The Keystone Life of Coral

Adventures in Sustainable Living Podcast

Episode 25

The Keystone Life of Coral

Hello everyone and welcome back to the Adventures in Sustainable Living Podcast. This is your host Patrick and this is episode #25 called The Keystone Life of Coral. 

In this episode I am going to introduce the concept of a keystone species, the importance of a keystone species and what happens if that species is taken out of an ecosystem. And as you could guess, the keystone species that I am speaking of in this episode is coral. I am going to discuss the importance of our coral reefs, what is happening to them, and why we should truly be concerned.  

You know, I have always been an avid outdoorsman. Hiking, backpacking, climbing including ice climbing, kayaking, hunting, fishing, traveling in an RV. Wilderness survival training, first aid and EMT training. One year I did a 2 week solo kayaking trip on Lake Powell. Anything and everything I could possibly do to be outside. Then I started traveling abroad and doing the same sort of thing except out of the country. On one trip I traveled 250 miles by boat on the Napo River in the Amazon Basin and kayaked and hiked to remote lakes. I truly saw many things that most people never appreciate except on the pages of National Geographic. 

Then I think it was about 10 to 12 years ago that my wonderful long time partner Annette started suggesting that we learn how to scuba dive. For a couple of years, I dismissed the idea. I kept thinking I already had so many things that I enjoyed. Why would I take the trouble to do something like that. Besides, I was busy with work and many other things. But, man oh man was I wrong. 

Finally she convinced me to take a class. We started at a dive shop in Denver. The first step when you are learning to dive is to learn the basics in confined water, which in Colorado that means a swimming pool. Once you do that you progress to open water dives. Fortunately, in Denver there is a huge salt water aquarium that is large enough to be considered an open water dive. 

So, we had been to the aquarium before but just as tourists so to speak.  And like most people, walked around outside observing some really amazing fish. But, when you go there to dive, you are of course IN the tank with the fish, including the sharks. In fact they have a specific shark dive you can go on.  

Once we did this, I was hooked on diving because I was introduced to a world that I did not know even existed. For most of my life, I had been above the water hiking and climbing and seeing some amazing places.  But it is a totally different world when you are diving. And one of the best parts for me is that is is amazingly quiet. 

Secondly, most of the time the fish are truly curious. I cannot speak enough about how amazing it is to have a sea turtle swim up and get right in your face. To see schools of sharks swim by. On one trip I went with a friend of mine to the Baja area of Mexico. 

My dive buddy and good friend Greg was swimming not even 6 feet away and I could not see him because there were SO MANY fish swimming around us. Absolutely an amazing experience. And one of the things that always fascinates me is how an octopus can swim from one rock to another, and completely change their body color in a matter of seconds in order to be completely camouflaged.  

But anyway, as the years went by, Annette and I gained more and more experience. We then spent 6 weeks in Honduras getting some advanced training. And about 2 years after that, we both got certified as instructors. 

Now why do I love diving so much? Two main reasons: first of all I am outside doing something, getting some exercise. Secondly, it is a completely different way to enjoy the natural world. Thirdly, there is a huge variety of things you an do as a diver. The list is endless. 

At least in the United States, only about 1% of the population is certified to dive and only about half of those are actually active divers. That truly is not that many people. 

Now as you can imagine, the majority of divers enjoy the natural world. They go diving because you always see some amazing creatures and plant life. Even swimming through millions of tiny floating crustaceans is an exciting experience. Additionally, and the subject of this podcast episode, swimming along a huge coral reef is a stunning experience. 

Did you know that coral reefs are often referred to as being the “rain forests of the sea”. Coral actually covers less than 1% of the ocean floor yet coral reefs support approximately 25 percent of all known marine species. Reefs provide homes for more than 4,000 species of fish, 700 species of coral, and thousands and thousands of plants. 

But what exactly is coral and why is it so important? You know it took me several years after I started diving to learn about and truly appreciate what coral really is and the vital role that coral plays in the ocean ecosystem. It really truly is amazing. But is it a plant? Is it an animal? Or is it just a rock. How does it form? Why is coral so important.   

