Reasons to Conserve Biodiversity

  • Ecosystem Services - benefits to humans, like maintaining atmospheric composition, biogochemical cycles, soil maintenance
  • Materials - raw materials like timber for buildings and structures, etc
  • Food - many species of wild crops have higher salt tolerance and can withstand drought, which could prove useful in the future
  • Keystone Species - without these important species, the ecosystem would not function well
  • Money - through ecotourism, more money can be made than through poaching and trade
  • Biomimetics - using species' adaptations in the human world, eg in architecture and design
  • Research - eg squid nerve cells are very large, so easier to study than human nerve cells
  • Medicine - over half of the USA's medicines are derived from natural sources
  • Genetic Resources - though controversial, there is potential for genetic engineering to help humans
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Human Threats to Biodiversity

Biggest causes of biodiversity loss are fragmentation/loss of habitat due to agriculture, food production and extraction of fossil fuels

  • FOOD - over-exploitation, especially of fish like Blue Fin Tuna
  • INVASIVE SPECIES - humans have both intentionally and accidentally introduced new species, posing threats to existing ones
  • TRADITIONS - some indigenous tribes hunt for bushmeat, and tradtional Chinese medicine involves tigers
  • AGRICULTURE - ploughing of grassland, and increase in monoculture crops
  • PESTICIDES - can kills or fatally deform non-target species like bees or the Mauritius Kestrel
  • ABIOTIC CHANGES - includes changes in dissolved oxygen levels, pH, water availability, temperature, and physical damage due to human processes
  • HYBRIDISATION - closely related species breed and produce fertile offspring - not natural
  • HABITAT DESTRUCTION - deforestation, ploughing grassland, reservoir creation, mineral extractio, urbanisation, farming, trawling
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Visual - Threats to Biodiversity

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Endangered Species: Example


Endangered, with a severely fragmented and declining population


  • habitat loss as a result of clearing of land for non-timber purposes (agriculture) and wood plantations 
  • poaching - hunted and trapped for local food as well as international jewellery and clothing
  • poaching - specifically for ivory can distort the adult sex ratios, making breeding difficult
  • human expansion - fragments the population as human settlement grows (urbanisation)
  • human population growth - Asian elephants live in the most densely human populated region in the world, growing annually 1-3%
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Conservation: Legislation

Case Study: 1981, UK Wildlife and Countryside Act

Main Features

  • designation of protected areas (eg Ramsar sites, SSSIs, Marine Conservation Zones, local nature reserves)
  • protection of most animals, as well as many birds and their nests
  • control of selected activities
  • prohibition of uprooting wild plants

Management Strategies

  • catchment sensitive farming, reducing fertiliser use
  • phosphate ********* at water treatment plants to prevent algae blooms 
  • biomanipulation - deliberate alteration of ecosystem by adding/removing species
  • removal of invasive species
  • targeted species recovery of particular endemic species
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Designated Protected Areas

Marine Conservation Zones (MCZ)

  • Areas which protect a range of nationally important, rare or threatened species and habitats
  • To become an MCZ there must be evidence of what habitats are present, species found there, and how the site is used

Local Nature Reserves

  • Sites usually protected for 21 years and owned locally
  • Regulations cover the countryside code, footpaths and sometimes fences

Ramsar Sites

  • Any wetland representing a rare area - e.g: lakes, aquifers, marshland
  • Important for zoology and conserves biological character

SSSI = Site of Special Scientific Interest

  • Two types - biological and geographical; law prevents damage of sites and landowners require consent for things
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Regulation of Sustainable Exploitation

A number of organisations aim to sustainably use/exploit natural resources

International Whaling Commission (IWC)

  • Regulates and manages whaling, only allowing certain places to whale for particular reasons (like science/research-based, and for traditional aboriginal purposes)
  • Actions include protection of species, designation of sanctuaries, quotas set, research done

European Union Common Fisheries Policy (EU CFP)

  • Regulates fishing in the EU, aims for environmentally, economically and socially sustainable fishing and aquaculture
  • Regulations include catch quotas, ban on discarding bycatch, fish size limits and net mesh size limits to allow smaller fish to escape and grow

International Tropical Timber Organisation (ITTO)

