Coral Reefs, Climate Change, & the Importance of Ocean Conservation

As climate change progresses and temperatures continue to rise across the globe, coral reefs have become a staple in the cycle of climate news. Reefs are vitally important to ocean wildlife, but global warming, ocean acidification, and human intervention are causing them to diminish and die off. Let's talk about coral reefs, why they're important, and how climate change is threatening their health and existence.

What Are Corals?

Corals are a kind of **marine invertebrate** related to jellyfish and sea anemones. They form colonies made out of hundreds of individual coral animals called polyps, and most species slowly excrete **hard exoskeleton material that forms coral structures**.
Some coral catch prey like plankton, but many live in a **symbiotic relationship with a specific kind of algae** that provides food for both through photosynthesis.

What Are Coral Reefs?

Coral reefs are underwater ecosystems made up of coral colonies. They are full of complex food webs that include fish, plants, plankton, sponges, and many other species.

Coral reefs are found all over the world, both near the shore and deep into the ocean, but most are in warmer water around the Equator. There are many different kinds, and some can even form island-like structures called atolls.

The largest is the Great Barrier Reef off the coast of Australia, but some of the other largest are found in the Caribbean and throughout the South Pacific.

Why Are Coral Reefs Important?

Although coral reefs take up only a small amount of underwater real estate around the world, **they host an estimated 25% of all marine species**.
Reefs **provide protection** from waves, storms, and harsh water conditions, and they **recycle nutrients** from the ocean around them. They are a carefully balanced ecosystem of coral, plants, fish, and more who all **feed from one another and supply nutrients through the food chain**.
For humans on land, coral reefs provide **fishing supplies**, tourism industries and related **economic growth**, and **shoreline protection** from storms and tsunamis. Many small islands only exist because of such protection, and a lot of **human infrastructure benefits from their existence**.

The Biggest Threat to Coral Reefs Is Climate Change.

As the oceans get warmer, coral reefs are in extreme danger of dying and wiping out huge numbers of ocean wildlife along with them. Higher temperatures can kill the algae that many species of coral rely on, resulting in coral bleaching. This event doesn’t always kill them, but it causes them a lot of stress, and can open them up to disease and starvation.

Prolonged periods of bleaching and high ocean temperatures will kill coral. In 2016, a mass bleaching event in the Great Barrier Reef killed around 22% of the area’s coral. These events continue to be more frequent as more greenhouse gas emissions contribute to global warming.

Other Threats to Coral Reefs are:

Ocean Acidification: As carbon dioxide is released into the air, the ocean absorbs it and becomes more acidic. This causes fewer minerals and nutrients that coral need to be available.

Excess Nutrient Pollution: Coral reefs thrive in relatively low-nutrient water. When fertilizer runoff and sewage put excess nitrogen and phosphorus into the ocean, it throws the balance of these ecosystems off and can cause bacteria and pathogens to grow.

Litter and Microplastics: These are cause for concern in other parts of the ocean, too. Trash can damage coral or be unwittingly consumed by animals that live in the reefs. Microplastics can be consumed by coral, fish, and all kinds of wildlife, and can cause major health problems or even death.

Overfishing and Human Damage: Taking too many fish out of coral reef ecosystems can have major effects on the balance of the food chains, and humans who touch, damage, or harvest coral destroy important habitats.