APPELDOORN: MORTALITY IN QUEEN CONCHS 



Figure 2. — Posterior view of adult Strombus gigas with numbered tag tied around the shell 



spire. 



mortality, emigration, and recruitment can be 

 significant between sampling periods. The as- 

 sumptions of the method and their relation to the 

 present sampling design are presented in the Dis- 



cussion. 



RESULTS 



Over 2,000 individual queen conchs were 

 tagged, spanning a range from 9 cm to 28 cm in 

 length. Adult queen conchs averaged 24 cm in 



length and represented between 22% and 59% of 

 sample populations, varying due to fishing activ- 

 ity and juvenile recruitment. 



Tag return data are given in Tables 1 and 2 

 according to the methods in Seber (1982), with 

 the results of the analysis given in Table 3. At 

 any given time, roughly one-quarter of the popu- 

 lation in the study area was tagged (Table 3, col. 

 2). Note the effect of increasing the sampling area 

 at time 3 had on the estimate of abundance (A'^) at 

 that time and on the estimates of survival (S) and 



Table 1 . — Tabulation of the number of queen conchs caught in the /th sample last caught in the 

 /7th sample (after Seber 1982). ; and h designate sampling periods; n, = number of conchs 

 caught in the /th sample; R, = number of conchs released at the /th sample; r^ = total number of 

 conchs recaptured, last caught in the /7th sample; m, = number of conchs recaptured in the /th 

 sample. 



h 

 1 

 2 

 3 

 4 

 5 

 6 

 7 

 8 



42 



42 



46 



36 



88 



106 



65 



54 



65 



799 



