The voice of impact
ESG / CSR
Industries
MEASURE
ACT
COMFORM
Everything You Need to Know About Coral Reefs
Level
If you’ve ever ventured to visit coral reefs or look up information about them, you may have come to learn some alarming facts – such as that the Great Barrier Reef is dying, or that tourism in areas which offer scuba diving or snorkeling to visit coral reefs are likely to suffer.
However, coral reefs aren’t just an enjoyable water-activity or to sight-see when traveling – but remain essential to our oceans, ecosystems and keeping our economies above water in good shape.
According to the Coral Reef Alliance, coral reefs support around 25% of all marine species despite covering less than 1% of the ocean floor, making coral reef ecosystems some of the the most biodiverse ecosystems on Earth.
Reef building corals and coral reef diversity are valuable, bringing in over $36 billion annually to the global economy through tourism, fisheries, and coastal protection – making it important to maintain and protect healthy coral reefs.
In this article, we’ll explain everything you need to know about coral reefs – including why coral reefs are important, what is currently happening with coral reefs, and what we can do to protect coral reefs moving forward.
What are Coral Reefs?
Coral reefs refer to the large, underwater species made up of the skeletons from colonial marine invertebrates – more commonly known as sponges, corals, and specific kinds of anemones. As a result of their hermatypic nature, coral reefs are rough to the touch seeing as they develop a strong exoskeleton as a defense mechanism for their soft incides.
Unbeknownst to most people, coral reefs are not plants – but animals living underwater just like turtles, fish, and jellyfish.
“ Practically the whole world depends on coral reefs, so if the coral reefs get all killed, then the ocean will start going out of whack, and if the ocean goes out of whack, something might happen on land. – (Alexander Gould). ”
Close
How Are Coral Reefs Formed?
Coral reefs are formed through a multifaceted biological process that can take up to 10,000 years.
The foundation of reef structure begins with tiny coral polyps, which are marine animals closely related to sea anemones. Coral polyps are the organisms which take charge in building coral reefs. No matter how big, small, colorful, or soft coral reefs are – these “rainforests of the sea” help to support thousands of species under the ocean.
These polyps secrete calcium carbonate to create hard, limestone skeletons that serve as the building blocks for entire reef systems. Coral growth is enchanced via a symbiotic relationship with microscopic algae called zooxanthellae, which live within coral tissues and provide up to 90% of the coral's energy through photosynthesis.
According to research from the Marine Biology & Sustainability Learning Center, this relationship allows coral reefs to thrive in nutrient-poor tropical waters where other diverse ecosystems would struggle. As generations of coral polyps live and die, their coral skeletons are eventually infused together – creating the complex three-dimensional reef structure that provides habitat for countless marine species, including sea urchins, fish, and other invertebrates on the ocean floor.
Coral Reef Diversity: Different Types of Coral Reefs
The National Ocean Service explains how there are three main types of coral reefs: fringing, barrier, and atoll.
Here's a breakdown of the three different types of coral reefs:
- Fringing Reefs – Known as the most common type of coral reefs, these reefs grow directly from the shoreline and extend into shallow coastal waters – such as with the coral reefs found along the coasts of Hawaii and the Red Sea.
- Barrier Reefs – With it's infamous example being Australia's Great Barrier Reef, or the world's largest coral reef system – barrier reefs are down to develop parallel to coastlines, but are separated by deeper lagoons. According to UNESCO, the Great Barrier Reef serves as one of the most complex marine ecosystems on Earth.
- Atoll Reefs – These are ring-shaped coral islands that form around submerged volcanic peaks, such as how coral reefs grow in the Maldives – known as a once volcanic island having been formed from the tips of sunken volcanoes.
Stony Corals vs. Deep Sea Corals
Most coral reefs that people are familiar with are built by stony corals (scleractinian corals), which form the foundation of tropical reefs in shallow, sunlit waters of the Pacific Ocean, Atlantic Ocean, and Indian Ocean. These hard corals create the massive limestone structures that support vibrant coral colony communities bursting with colorful sea life – of which attracts tourists from around the world.
On the other hand, deep seal corals are not known to be as visually appealing, but are more scientifically intriguing. According to National Oceanic and Atmospheric's Deep Sea Coral Research and Technology Program, deep sea corals represent a completely different ecosystem, thriving in cold, dark waters at depths ranging from 50 to over 6,000 meters without relying on sunlight or symbiotic algae.
Unlike their shallow-water counterparts, stony coral colonies, deep sea corals are primarily soft corals and black corals that filter-feed on plankton and organic matter.
