AGE AND GROWTH OF KING MACKEREL, SCOMBEROMORUS CAVALLA, 

 FROM THE ATLANTIC COAST OF THE UNITED STATES' 



Mark R. Collins, David J. Schmidt, C. Wayne Waltz, and 

 James L. Pickney^ 



ABSTRACT 



Whole sagittae from 683 and sectioned sagittae from 773 "adult" (age > ; 437-1,310 mm FL), and 

 lapilli from 29 larval (2-7 mm SL) and 69 young-of-the-year (79-320 mm FL) king mackerel, were ex- 

 amined. All fish were from waters off the Atlantic coast of the southeastern United States (Cape 

 Canaveral, Florida to Cape Fear, North Carolina). Back-calculated lengths at ages and von Bertalanffy 

 growth equations were calculated from both whole and sectioned sagittae. Ages determined from sec- 

 tioned sagittae were significantly greater than ages determined from whole sagittae, and the magnitude 

 of the difference increased with age (from sections). Rings on sectioned sagittae are considered to be 

 true annual increments, forming during June-September. There was no clear pattern to ring formation 

 on whole otoliths. The oldest fish examined was age 21. The daily nature of rings on lapilli of age king 

 mackerel was not validated, but if the marks are formed daily they suggest growth rates of approx- 

 imately 0.47 mm/d for early larvae and 2.9 mm/d for fish 1-3 months of age. 



The king mackerel, Scomberomorus cavalla, is a 

 migratory pelagic scombrid occurring in coastal 

 waters of the western Atlantic from Massachusetts 

 to Brazil and throughout the Gulf of Mexico (Col- 

 lette and Russo 1984). In the United States, this fish 

 is highly sought by both commercial and recreational 

 fishermen from North Carolina to Texas (Manooch 

 1979; Trent et al. 1983). Decreased abundance in 

 part of its range has lead to the establishment of 

 landings quotas and limits.^ Tagging studies indicate 

 that king mackerel from the Atlantic coast and those 

 from the Gulf of Mexico form separate migratory 

 groups, with some overlap and mixing in the waters 

 of southern Florida." Biological studies in each 

 geographic area are essential due to the importance 

 of the species, possible reproductive isolation of the 

 groups, and the potential for group-specific life 

 history traits. Considerable research effort has been 

 directed toward king mackerel in the Gulf of Mex- 

 ico, but fish from the Atlantic coast of the United 

 States, especially north of Florida, have received 

 little attention. Beaumariage (1973) utilized fish 



'Contribution No. 265 of the South Carolina Wildlife and Marine 

 Resources Department, Charleston, SC 29412. 



^South Carolina Wildlife and Marine Resources Department, 

 Marine Resources Research Institute, P.O. Box 12559. Charleston, 

 SC 29412. 



'South Atlantic Fishery Management Council, Charleston, SC. 

 News release. 7 July 1987. 



'Powers, J. E.,andP. Eldridge. 1983. Assessment of Gulf of 

 Mexico and south Atlantic king mackerel. Unpubl. manuscr.. 24 

 p. Southeast Fisheries Center. National Marine Fisheries Service, 

 NOAA, Miami, FL 33149. 



Manuscript accepted September 1988. 

 Fishery Bulletin, U.S. 87:49-61. 



from both coasts of Florida, but the only sample he 

 had from northeastern Florida was combined with 

 the rest of his data. Similarly, Johnson et al. (1983) 

 sampled fish from North Carolina and South Caro- 

 lina, but they were pooled with larger samples from 

 the Gulf of Mexico. A more recent study (Manooch 

 et al. 1987) utilized only Gulf of Mexico fish. Thus, 

 there are no previous studies of Atlantic group king 

 mackerel on which to base management. 



Despite evidence that otolith sections may give 

 more accurate ages than whole otoliths in long-lived 

 species (Beamish 1979), major studies of king mack- 

 erel age and growth have been based principally on 

 data derived from whole otoliths (Beaumariage 

 1973; Johnson et al. 1983; Manooch et al. 1987). Ade- 

 quate validation of the use of whole sagittae has 

 apparently been achieved in at least one of these 

 investigations (Manooch et al. 1987), but we en- 

 countered difficulties in the interpretation of whole 

 otoliths while using similar methods in the present 

 study. This report describes age and growth of king 

 mackerel from the Atlantic coast of the southeast 

 United States, compares results from whole and sec- 

 tioned otoliths, and describes presumed daily growth 

 of larval and young-of-the-year (YOY) king mack- 

 erel from the same geographic area. 



METHODS 



King mackerel were collected along the Atlantic 

 coast of the southeastern United States (lat 29° to 



49 



