Whale sharks, while appearing terrifyingly massive, are one of the gentlest creatures to humans. They are the largest species of shark, but unlike their cousins, they are not violent animals. These noble fish feed mainly on plankton, which is where the “whale” part comes in. The whale shark has been on the endangered species list for almost ten years, and while the decline in population may not be a direct effect of the loss of coral reef biomes worldwide, the whale shark numbers have certainly taken a hit as a result. 
Image via Natural History Museum
Many species of plankton (whale sharks’ primary source of food) live in and around coral reefs, sometimes forming symbiotic relationships with coral colonies. Mass death of coral reef populations worldwide consequently kills of plankton, starving the whale sharks to death.
The Great Barrier Reef, famously the largest reef system in the world, has faced a huge drop in coral recently. According to barrierreef.org, in 2025, the Great Barrier Reef experienced its sixth mass bleaching since 2016. In the summer, temperatures rise and water quality drops due to agricultural uses. Just one increase in degrees Fahrenheit for a period of four weeks can cause mass coral bleaching across entire reef systems. 
Image via AATKings.com
Coral bleaching is the result of stress. When corals are stressed, they release algae in their system, which turns their bodies white. Bleached corals are not a sign of death, necessarily, but death almost always follows bleaching. Without these vital algae, corals are at a huge risk of starvation.
The Great Barrier Reef is the most well-known case of coral bleaching in recent years, but reefs all over the world have experienced this as well. The Florida Reef Tract, which runs parallel to the Florida Keys off the south tip of mainland Florida, has lost 90% of its live coral in the past 40 years. Many scuba-diving tourists are victims of what Xylem, an organization dedicated to studying water sustainability, calls “shifting baseline syndrome,” which occurs when a new generation accepts how they see struggling environmental conditions as the norm. If you take a vacation in the Florida Keys, you’ll see countless flourishing species of fish and coral alike, and assume all is well, but what you won’t see is the thousands of coral skeletons you swim by. 
Image via seallegacy.org
The final part of the puzzle in the Great Barrier is the El Niño phenomenon. This annual event occurs, when the trade winds, which normally blow from east to west, weaken or even reverse, which brings warmer water to the coast of Australia. This generally occurs in the hot summers, ever increasing the blistering heat upon the coral reefs.
In 2023, the Florida Keys experienced water temperatures up to 93 degrees Fahrenheit, which is about 5° above normal. Scientists in Florida recorded 100% coral bleaching on many reefs. This mass bleaching event occurs every year, killing coral before they have time to recover.
To fully understand the effects of coral bleaching, we have to look under a microscope. The algae that form a relationship with coral is called zooxanthellae, a type of dinoflagellate. These algae give coral their color, and also serve as a food source for the coral. When expelled from the coral, these algae float around the ocean for weeks, all while the coral starves to death. The algae can return to its coral, but that is unlikely, and both the coral and the algae die.
In the Philippines, whale sharks draw many tourists to the shores and to coral reefs. Oslob, a small municipality on the south coast of Cebu, attracts its tourists because it has whale sharks visiting its shores year-round. These tourists are allowed to feed the whale sharks shrimp. The whale sharks are fed around 50 tons of shrimp each year, and without the whale sharks keeping the local plankton populations at a minimum, plankton overrun and kill the coral populations. The University of Hong Kong has recorded mass die-off of coral in the Philippines mainly from whale shark tourism.
So, what can we do? The easy answer is not much. Climate change and global warming will reach a point in about 3 years where we can’t recover, according to BBC. The global temperature has risen about 1.2 degrees Celsius since pre-industrial times, and a limit of 1.5 degrees is suggested, but it is estimated that we will reach that threshold very soon unless drastic measures are taken. However, we can all do our part to help, and every person matters in a crisis such as this. The United Nations suggests recycling, using renewable energy, changing to a more sustainable diet, or growing your own garden to do your part.
There are also thousands of fundraisers for coral reef protection alone, like the Coral Reef Alliance, which is a reliable nonprofit that is dedicated to saving reefs worldwide.
The endangerment of coral reefs and many other biologically diverse biomes across the world seems hopeless, but we every act matters. Do what you can to help save the planet.