The battle cards below will demonstrate the differences between stony corals and deep sea corals:
🪸 Stony Corals
- Build reef structures with calcium carbonate
- Found in shallow, sunlit waters
- Rely on symbiosis with zooxanthellae algae
- Common in tropical oceans
🌊 Deep Sea Corals
- Do not form traditional reef structures
- Live in dark, cold ocean depths
- Do not depend on sunlight or algae
- Grow much slower than stony corals
Where in the World Are Coral Reef Ecosystems Found?
Coral reefs can be found all over the world, but are commonly found in warm, tropical climates and in more shallow waters – such as in the Caribbean, Florida, or off the coasts of Australia. Coral reefs are found in these regions near the equator seeing as they need year-round sunlight to sustain themselves.
This includes the most well-known coral reef of all time: which is the Great Barrier Reef found off the coast of Cairns in Queensland, Australia.
Did you know? The Great Barrier Reef in Australia is over 1,500 miles (or 2,400 kilometers) long, and is also home to more than 9,000 species. In fact, the Great Barrier Reef is so massive – you would be able to see it from outer space!
Additional Facts on Coral Reefs
Here are some facts about coral reefs you may not have known before:
- Coral reefs don’t have a brain or a heart, but are still considered animals;
- The majority of coral reefs still alive today are anywhere from 5,000 to 10,000 years old;
- Coral reefs exist in both shallow and deep water;
- Coral reefs were able to survive the era that made dinosaurs extinct and also existed long before dinosaurs did;
- Coral reefs provide protection for sea turtles throughout various stages of their lives;
- 14% of the world's coral reefs have been lost since 2009;
- There are other famous coral reefs besides the Great Barrier Reef, such as the Apo Reef, the Tubbataha Reef, and the Miami Terrace Reef.
Ultimately, coral reefs aren’t just visually appealing to look at – but have been on our Earth for millions of years before us and have proven vital to ocean ecosystems and even modernized human life.
Why Are Coral Reefs Important?
Coral reefs are important because they provide homes for over 25% of all marine life and serve as a vital asset to oceanic ecosystems. This means without coral reefs, large areas of sand, ocean currents, and deep or shallow areas of water would fail to be created in the first place.
Think of Marlin and Nemo in the famous Disney Pixar film – without coral reefs, copious amounts of marine life would be homeless and would ultimately throw off the rest of the marine ecosystem and food chain.
“ Coral reefs represent some of the world's most spectacular beauty spots, but they are also the foundation of marine life: without them many of the sea's most exquisite species will not survive. – (Sheherazade Goldsmith). ”
Close
Much of why coral reefs are pivotal is a result of cause-and-effect. For instance, if coral reefs begin to die, then they won’t be able to absorb as much wave energy – which would mean more damage would occur after a tsunami.
Additional reasons why coral reefs are important include:
- Medical Research for Diseases – Coral reefs have been used for scientific research to help develop treatments for various diseases, including arthritis, heart disease, asthma, and even cancer.
- Economic Value – As a result of fishing and tourism, coral reefs have been estimated to generate an overwhelming $375 million worth of goods and services in addition to creating and providing jobs.
- Coastal Protection – Coral reefs can help to sustain homeowner’s properties and economic values by absorbing wave energy and ultimately reducing the damage from natural disasters, which are only becoming more common in the midst of climate change.
- Vital Food Source – A whopping 8% of the global population relies on coral reefs as a food source, especially in developing countries where importing or exporting goods is more difficult.
- Tourism – Many places in the world, such as Australia, would lose their tourism appeal without the Great Barrier Reef – seeing as coral reefs bring in around $30 billion a year from touristic activities alone.
The flip cards below will depict how tourism, fishing, and medical research would be negatively impacted if coral species were to go extinct:
🏝️ Tourism
Coral reefs attract millions of visitors annually. Without them, local economies that rely on eco-tourism would suffer major financial losses.
🎣 Fishing
Coral ecosystems are nurseries for fish species. Their collapse would devastate fisheries, threatening global food security and coastal livelihoods.
🧬 Medical Research
Corals are vital in biomedical research. Losing them could delay discoveries in treatments for cancer, infections, and other critical diseases.
Overall, coral reefs are more a part of our everyday lives than the majority of us realize – and we would undoubtedly feel the effects if coral reefs are to succumb to the negative impacts of climate change.
What is Coral Bleaching?
Coral bleaching refers to when coral reefs turn white, or appear “bleached” due to stressful circumstances such as changes in sunlight, temperature, and the availability of resources nearby – many of which are dying out due to climate change itself.
Algae and coral reefs depend on one another for survival. However, when coral reefs become stressed, algae will detach itself from the coral reel – which leaves the coral more susceptible to coral bleaching.
