biodiversity loss by over-harvesting

Human activity causes biodiversity loss – one of the ways that we do this is by targeting particular species and taking too many of them for that species to have sufficient numbers to continue.


In the modern world this applies particularly to marine animals: many whale species were nearly exterminated in the mid-twentieth century, cod fish on the Grand Banks in the North Atlantic Ocean were driven to a collapse in the second half of the twentieth century from which they have never recovered, in the northern Pacific Ocean blue-fin tuna are currently reduced less than ten percent of their natural population level.     


Direct targeting of particular species also applies to large land animals that have not been very susceptible to human predation in the past, until modern weapon technology was developed.  These species are usually long lived and are slow to breed as so are very susceptible to a sudden increase in the effectiveness of predation; elephants and rhinoceros are some such species.  

In the historic past dodos, passenger pigeons, Pinta Island tortoises, and moa  have all be exterminated by human predation.  In the prehistoric past, large animals, collectively called megafauna were arguably exterminated all over Earth as humanity spread out of Africa, and across all of the other continents. 


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biodiversity loss


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