  • Aims to encourage sustainable forestry in tropical areas and management of rainforests
  • success has been limited - goal of absolute sustainble timber by 2000 has not been reached
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Assessing Species

IUCN = International Union for the Conservation of Nature

Responsible for the gathering of data on biodiversity and implementing nature-based solutions for conservation challenges

Red List = used by the IUCN to evaluate species, with seven categories. Selected taxa are reassessed annually

  • Red list is based on factors like population decline over the last decade, area of habitat, number of areas found, number of mature adults, overall possibility of extinction

Species for Categorisation - those with significant habitat threat/loss, those with poor population dispersal, keystone and flagship species, EDGE species and endemic species

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Visual - Species on the Redlist

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Keystone Species: Example

ASIAN ELEPHANT - ecosystem engineers

- elephants spread the seeds of many species of tree through their dung, which is very effective   as they walk many miles a day

- their dung acts as a fertiliser as it is nutrient-rich

- creation of clearings in the forest helps to enable plant growth as the sunlight can filter down

- elephants dig wells for water, making water available for other species

- in walking every day through the forest, elephants maintain the forest paths for other animals   to use

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Conservation Challenges to Zoos

  • Lack of genetic diversity of a critically endangered species due to a small gene pool - breeding likely to cause disadvantageous genetic defects
  • Increasing the global population of a species through breeding programmes can take too long - the habitat is lost (eg: by deforestation)
  • Release can be hard, as the animals can be used to humans - vulnerable to poaching
  • Expensive procedure
  • Loss of natural behaviour - particularly with hand-rearing

Problems of Released Individuals

- recognising poisonous food and sourcing safe food

- recognising and avoiding predators

- acceptance into the wild community

- developing hunting skills

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Increasing Captive Breeding Success

- Use of stud books: improves genetic diversity in the captive population by pairing members with different genes

- Cryopreservation: freezing sperm, eggs, and embryos for future use (useful if there's a lack of individuals of breeding age at the present time)

- Artificial Insemination: inserting collected sperm into female, useful to avoid issues with transportation of animals, dangerous mating and partners not accpeting each other

- Embryo Transfer: use of a surrogate mother from a closely related species (eg: Sumatran rhino embryo in a black rhino) useful when the number of mature females is few or gestation period is long

- Micro-Propagation: tissue culture from a single plant (asexual reproduction)

- Cloning: potential for wild animals but not been done yet. Deep-frozen stem cells could be used following the death of the living population. Could be used to maintain a pure gene pool in plant species

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Hard VS Soft Release

KEY - Hard release has little or no post release support, whereas soft release involves support like the gradual enlargement of habitat and the provision of food while the species learns to hunt

Hard - translocation

  • Occurs only when a species can immediately be independent (hunt, mate without human intervention)
  • Happens with birds, insects and elephant families

Soft - from captivity to wild

1) produce cubs/litter which then go to reserve and mate as adults

2) cubs fed by drones to reduce human intervention

3) next set of cubs live in enclosures with prey (develops natural skills)

4) release into wild

Whole process can take over 25 years to see whether it's successful

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Conservation: Example


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In-Situ Conservation

In-situ conservation protects communities of species not just one targeted species, and may include habitat creation or restoration (rewilding).

Features of Successful New Habitats:

  • Large Area - can support a viable population and a larger biodiversity of species, as well as apex predators (frequently roaming species)
  • Round Shape - less surface area, so reduces the contact wth humans
  • Vegetation Age Structure - eg in wooded areas a varitation in tree age will result in clearings created, therefore light variations
  • Biological Corridors - link two otherwise isolated areas of one type of habitat: this can increase the gene pool, preventing inbreeding, and can reduce human conflict
  • Introduction/Ease of Colonisation
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Things to Consider for Habitat Creation

- space required for a viable population of the species targeted (eg a single tiger will roam up to 100km2)

- food webs and inter-species relationships (what the species all need to flourish)

- temperature (if it needs to be varied then water could be introduced, or shade made from trees)

- water requirement (does it need a lake? or is it adapted to naturally live in an area with low water abundancy?)

- abiotic factors like pH, water depth, light, in addition to temperature

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