“ Think about this: If water is the blood of our planet flowing through veinous rivers, streams, and into our oceans, what does that make coral? Our heart. We simply cannot survive without our heart; therefore, it's mandatory we heal and protect our coral reefs now. – (Ian Somerhalder). ”
The most common causes of coral bleaching include:
- Changes in Ocean Temperature – Known as the leading cause of coral bleaching, the general increase in ocean temperatures are the number one cause of coral bleaching. Think of how you feel in the midst of a heatwave: probably stressed, irritated, and unable to perform at your best. The same goes for coral reefs, and as a result – algae will detach themselves from coral and leave coral reefs vulnerable to coral bleaching.
- Stormwater Runoff – When water pollutants and superfluous stormwater end up in the ocean, it can be strong enough to dilute surrounding healthy ocean water. In turn, this can have a direct impact on the vitality of coral reefs – and end up bleaching those which reside closest to the shore, where the majority of stormwater runoff ends up.
- Excess Sunlight – Coral reefs need year-round sunlight to thrive, but too much of anything is good – which includes excessively sunny days for coral reefs. Think of when you go to the beach, and forget to put sunscreen on. For a while, the harmful effects of UV-B rays aren’t noticeable and may even give you a nice tan – but after hours of consecutive exposure, you’ll probably end up burning your skin. The same goes for coral reefs.
- Low Tides – When the tide is too low, it causes excessive air exposure – which in turn can result in coral bleaching for coral reefs which reside in shallow water. This is because these coral reefs have a better chance of being overexposed to sunlight.
It is important to remember that coral reefs are crucial to ocean life and marine ecosystems, and if coral bleaching is to continue – everyone below and above the ocean will feel the effects, seeing as tourism, fishing, and even food supply is likely to take a hit.
Ocean Acidification: Impact on Marine Life & Coral Growth
In addition to coral bleaching, ocean acidification can severely compromise coral growth and the structural integrity of entire reef systems.
According to PNAS, ocean acidification, which is caused by the absorption of excess atmospheric CO₂, reduces the availability of carbonate ions that corals need to build their calcium carbonate skeletons. This could could ultimately have an impact on reef growth and the process by which corals grow and form reefs.
Therefore, ocean acidification is a serious threat to coral reefs alongside rising water temperatures – in addition to having a profound impact on marine life, as it could alter marine food chains and ultimately our own food supply.
Close
What Causes Ocean Acidification?
Ocean acidification is caused by:
- various industrial processes
- human activities increasing air pollution
- deforestation
- unsustainable fishing practices
- climate change
The drop down sections below will explain how each of these activities contributes to ocean acidification:
🏭 Various Industrial Processes
Factories release large volumes of carbon dioxide and other pollutants into the atmosphere, which can dissolve into oceans and lower their pH.
🚗 Human Activities Increasing Air Pollution
Transportation, heating, and electricity use release excess CO₂, which is absorbed by oceans, leading to increased acidity in marine environments.
🌲 Deforestation
Trees help absorb CO₂. Cutting them down decreases this natural filter, increasing atmospheric CO₂ that eventually gets absorbed by oceans.
🐟 Unsustainable Fishing Practices
Overfishing disrupts ecosystems and removes species that help maintain ocean balance, making marine environments more vulnerable to acidification.
🌡️ Climate Change
Rising global temperatures and greenhouse gases increase CO₂ in the atmosphere, accelerating its absorption by oceans and increasing acidification.
Managing your industrial emissions and environmental impact to preserve coral reefs and protect the planet can be challenging, but companies like Greenly are here to help your business succeed as industries worldwide push for greater sustainability.
Close
How Can We Stop Coral Bleaching and Protect Coral Reefs?
In order to stop coral bleaching and protect coral reefs moving forward, we all need to be more mindful of our day-to-day actions and how they contribute to global warming – as coral reefs will require more stable, global temperatures to survive.
The good news about coral bleaching and global warming is that coral reefs aren’t entirely helpless in the fight against climate change.
Coral reefs, such as the ones in the Great Barrier Reef, are self-healing and are often able to recover from damage by themselves – but this doesn’t mean that they are no longer under the threat of climate change or that we should stop making an effort to protect coral reefs.
If the world is to reach 1.5°C in the midst of global warming, the Intergovernmental Panel on Climate Change has claimed that up to 90% of coral reefs around the world will die off. Therefore, mankind can certainly play a role in mitigating this desolate and currently inevitable fate for coral reefs.
Here are some things that can be done to help prevent coral bleaching and protect coral reefs:
- Stop Fishing Near Coral Reefs – We can’t expect the ecosystems in the coral reefs to thrive if we’re constantly fishing them up. Dory said it first: it’s best if we just let them “keep swimming”!
