International Day for Biological Diversity

What is International Day for Biological Diversity, and why is it celebrated?

Loss of biological diversity threatens the survival of life on Earth. We rely on biological diversity for food, medicine, and healthy ecosystems. However, human activities are significantly reducing the number of plant, animal, fungi, and microorganism species on Earth.

The International Day for Biological Diversity aims to bring these issues to the forefront. In 2025, the theme is “harmony with nature and sustainable development”. It draws attention to the link between the UN’s 2030 Agenda, its sustainable development goals, and biodiversity. It also boosts public awareness of the importance of biodiversity and encourages bolder environmental initiatives.

What are 6 facts about World Biodiversity Day?

1. Biodiversity is essential for safeguarding our water resources. It acts as a natural shield by filtering and purifying water through wetlands and riparian forests. It regulates the water cycle through vegetation that influences rainfall and recharges aquifers, and maintains healthy soils that retain water and filter pollutants.
2. Biodiversity is essential for agriculture and food security. Biodiversity in food provides a variety of nutritious options that cater to diverse cultural tastes and dietary preferences. It also delivers vital “ecosystem services”, including nutrient cycling, carbon sequestration (the removal of carbon dioxide), pest regulation, and pollination. Bees, a key pollinator, pollinate 70 of the approximately 100 crop species that feed 90% of the world's population. Unfortunately, bee populations are in decline.
3. Factory farming is a major driver of biodiversity loss. In Brazil and beyond, forests are being cleared to grow soy, primarily to feed livestock, which puts immense pressure on wildlife and ecosystems. Globally, agriculture is responsible for 80% of all land-use change. Deforestation, fires, and habitat loss in places like the Amazon Rainforest threaten countless species.
4. The commercial exploitation of wild animals is driving biodiversity loss. Industries such as tourism, traditional medicine, and wildlife farming remove animals from their natural habitats, disrupting ecosystems and accelerating species decline. This growing demand fuels the illegal wildlife trade, introduces invasive species, and threatens the balance of nature — all in the name of profit. Protecting biodiversity means ending the commodification of wild animals.
5. Ghost gear threatens marine biodiversity. 640,000 tonnes of ghost fishing gear are left in our oceans each year. This gear traps, injures, and kills hundreds of thousands of whales, seals, turtles, and birds. Marine pollution and intensive fishing are harming the biodiversity of our oceans.
6. Biodiversity and climate change are closely linked. Climate change is harming biodiversity. Rising temperatures, extreme weather events, rising sea levels, and changing habitats are making it harder for species to survive. But biodiversity conservation can help to combat climate change. Nature-based solutions — such as helping rainforests and mangrove forests regrow — help capture more carbon and make ecosystems more resilient.

World Biodiversity Day FAQs

What is biodiversity, and how is it measured?

Biodiversity is the variety of species within an ecosystem. This includes the animals, plants, fungi, and microorganisms that make up our natural world. We can measure biodiversity using three different components:

• Genetic diversity: the genetic variations within a species
• Species diversity: the number of different species and the proportion of those species within an ecosystem
• Ecosystem diversity: the number of distinct ecosystems within a defined area

These different measures of biodiversity are equally important and interconnected.

Why is biodiversity important, and how does it affect the stability of an ecosystem?

Biodiversity is essential for life on Earth. It supports healthy ecosystems that provide enough oxygen, food, and fresh water for all organisms on the planet, including humans.

Biodiversity is also important to ecosystem stability. Ecosystems with lots of species and genetic variation are more resilient.

Biodiversity is a particularly important issue right now because of the rate at which we’re losing it. Currently, species extinctions are 10 to 100 times higher than the natural baseline, so it’s important to support biodiversity and its conservation. 

How do invasive species affect biodiversity?

Invasive species affect biodiversity because they prey on native species and compete for resources like food and water. They sometimes also transmit deadly diseases to native species.

As they challenge native species, invasive species disrupt the balance of the ecosystem, causing species loss and biodiversity to suffer.

What is mega diversity in biology?

Megadiversity is a word we use to describe countries or regions with high levels of biodiversity. To be classified as megadiverse, a country has to have at least 5,000 different native plants that occur only within its borders. It also needs to have a marine ecosystem.

There are 17 megadiverse countries in the world, including Australia, Brazil, China, Indonesia, and Mexico. These countries account for around 70% of the world’s biodiversity.

How could restoration ecology help with biodiversity?

Research shows that restoring 30% of lands that have been used for agriculture and protecting natural ecosystems would prevent over 70% of the predicted extinctions of mammals, birds, and amphibians. It would also help to combat climate change by sequestering huge amounts of carbon dioxide (CO2).