Changes between Version 1 and Version 2 of EwEugEcospaceParameters


Ignore:
Timestamp:
2010-11-23 09:25:41 (8 years ago)
Author:
shermanl
Comment:

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  • EwEugEcospaceParameters

    v1 v2  
    1212'''''Habitat-adjusted biomasses''''' 
    1313 
    14 Distributes the entire Ecopath mean biomass for each pool into just those cells that are suitable for the organism, i.e., concentrates the overall mean biomass into those map cells where the biomass is actually found. For example, a creature with overall Ecopath mean biomass of 10 t/km² would be assigned a biomass of 100 t/km² in suitable cells, if just 10% of the cells are assigned a habitat type suitable for it. In this second option, predation vulnerabilities, predator search rates, and primary producer P/B vs B parameters are adjusted to reflect the new, localized ‘mean’ biomasses expected in habitat types where animals actually are abundant. 
     14Distributes the entire Ecopath mean biomass for each pool into just those cells that are suitable for the organism, i.e., concentrates the overall mean biomass into those map cells where the biomass is actually found. For example, a creature with overall Ecopath mean biomass of 10 t/km² would be assigned a biomass of 100 t/km² in suitable cells, if just 10% of the cells are assigned a habitat type suitable for it. In this second option, predation vulnerabilities, predator search rates, and primary producer P/B vs B parameters are adjusted to reflect the new, localized 'mean' biomasses expected in habitat types where animals actually are abundant. 
    1515 
    1616See [wiki:EwEugAssignHabitats Assign habitats] for further details on setting suitable habitats. 
     
    5656'''Predict effort''' 
    5757 
    58 Ecospace can be used to predict distribution of fishing effort over space for each of the fleets. Fishing effort is assigned to spatial cells through a ‘gravity model’, wherein effort is proportional to the net benefits gained from exploiting a given cell. 
     58Ecospace can be used to predict distribution of fishing effort over space for each of the fleets. Fishing effort is assigned to spatial cells through a 'gravity model', wherein effort is proportional to the net benefits gained from exploiting a given cell. 
    5959 
    6060In the simple case that all exploited group have the same economic value (default = 1 monetary unit per tonne), and that all cells require the same sailing cost (default), fishing effort will be assigned to the (water) cells of the base map in proportion to their fishable biomass. Thus, for example, fishing effort will tend to concentrate at the edges of protected areas – one reason, incidentally, why these edges should be as short as possible.