Coral reefs are among nature’s most beautiful creations. Anyone who’s ever seen a coral reef knows the feeling of awe and admiration that they inspire. Dubbed the “rainforests of the sea,” these marvelous formations are home to some biologically richest and most diverse ecosystems in the world. Not only that, coral reefs are an invaluable source of income for many coastal communities worldwide. For all their might and beauty, coral reefs are in serious danger.
Back in 2011, the World Resource Institute, Nature Conservancy, and more than 25 other organizations like NOAA and NASA conducted the largest ever study of global coral reef formations. Armed with completely new insights into coral reef conservation, the scientists were able to pinpoint the main threats to coral reefs on a global scale.
More importantly, the scientists concluded that if left unchecked, more than 90% of the world’s reefs will be threatened by 2030. That was more than eight years ago.
The main threats to coral reefs included: overfishing, coastal development, pollution, and climate change. Since the findings were published, however, new threats have appeared, endangering coral reefs even further.
With this in mind, we will examine all the dangers coral reefs face today, as well as what we can do to stop the corals from disappearing forever.
To fully understand the ins and outs of coral reef conservation, we’ll first take a look at what corals are, and what makes them so important.
The Rainforests of the Sea
Coral formations make up just about 0.1% of the world’s oceans. Astonishingly, this 0.1% is able to hold 25% of all marine life on the planet! From crustaceans and mollusks, to sea mammals and fish, coral reefs are home to an astounding variety of lifeforms.
For almost all of these organisms, coral formations provide shelter, a place to spawn, as well as a food source or two. Needless to say, coral reefs are a vital part of a marine ecosystem.
Contrary to popular belief, corals are not plants. They’re animals. Made out of thousands of tiny clustered organisms called polyps, corals are very close relatives to sea anemones and jellyfish.
In order to create a coral formation, corals attach themselves to rocks or other hard underwater structures that lie near the edges of islands or continents. When they form, corals grow and expand into one of three reef structures:
- Fringing reefs – Coral formations located directly on the shoreline of an island or continent (The Red Sea Fringing Reef).
- Barrier reefs – Corals that form near the shoreline, but at a greater distance than a fringing reef. Barrier reefs are often separated from the coastline by a deep, open body of water (The Great Barrier Reef, Australia).
- Atolls – Coral formations that were once fringing reefs, but whose islands collapsed, leaving only the coral behind (Rosalind Bank, The Caribbean).
Why Are Coral Reefs Important?
Aside from providing a habitat for countless marine organisms, coral reefs are important in a number of other ways.
- Purify the water: Corals are filter feeders, which means that they consume small particles that swim in the water. As a result, the waters that surround a coral formation are usually clear and of good quality.
- Protect the shore: Coral formations, especially barrier reefs, act as a shield against storms and high waves. They also help stabilize mangroves and seagrass beds, which are very important in preventing coastal erosion.
- Feed people: Historically, corals have always brought fish close to the shore. This provided local populations with a steady food source, and allowed coastal communities to grow.
- Make big money: Coral reefs attract thousands of tourists every year. According to the WWF, coral reefs generate US$30 billion world-wide.
- Treat illnesses: Corals and coral-bound organisms are sources of new medicines. These are used to treat cancer, arthritis, Alzheimer’s, and various viruses.
How are coral reefs endangered?
Thanks to conservation studies like the one we mentioned above, we are able to see how vulnerable corals have become. We can also tell what dangers threaten coral reefs around the world. Some of these dangers are specific to a locale, while others are global, affecting all coral formations.
The local threats include overfishing, illegal fishing, coastal development, and pollution. The global threats include climate change and coral diseases.
Coastal communities have always relied on reef fishing as a source of food and livelihood. As coastal and global populations grow, so does the demand for seafood. In addition, coral reefs attract thousands of recreational anglers, which puts an additional strain on a reef ecosystem.
What’s even worse is that many of the targeted reef fish are top predators. Removing these fish from the food chain often throws the entire system out of balance. Once the top predators are out of the equation, fishermen usually move down the food chain, and on to the next predator. Over time, even the smaller herbivorous fish become overfished.
What ultimately happens is this:
- Without top tier predators, invasive species are free to roam and destroy the corals.
- Without the smaller herbivorous fish, algae tend to overgrow and overwhelm the corals. This makes the reefs less resilient to stressors and more susceptible to disease.
