There is a reason for this emphasis on corals and their habitats, and this piece will hopefully give you a better idea into the big picture. Let’s dive in and explore the magnificent coral reefs!

What are they?


The shallows are a wonderful place, both for creatures of land and sea. Land animals, such as humans, head to the shallows to cool off, and many, such as seals and walruses, choose the boundary between the elements as the best place to raise their young.

Unfortunately, shallows can be a torrid place for any true life to take hold, as the current is strong, the waves crash relentlessly, and sand does not hold a significant amount of nutrients. This is where coral reefs come into the picture.

At the most basic level, corals came from polyps. These are single, columnar bodies with a mouth surrounded by tentacles. Most of them are only sparingly mobile but can detach and “jump” from places that have become unsuitable. Polyps colonize together to form hard corals, and many hard corals secrete calcium carbonate to build their own reef structure that suits their habitat.

Anemonies travel far and wide to find the perfect reef to settle down in. Fish join the fray, with some living their entire lives in this community, while others just pass by to drop their spawn, as if the reef was a nursery. Individual food chains and ecosystems run harmoniously alongside each other, and slowly they grow a dependence upon one another, forming complete coral reef systems.

“Coral reefs are invaluable to the planet.”

Looking at it from the outside in, it is a sum of many, many moving parts that work together. However, looking from the inside out, the coral reef is one biologically and chemically stable living being. Fascinating, is it not?

(Oh, you wanted the short answer? Well, corals don’t photosynthesize, so the polyps are animals! Really, corals are just a huge colony of animals)

How does it grow?

Okay, remember those little polyps? Each one of those has the ability to live on its own if it wanted to, just like many other small organisms. However, there is a safety in numbers, so most do choose to settle in together for the long haul.

Growth happens after polyps gather together and attach themselves to a suitable rock or hard surface underwater. They secrete calcium carbonate from under their skin and push it outward to cover themselves, somewhat like an exoskeleton. These skeletons not only act as protection from the current and predators, but also provide a great place for more polyps to attach themselves onto!

Skeleton growth is a very energy intensive process, as you can imagine, and most have algae living within the polyp’s tissues to provide that energy. However, external factors do come into play, such as water temperature, salinity, depth, turbulence, and the availability of food and sunlight. Different species grow at different rates, too.

As a general outline, corals do better in warmer, clear, shallow waters that have a higher salinity. This allows for more sunlight, and the photosynthetic algae are able to produce food for the corals. Many corals are also filter feeders, so waters that have plankton blooms from time to time will be a benefit for the corals.

What are corals for?

Shallow waters that corals frequently take hold are usually relatively nutrient-sparse. Most life is unable to take hold there, not only because of its nutrient-deficient waters but also because of the crashing waves.

The coral reef is important in that sense, because once it takes hold and begins growing, small invertebrates and fish can begin to move in and inhabit these areas. This brings more life into the shallows, with even larger fish coming inland to feed or to breed and keep their young safe.

In fact, over 4000 species of fish (and almost 25% of all marine life) can be found in a coral reef anywhere around the world.

Essentially, coral reefs are the rainforests of the ocean. Not only are they full of life, but they are also filled to the brim with natural resources and potential.

Benefits to humans?

Alright, while reefs are obviously a benefit for marine life, as was intended, are they any good for humans?


Think about it – how many people in the world do you think eat something that comes from the ocean? Well, more than 3.5 billion people today rely on the ocean for their primary source of food, usually fish. The ocean is so expansive and taking from something this wide means that ideally, there would be a lot more left for the next time.

70-75 million tons of fish is caught from the ocean every year.

Those 4000 species of reef fish account for almost 25% of all fish species. Meaning that statistically, just under 1 billion people rely on the coral reefs directly for their primary protein source. This is all not taking into account the many other species that are consumed, such as sharks, rays, shellfish, and invertebrates like crayfish and crab, that use the coral reefs either for shelter or for brooding.


With such a large industry, there is so much money to be pulled in from the average consumer. Given that most countries are surrounded by water (and those that do not have some sort of access to the ocean), this is a huge income earner.

Billions of dollars (and millions of jobs) rely on the ocean providing the food. Plus, many small market fishermen do not have access to large commercial ships, and the easiest, most risk-free way of fishing out of the little dinghies would be to fish within the boundaries of the coral reefs.


¾ of all major cities are by the sea, and over 80% of people live within 60 miles of a coast. Plus, tropical coral reefs line the shores of 109 countries. In this sense, coral reefs are invaluable, as they do provide some of the best views and opportunities for jobs and leisure to the people of these big cities (and many little towns, too).

However, it goes a lot deeper than that, as coral reefs are tough structures and make excellent wave breakers. There have been typhoons that have stopped short, or at least been slowed way down, by coral reefs before heading inland, helping prevent excessive damage had they not been present.

With so many people living by the water today, coral reefs are amazing at providing the barrier between land and sea.


