Quiz of the Day
World Nature Conservation Day
Tuesday, 28 July 2026
Coral bleaching, species extinction, and the race to save what remains — conservation science in crisis
1. Scientists estimate we are currently in the Earth's sixth mass extinction event. What is the primary cause?
- Solar flare activity
- Human activity
- Volcanic eruptions
- Asteroid impacts
The current extinction rate is estimated to be 100-1,000 times the natural background rate. The five previous mass extinctions had natural causes — this is the first driven by a single species. Habitat destruction is the leading driver, followed by overexploitation, invasive species, pollution, and climate change.
2. The Great Barrier Reef experienced its most widespread coral bleaching event in recorded history in which year?
- 2016
- 2005
- 2020
- 2010
The 2016 bleaching killed about 29% of the Great Barrier Reef's shallow-water corals — the worst single event in its history. Bleaching occurs when ocean temperatures rise and corals expel the algae that gives them colour and nutrition. If temperatures drop quickly, coral can recover; sustained heat causes death.
3. The 'IUCN Red List' classifies species by conservation status. Which category indicates a species is closest to extinction?
- Critically Endangered
- Vulnerable
- Endangered
- Extinct in the Wild
The IUCN (International Union for Conservation of Nature) Red List has categories from Least Concern through Near Threatened, Vulnerable, Endangered, Critically Endangered, Extinct in the Wild, and Extinct. As of 2024, over 44,000 species are threatened with extinction on the list. The Vaquita porpoise, with fewer than 10 individuals remaining, is the world's most critically endangered marine mammal.
4. Rewilding is a conservation approach that famously reintroduced which species to Yellowstone National Park in 1995, transforming the ecosystem?
- Bison
- Grey wolves
- Mountain lions
- Grizzly bears
Reintroducing 41 wolves triggered a 'trophic cascade' — wolves controlled elk numbers, allowing riverbank vegetation to recover, which stabilised river banks, altered water flow, and increased habitat diversity. The rivers themselves changed course. This phenomenon — where predator reintroduction transforms entire landscapes — became one of ecology's most celebrated examples.
5. How much of the world's biodiversity is estimated to live in tropical rainforests, which cover only about 6% of Earth's surface?
- 40%
- 25%
- 50%
- 80%
Tropical rainforests house approximately 50% of the world's species on just 6% of land surface — the most species-dense ecosystems on Earth. The Amazon alone contains 10% of all species. A single hectare of Amazonian rainforest can contain more tree species than all of Europe.
6. The 'sixth mass extinction' is sometimes called the Holocene or Anthropocene extinction. What does 'anthropocene' mean?
- Age of animals
- Age of extinction
- Age of climate
- Age of humans
'Anthropocene' combines the Greek 'anthropos' (human) and 'cene' (epoch). The term was popularised by chemist Paul Crutzen in 2000 to describe the geological epoch dominated by human influence. Whether to formally adopt it as an official geological epoch is still debated by scientists — the evidence of human impact on the geological record is overwhelming.
7. The Convention on International Trade in Endangered Species (CITES) bans commercial trade in species at risk. How many countries are signatories?
- Around 80
- Around 120
- Around 183
- Around 200+
CITES was signed in 1973 and has been remarkably effective at reducing legal trade in listed species. However, illegal wildlife trade remains the world's fourth largest criminal industry after drugs, arms, and human trafficking, estimated at $23 billion annually. Demand, particularly from East Asia, drives most of the market.
8. Bees are considered a keystone species. Approximately what fraction of global food crops depend on pollination by bees?
- One-quarter
- One-third
- One-half
- Two-thirds
About a third of all food humans eat depends on bee pollination — including almonds, apples, blueberries, cucumbers, and avocados. Colony collapse disorder and habitat loss have dramatically reduced bee populations. Some almond orchards in California now truck in bee colonies from across the country, as local wild pollinators are no longer sufficient.
9. What percentage of the ocean is currently protected in marine reserves?
- Around 30%
- Around 17%
- Around 2%
- Around 8%
As of recent estimates, only about 8% of the ocean is in some form of protected area, and only 3% is 'highly protected' (no-take reserves where all fishing is prohibited). The global '30x30' target — protecting 30% of land and ocean by 2030 — was adopted by 196 countries at COP15 in 2022.
10. Plastic pollution in the ocean: approximately how many tonnes of plastic enter the ocean each year?
- 50 million tonnes
- 2 million tonnes
- 200,000 tonnes
- 8-10 million tonnes
About 8-10 million tonnes of plastic enter the ocean annually — equivalent to a truckload every minute. At current rates, plastic in the ocean could outweigh fish by 2050. Microplastics (particles under 5mm) are found in the deepest ocean trenches, Arctic sea ice, human blood, and placentas — essentially everywhere scientists have looked.
11. The Dodo bird, famously driven to extinction in the 17th century, lived only on which island?
- The Maldives
- Madagascar
- Mauritius
- Sri Lanka
The Dodo (Raphus cucullatus) went extinct around 1681, roughly 80 years after Dutch sailors first encountered it. It had no fear of humans because it had evolved without predators — making it easy to hunt. Introduced cats, rats, and pigs also destroyed its eggs and habitat. The phrase 'dead as a dodo' entered English as shorthand for complete obsolescence.
12. Carbon offsetting involves compensating for emissions by funding what?
- Projects that remove or reduce CO₂, like tree planting or renewables
- Carbon capture technology only
- Purchasing carbon credits on financial markets
- Government environmental bonds
Carbon offsetting is highly controversial. Critics note that trees can burn, die, or be cut down — releasing their stored carbon. Some studies found major voluntary offset programmes hadn't delivered promised emissions reductions. The science of accurately measuring offset quality is still maturing, and 'greenwashing' through low-quality offsets is a documented problem.
13. The Amazon rainforest is sometimes called the 'lungs of the Earth.' Is this technically accurate?
- No — oceans produce far more oxygen
- Partially — it produces net oxygen only in the growing season
- Yes — it produces more oxygen than any ecosystem
- No — it consumes as much oxygen as it produces through respiration
The Amazon produces vast quantities of oxygen through photosynthesis, but it also consumes approximately the same amount through respiration (by plants, animals, fungi, and decomposers). The net oxygen contribution is roughly zero. The rainforest is critical for other reasons: carbon storage, water cycling, rainfall generation, and biodiversity — but 'lungs of the Earth' is a simplification.
14. Which international agreement, adopted in 2015, committed countries to limiting global warming to 1.5-2°C above pre-industrial levels?
- The Rio Declaration
- The Kyoto Protocol
- The Copenhagen Accord
- The Paris Agreement
The Paris Agreement, adopted by 196 parties in December 2015, was the first legally binding global climate treaty. Countries submit Nationally Determined Contributions (NDCs) — voluntary pledges on emissions reductions. Critics note the pledges are insufficient to meet the 1.5°C target, and the agreement lacks enforcement mechanisms.
15. Jane Goodall's groundbreaking research on chimpanzees at Gombe in Tanzania changed science by demonstrating what?
- Chimpanzees have advanced language skills
- Tool use was not unique to humans
- Primates experience grief
- Chimpanzees can form governments
In 1960, Goodall observed chimpanzees stripping leaves from twigs to extract termites from mounds — deliberately making and using tools. When she reported this to her mentor Louis Leakey, he famously responded that science now had to 'redefine tool, redefine Man, or accept chimpanzees as humans.' The discovery fundamentally altered our understanding of what makes humans unique.