Human Impact on Coral Reef Degradation

This article provides information on coral reefs, coral bleaching, how this impacts humans, and what we can do to help. For more information on coral reefs, please see the links provided within.

Written by: Thomas Tinmouth


A major misconception when it comes to people’s perception of ocean conservation is that if you do not live near the sea, then you can’t do anything to help it. The reality is no matter where you are located on planet earth, your actions have the ability to impact our valuable ocean systems in a positive or negative way. Initially, videos displaying the sheer power of strong waves crashing against the shore, or pictures of beautiful sparkling blue water glistening under the sunlight may come to mind when thinking about the ocean. Schools of colourful fish swimming past mighty blue whales and a shiver of sharks speeding through the water. What if we dive a little deeper? What allows this system to operate and survive? What is the world’s greatest secret that connects both humans and dolphins to the same life source allowing us to breathe? The answer is coral. 

What is Coral?

Figures 1-3 – Canva Stock Photos of Coral Reefs

Upon initial glance, coral is a beautiful colourful sea plant that lines the ocean floor. A truly amazing aesthetic that is not replicated anywhere else on earth. If you look closely, coral is not just an aesthetic, it is very much alive. A living breathing organism made up of plankton-eating invertebrate animals called polyps. These polyps make up the forest of the ocean which is a driving force that supports life within the sea. Coral supplies habitats, food sources, and protected areas for sea life to lay eggs and reproduce. Simply put, without coral an estimated 25% of marine life will face direct negative consequences creating a terrifying domino effect felt throughout the ocean, and onto our lands. 

Coral Bleaching

Figure 4 – Coral Bleaching

Figure 4 shows the before and after of coral bleaching. This is not old coral or a seasonal colour change, this is death, in a vast amount. There are multiple reasons that cause coral bleaching to occur. The first reason is warmer water temperatures. As the global temperature continues to rise, so does the temperature of the ocean. When oceans warm the polyps lose algae which deteriorates the coral, leaving a white skeleton in place of what was once a bright fluorescent colour. Another reason for this bleaching is ocean acidification.

With mass amounts of carbon dioxide and other greenhouse gasses being released into the atmosphere, there is a constant interaction between ocean waters and carbon dioxide creating carbonic acid. Carbonic acid increases the pH of the seawater which makes it harder for coral to generate calcium carbonate and build their core. 

Video 1 – Chasing Coral

Video 1 shows something that appears to be a very cool natural phenomenon in the ocean producing a cool aesthetic. A beautiful picture with an ugly message. This is a cry for help. This is coral bleaching taking effect, but instead of the common white skeleton, the coral has turned a bright fluorescent colour. A last-ditch effort for humans to notice them. We must answer the call. Next time you see coral online or in person, notice more than the aesthetic. Notice the living breathing species that is buying us a little more time to make a change. Now we must return the favour. 

Why Should Humans Care?

Not only is coral an integral part of sustaining life within the oceans, it also has a monumental impact on humans’ ability to thrive on earth. First off, there is the fact that coral is a necessary piece for many marine species to survive, which is a massive food source for humans around the globe. Without coral, this food source will quickly deteriorate leaving many people hungry, but also struggling economically with perishing fisheries, marine excursions, and tourism to name a few. Another large impact on humans is the job coral does to protect our coasts.

Figure 5 – Zooxanthellae & Polyp Anatomy

Coral acts as a buffer that slows waves, storms, floods, and erosion on coastal lands. Without this buffer, storms and flooding will arrive at a higher pace increasing damages to property and the rate of erosion, also posing major safety risks to those who live on or near coastal areas. Though these are detrimental impacts on the livelihoods of millions of people on the planet, it is the third major issue that does not care about location, status, or even species. This is the issue of oxygen. The ocean produces over half of the earth’s oxygen and intakes approximately 1/3 of carbon dioxide from burning fossil fuels. Zooxanthellae is a photosynthetic alga that lives in coral polyps providing the tools for photosynthesis (see Figure 5). This photosynthetic process is a major contributor to the ocean being able to take in so much carbon and produce large amounts of oxygen. It is becoming increasingly difficult for the ocean to keep up with the number of fossil fuels being burned, and if we continue at this pace, we will exhaust the ability of the ocean to keep up with our pollution. It is very clear how important the role coral plays in our ability to breathe clean air, which is why it is extremely alarming that over 50% of coral reefs have died in the past 30 years. If coral bleaching persists, it is projected by 2050 we may have lost over 90% of coral reefs.  

What Can We Do?

Now, the question on everyone’s mind is, what can I do to help? There are various ways that we can alter our everyday lives to reduce our impact on coral degradation. The first simple change we can make is in our sunscreen choice. Common brands contain harmful chemicals to coral and other marine life that wash off our bodies while showering and swimming in the ocean.

Next time you are buying sunscreen take a look to see if the product contains these common chemicals that harm our marine ecosystems. Also, if you are ever fortunate enough to snorkel or dive around coral reefs do not touch or disturb them! Touching coral can cause damage, which includes dive gear, anchors, fishing equipment, and our hands. Another thing we can do is green our lawn care. Whether you live 1 mile or thousands of miles from the ocean, the chemicals we use in lawn care create runoff into water systems when it rains with the final destination ocean.

Avoid using pesticides and fertilizers, switch to ecologically safe products or preferably just water. Remember to also be mindful of pouring household chemicals into storm drains as previously mentioned these drains make their way into water systems eventually ending up in the ocean. Thirdly and most importantly, we can be mindful of our personal carbon footprint. This means when possible choosing to walk or ride a bike rather than driving a car, and carpooling when sharing similar destinations.

There are many ways you can alter everyday actions to reduce your greenhouse gas emissions in an effort to slow our changing climate and protect our corals and marine ecosystems. In addition to the above changes, you can make to reduce your impact, check out East Gwillimbury’s 11 tips, or Blue Oceans 25 ways to prevent coral bleaching. Lastly, spread the word! Share what you learn and inform others about why coral is so important and what we can do to save this precious species. To learn more about what you can do, and be part of the solution.

Interested in learning more about our oceans? Find more articles here.

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