Because coral has such hardened surfaces, they are sometimes mistaken as rocks. And because they are attached, essentially “taking root” to the ocean floor, they are also often mistaken as plants. But, unlike rocks, corals are actually alive. And unlike plants, corals do not make their own food.  So what that means is that coral are in fact animals. 

The mound or branch that we call coral is actually made up of hundreds to thousands of tiny soft bodied creatures called polyps. Most of them are no thicker than a nickel.  A coral polyp is shaped like a small cylinder, with a mouth at one end which is surrounded by tentacles. These tentacles gather food and will actually sting other creatures that are considered a threat. But this soft-bodied poly secretes a hard outer skeleton of limestone (calcium carbonate) that attaches either to rock or the dead skeletons of other polyps.

In the case of stony or hard corals, these polyp conglomerates grow, die, and endlessly repeat the cycle over time. This cycle of life and death is what slowly lays down the limestone foundation for coral reefs and gives shape to the familiar corals that we have come to recognize.  Additionally because of this cycle of life, growth, death, and regeneration among individual polyps, many coral colonies can live for a very long time. 

And the variety of species living on coral reefs is greater than almost anywhere else in the world. Scientists estimate that more than one million species of plants and animals are associated with coral reef ecosystems.

But coral are actually “sessile” animals, which means they actually take root to the ocean floor similar to a plant. But, corals do not make their own food like a plant does. And most of the time coral polyp bodies are actually clear. The bright colors that characterize many corals are actually the result of various types of algae growing in the tissues of the polyps. 

Most corals have a  symbiotic relationship with this algae which is  known as zooxanthellae (pronounced zo-UH-zan-thuh-lay), which are plant-like organisms. As I said, this microscopic algae resides within the coral's tissues and is consequently well protected and makes use of the coral's metabolic waste products for photosynthesis, which is the process by which plants make their own food. The bye products of photosynthesis include oxygen and carbohydrates, which the coral consumes and uses the energy to build reefs. 

And due to this clever collaboration between the coral polyps and the algae, which has endured between some of the tiniest ocean animals and plants for some 25 million years, this mutual exchange is the reason why coral reefs are the largest structures of biological origin on Earth, and rival old-growth forests in the longevity of their ecological communities.

And once I learned all of this about coral, every time I went diving, it completely changed how I viewed a coral reef and I became much more respectful not to touch, damage, much less destroy a single piece of coral.  

But, why is it that coral is so important. 

First of all coral reefs are spread out over the more shallow portions of the oceans in the world's tropical and subtropical regions. Approximately 25% of the 500,000 known animal species living in the world's oceans inhabit the areas with coral reefs.

Coral reefs provide shelter and spawning grounds to a wide range of ocean life and serve as a vital role in the marine ecosystem. Coral reefs also help to regulate the carbon dioxide levels in the ocean. They also act as a barrier which protects the shoreline from strong currents and wave impact. Thus you hear the term “barrier reef” because the coral reefs protect the shorelines from storm surge and erosion. 

And by the way, the water that is between a barrier reef and the shoreline is amazingly calm and is a great place to swim and free dive in order to see lots of fish. 

But coral reefs also provide employment opportunities for local communities due to the recreational aspects that they provide. Over half a billion people depend on reef for food and income, as well as protection of the shorelines.  

Fishing, diving, and snorkeling on and near reefs add hundreds of millions of dollars to local businesses. The net economic value of the world’s coral reefs is estimated to be tens of billions of dollars world wide. Obviously the coral reefs around the world are extremely important.  

But what would happen if they were gone, they all died. 

Well, this is where I want to introduce the concept of The Keystone Life of Coral. 

Have you ever heard of the concept of a “keystone species”? This is a concept that was introduced in 1969 by a zoologist named Robert T Paine. A keystone species is a species that has a disproportionately large affect on the natural environment relative to its abundance. So what this means is that other species in the ecosystem depend heavily on the presence and activity of the keystone species because this one single species plays an important ecological role in the community. 

