Human Impact on the environment

Threats to Biodiversity

• Natural Selection → genetic mutation gives one animal an advantage over another.

• Predators can wipe out whole populations.

• Environmental Change→ Asteroid.

• Disease.

• Human Activity→ Destruction of habitats, change in land use.

• Overharvesting → Overhunting, Timber.

• Pollution → Global to local scale, change habitat ot land, reduction of air quality.

• Introduced and domestic species → Invasive species with no natural predators carriers of disease, resistant ‘super-pests’ e.g MRSA.

Habitat Loss

• Deforestation → Increases CO2, Soil erosion, Overharvesting, Soya and Beef in Amazon, forcing out indigenous people.

• Solutions to deforestation- Bans, Sustainable management, Selective cutting, Reforestation.

• Loss of fungal connection- Fungus communicates with trees.

• Why should we conserve? -Aesthetic, Biodiversity, Climate stability, Future generations, Cultural preservation, Soil conservation.

Pollution

• PCBs (Polychlorinated Biphenyls)

• Manmade organic chemicals used in electrical equipment, often contaminated with carcinogens, are now widely banned but still in the environment due to bioaccumulation and biomagnification.

Overfishing

• ‘By-catch’-non target organisms caught when fishing.

• Drift nets can kill whales,

• Crabs can get caught in shrimp nets,

• Albatross are caught in pelagic long lines.

• ‘Ghost-Fishing - Fishing gear is lost in the ocean and subsequently continues to catch and kill marine organisms.

• ‘Catch quota’- Limits the total weight of fish caught.

• ‘Closed Fishing Seasons’ - Limits the size of nets, engines and boats.

• ‘No-take Zones’ - Complete fishing ban in an area so marine life can go undisturbed.

• Aquaculture- Fish Farming

• Fish are bread- Sports fishing, carp, trout, salmon.

• This can cause problems such as pollution, pests, genetic pollution, Bacterial decomposition and pesticide resistance.

Conservation

• Conservation - The management of organisms and ecosystems of the landscape to enable protection, enhancement or restoration.

Rationale for conservation

• Gene pool

• Medicines

• Biological Control

• Aesthetic reasons

• Economic Benefit

• Educational Reasons

• Moral & Ethical Reasons

Methods of conservation

• Legal Protection (CITES)

• Designations and Environmental Schemes

• Captive Breeding

• Habitat Management

Planetary Boundaries

• The limits between which global systems must operate to prevent abrupt and irreversible environmental change.