Illegal fishing techniques are among the most destructive human activities. You’ll mostly see them take place in economically less developed countries with poor environmental regulations. For example, in Southeast Asia and East Africa, dynamite fishing is a widespread activity. We don’t need to tell you how destructive this can be to a nearby coral reef.
Other illegal fishing activities include:
- Poison fishing: Using cyanide or other poisons to stun or kill fish.
- Illegal Trawling: Pulling a net along the waterbed behind one or more boats. Trawling nets rip off corals from the structure, and create huge amounts of unintended catch, as well.
- Muro-ami: A Southeast Asian fishing technique that involves throwing large nets with cement blocks onto a coral reef. The cement blocks are used to pound the reef and scare the fish into moving.
- Ghost Fishing: Unintentionally or deliberately leaving fishing gear on the seafloor. Abandoned fishing traps, nets, and lines are known to damage corals.
Overfishing and illegal fishing are two of the biggest threats to coral reef conservation. Tackling them is incredibly complex, but an absolute must if we want to see coral reefs survive.
Coastal Development and Pollution
Another human-caused threat to coral reefs is coastal development. Over the last 120 years, the world’s population grew from 1.6 billion to 7.5 billion. A good part of this growth happened in coastal towns and cities around the world.
To follow this trend, countless construction projects were carried out near the shorelines. Where once there was water, piers, bridges, resorts, and sometimes entire neighborhoods rose. In many of these places, entire mangrove forests were cleared, causing beaches to erode and smother nearby corals.
In the last 50 years, many of Florida’s coral reefs have disappeared due to this type of urbanization. Things aren’t very different in the Caribbean. Here, tourist resorts line pretty much every coast that’s even remotely close to a coral reef.
And where there’s coastal development, there’s pollution. Many countries rich with coral reefs have little to no sewage management. In the Caribbean, South East Asia, and throughout the Pacific, as much as 90% of wastewater gets discharged into the ocean completely untreated.
That’s not to say that all development is bad. Far from it. Coral reefs have always been an important source of food and income for people. According to NOAA, the Florida coral reef alone brings an annual US$8.5 billion to the local economy, and helps support as many as 70,000 jobs.
However, giving these places “more love than they can handle” will inevitably ruin them. The environment will suffer, as will the many families whose livelihoods depend on healthy coral reefs.
So, how do you protect coral reefs from these local threats? In short, by declaring stricter regulations, and educating local communities on coral reef conservation.
Solving Overfishing and Illegal Fishing
Through stricter bag and size limits, seasonal closures and geographical restrictions, regulators will ensure healthy population levels. In the short run, recreational fishing will still be able to flourish with catch-and-release practices. In the long run, recovered fish populations will allow both recreational and commercial fishers to harvest more fish as time goes by.
Solving overfishing doesn’t just happen on the boat, mind you. By making sustainable food choices, you’re directly influencing the demand for a certain species.
Through education, coastal communities will be able to understand the impact they can have on coral reefs. In time, this will empower them to make their own conservation efforts.
One shining example of how local communities can rally to make a difference and save their natural treasure is Cabo Pulmo, a marine reserve in the Sea of Cortez. After decades of relying on fishing for sustenance, the residents had depleted their only resource to the brink of collapse.
The fish they relied on were disappearing. The villagers had a choice: to continue to fish until there were no more fish to catch, or to completely change the way they lived. Thankfully, the locals chose to ask the government to declare Cabo Pulmo a National Park. Fast forward 20 years, the fish populations had increased by more than 400%, and Cabo Pulmo is now one of the most popular dive sites in the world!
Dealing with Coastal Development and Pollution
The number one solution to coastal development is long term urban planning. Thankfully, there are countries that have already recognized the dangers of excessive coastal development. In Barbados, any construction work must be carried out at least 30 meters behind the high water mark.
Australia, home to the largest coral reef in the world, opens only 7% of it to tourism. As a part of its Reef 2050 Plan, the country invests over US$200 million in coral reef conservation every year. With this money, Australia is able to invest in water purification, as well as supporting farmers and land managers in practicing eco-friendly agriculture.
Over the last century, human activity has seriously hurt coral reefs around the world. In some places, coral formations have decreased by more than 50%. Thankfully, with enough effort, man-made threats can become man-made remedies. As conservation awareness spreads, we can be hopeful that local threats to corals will decrease.
The thing is, however, that coral reefs are threatened by a lot more than just local stressors.
Over the last 200 years, the world’s oceans have soaked up around 500 billion tons of carbon dioxide from the atmosphere. That’s a lot of gas. Soaking up all that CO2 did save the earth from becoming warmer, but in return, made the oceans a lot more acidic. Acidic waters hurt almost all marine life, including corals.
