The Current State of Coral Reefs in the Marine Ecosystem

Did you know that coral reefs are the most diverse marine ecosystems on earth? Coral reefs give shelter to thousands of animal species and are essential to people on earth. However, coral reefs are dying at an alarming rate due to pollution, overfishing, and climate change. As a result of this, more than 50% of the world’s coral reefs have died in the last 30 years, and it is expected that up to 90% will die within the next century. 

Why are Coral Reefs Important? 

1. Biodiversity & Habitats 

Coral reefs provide habitats to over 25% of all marine life on earth including sponges, oysters, clams, crabs, sea stars, sea urchins, etc! Thus, without coral reefs, many species will lose their habitats! 

2. Food Resource

Coral reefs provide protein to fish and other marine animals that humans eat. Did you know that coral reefs provide about 10% of the fish caught worldwide? Some estimates say that over 1 billion people rely on food from coral reefs. A large proportion of these human populations live in developing countries and they rely on food provided by reefs such as fish. 

3. Economic Importance

As a result of direct revenues from fishing, coral reefs provide a plethora of resources and services that are worth billions of dollars each year. As mentioned before, millions of people around the world depend on reefs for food, protection and employment. The total net benefit of the world’s coral reefs is about $29.8 billion! 

4. Tourism

Did you know that coral reefs are the backbone of tropical regions’ economics! Coral reefs attract divers and beach-lovers! More than 100 countries benefit from reef-related tourism, and in many small islands, more than 90% of new economic development depends on coral reef tourism! 

5. Medicine

Did you know that coral reefs are important sources of new medicines being developed to treat cancer, arthritis, and many other diseases! Since corals are stationary, many have evolved to form chemical defences to protect themselves from predators. With that said, scientists continue to research the medicinal potential of coral reefs. In the future, coral reef ecosystems could provide an abundant amount of medical treatments. 

Why are Coral Reefs Dying? 

1. Land-based Pollution

Many coral reef ecosystem stressors originate from land-based sources such as toxicants, sediments, and nutrients. When sediment and other pollutants enter the water, they suffocate coral reefs, speed the growth of damaging algae, and lower water quality. Land-based pollution can also make corals more susceptible to disease and cause changes in food structures on the reef. 

2. Overfishing

Overfishing occurs when fish or other marine animals are harvested at rates faster than they can reproduce. Overfishing affects coral reefs as they take a long time to reproduce. Scientists estimate that 36% of the world’s reefs are already overexploited by overfishing! 

3. Climate Change

Climate change raises seawater temperatures and causes coral to bleach worldwide. When corals are stressed by changes in conditions such as temperature, they expel symbiotic algae called zooxanthellae, causing them to turn white. This then results in reduced coral growth rate, decreased reproductive ability, increased chances of getting diseases, and greater mortality rates. Thus, when seawater is too warm, coral bleaching can occur, which is detrimental. 

Although coral reefs are beautiful and important aspects of nature, they are slowly dying. It is evident that coral reefs provide the marine ecosystem and humans with a multitude of benefits! Thus, it is important to raise awareness and research about what is occurring within our marine ecosystem!