Sutter et at: Movement and stock affinities of Scomberomorus cavalla 



319 



year (Fig. 3). Insufficient returns in the other SE U.S. 

 subareas precluded further analysis of the fish released 

 from the South Carolina region. 



King mackerel released from the Ft. Pierce region 

 (6416 tagged; 543 returned) were recaptured in all 

 seven subareas; numbers in four subareas were ade- 

 quate to describe temporal trends (Fig. 4a-d). Peak 

 periods of recapture in the SEFL subarea (N 423) oc- 

 curred from December through March, with a smaller 

 peak from May through July (Fig. 4a). The number of 

 recaptures was highest during the first recapture year, 

 progressively decreasing from year 2 through year 5. 

 Fish recaptured in the FK subarea (N 37) from the Ft. 

 Pierce tagging region (Fig. 4b) also showed a strong 

 annual cycle of recapture from winter through early 

 spring, generally following the peak recaptures from 

 SEFL by 1-3 months. A bimodal annual cycle was 

 noted for fish recaptured in the NEG subarea (N 29; 

 Fig. 4c); the first cycle occurred during June and July, 

 and another occurred from August through October. 

 In NWG waters (N 18), returns of fish tagged in the 

 Ft. Pierce region occurred most frequently from July 

 through August (Fig. 4d). 



The regularity of seasonal increases in tag returns 

 from fish released in each of the Ft. Pierce region 

 subareas indicates a predictable movement pattern. 

 Fish move progressively through SEFL and FK waters 

 in the late-winter and early-spring and travel to the 

 northern Gulf of Mexico subareas during warmer 

 spring and summer months. King mackerel then com- 

 plete the cycle in late-summer and early-fall by return- 

 ing to their release sites. This pattern of movement 

 may occur over a period of 3-5 years. Whether all fish 

 participate in this movement as part of an annual event 

 is unknown. 



Recaptures of fish released in the Jupiter region 

 (2674 fish tagged; 207 returned) were concentrated in 

 the SEFL and FK subareas (Fig. 5a-b). The temporal 

 return pattern from SEFL (N 127; Fig. 5a) was not 

 well defined; fish were returned in all months (most 

 during May and June), although not in every year. The 

 lack of a seasonal return pattern may be indicative of 

 a year-round resident population of king mackerel in 

 this subarea. An annual, cyclical trend for returns in 

 the FK (N 25) was noted during winter months, with 

 the magnitude of this trend decreasing over a 3-year 

 recapture period (Fig. 5b). 



King mackerel released from the Florida Keys region 

 (2594 tagged; 251 returned) were recaptured often 

 enough to allow a description of temporal return pat- 

 terns in four subareas (Figs. 6a-d). Fish were recap- 

 tured in the SEFL subarea (N 34) from July through 

 September, as well as from December through March 

 (Fig. 6a). Recaptures in the Keys subarea (N 166) sug- 

 gested an annual trend of returns during February and 



MAY SEP JAN MAY SEP JAN MAY SEP JAN WAY SEP 



Figure 5 



Monthly return percentage of king mackerel released from 

 Jupiter region and recaptured in the (a) southeastern Florida 

 (SEFL) and (b) Florida Keys (FK) subareas, using a continuous 

 time-scale representative of relative time of freedom. Returns 

 begin with May of year 1 . 



March, with numbers of recaptures steadily declining 

 from Year 1 through Year 4 (Fig. 6b). A bimodal trend 

 similar to that noted for fish released from the Ft. 

 Pierce region (Fig. 4c) was also found for fish released 

 from the Florida Keys region and recaptured in NEG 

 waters (N 20; Fig. 6c). King mackerel returns were first 

 reported during May and June from the NEG subarea. 

 An increase in the frequency of tag returns from the 

 NWG subarea (N 17) was then noted from June 

 through August (Fig. 6d). King mackerel returned 

 eastward to the NEG during August and September. 

 These observations provide additional support for the 

 possibility that king mackerel move annually through 

 southeastern Florida and Gulf of Mexico waters. 



Spatial patterns of movement 



King mackerel exhibited different patterns in relative 

 magnitude and directionality as they moved away from 

 their release regions. Of fish recaptured from releases 

 from the South Carolina region, 54.3% (A^ 25) moved 

 more than 100km. None of these fish were reported 

 farther north (Atlantic-ward) than North Carolina 

 (450 km), whereas 78.6% of those moving Gulf-ward 

 moved at least 650 km to southeastern Florida waters 

 (Fig. 7a). There was no significant difference (x 2 0.36, 

 0.50<P<0.75) in the king mackerels' direction of move- 

 ment away from the South Carolina region: 44.0% 

 (N 11) moved Atlantic-ward and 56.0% (N 14) moved 

 Gulf- ward. 



