Ecosystem models are becoming increasingly important as pressure from fisheries and ecosystem-based fisheries management becomes more widely used. Trophic webs form the basis of ecosystem models and ecosystem-specific dietary information is crucial for model performance. This is particularly the case if model predictions are used in management . The Tasmanian live fish fishery for banded morwong was used as a case study to the importance of trophic information, model simplification and aggregation error on model results. Dietary analysis of 6 commonly captured reef fish was undertaken. Significant overlap was found between blue throat wrasse Notolabrus tetricus and purple wrasse . fucicola, and banded morwong Cheilodactylus spectabilis and bastard trumpeter Latridopsis . Marblefish Aplodactylus arctidens and long-snouted boarfish Pentaceropsis recurvirostris significantly different diets from other species studied. Using this information, a detailed qualitative was produced and then simplified through the aggregation of variables. Variables were using 3 methods: Euclidean distance, Bray-Curtis similarity, and regular equivalence for in 3 simplified models. Variable aggregation is undertaken in many studies and may create error. Each aggregation method produced a different proportion of incorrect model as a result of aggregation error. The model simplified using regular equivalence produced least aggregation error and a web structure aligned with the dietary analysis. More widespread of these methods in fisheries management should be considered.
No takes yet. Share an insight, caveat, or question.
Metcalf et al. (2008) studied this question.