970's was 29.4-41.8%. These of these studies. Releases and recaptures resident population in southeast Florida estimates were based upon the present within the Florida Keys region were during earlier FDEP tagging. Temporal management strategy, which classifies sorted by latitude and longitude to es patterns from 1987 and 1988-93 tag all king mackerel off southeast Florida tablish Gulf of Mexico or Atlantic ging show that the highest number of in the winter (l November-31 March) Ocean status. returns within southeast Florida oc as eastern Gulf migratory group. Pre When recaptures are grouped accord curred during the same season as tag liminary results of these NMFS studies ing to current stock boundaries (Fig. ging regardless of time at large, imply continue to support the theory of sepa 13), the percentage of returns classified ing that there is a regrouping of some rate Gulf of Mexico and Atlantic king as Gulf group is inflated by the large of the same fish each winter and spring mackerel stocks, but may indicate less number of winter returns from south in southeast Florida (Tables 4, 5). mixing of these two groups along east Florida. If this area is actually no In conclusion, long-distance migra Florida's east coast than previously longer a major mixing area for stocks tion of winter fish away from southeast theorized. from the Gulf of Mexico and the Atlan Florida seems to start in early spring Returns from the NMFS tagging tic Ocean, as suggested by recent tag with a small percentage of fish moving studies along eastern Florida, which are ging, the majority of these returns may into the Gulf of Mexico by summer and likely to increase in the future (Table actually be Atlantic group fish. We thus a larger percentage moving northward 2), suggest that only a small percent decline to offer a percentage of stock in the Atlantic, as far as Virginia, by age of king mackerel tagged in the mixing off southeastern Florida based summer and fall. Spring and early sum southern Atlantic from winter through on current variable stock boundaries. mer tagging in the Jupiter, Fla., area early summer migrated into the Gulf of Tagging results also indicate the pos showed that long-distance migrating Mexico. This decrease in Gulf of sibility of a nonmigratory (resident) fish moved predominately northward Mexico recaptures, coupled with an in crease in recaptures from north of south east Florida, could be indicative of an alteration of migration patterns since G~I~ < D (above Collier/Monroe border) completion of the FDEP tagging 15 Gulf group years ago. It may be that as the Gulf D MIxing :l:one (Nov.-Mar./ < D Mixing zone lApr.-Oct.1 group decreased in biomass in the early Atlantic group 1980's the number of fish migrating nrn AtlantiC (above VoluslafFlagler border) from the Gulf of Mexico to southeast Florida in the winter also decreased. 2.6 0.9 5.8 4.2 2.1 This may have decreased the size of the 100 winter population off southeast Florida, thereby causing the Atlantic stock to 80 occupy a greater percentage of that 33.3 32.2 40.8 36.2 35.4 population. Differential fishing mortal ity rates and changes in fishing patterns 60 ~ since the FDEP study may be other ex c Q) planations for differences between the ~ Q) two studies. Environmental and biologi Cl. 40 35.9 65.7 49.6 30.8 44.7 46.4 cal parameters, such as water tempera tures, storms, and the abundance of food may also influence annual migration 20 patterns. A brief overview of the entire NMFS 0 Cooperative Gamefish Tagging Pro 1985-86 1987 1988-89 1989-90 1991-92 1992-93 gram king mackerel release and recap Tagging period ture database 1985-1993 (20,393 re leases, 994 returns) indicates that only two fish from outside of these studies Figure 13.-Percentage of recaptures within present management zones. 