And then, there’s the sheer temperature of the seas. Corals are very sensitive to changes in water temperature. When the waters become unusually warm, corals exhibit a stress response called bleaching. When this happens, corals lose the microscopic algae that live inside them. As a result, they become transparent, often revealing the structure below.
Depending on how severe the bleaching is, coral formations will survive or die. However, even if they do survive, these corals will likely be handicapped when it comes to growth and reproduction.
Coral bleaching has always existed to some extent. Seasonal changes in water temperatures have always been causing milder bleaching episodes. However, with global warming, sea temperatures are rising too, causing more and more severe coral bleaching events along the way.
The cause of coral bleaching is not something we can hope to eradicate quickly. Unless we reduce greenhouse gas emissions to the point where they don’t negatively affect the biosphere, the outlook is bleak.
One way we could instantly help the corals deal with bleaching is by eliminating the local threats that they face. With reduced pollution, less coastal development and no overfishing, corals will be more resistant to bleaching. They will also be much better suited to recover and reproduce.
In recent years, the world’s corals have been hit by yet another threat: disease.
In 2014, the Florida Coral Reef was hit by an outbreak of a fast-spreading sickness called stony coral tissue loss disease (SCTLD). Coral disease is not an uncommon thing, and scientists have been monitoring and managing them for years. However, this disease quickly proved to be much deadlier than any other in recent memory.
Gena Parsons, National Marine Sanctuary Foundation representative and NOAA affiliate recalls: “We first noticed the outbreak in the fall of 2014, off of Virginia Key. At the time, the reefs were monitored by a number of marine scientists, but only after it started to spread did we realize what it was.”
Within weeks, a number of coral formations had died. But that was not all.
“Compared to other coral diseases, SCTLD was much more severe, in part because it had no seasonal restrictions, and it attacked nearly half of all stony coral species in the Florida Reef Tract.”
Scientists think that SCTLD was caused by bacteria, but unfortunately, they haven’t been able to single out the exact pathogen yet. What’s even more troubling is that the disease doesn’t just spread to other corals by direct contact, but also by water circulation.
Within less than a year from its outbreak, the disease had spread from Biscayne National Park, all the way to Pompano Beach. By the summer of 2016, SCTLD was confirmed from St. Lucie inlet in the north, all the way down to the lower Keys. In 2018 and 2019, the disease had spread to the Caribbean, infecting corals in Mexico, The Dominican Republic, Turks and Caicos, as well as Belize.
NOAA, AGRRA, and a number of other coral reef conservation organizations have joined to preserve the coral reefs in Florida and the Caribbean. Together, they’ve launched several important conservation initiatives.
Gena Parsons explains: “We are sharing our experience from Florida with other countries affected by SCTLD. Whether it’s limiting runoff, using mooring buoys instead of anchors, or simply sharing best practices, we should do everything we can to relieve stress on the corals”
Some of the initiatives include:
- Salvaging coral species: Rescuing coral species that are at risk of extinction
- Spawning corals: Scientists are actively spawning corals both in labs and in the wild
- Restricting infected areas: Parts of the Cozumel National Park in Mexico have been closed off for recreational use in order to protect the local coral reef
What can you do?
The first step is to get educated. Organizations like the Southeast Florida Action Network (SEAFAN) can teach you how to spot and report a coral disease. If you’re able, you can also join one of the marine debris cleanup efforts. If you’re a diver or spearfisher, you should follow the NOAA best practices guide. And last but not least, spread the word!
A Treasure Worth Saving
Coral reefs are incredibly valuable for the planet. Like an oasis in the middle of the ocean, coral reefs are a refuge, a dining table, and a nursery for countless marine creatures. For humans, they are a healthy food supply, a source of income, and a fountain of joy and recreation. But this might not be the case for long.
Unless we tackle all the threats corals are facing today, it won’t be long before the colorful underwater oases become wastelands. There is still time to turn things around, however.
If we follow all the coral reef conservation initiatives we mentioned, we could be looking at a very different scenario in the next 10 years. According to the United Nations Environment Program, following sound conservation practices in the coming decade could unlock tens of billions of dollars for local economies.
More importantly, the corals will live to see another day, and so will many of the species that call the corals their home.
And now, we turn it over to you. What’s your take on coral reef conservation? Have you ever visited a coral reef before? Let us know in the comments below.