BIOL 2060 Lecture Notes - Lecture 17: Inbreeding Depression, Population Ecology, Desert Bighorn Sheep
26 Feb 2018
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Document Summary
Low or declining density makes populations vulnerable to extinction: eg. North atlantic right whales in bay of fundy were protected in 1936, now ~60 individuals left: slow increase to ~450 globally. Fisherman were suggesting to look for "ghost gear" (nets floating in ocean not in use, old machinery floating around: eg. Whooping cranes in wood buffalo national park near extinction in 1941, ~15, slow increase to. Cod in atlantic canada, fishery collapsed in 1992-93, ~98-99% decline, fishery moratorium (stop fishing) but overestimates/mismanagement allowed fishing again: endangered again, eg. Been some recovery in pinnipeds, otters, whales, coastal birds, ground fish through recovery efforts: a lot of predators (lynx, bears, wolves) have been contracted to smaller zone and have to find new places to live. Inherent problems of small populations: allee effect (can"t find someone to reproduce with, plus factors increasing likelihood of extinction in small populations.
