Human Impact on the environment

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.

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