Coral reefs are vibrant, diverse ecosystems that serve as home to 25 percent of marine species, including 4,000 species of fish. Often referred to as “the rainforests of the ocean,” they provide food, shelter, and protection from predators that help an estimated two million species thrive. It’s also estimated that up to eight million unknown species also call the reefs home.
These lifelines of the ocean also protect the coast from erosion and flooding by acting as a buffer against intense waves, protecting homes and natural habitats in the process.
Unfortunately, environmental changes like rising ocean temperatures, changes in ocean pH, and the presence of litter and toxins are placing stress on these strong, yet vulnerable structures. This stress results in bleaching, a process where coral expels the colorful symbiotic algae that helps keep it nourished. What’s left behind is the coral’s white skeleton which, without a source of nourishment, becomes more susceptible to disease that can prohibit future colony growth. And without that new growth, the coral dies.
We’ve already lost 27 percent of the world’s coral since the 1980s, and it’s expected that number will increase to 60 percent over the next 30 years. Coral reefs used to have decades to recover from the stress that causes bleaching, but bleaching incidents are now so frequent and widespread that they no longer have sufficient time to recover.
A study of 100 different reefs found that more than half were severely bleached, meaning at least 30 percent of the coral had been damaged or killed. In 2016, it was discovered that nearly 85 percent of the Great Barrier Reef was damaged by a mass bleaching event, and the recovery is expected to take decades.
Our coral reefs play an important role in the survival of marine life, but climate change, as well as water and air pollution, are destroying these vital ecosystems at an alarming rate.
Rising Temperatures and Acidification Are Killing Coral
Global warming is a leading cause of the frequent mass bleachings that are killing off the world’s coral. Ocean temperatures are rising at a rate 13 percent higher than originally thought, placing stress on the coral and causing bleaching. Coral can recover if the water cools and the symbiotic algae return, but if temperatures stay warm for a few weeks, the coral is typically unable to recover, and it dies.
Air and water pollution are another cause of damage to coral reefs. Carbon dioxide is absorbed by the ocean as part of a natural process, but billions of tons of excess carbon dioxide have been released into the air because of fossil fuels. It’s estimated that oceans absorb around 22 million tons of human-created carbon dioxide emissions a day, and the resulting acidification of the ocean’s water is happening at a rate 30 times faster than it should.
When water becomes too acidic, it weakens coral by slowly dissolving its skeleton, which is built from calcium carbonate deposits. The dissolving of calcium carbonate deposits also stunts the growth of coral, affecting regrowth that is essential to the survival of reefs. This damage not only affects the coral itself, but also the marine species who rely on coral reefs for food and habitat.
Sewage, runoff, and fertilizer from farming operations, as well as residential lawns, also alter the chemistry of water by increasing levels of nitrogen and phosphorous. These elevated levels pollute the water and create surface algae and “dead zones” that suffocate aquatic life and cause stress that can bleach coral reefs.
Our Plastic Trash Makes Coral More Susceptible to Disease
Around 8.8 million tons of plastic trash are dumped into oceans every year. Over time, it photodegrades into microplastics that kill marine life and release toxins into the water. And now it’s starting to harm the world’s coral as well.
During a recent four-year study, researchers assessed and examined approximately 150,000 corals located in 159 reefs in the Pacific Ocean, where more than half of the world’s coral reefs are located. They concluded that an estimated 11 billion pieces of plastic trash are floating through the Asia-Pacific region, causing damage to reefs in Australia, Indonesia, Myanmar, and Thailand. What’s also concerning is that number is expected to increase by 40 percent by 2025.
Plastic damages the surface of the coral by clinging to it or creating scratches and gouges in its skeleton. According to the study, “Plastic debris stresses coral through light deprivation, toxin release, and anoxia, giving pathogens a foothold for invasion.” Coral that has been damaged by plastic has an 89 percent chance of becoming diseased, compared to only four percent if the coral hasn’t come into contact with the toxic trash.
Efforts to Save Our Coral Reefs
With coral dying at staggering rates, advocates are working to spread awareness and researchers are working to find ways to replace what’s already been lost. One of these efforts involves restoration efforts that involve replanting coral. SECORE International has developed a technique that they hope will increase the rate at which coral can be replanted.
Current techniques involving hand planting coral larvae and fragments take a lot of time and labor and can only cover areas of about 10,000 square feet at a time. But their new sowing method, which involves using a larvae-lined substrate that allows the coral to attach by itself naturally, can cut the time it takes to replant an area of that size by 90 percent. This method is also more cost-effective, which can allow for larger areas of coral to be restored. There are even efforts to breed climate change-resistant coral, similar to those found in a remote lagoon in the South Pacific, that can withstand warm and increasingly acidic water.
These breakthroughs give us hope that some of the damage can be reversed, but the key to preventing further damage and destruction lies in working to help stop the warming of our planet and reducing toxic plastic waste by making changes to our daily habits.
Small Changes to Our Daily Habits Can Have a Big Impact
Wise Hok Wai Lum/Wikimedia
Everything we do, from the cup of coffee we purchase each morning, the meal on our plate at lunch, and how we travel to and from work, has an impact on our oceans and the planet. By making ourselves aware of our environmental impact and making small changes to our daily habits, we can help protect precious resources like coral reefs from further destruction.
Industrialized animal agriculture causes water pollution by releasing toxic farm runoff from manure and fertilizer into our water supplies, and it is also responsible for more greenhouse gas emissions than the entire transportation sector. Help keep our air and water clean by choosing to leave meat and dairy off your plate — even limiting consumption can make a difference. To learn more about the environmental impact of our food choices as well as trends and developments in the plant-based food space, check out our podcast #EatForThePlanet with Nil Zacharias.
By 2050, there will be more plastic in the ocean than fish, but we can help turn that statistic around by changing our wasteful ways. Join One Green Planet’s #CrushPlastic movement and make a pledge to reduce your plastic usage. Start by using reusable shopping bags and mesh produce bags instead of plastic. Stay hydrated and caffeinated on-the-go by carrying reusable water bottles and coffee cups, and swap the disposable straws, silverware, and takeout containers for reusable options.
Work to cut your carbon footprint by walking, biking, carpooling, or utilizing public transportation whenever possible. Even the smallest of changes can have a big impact, and we need to start before it’s too late.
Lead Image Source: prilfish/flickr