3.6 Human Impact on the Environment

what is conservation

the protection and preservation of natural habitats to maintain species

endangered

when a species is at risk of extinction

extinction

complete loss of a species

examples of conservation

seed banks

legislation

protecting habitats

reasons organisms become endangered or extinct

natural selection

loss of habitat

overhunting

competition

pollution

examples of habitiat destruction

deforestation

loss of hedgerows

examples of pollution

oil

PCBs

agricultural exploitation

intensive farming

use of chemical fertilisers and pesticides

ethical reasons for conservation

medical uses of organisms

resources needed for the future

why is it neccessary to conserve gene pools

some alleles provide advantages to prevent extinction

risk of reccessive diseases is reduced

maintains biodiversity

SSSI

site of special scientific interest

nature reserve

a protected area of importance

trade restriction

limits on the movemet of organisms, their parts or products for conservation purposes

CITES

convention on international trade in endangered species

2 main reasons for deforestation

use of timber for building

agriculture

consequences of deforestation

soil erosion

desertification

flooding

how can forests be managed so they are sustainable

coppicing

selective cutting

long rotation time

consequences of over fishing

depletes fish stocks

impacts food chains

loss of biodiversity

3 ways fishing is regulated

regulated mesh size and use of long lines

exclusion zones

legislation limiting size of fishing fleets

problems caused by fish farming

rapid spread of disease and parasites

pesticides bioaccumulate - reducing fertility

nitrogenous waste pollution leads to eutrophication

farmed fish are larger and outcompete wild fish for resources