Human Impacts

Acid Rain

Invasive Species An alien species is any species that has spread beyond its natural range into new locations as a result of human activity. An invasive alien species moves into a new habitat and takes over. They can cause harm to the environment, the economy or even human health. Some can arrive accidentally and some can arrive intentionally.

Effect on the Environment/ecosystems Competition Purple loosestrife compete with local plants for resources Predation Green crab prey on mussels, clams and other crabs Disease West Nile Virus – a recent epidemic in American Continents Parasitism Sea lamprey attach to side of fish, slowly eating away at the flesh

War Against Invasive Species Physical Control Biological Control Chemical Control

A PEST is an organism that people CONSIDER HARMFUL OR INCONVENIENT A PEST is an organism that people CONSIDER HARMFUL OR INCONVENIENT. Pesticides are chemicals designed to kill pests. Why Use? 1. Approximately 30% of Canada’s annual crop can be lost to pests, which means a staggering cost to consumers. 2. Diseases control - such as malaria in tropical areas can affect millions of people.

Pesticide Types a) First-Generation Pesticides – DEVELOPED FROM PLANTS THEMSELVES b) Second-Generation Pesticides – CHEMICALS MADE IN A LABORATORY

Bioaccumulation Pesticides containing chlorine such as ______ (dichlorodiphenyltrichloroethane) are SOLUBLE IN ____ BUT NOT IN _______. As a result, they can not be excreted in ______ or ______ causing them to ___________ IN THE _____ tissues of various bodies.

Although there is only a small amount of the toxin in each prey that is eaten, as the food chain continues MORE TOXIN BECOMES _______ AND _________________ IN THE TISSUES of the organisms at a high __________ level. These higher concentrations are now at a poisonous level, thus causing the top consumers to die.

Modern Chemical Pesticides Newer pesticides are ____________. Animals can remove them from their bodies by ____________. They are broken down in the soil (must be applied often) and operate like nerve gas that kills or weakens pest for predators. These can still be a problem as they can harm animals that the pesticide was not ____________ for and still can cause ____________________ in these organisms.

Endangered Species

Endangered Species Conservation of organisms begins when their population declines over time and the species is at risk. Levels of danger can be classified as: ______________________ – no longer exists in certain areas _____________________ – a species that faces extinction/extirpation

Conservation Conservation of ecosystems occurs in two ways: ___________ occurs when species are being conserved in their natural habitat whereas ___________ conserves species by removing them from natural habitats.