So, look at it this way. Every ecosystem has certain species that are critical to the survival of the other species in the system. The keystone species could be a predator or an unassuming plant, but without them the ecosystem may not survive.

There are three types of keystones species that are often cited by most scientists:

Predators, ecosystem engineers, and mutualists. 

Predators; often go after weaker animals and help to control the population of the prey species. Otherwise the herd would over graze, over populate, and die of disease. 

Ecosystem Engineers

An ecosystem engineer is an organism that creates, changes, or destroys a habitat. There is no better example of a keystone engineer than the beaver. Beavers produce ponds, help to produce wetlands, take down trees so that new plants will grow and thus create habitat for over animals. 

Mutualists

When two or more species in an ecosystem interact for each other’s benefit, they are called mutualists. Bees are a primary example of this. As bees take the nectar from flowers, they collect pollen and spread it from one flower to the next, enhancing the odds of fertilization and greater flower growth. 

The relationship between algae and coral is another example of a mutualist or symbiotic relationship.  

But what most people do not realize is that if you take a keystone species out of the ecosystem, it leads to a domino effect of destruction. And since we are talking about coral, let’s consider what would happen if coral reefs were to disappear. 

What would happen?

• Thousands of marine species would disappear due to lack of food and over predation due to lack of shelter.  
• There would be a major world wide food crises especially in coastal regions because people would loose a significant portion of the food supply.
• Coastal regions would experience flooding and erosion due to lack of protection from barrier reefs. 
• The health industry would loose a major source of important drugs
• Due to coral bleaching, tourism would fail because people want to see bright colorful reefs and lots of fish. Small island countries would loose numerous jobs which would lead to poverty. 
• And I am certain there are many more serious repercussions that we are unable to perceive at this moment.

And the most surprising part is that this is not a hypothetical scenario or just a figment of imagination proposed by an imaginative scientist. This threat is very real.

According to the Intergovernmental Panel on Climate Change, a meager 1.5°C rise in global temperature can lead to the extinction of 70-90% of coral reefs around the globe. This number could go as high as 99% if global temperature rises by 2°C.

The oceans have already lost at least 20% of the coral reefs world wide. In fact, the barrier reef off the coast of Florida is now 90% destroyed. 

But what you must understand is that coral reefs do not develop in a day, a month, or even a year. They are very slow-growing creatures. Coral reefs grow at a rate of approximately 15 cm per year, which is about 6 inches. The Great Barrier Reef in Australia has been building for over 20,000 years!

But what exactly is happening? 

First of all, allow me to give you a single example from our own country. The Florida Keys are home to North America's only coral barrier reef, which stretches for nearly 150 miles in length and is about four miles wide.

Coral reefs need clean, clear water to survive. When sediment and other pollutants contaminate the water it lowers the water quality, smothers the reef and speeds the growth of damaging algae. Pollution can also make corals more susceptible to disease. It can impede coral growth and reproduction, and cause changes in food structures on the reef.

As far as the Florida Keys is concerned, our expansive watershed includes all of the rivers and streams that drain into Florida Bay, the Southwest Florida Shelf, the Gulf of Mexico, the Florida Straits, and the Atlantic Ocean. This means that pollutants from as far away as the Mississippi River Basin are entering this ecological system.

And Florida is of course not the only place in the world that is affected by similar environmental changes. 

On a global scale, one of the most important threats facing coral reefs is climate change. Most scientists agree these days that climate change is a real thing and this spells out some serious trouble for the coral reefs. 

Since the late 19th century, global ocean temperature has risen 1.3 degrees F and is continuing to climb. These changes in water temperature places the coral polyps under stress. Consequently they loose the algae that lives in their tissues. Since it is the various algae species that gives coral the vibrant colors that we appreciate, once the algae are gone, the corals turn white, thus the term bleaching. 

