The animals and plants that call the Great Barrier Reef home are all remarkably different - and yet, they all have one thing in common. They make up the Reef's biodiversity. From microscopic plankton to massive coral bommies, every species is important to the health and prosperity of the Great Barrier Reef.
What is biodiversity?
Biodiversity is the term used to describe the variety of life on Earth - or in this case, on the Great Barrier Reef. It encompasses all living things, from microbes and single-cell algae to marine turtles and whales and their habitats.
Biodiversity has many layers. It is the biodiversity of ecosystems, the biodiversity of species and the biodiversity of genetics, within those species.
Importantly, it is not just a measure of how many species there are, rather, it encompasses all natural variation - from genetic differences within one species to variations across a habitat or a whole ecosystem.
- Five fascinating biodiversity facts
- Fact 1: There are around 1625 species of fish on the Great Barrier Reef.
- Fact 2: While coral reefs only cover about 7% of the Great Barrier Reef Marine Park area, they build its foundations and can even be seen from space. Coral reefs are closely connected to the extraordinary variety of of other marine habitats, which include shallow inshore areas (like seagrass, mangroves, sand, algal and sponge gardens), inter-reefal communities, and deep oceanic areas more than 250 kilometres offshore.
- Fact 3: Australia is part of a unique group of 17 'mega-diverse' countries, which means they cover less than 10% of the world's area but boast more than 70% of its biodiversity.
- Fact 4: There are only 7 species of marine turtle in the world - and the Great Barrier Reef is home to 6 of them.
- Fact 5: The Great Barrier Reef contains highly diverse mangroves, which represent 50 per cent of mangrove species worldwide.
Why is biodiversity important?
The Reef is internationally recognised for its outstanding biodiversity. In fact, the Reef's world heritage status recognises its great diversity of species and habitats. From about 1625 different types of fish to its 70 distinct bioregions (broadscale habitats), each square metre of the Reef can look different to the next. Biodiversity is not just an interesting feature of the Reef; it is essential for the health and functionality of the entire ecosystem.
In other words, the Reef's biodiversity helps make its ecosystems more resilient. For example, herbivorous fish play an important role by eating algae and creating space for corals to grow. If one species were to disappear, another species with a similar ecological role may be able to fill the gap left behind. This is one way biodiversity can help an ecosystem cope with the loss of individual species. Without this diversity, the loss of one species could have greater flow-on effects, putting pressure on other species and disrupting the balance of the ecosystem.
Biodiversity also helps the Reef bounce back from disturbances, such as coral bleaching or cyclones. Diversity plays an important role in a system's ability to adapt to changing circumstances (like climate change). The more species and ecological roles an ecosystem contains, the more likely it is that some species will be able to survive and continue performing important functions as conditions change. With the Reef facing mounting pressures from a changing climate, it's critical that we protect the Reef and its incredible biodiversity.
The Reef is divided into a network of zones , including highly protected 'green zones' where fishing and other extractive activities are not allowed. These zones help protect biodiversity by reducing pressure on fish and other marine species. They can also provide safe areas for fish to grow and reproduce, with larvae and adult fish able to move into surrounding areas where fishing is allowed.
What are the threats to the Great Barrier Reef's biodiversity?
Threats to the Reef's biodiversity include habitat loss, coral bleaching, marine heatwaves, ocean acidification, overfishing, water pollution and coastal development.
Climate change, driven by increased greenhouse gas emissions is driving some of these impacts, notably habitat loss, coral bleaching, marine heatwaves, ocean acidification and water pollution. While the Great Barrier Reef is resilient because of its biodiversity, climate change is shortening recovery windows for the reef as disturbance events become more frequent.
We use a suite of management tools to help protect the Reef's biodiversity, including legislation, zoning plans, permits and coral predator control, as well as research, partnerships, education and compliance measures. Each tool plays a different role. Zoning can protect important habitats and reduce pressure from activities such as fishing, while permits help manage activities that take place in the Marine Park. Research and monitoring help us understand how the Reef is changing and where management action may be needed. Direct intervention like coral predator control through the Crown-of-thorns Starfish Control Program is directly protecting coral biodiversity, and in turn, supporting species that rely on corals for shelter or food.
We also work with Traditional Owners, scientists, government agencies, industry and communities to share knowledge and support actions that benefit the Reef. Education and compliance help people understand and follow the rules that protect the Marine Park.
Together, these approaches help reduce pressures on the Reef and support the diverse species, habitats and ecological relationships that make the Great Barrier Reef such a unique and important ecosystem.
