Conservation

· Conservation = protecting and managing species, populations, habitats and ecosystems to reduce extinction risk.
· Main exam focus: why species become extinct, why biodiversity should be maintained, and how endangered species are conserved.
· Conservation can be in situ = within natural habitats, or ex situ = outside natural habitats.
· Examples of conservation strategies include zoos, botanic gardens, conserved areas, frozen zoos, seed banks, assisted reproduction, control of invasive alien species, IUCN and CITES.

Causes of extinction

· Extinction = when a species no longer exists anywhere on Earth.
· Climate change can alter temperature, rainfall, sea level and habitat conditions, so species may no longer be adapted to survive or reproduce.
· Competition can reduce access to food, light, space, mates or nesting sites; weaker competitors may decline.
· Hunting by humans can reduce population size below a sustainable level, especially if individuals are killed faster than they reproduce.
· Degradation and loss of habitats reduce available resources, breeding sites and shelter.
· Habitat loss can cause fragmentation, isolating small populations and increasing risk of inbreeding, genetic drift and local extinction.
· Small populations are especially vulnerable because random events can remove a large proportion of individuals.

Habitat fragmentation reduces continuous habitat into smaller isolated areas. This can separate populations, reduce breeding opportunities and increase extinction risk. It links directly to habitat degradation and loss as a cause of extinction. Source

Why maintain biodiversity?

· Biodiversity = variety of life, including ecosystem diversity, species diversity and genetic diversity.
· Maintaining biodiversity helps preserve stable ecosystems and reduces the risk of ecosystem collapse.
· Genetic diversity gives populations a better chance of adapting to changing conditions, such as climate change or disease.
· Biodiversity provides resources for humans, such as food, medicines, raw materials and crop wild relatives for breeding programmes.
· Biodiversity supports important ecosystem services, including pollination, nutrient cycling, soil formation, water purification and carbon storage.
· Many species also have ethical, aesthetic, cultural, scientific and educational value.

In situ conservation: conserved areas

· In situ conservation protects species in their natural habitat.
· Conserved areas include national parks and marine parks.
· These areas protect habitats from activities such as deforestation, overfishing, pollution, development and excessive hunting.
· Conserved areas can maintain whole ecosystems, not just single species.
· They allow species to continue natural behaviours, ecological interactions and natural selection.
· Limitations: may need active management, monitoring, law enforcement and control of invasive species.

Ex situ conservation: zoos and botanic gardens

· Ex situ conservation protects endangered species outside their natural habitat.
· Zoos help conserve endangered animals by using captive breeding programmes.
· Zoos can maintain populations, protect individuals from hunting or habitat loss, and support reintroduction into the wild.
· Zoos also provide education, research and funding for conservation projects.
· Botanic gardens conserve endangered plants by growing, propagating and storing living plant collections.
· Botanic gardens can maintain rare plants, support research and provide material for reintroduction or habitat restoration.
· Limitations of ex situ conservation: small captive populations may have reduced genetic diversity, and reintroduced organisms may struggle to survive in the wild.

Frozen zoos and seed banks

· Frozen zoos store genetic material from animals, such as sperm, eggs, embryos, tissue samples or cells, at very low temperatures.
· Frozen zoos help preserve genetic diversity for future breeding or assisted reproduction.
· They are useful when a species has very few surviving individuals.
· Seed banks store seeds from plant species under controlled conditions, usually with low temperature and low moisture.
· Seed banks conserve plant genetic diversity and provide seeds for future restoration, breeding or reintroduction.
· Seed banks are especially useful because seeds are often small, easy to store and can remain viable for long periods.

Seed banks store seeds under controlled conditions to preserve plant genetic diversity. This provides a backup if wild populations decline or become extinct. It is an important ex situ conservation method for endangered plants. Source

Assisted reproduction in endangered mammals

· Assisted reproduction is used when endangered mammals have low reproductive success or very small populations.
· IVF = in vitro fertilisation, where eggs are fertilised by sperm outside the body to form embryos.
· Embryo transfer = embryo produced by IVF or from a donor female is placed into the uterus of a female.
· Surrogacy = a female, sometimes of a closely related species, carries and gives birth to the offspring.
· These methods can increase the number of offspring from valuable individuals.
· They can help maintain or increase genetic diversity in endangered populations.
· Frozen gametes or embryos from frozen zoos can be used in assisted reproduction.

IVF involves fertilising an egg outside the body to produce an embryo. In conservation, IVF can help endangered mammals reproduce when natural breeding is unsuccessful. The embryo can then be transferred to a female or surrogate. Source

Controlling invasive alien species

· Invasive alien species = non-native species introduced into an ecosystem that spread and cause harm.
· They may become successful because they have few natural predators, parasites or diseases in the new area.
· They can outcompete native species for food, space, light, water or breeding sites.
· They may prey on native species, introduce disease, alter habitats or disrupt food webs.
· Controlling invasive alien species helps protect native biodiversity and reduce extinction risk.
· Control methods may include prevention, monitoring, physical removal, chemical control or biological control, depending on the species and ecosystem.
· Exam answers should link invasive species to competition, habitat change, reduced native population size and loss of biodiversity.

IUCN and CITES

· IUCN = International Union for Conservation of Nature.
· The IUCN assesses extinction risk and publishes the IUCN Red List.
· The Red List helps identify species needing conservation action and classifies species by threat level.
· Key threat categories include Vulnerable, Endangered and Critically Endangered.
· CITES = Convention on International Trade in Endangered Species of Wild Fauna and Flora.
· CITES regulates international trade in endangered plants and animals.
· Its role is to ensure trade does not threaten the survival of wild species.
· Exam answers should distinguish IUCN as mainly linked to assessment and monitoring, while CITES is linked to control of international trade.

The IUCN Red List classifies species according to extinction risk. This helps governments and conservation organisations prioritise species for protection. The highest-risk living categories include Vulnerable, Endangered and Critically Endangered. Source

Exam technique: high-scoring conservation answers

· Always link conservation methods to reducing extinction risk or maintaining biodiversity.
· For extinction causes, explain the biological consequence: reduced population size, reduced reproductive success, reduced genetic diversity or increased competition.
· For zoos, botanic gardens, seed banks and frozen zoos, state whether the method is in situ or ex situ.
· For assisted reproduction, use the correct sequence: IVF → embryo → embryo transfer → surrogate pregnancy.
· For organisations, remember: IUCN = Red List / extinction risk assessment; CITES = international trade control.