Ch 55 – Conservation Biology

• Focus on loss of biodiversity, due to human activities

• Increased rates of extinction

Biodiversity

• 3 main levels:• 1) Genetic diversity

• 2) Species diversity

• 3) Ecosystem diversity

Human impact• Habitat Destruction:• 90% of world’s plant activity takes place where

people play a significant role• 38% of earth’s ice-free land has been been

cultivated for farming• Destroyed original forests in N. America &

Europe, deforestation of tropical rainforests• Use of fossil fuels has warmed atmosphere• Pollution affects oceans

Human impact• Overexploitation– Overfishing – California Sardines – harvested to brink of

extinction in early 1900’s– Collapse of orange roughy, Chilean sea bass, blue

fin tuna populations

Estimated that overfishing has reduced large fish populations to 10% of pre-industrial population

Introduced species

• – Kudzu in South -introduced for erosion control

•

• - Burmese python in Florida – exotic pets, now established in Everglades

• - Asian carp in Great Lakes• Aggressive, out compete native fish

Bioaccumulation

• Accumulation of substances (i.e. toxins, pesticides) in an organism

• We are surrounded by chemicals:• In personal products, furniture, food, etc.

• i.e. Phthalates – shampoo, soap, lotion– Can cause reproductive disorders

Biomagnification

• Poisoning of small consumers can be passed along the food chain to affect the consumers later on.