- Improve Water Quality & Environmental Regulations – In order to revive coral reefs around the world, greater climate legislation will be needed to improve water quality – seeing as many people will lack the intrinsic motivation to make this effort themselves.
- Recycle or Throw Away Trash Correctly – You’ve probably heard how plastic straws end up in the ocean and harm marine life, but did you know that there could be traces of plastic in the fish you eat? If we want to protect coral reefs, we have to protect the surrounding species which rely on coral reefs for shelter and vitality – meaning it’s imperative to dispose of trash properly and recycle whenever possible.
- Don’t Touch the Reefs! – As a pun intended from “Finding Nemo”, it is crucial to leave coral reefs alone when snorkeling and scuba diving to see coral reefs. This is because touching coral reefs could damage or even kill them. Therefore, it’s best to reach for sand whenever you need to grasp onto something while underwater.
- Live More Sustainably – Although this tip is general advice, it really will help to control global temperatures and keep coral reefs alive. This can be done by incorporating small, but effective sustainable choices into your day-to-day life – such as by making sure you turn the lights off when you leave a room or choosing to take public transportation to work.
Ultimately, coral reefs are not only essential to ocean life – but for all of us living above the water. It’s possible for us to take action to protect coral reefs from coral bleaching, but we need to take action now in order to preserve this extraordinary facet of marine life that has somehow survived all of this time on Earth.
This time, coral reefs need a little help making it through – and we have the power to do so.
What About Greenly?
If reading this article coral reefs has made you interested in reducing your carbon emissions to further fight against climate change – Greenly can help you!
Seeking to understand how coral reefs could have an impact on the ocean and subsequent economic activities which may relate to your business, but don’t worry – Greenly is here to help! Click here to book a demo and get personalized expertise on how you can start to reduce your own emissions and decrease your environmental impact.
Greenly can help you make an environmental change for the better, starting with a carbon footprint assessment to know how much carbon emissions your company produces.
Sources
Coral Reef Alliance https://coral.org/en/coral-reefs-101/why-care-about-reefs/biodiversity/ and https://coral.org/en/blog/the-dynamic-connection-between-sea-turtles-and-coral-reefs/
UN Environment Program https://www.unep.org/topics/ocean-seas-and-coasts/blue-ecosystems/coral-reefs and https://www.unep.org/news-and-stories/press-release/rising-sea-surface-temperatures-driving-loss-14-percent-corals-2009
We Forum https://www.weforum.org/stories/2017/06/healthy-coral-reefs-are-good-for-tourism-and-tourism-can-be-good-for-reefs/
National Ocean Service https://oceanservice.noaa.gov/education/tutorial_corals/coral01_intro.html and https://oceanservice.noaa.gov/education/tutorial_corals/coral04_reefs.html and https://oceanservice.noaa.gov/facts/threecorals.html
International Fund for Animal Welfare https://www.ifaw.org/international/animals/coral
Northwest Atlas https://eatlas.org.au/nwa/global-coral-bleaching-causes
Marine Biodiversity & Learning Center https://www.marinebiodiversity.ca/coral-reef-ecosystems-a-vibrant-underwater-world-to-cherish-and-protect/
National Geographic https://education.nationalgeographic.org/resource/great-barrier-reef/
Queensland Government https://www.detsi.qld.gov.au/our-department/news-media/down-to-earth/dive-in-exploring-the-great-barrier-reef-ecosystem
Environment Protection Agency https://www.epa.gov/coral-reefs/basic-information-about-coral-reefs
Coral Guardian https://www.coralguardian.org/en/coral-reef-important/
Ocean Climate https://www.ocean-climate.org/wp-content/uploads/2017/03/coral-reefs-climate-change_ScientificNotes_Oct2016_BD_ppp-6.pdf
UNESCO https://whc.unesco.org/en/list/154/
Maldvies Manta Conservation Program https://www.maldivesmantaconservation.org/maldives-natural-history
NOAA Fisheries https://www.fisheries.noaa.gov/national/habitat-conservation/deep-sea-coral-habitat
Research Gate https://www.researchgate.net/publication/7136348_Reefs_of_the_Deep_The_Biology_and_Geology_of_Cold-Water_Coral_Ecosystems
Conservation International https://www.conservation.org/nature-is-speaking/the-voices
PNAS https://www.pnas.org/doi/10.1073/pnas.1712806115
Great Barrier Reef Foundation https://www.barrierreef.org/news/news/unlocking-the-secrets-of-natural-reef-recovery
Woods Hole Oceanographic Institution https://www.whoi.edu/oceanus/feature/is-the-great-barrier-reef-making-a-comeback/
Salon https://www.salon.com/2023/03/08/microplastics-ocean-fish-seafood/