On the Fishy Business Involving Earth’s Coral Population

In the Spring of 2015, my father and I took an overcrowded bus to the Florida Keys. We were with my first and his maybe hundredth dive group hailing from Atlanta headed south with the intention of diving at some of the most beautiful coral reefs the United States offers, the various reefs surrounding the southernmost island in the Keys, Key Largo. The first few minutes in the water are always nerve-racking, at least for me. Floating with nothing below you but what appears to be an azure abyss is nothing less than extremely unsettling. However, after our DiveMaster beckoned my father and I deeper into this alien world, what lay at the bottom of the ocean slowly came into view. Beautiful, cascading formations of exotic colors and shapes filled our eyes. Fish, large and small, darted in and out of the sprawling caves in an attempt to avoid our group’s obnoxious bubbles and awkward movements. I can only owe our awkwardness to the sheer sense of awe instilled in us by the unbelievably gorgeous landscape before our group. We spent the next hour floating above and exploring this underwater city. It wasn’t until after we had moved past the most beautiful corals that I began to realize something.

Most of the corals were dead.

Bleached white, or covered in their own rotting tissue, over half of the corals we came upon were either already dead or quickly fading away. To see such beauty literally melting away into nothing was heartbreaking. These areas of dead corals hosted almost no fish, with the exception of a few bottom feeders. I remember vividly stopping in the water and just looking at it all. Behind me was a bustling metropolis of an unbelievably complex and beautiful underwater ecosystem, and not ten feet away from it was a graveyard.

After the dive, I had asked the DiveMaster what was happening to the reefs, why they were all dying if not already dead. His reply was unsatisfying, something along the lines of a “natural order of things”, but I knew that wasn’t true. I decided to do a little digging, and figured out that corals have been in a state of decay for since the 1980s.

Contributing Factors

One would assume that the factors causing coral populations to be endangered like fishing or the digging of canals are the only things affecting the coral population, but most of the blame points to ocean acidification. Ocean acidification is the theory that “the release of carbon dioxide (CO₂) from humankind’s industrial and agricultural activities has increased the amount of CO₂ in the atmosphere. The ocean absorbs about a quarter of the CO₂ we release into the atmosphere every year, so as atmospheric CO₂ levels increase, so do the levels in the ocean” (PMEL/NOAA). This seems like a relatively mild problem, but the ocean’s rapidly changing CO₂ levels are “changing the chemistry of the seawater” and creating an environment in which corals cannot survive (PMEL/NOAA). When a living thing’s habitat is threatened, it has two options: move or die. Unfortunately, coral cannot move, so the latter is the only option. The following image represents a healthy coral (left) versus a bleached coral (right). There are few reefs around the world where you will not see bleached corals.

What’s Happening

The deaths of most corals around the world is due to bleaching, a process in which, due to surrounding water being too warm, corals “will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white. When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality” (NOAA). These high levels of stress in corals post-bleach is basically death’s door for corals. Their massive impact on underwater ecosystems, and therefore extremely high responsibility to keep the ecosystem functioning efficiently prove too much for the corals under stress to perform, and they die. Additional factors besides the change of seawater chemistry due to pollution include rising water temperatures (which is also arguably a product of increased CO₂ emissions), overexposure to sunlight, and low tides.  The following graphic assists in understanding of the process of coral bleaching.

The Consequences

There are various consequences to the death of corals across the globe. Firstly, we lose beautiful underwater landscapes that contribute to the tourism industry in countless countries which enjoy the economic benefits of reefs. Tourism with regard to reefs is a $375 billion industry, and as more of them die off, these countries – some of which rely heavily on the economic benefits of tourism – will suffer. On a more environmental note, however, thousands of fish species rely on reefs for shelter, food, and breeding. Taking away this shelter allows for weaker species to be either hunted to extinction by predators, or die by starvation (oceana). Geographically, corals also serve a purpose. Their immense size helps to break waves and keep nearby coasts safe from high tides or destructive waves. So, if the corals die off, the nearby coasts are absolutely at risk of some pretty extensive water damage (oceana). Lastly, when the reefs die, fish must abandon them in order to find more shelter and food sources, this exodus affects local fishermen and coastal peoples who rely on the reefs for food and economy (oceana).

What can we do?

The best way to combat coral bleaching and death has been put forth time and again for thousands of environmental issues. This solution of course is the phasing out of fossil fuels that produce CO₂ emissions. Unfortunately, I don’t see this change coming anytime soon. The ofssil fuel industry is simply too integral in the world’s economy. Doing away with this industry as a whole would jeopardize millions. Thousands would be jobless, many cities and towns (and even some countries) would lose their primary source of income, and who knows what kinds of political drama it would produce. The only thing we can do if this industry isn’t going to go away would be to advocate for more sustainable methods of energy like solar or wind power. Across the US, we are seeing more and more solar and wind farms, but they are extremely expensive, and unfortunately people tend to cling to what is familiar (and cheap, for that matter), so in the immediate future I can’t see any massive change coming to our society as far as renewable energy goes.

As depressing as it is, I think we should all take the time and effort to appreciate reefs while we still can.

 

Sources

https://www.pmel.noaa.gov/co2/story/Ocean+Acidification

https://oceanservice.noaa.gov/facts/coral_bleach.html

https://oceana.org/blog/glance-coral-reefs-are-dying-heres-why

 

-Noah Barnes