22 Marine Fisheries Review during the first few months following vary yearly. Mark-recapture work has those at the NMFS Southeast Fisheries tagging, reaching North Carolina by fall helped to define migration patterns, but Science Center in Miami who helped (Table 4). The large number of returns there are many variables affecting tag with this project, including N. Thomp from North Carolina from both winter returns. son, G. Davenport, and N. Parrack for and spring tagging in southeastern Recent electrophoretic variation re editorial assistance, along with A. Florida suggests that there may be sub search has identified limited genetic Martinez and J. Javech for help with stantial migration between these two variation of king mackerel in U.S. wa several figures used, and the NMFS areas. ters. Fish samples taken from the west Cooperative Gamefish Tagging Pro Movement of king mackerel from ern zone of the Gulf of Mexico showed gram. Partial funding for this research North Carolina to southeast Florida has genetic variation from fish samples was provided by grants from MARFIN. been documented by the North Caro taken in the Atlantic, but fish captured lina Division of Marine Fisheries. Noble off western Florida in the Gulf of Literature Cited et al. 4 reported that the state of North Mexico are thus far genetically indis Fable, W. A., Jr. 1990. Summary of king mack erel tagging in the southeastern USA: mark Carolina tagged and released king tinguishable from those found in the recapture techniques and factors influencing mackerel off the central and northern southeastern Atlantic (Johnson et a!., tag returns. Am. Fish. Soc. Symp. 7: 161-167. Gulf of Mexico and South Atlantic Fishery Man 2). coast of North Carolina (4,364 releases, 1994; NMFS Research to better de agement Councils. 1985. Final amendment 1, 86 returns) from 1985 through 1990. fine king mackerel populations is un fishery management plan and environmental The majority of recaptures from south derway, and it includes mitochondria impact statement for coastal migratory pelagic resources (mackerels) in the Gulf of Mexico of North Carolina occurred in southeast DNA analysis by Texas A&M Univer and South Atlantic region. Gulf Mex. Fish. Florida (15), all in an area from Fort sity and a multivariate statistical proce Manage. Counc., Tampa, Fla., var. pagin. Pierce to Pompano Beach. Seven of dure based upon otolith shape being Johnson, A. G., W. A. Fable, Jr., C. B. Grimes, and L. Trent. 1994. Evidence for distinct these Florida returns were from fish tested by NMFS. The NMFS has con stocks of king mackerel, Scomberomorus cav tagged in the early winter in North tinued mark-recapture of king mackerel alia, in the Gulf of Mexico. Fish. Bull. 92(1 ):91-10 I. Carolina and recaptured in the Jupiter in southeast Florida during the winters Moe, M. A., Jr. 1963. A survey of offshore fish area in April and May. of 1993-94 (495 releases) and 1994-95 ing in Florida. Fla. State Board Conserv., Prof. Southeast Florida remains an active (952 releases). Results of this recent Pap. Ser. 4, 117 p. NMFS. 1992. Marine recreational fishery statis fishing area for king mackerel. Results tagging are still preliminary, but do not tics survey, Atlantic and Gulf coasts, 1990 of these studies indicate that the pro yet include any recaptures from the Gulf 1991. U.S. Dep. Commer., NOAA, Natl. Mar. portion of mixing of presently defined of Mexico. Fish. Serv., Curro Fish. Stat. 9204, 275 p. Sutherland, D. E, and W. A. Fable, Jr. 1980. Re stocks during winter in this area may Acknowledgments sults ofa king mackerel (Scomberomorus cav alia) and Atlantic Spanish mackerel (Scom We thank those directly related to the beromorus maculatus) migration study, 1975 4 Noble, E. B. L. P. Mercer, and R. W. Gregory. 79. U.S. Dep. Commer., NOAA Tech. Memo 1992. Migration, age and growth, and reproduc success of these studies, including con NMFS-SEFC-12, 18 p. tive biology of king mackerel (Scomberomorus tracted commercial fishermen and the Sutter, E c., III, R. O. Williams, and M. E cavalla) in North Carolina. N.C. Div. Mar. Fish., Godcharles. 1991. Movement patterns and Mar. Fish. Completion Rep. Proj. F-29, Study 1, many NMFS personnel who helped stock affinities of king mackerel in the south 74 p. with fish tagging. We also thank all of eastern United States. Fish. Bull. 89(2):315-324. 56(3),1994 23