A Model for estimation of fishing mortality; Parameter 

 estimation (F) in a population life history model for sea turtles 

 must be approached "piece meal," with initial emphasis on those 

 mortality rates that are most accessible to estimation; other 

 rates become the subject of informed speculation or are assigned 

 orders of magnitude derived from a consideration of the life 

 history, age structure, and longevity of the stock as a whole. 

 Fishing mortality parameters for the various life history 

 components and general comments pertinent to estimation of F 

 within these components are presented below. 



Parameter Estimation 



Fj Atj Egg harvesting mortality might be estimated 



in terms of the number of eggs harvested as a 

 proportion of the mean number of eggs present 

 during the season: i.e.. 



Number of eggs harvested/Mean number of eggs 

 seasonally on beach during 



nesting season 



FjiAtji Are hatchlings susceptible to harvest on the 



beach or in the littoral zone? (if not, set 



FiiAtii = 0) 



Fjii Atjjj and FyAty Included here are ' directed • fisheries on 



juvenile and adult turtles at sea, as well as 

 incidental deaths due to capture in fishing 

 gear. Estimates of number of deaths caused 

 by these two impacts should be made 

 separately, as well as estimates of the 

 population size of adults at sea, and these 

 adjusted for number of females using 

 available information on sex ratio. A rough 

 estimate of number of mature females at sea 

 might be: 



# of females = Number nesting X Mean time interval 

 annually between successive 



egg laying 



FjyAtiv Harvest of females onshore would be 



documented. A rough estimate of mortality 

 might be: 



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