18.19 Protecting Endangered Species

Key Concepts

• Endangered Species: Species at high risk of extinction.
• Conservation Methods: Efforts to preserve biodiversity both in natural habitats (in-situ) and in controlled environments (ex-situ).

Conservation Methods

1. In-Situ Conservation

• Definition: Protecting species within their natural habitats.
• Goal: To preserve entire ecosystems, maintaining species interactions and natural behaviors.

A. National Parks and Protected Areas

• Purpose: Designated areas protected by government legislation to conserve biodiversity.
• Activities Restricted: Agriculture, industrial activities, hunting, and construction.
• Examples:
  • Yellowstone National Park (USA):
    • World’s first national park, established in 1872.
    • Home to endangered species like the bald eagle, grizzly bear, and grey wolf.
  • Galapagos Islands National Park (Ecuador):
    • Protects unique endemic species with restricted human access.
    • Marine reserve established to limit fishing, with invasive species control and captive breeding programs (e.g., Galapagos tortoises).
  • Amboseli National Park (Kenya):
    • Protects African wildlife like elephants, which are keystone species in the savannah ecosystem.

B. Marine Reserves

• Purpose: Protect marine ecosystems from overfishing, pollution, and habitat destruction.
• Examples:
  • Little Cayman Marine Reserve (Caribbean):
    • “No-take” reserve to protect endangered Nassau grouper spawning grounds.
  • Marine Reserves in New Zealand:
    • Resulted in increased fish biodiversity and enhanced fish catches in surrounding areas.

C. Importance of Proper Management in Protected Areas

• Local Involvement: Engaging local communities as park rangers, allowing limited use of resources, and sharing tourism revenue.
• Tourism: Revenue helps maintain parks and educates the public on conservation.
• Challenges: Lack of funding or political will can limit effective management, especially in developing countries.

2. Ex-Situ Conservation

• Definition: Conservation of species outside their natural habitats, often used when in-situ conservation is not viable.

A. Zoos

• Roles:
  • Education: Teach the public about endangered species and conservation efforts.
  • Research: Study animal behavior, genetics, breeding, and habitat needs.
  • Captive Breeding:
    • Breeding programs to increase populations of endangered species with the goal of reintroduction to the wild.
• Challenges in Captive Breeding:
  • Inbreeding: Reduced genetic diversity due to small populations.
    • Example: Cheetahs have low genetic diversity due to a historical bottleneck event.
  • Behavioral Challenges: Some animals struggle to adapt to captivity or do not learn essential survival skills, like predator avoidance.
  • Reintroduction Issues: Captive-bred animals may lack the skills needed for survival in the wild.
    • Examples:
      • Giant Panda: Despite over 300 pandas in captivity, none have been successfully reintroduced to the wild.
      • Golden Lion Tamarin: Reintroduced tamarins often lack necessary climbing and foraging skills.

B. Assisted Reproduction Techniques

• Purpose: Aid breeding in captivity, maintain genetic diversity, and address breeding challenges.
• Techniques:
  • Artificial Insemination (AI):
    • Semen collected and injected into a female’s uterus.
    • Useful for species where natural mating is challenging.
  • Embryo Transfer:
    • Embryos from an endangered species are transferred to surrogate mothers (often a related but non-endangered species).
    • Example: African antelope species using surrogate females for embryo transfers.
  • In Vitro Fertilisation (IVF):
    • Eggs are fertilized outside the body and embryos are cultured before being implanted into the mother or surrogates.
  • Sperm and Embryo Banks (Frozen Zoos):
    • Store genetic material (sperm, eggs, embryos) at very low temperatures (-196°C) for future breeding.
    • Example: San Diego Zoo’s Frozen Zoo holds genetic samples from many endangered species for future conservation use.

Botanic Gardens and Seed Banks

A. Botanic Gardens

• Roles:
  • Protection of Endangered Plants: Cultivating endangered plant species.
  • Research: Study plant reproduction, growth, and conservation methods.
  • Public Education: Raise awareness about plant diversity and ecological importance.
  • Reintroduction: Reintroduce plants to their natural habitats when possible.
  • Example: Sargent’s cherry palm cultivated at Fairchild Tropical Botanic Garden before reintroduction to Florida Keys.

