Overexploitation

Overexploitation of natural resources — through unsustainable hunting, fishing, or extracting raw material — has serious implications for biodiversity. Besides reducing the number of species, it also diminishes diversity within the genetic pool. Decreasing species abundance impacts more than just the individual species: it disrupts the interaction between  species in the ecosystem.

Overexploitation has resulted in the extinction of many species and the loss of genetic diversity within others. Even seemingly infinite populations are vulnerable to uncontrolled human use. The now extinct Passenger Pigeon was once the most populous bird on the planet, and a population of millions of American Buffalo was reduced to less than 1,000 head within a century. Many types of whales, seals, bison, birds and fish have been pushed to the brink of extinction, and only intervention has prevented it. It's rare for an animal to return to its historical abundance once it has experienced an abrupt decline.

Overfishing is leading to a dramatic population loss of large, predatory fish such as tuna, marlin, swordfish and cod that we prize for food. One study of these large fish indicates that their populations have declined by 90 per cent since the 1950s - and populations in the 1950s were already depleted. The Atlantic cod fishery, once the most productive in the world, is now estimated to have less than one per cent of its original capacity. This radical drop has created a devastating social crisis. The social costs of overexploitation are high, leaving communities with little alternatives for employment and possibly even food.

Sustainable use of natural resources is essential to ensuring that future generations have the same quality of life that we have today. Sustainability within a Generation, a publication of the David Suzuki Foundation, provides a blueprint for a sustainable Canadian economy.