This also means that coral loose the valuable symbiotic relationship that provides them with a valuable source of food. Coral can survive a bleaching event but they are under great stress, are less resistant to disease, and very susceptible to mortality. 

You see, increased carbon dioxide in the atmosphere is one of the recognized causes of the climate change we are experiencing. And it is also problematic for coral reefs. The ocean absorbs approximately one-third of the atmosphere’s excess carbon dioxide. This results in a more acidic ocean. In order for a coral reef to grow, it must produce limestone (or calcium carbonate) at a rate that is faster than the reef is being eroded. Ocean acidification slows the rate at which coral reefs generate calcium carbonate, thus slowing the growth of coral skeletons.

Climate change can cause sea level rise; changes in the frequency, intensity, and distribution of tropical storms; and altered ocean circulation. All of these impacts can have negative consequences for the health and diversity of reefs around the world, including what is happening in the Florida Keys.

But you must also know, there are many people, organizations, and governments making great and extensive efforts to save the reef systems around the world.. 

In order to address this issue there is an enormous coral restoration project is progress. Using some very innovative techniques, such as underwater coral farming and reattaching broken coral pieces, these projects transplant and restore thousands of coral colonies on damaged reef sites.

And this is the part that is fun for me, trained scuba divers are given special permission to work on the reefs.These divers transplant the new pieces of coral by using cement or epoxy putty. The goal here is to restore the coral reef to allow the natural inhabitants a chance to thrive.

And what is encouraging is that scientists have found that the corals grown in the nurseries are able to reproduce in their new homes.  This means staghorn and elkhorn have a chance for a comeback. It also means genetic diversity may be achieved along the reefs – allowing for stronger and more resilient ecosystems in our ocean.

Since healthy coral is a vital part of the ocean ecosystem, restoring reefs is of vital importance.

But you see, here is the thing. Every effort made at reef restoration will be in vain until each and every human being is ready to work together and address this crisis.

This is not just about coral reefs. Howsoever insignificant a species might appear, even if one goes extinct, it can lead to serious disruptions in the food chain across the globe. 

Now on the subject of keystone species. Are humans considered a keystone species. Well, scientist look at humans as a hyper keystone species because we obviously drive complex interactions with other keystone species in the environment. But I almost take offense to such a thought. 

It seems to me that the natural world greatly benefits from the absence of human beings. It was clearly noted during the pandemic, and the wide spread general absence of humans due to quarantine, that water ways began to clear, plants began to regrow, and animals species not seen in decades began to return. 

And I have personally witnessed such things even close to home. On the north side of my property is a county road that dead ends at a trail head. For years there were numerous free camping sites along the creek drainage. Every Spring and Summer these camp sites were over run with people who had no respect for the environment. After every weekend, I would go along the county road and put out smoldering fires and clean up trash. Finally the Forest Service closed all the camping sites. With the absence of people, it only took one season for all the grass to grow back and for new plants and trees to sprout. 

Consequently, I think that humanity has the potential to be a very important keystone species. But we also hold in our hands the ability to either take all of nature down with us or to make sure it gets restored and preserved for future generations. 

The destruction of the coral reefs is just another example of how humanity continues to destroy the very things that are needed for a sustainable future. If you really look at the concept of a keystone species, that species actually has a beneficial affect on other species in the ecosystem. Yet we as humans are always destroying things simply for short sighted benefits. The only way we can truly be a keystone species is that if every single person takes responsibility for every other creature on this planet that we call home. 

As I recently said to someone, you had better learn the skills of sustainability because in the not too distant future you may not have a choice. 

I hope that this episode has made you take pause in how you live. I hope you are now questioning all the things that you take for granted and are now considering the impact you have on planet Earth every single day. Because if you are, that is the first step to building a sustainable future.

And folks, please remember to sign up for Off Grid Living News and the Adventures in Sustainable Living podcast.  

This is your host Patrick signing off. Please join me  again next week for another exciting episode.