So many of the world’s medicines today come from animals, plants, and fungi. Coral reefs are basically a gathering of many different species from all around the ocean. Do the math.

With so many benefits to humans, surely coral reefs should be protected at all costs, right?

Reef damage?


Coral reefs are complete ecosystems, meaning that even the smallest tip of the scale can throw them off. Typhoons and tsunamis wreck coral reefs on a consistent basis, leaving them skeletons of their former selves, killing off thousands, if not millions, of individuals that live within the reef, and leaving many more homeless, to fend for themselves.

This, however, is not even scratching the surface of reef damage.

Coral bleaching is a hot topic right now, with the Great Barrier Reef (and the Tubbataha Reef, much closer to home) being one of the worst hit. For some perspective: from 1876-1979, there were 3 bleaching incidents worldwide. From 1980-1993, there are 60 on record, and even more recently, 400 events were recorded in 2002 alone.

Coral bleaching does not happen when a typhoon rips it off its rock, it happens when the water chemistry shifts. If temperature, light, or nutrients suddenly shift, corals are placed under immense stress, and they expel the algae living inside them (to try and keep them alive), turning them completely white.


When this happens, corals are unable to take in food from their main food source, and it causes them to be susceptible to disease. If nothing is done in time, the coral dies.

Where does this change in water chemistry come from? Well, a large part of it comes from pollution and 80% of all pollution of the ocean comes from land-based activities. Run-off is some of it (a lot of it manmade, whether it be coastal development or factory dumping of waste), but a much larger part comes from things like sedimentation, destructive fishing methods, tourism, and global warming.

(Many still deny global warming as a manmade phenomenon. This article is not about global warming, even though the overwhelming scientific consensus is that yes, while global warming was always going to happen, humans releasing carbon-based gases and compounds into the atmosphere has sped it up at a rate never before seen in historical records.)

What does that mean for marine life and humans?


Coral bleaching is devastating for marine life. The mortality rate of corals after the algae is expelled is quite high, due to the stresses still usually being present in the water during/after the bleaching. As corals die out (almost 30% of all coral reefs are now dead), the sea life it holds slowly begins to die out as well, as many live their entire lives within the shelter of coral reefs.

The others have to leave the area and fend for themselves while searching for another reef nearby. Unfortunately, due to the chain-like nature of corals (just like the Coral Triangle), if the waters of one part of the reef are less than ideal, its neighbouring corals will also be affected. This does result in the deaths of most of the marine life within the reef.

This spells disaster for the people who rely on reefs to feed their families and earn a living. Here in the Philippines, there are so many stunning reef fish on display in wet markets for food (many caught by dynamite/cyanide fishing, which kills a lot of reefs yearly. It has been outlawed, but many still continue this disgusting practice). Just imagine most of it leaving the markets and with the ever-growing number of people, it spells disaster for most countries, including this one.

Helping the reefs?


Thankfully, people are beginning to wake up to the importance of keeping reefs healthy, seeing as the most damage was done by humans, to begin with. There are many ways to help, and seeing as coral reefs are always close to the shore, the first way is probably the easiest. When you’re scuba diving at a reef, do not step on the corals and don’t take anything from the reef! Simple stuff.

Heading a little into deeper waters, do not throw anything that does not belong in the ocean into the ocean. This starts from the consumers, be it plastic bags and rubbish into the ocean with the mantra ‘out of sight, out of mind’. Further along the production chain, producers need to stop dumping toxic waste into the ocean. It is vast, yes, but it does suffer the consequences of our actions.


Dynamite and cyanide fishing have been proven many-a-times to be not only destructive for the fish and corals, but also toward humans. Fishermen have lost fingers, limbs, and even their lives practicing this stupid, outdated fishing method. More policing is needed, with stricter penalties for the offenders and re-offenders.

Coral nurseries are doing a wonderful job of helping repopulate once barren reefs, and the efforts have continued onward. Marine reserves do the same thing, but at present, only less than 0.5% of all marine habitats are protected; and with 93 (out of 109) countries experiencing significant reef degradation, it is about time to step in, and step up.

One prime example of a protected reef that is able to protect itself has to be the Tubbataha Reef, a UNESCO World Heritage Site, and a protected marine reserve. In 2010, Tubbataha was among some of the worst hit by El Nino. However, there was only a total of 1% coral loss after the year’s El Nino had passed, proving that given the opportunity, coral reefs are able to rebuild and flourish.

Coral reefs are invaluable to the planet, especially to the life it sustains, and the humans it feeds. For something this financially and biologically viable so much more needs to be done to protect them.

Once upon a time, the Great Barrier Reef was the biggest living object to be visible from space. Today, large bleached patches plague the reef, and much of it is already dead. This must not be allowed to happen worldwide, and wherever it is happening must be stopped and protected right away.

Without the reefs, the world is a lot worse off.