Tuna Model
Wednesday, 26 August 2009 15:00

Tuna are highly specialized migrating species. They swim continuously to counterbalance their negative buoyancy, travelling hundreds of miles. This strategy has a high energy cost, forcing them to move in search of food and has resulted in morphological and physiological adaptations for thermoregulation and high oxygen extraction efficiency. Therefore, temperature and dissolved oxygen concentration affect tuna behavior significantly (Brill, 1994). Sea surface temperature and oxygen concentration have been used to define large-scale limits for potential tuna habitat (Barkley, Neill, & Gooding, 1978).  The tuna forage distribution might have also a major influence on tuna distribution. Surface tuna like skipjack and yellowfin tuna feed during daylight hours. Thus, water clarity is also likely to influence their distribution.

 

 

In SEAPODYM we have defined some indices playing an important role in the tuna spatial population dynamics. In general, physical and biogeochemical conditions influence tuna population dynamics through changes in spawning conditions, habitat suitability, and food resources distribution, thus inducing migration behavior, reproduction and mortality. Therefore, Environmental data are used in SEAPODYM to characterize the population habitat depending on tuna's thermal biochemical and forage preferences. There are four types of indices in the model:

 

More on the Tuna model: icon Tuna Model (116.33 kB)

 
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