| Summary: | This paper presents a discrete-time bio-economic model of Northern Atlantic bluefin tuna. The bluefin tuna is caught by several gears, targeting different age classes in different areas. To properly capture the dynamics of this species, an age-structured and multi-gear model was used. The model captures the dynamic interrelations between gears. In this way, the migrations are implicitly modelled, as gears can be associated with age classes and locations. Three cases are simulated and analysed: open-access, total allowable catch (TAC) and constant fishing effort. Two alternative links between the economic and biological parts of the model were used and it is shown that the simulation results are very sensitive io the functional form of the production function. For both functional relations there are substantial gains to be had by departing from a situation of open access to a regulated one.
|
|---|