BIOL 3130 Lecture 20: Lecture 20
27 Oct 2017
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Document Summary
3rd most important driver of freshwater fish extinction. Trophic cascades occur when predators in a food web suppress the abundance or alter the behaviour of their prey, thereby releasing the next lower trophic level from predation. Venisulian example: island predators removed, prey population exploded, plants decreased. Case study: fishing down marine food web switch resources: eat something you may not normally eat, less fussy on what we eat. Lobster- don t usually eat but cod and other more popular fish over- 1st thing you can get, unexpected increase in a certain population. 2nd trigger changes in reproductive performances, less resources, more room exploited so switch resources for population growth (max. sustainable yield)
