Fishing disturbances were modeled by changing the Ecopath base fishing effort in each Ecosim scenario. Hypothesis evaluation with Ecosim Ecosim was used for assessing the possible existence of ASSs at Lac la Biche and for describing the relationship between the size and nature of a change in fishing effort and the intensity of the ASS response.In all models, cormorants were included as a fishery to allow annual reductions in the cormorant population resulting from control activities, i. A representative example of the modeled ecosystem for each era showing pathways of energy flow between functional groups is included in Appendix 2 Figs. Where local data were not available, the contemporary models were parameterized using data or literature values from other systems.Main data sources and estimation methods for the models are described in McGregor a. The relationship between the number of breeding cormorants and the level of foraging activity in.Where parameter changes were needed to achieve mass balance, they were bounded by the range of values used in other contemporary models Input parameters for the cormorant-dominated models are mainly from unpublished field data from Lac la Biche collected between andas well as estimates from biologists with knowledge of the lake.
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