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Threats to Coral Reefs

Preserving Our Precious Caribbean Coral Reefs

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The Caribbean Ecosystem

It is hard to overstate the importance of coral reefs, not just for the Caribbean but for the world. They are often compared to rainforests on account of their biodiversity, medical potential, and economic significance. One-quarter of all marine life depends on the habitat provided by reefs, and reefs economically support half a billion people worldwide, with an approximate value of around $30 billion per year.

Despite their ecological necessity and obvious monetary value, coral reefs are severely endangered. Nearly half of all coral reefs have disappeared in just the last 30 years; the die-off is even more drastic when you consider that those reefs took thousands of years to build. And scientists do not paint a rosy picture of the future for reefs: They estimate that 70% to 90% of coral reefs will die in the next 20 years, and the remainder will die off by 2100.

These are depressing statistics, but they are not cast in stone. Action today can help reverse forecasts for tomorrow. Through innovative ecotourism opportunities that double as data-collecting research dives, Alpha Submarine Adventures is fighting to keep reefs alive and ensure their preservation into the future. To get a sense of what we’re up against and why our mission is so critical, here’s an outline of the threats facing coral reefs today.

Rising Temperatures

Sea Turtle

This is perhaps the most consequential phenomenon threatening reef life today. Rising ocean temperatures are directly related to increased warming of the Earth due to humans’ excessive emission of greenhouse gases that trap heat in the atmosphere. The corresponding rises in ocean temperatures have been well-documented over the last several decades, and they have a range of effects on sea life. Temperatures even slightly higher than what corals have adapted to causes bleaching and leaves them vulnerable to disease. Warmer temps also result in more algae growth, which can overwhelm and kill coral.

Warmer air and water temperatures also lead to more intense storms that batter and damage reefs, while rising sea levels due to melting polar ice caps results in increased sediment runoff from land that can smother coral reefs near coastlines. 

Pink Earth


Overfishing is a major problem threatening all of the coral reefs and oceans of the world, and it has a cascading and catastrophic effect on ecosystems from the ocean floor to the open sea. Because reefs attract so many fish species, they are often favorite fishing spots. Fishing during spawning events, when certain species gather en masse to breed, is a particularly harmful practice. Of course, many coral reefs are part of protected areas, but many are not, and effects of overfishing elsewhere are felt on faraway reefs.


Overfishing of sharks, for instance, is one of the biggest threats to reef ecosystems. Sharks are apex predators, and if there aren’t enough of them to keep certain prey populations in check, ecosystems are thrown off balance and eventually collapse. A perfect example of this is the parrotfish. The parrotfish is a crucial part of the reef ecosystem, as it eats algae off the coral, allowing coral to thrive. Sharks eat the other large fish that prey on parrotfish. Without sharks, scientists have found that there are more fish to prey on the parrotfish, which compromises the reef’s ability to sustain itself.

Environment Pollution


There are many different sources of land- and sea-based pollution that threaten coral reefs. They can generally be grouped into several categories: sediments, toxic substances, pathogens, and nutrients. 

Sediment is runoff from rivers that is dumped on top of reefs, suffocating the coral; rising sea levels bring more coastal sediment down on reefs. Toxic substances including everything from crude oil seeping from underwater pipelines or tanker ships to agricultural pesticide runoff and certain types of sunscreen. Pathogens are disease-causing viruses and bacteria that enter reef environments through storm runoff or septic discharges. Finally, reefs can receive excessive nutrient loads from fertilizer runoff (usually from large-scale agriculture) and failed septic systems; the excessive nutrients lead to a spike in algae that can overwhelm and kill coral.

Pink Earth

Help Reefs by Donating to Alpha Today

Being aware of these dynamic and interconnected threats to coral reefs is the first step toward helping reefs adapt, recover, and endure in our future. Alpha Submarine Adventures is committed to a future with coral reefs. Help the cause today by making your donation!

Under the Sea

Learn More About Our Mission And Donate To the Cause

Ready to learn more about how you can invest in our submarine adventures, and how we’re working to protect our coral reefs in the Virgin Islands? Eager to get started right away? Make a donation here!

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