TRENT ET AL.: KING MACKEREL IN SOUTHEASTERN UNITED STATES 



TABLE 8. — Percentage of king mackerel caught within fork length intervals (mm) by gear, area, and year. 1 



1 Percent of fish caught by commercial snapper fishermen from Mississippi by length group in 1978 were: <699 mm. 1 .1; 700-799, 1 6.2. 800-899. 30 2, >899. 52 5. 



the legal size. A minimum size of 699 mm FL (27.5 in) 

 would have made significant portions (over 40%) of 

 the 1977 recreational catch in northwest Florida and 

 in North Carolina illegal. This minimum size of 699 

 mm FL would have made 17-36% of the commercial 

 hook- and- line catch and 7-14% of the gill net catch 

 illegal, depending on the year. 



DISCUSSION 



The seasonal distribution of adult king mackerel in 

 the coastal zone of the southeastern United States 

 can be inferred from catch data. These fish are 

 caught in abundance along the south Atlantic coast 

 (north Florida to North Carolina) in the spring and 

 fall, along the northeast and northwest segments of 

 the Gulf of Mexico in late spring, summer, and fall, 

 and off the south Florida and Louisiana coasts year- 

 round. Size and sex composition data indicate, 

 however, that fish found in these areas and times do 

 not belong to a homogeneous king mackerel popula- 

 tion (assuming that we are dealing with only one) and 

 should not be considered as such for management 

 purposes. To evaluate the impact of proposed 

 minimum size regulation and possibly to provide a 

 framework for managing minimum size, we have par- 

 titioned the U.S. portion of the North American king 

 mackerel population into four groups: 1) Florida win- 

 ter group; 2) the immmature group; 3) the spawning 

 group; and 4) Louisiana group. These groups are not 

 known to be stocks or genetic groups, but rather they 

 represent groups that can be identified in time, 

 space, or sexual maturity states. 



Florida Winter Group 



This group occurs along the east and west coasts of 

 the southern half of Florida, including the Florida 

 Keys during colder months (December-March), and 

 is thought to be sexually inactive during this period 

 (Beaumariage 1973; Finucane et aL 7 ). The group 

 includes all sizes of king mackerel known to exist in 

 the exploited populations. The abundance of 

 medium-sized king mackerel each winter is well 

 documented; several years of commercial hook-and- 

 line and gill net data show that about 90% of the king 

 mackerel landed by commercial fishermen in south 

 Florida are between 600 and 899 mm FL. Large king 

 mackerel (1,000-1,500 mm FL) caught by rec- 

 reational fishermen from the south Florida area have 

 been reported by Beardsley and Richards (1970). A 

 90-lb (about 1 ,800 mm FL) king mackerel was caught 

 in south Florida in February 1976 (Anonymous 

 1976). The Florida winter group becomes re- 

 organized, through movement and migration during 

 spring, summer, and fall, into the more northerly 

 immature and spawning groups. 



The Immature Group 



Members of this group include the small (300-600 

 mm FL) king mackerel from the Florida winter group 



finucane, J. H., L. A. Collins, H. A. Brusher, and C. H. Salo- 

 man. 1983. Reproduction ofking mackerel from the Gulf of Mexico 

 and south Atlantic. UnpubL manuscr., 15 p. Southeast Fish. Cen- 

 ter Panama Citv I ■•atorv. National Marine Fisheries Service, 

 NOAA, FL 32407. 



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