B. Seed Banks

• Purpose: Store seeds to preserve genetic diversity and provide a backup for future agriculture and conservation efforts.
• Examples:
  • Millennium Seed Bank (UK):
    • Aim: Collect seeds from 25% of the world’s plant species.
    • Seeds stored at -20°C to ensure longevity.
  • Svalbard Global Seed Vault (Norway):
    • “Doomsday” seed bank in the Arctic, storing over 900,000 seed samples from around the world as a backup for national seed banks.
  • International Rice Institute (Philippines): Houses all rice varieties to safeguard crop diversity.
• Seed Storage Process:
  • Drying and Freezing: Seeds are dehydrated to ~5% water content and stored at -15 to -20°C to prevent ice crystal damage.
  • Germination Testing: Regular viability tests (every 5 years) to ensure stored seeds remain viable; if germination rates drop, seeds are replanted to produce fresh samples.
• Challenges with Seed Banks:
  • Recalcitrant Seeds: Some seeds (e.g., coconut, cocoa) cannot be dried and frozen. Solutions include growing live plants or maintaining tissue cultures.
  • Genetic Diversity: Limited samples in seed banks may not capture full genetic diversity.

Importance and Challenges of Conservation Methods

Benefits of In-Situ Conservation

• Ecosystem Preservation: Protects species within their natural habitats and ecological roles.
• Natural Behaviors: Allows species to interact naturally, maintaining behavioral traits.
• Ecosystem Services: Protected areas provide benefits like carbon sequestration, water purification, and pollination.

Challenges of Ex-Situ Conservation

• Captive Breeding Limitations: Some species don’t adapt well to captivity, and maintaining genetic diversity is challenging.
• Adaptation and Reintroduction: Captive-bred animals may lack survival skills needed in the wild.
• High Costs: Establishing and maintaining zoos, botanic gardens, and seed banks require significant resources and funding.

Special Problems with Recalcitrant Seeds

• Storage Limitations: Recalcitrant seeds cannot be stored long-term using conventional seed bank methods.
• Alternative Approaches: Growing live specimens, using tissue culture, or establishing “living gene banks” like the International Cocoa Genebank (Trinidad).

Key Terminology

• Artificial Insemination (AI): Injection of semen into the uterus to aid reproduction in captivity.
• In Vitro Fertilisation (IVF): Fertilization of eggs outside the female body, followed by implantation of embryos.
• Embryo Transfer: Transferring embryos to surrogate females, which may be non-endangered but related species.
• Frozen Zoo: Facility storing genetic material (sperm, eggs, embryos) at extremely low temperatures for future use.
• Surrogacy: Use of a surrogate mother to carry embryos to term, enabling reproduction without risking the endangered female’s health.
• Seed Bank: Facility for drying and storing seeds at low temperatures to preserve plant genetic diversity.

Summary

1. In-Situ Conservation: Protecting species in their natural habitats (e.g., national parks, marine reserves).
2. Ex-Situ Conservation: Protecting species outside their habitats (e.g., zoos, botanic gardens, seed banks).
3. Assisted Reproduction: Techniques like AI, IVF, and embryo transfer to aid breeding in captivity.
4. Botanic Gardens and Seed Banks: Preserve plant biodiversity, support research, and serve as backups for future reintroduction.
5. Challenges: Maintaining genetic diversity, reintroducing captive-bred species, and managing recalcitrant seeds.

Questions for Review

1. Why is management crucial in protected areas like national parks?

• Ensures ecosystem stability, controls poaching, involves local communities, and balances conservation with sustainable use.

1. What are the benefits of seed banks like the Svalbard Global Seed Vault?

• Preserves genetic diversity, provides backup in case of crop failure or extinction, and supports future agricultural resilience.

1. Define and explain the importance of key terms:

Artificial Insemination, Embryo Transfer, Frozen Zoo, Seed Bank, Recalcitrant Seeds.