Conservation Off Site

Sometimes a species is so endangered that protecting its habitat is not enough — it needs urgent, hands-on care. In such cases we turn to ex situ (off-site) conservation, in which threatened animals and plants are taken out of their natural habitat and placed in a special protected setting where they can be looked after closely.

The familiar homes of ex situ conservation are zoological parks, botanical gardens and wildlife safari parks. Their value goes beyond display: there are many animals that have become extinct in the wild but still survive because they continue to be maintained in zoological parks. For such species, the off-site setting is quite literally the last line of defence.

Advanced Ex Situ Techniques

In recent years, ex situ conservation has moved well beyond simply keeping threatened species in enclosures. Modern biotechnology now allows us to preserve life at the level of cells and seeds.

The gametes of threatened species can be preserved in a viable and fertile condition for long periods using cryopreservation (storage at very low temperature). Eggs can be fertilised in vitro, so offspring can be produced even when natural breeding fails. Plants can be propagated by tissue culture methods, multiplying rare plants rapidly from small pieces of tissue. And the seeds of different genetic strains of commercially important plants can be stored for long periods in seed banks, safeguarding valuable genetic diversity for the future.

Conservation Is a Global Responsibility

Biodiversity knows no political boundaries, so its conservation is a collective responsibility of all nations rather than the concern of any one country alone. This recognition has driven a series of international agreements.

The historic Convention on Biological Diversity — popularly called 'The Earth Summit' — was held in Rio de Janeiro in 1992. It called upon all nations to take appropriate measures for the conservation of biodiversity and the sustainable use of its benefits, so that today's use does not rob future generations.

From Rio to Johannesburg

The Earth Summit set the direction, and a later meeting turned it into a firm target. In a follow-up to Rio, the World Summit on Sustainable Development was held in 2002 in Johannesburg, South Africa.

At Johannesburg, 190 countries pledged their commitment to achieve, by 2010, a significant reduction in the current rate of biodiversity loss at global, regional and local levels. Together these two summits show how conservation has grown from a local effort into a coordinated worldwide commitment — combining, in practice, both the in situ protection of habitats and the ex situ rescue of threatened species.

Quick Recap

  • Ex situ (off-site) conservation removes threatened species from their natural habitat and cares for them in special settings: zoological parks, botanical gardens and wildlife safari parks.
  • Some species extinct in the wild survive only in zoos.
  • Advanced methods: cryopreservation of gametes, in vitro fertilisation of eggs, tissue culture propagation of plants, and storage of seeds of commercial strains in seed banks.
  • Biodiversity crosses political boundaries, so conservation is a collective global responsibility.
  • Convention on Biological Diversity ('The Earth Summit'), Rio de Janeiro, 1992 urged conservation and sustainable use; the World Summit on Sustainable Development (Johannesburg, 2002) saw 190 countries pledge to reduce biodiversity loss by 2010.

Solved Examples — Section 10

Q1. What is ex situ conservation?

Answer: An off-site approach in which threatened animals and plants are taken out of their natural habitat and placed in a special protected setting where they are given special care.

Q2. Name three settings used for ex situ conservation.

Answer: Zoological parks, botanical gardens and wildlife safari parks.

Q3. How can the gametes of a threatened species be preserved?

Answer: By cryopreservation, which keeps them viable and fertile for long periods.

Q4. Name two advanced ex situ techniques besides cryopreservation.

Answer: In vitro fertilisation of eggs and tissue culture propagation of plants; seeds of commercial strains can also be stored in seed banks.

Q5. When and where was the Convention on Biological Diversity ('The Earth Summit') held, and what did it call for?

Answer: In Rio de Janeiro in 1992; it called on all nations to conserve biodiversity and use its benefits sustainably.

Q6. What did the 190 countries at the 2002 Johannesburg summit pledge?

Answer: To achieve, by 2010, a significant reduction in the current rate of biodiversity loss at global, regional and local levels.