Factors of the Extinction Crisis
Overexploitation: hunting/harvest by humans exceed natural reproduction rate of stocks ? decrease in stock size
- commercial whaling: low reproductive rate of whales
- timber: tropical woods (mahogany) overused; clear-cut of tropical forests inhibits re-growth of tropical woods
- fisheries: too many boats for too few fish (e.g. cod, sword fish); boats catch more fish than are reproduced; to keep fisheries profitable, catch efforts were increased, increasing the over-exploitation of decreased stocks; landed sword fish decreased in individual size, caught individuals are now so small and young that they had no chance to reproduce at all yet
- fur: furious hunting of big cats, otter, chinchilla, etc. due to high market value and demand
- stupid things: elephants for arts, rhinos, seahorses for potency