Top 10 Weirdest Things About Coral Reefs
Okay, let me stray away from the Dark Ages, the Salem Witch Trials, and the Great Potato Famine of Ireland, and move on to a more fun topic. Coral reefs are definitely a more upbeat and happy topic than the previous few, so why not tackle that next?A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
Most people understand that coral is rooted in a seabed, which is why there is often a mistaken narrative that coral is a plant. Truthfully, corals are creatures known as Cnidarians.
Coral consists of a central polyp with a rough exoskeleton. The polyp is a rather small creature that is only a few millimeters in diameter. Coral is a vase-shaped creature that has tentacles at one end. These tentacles move food towards the mouth of the polyp.
Polyps are attached to the substrate they grow on, using a pedal disc that drills into the stratum. They produce calcium carbonate, which creates an external shell for coral.
Corals cover vast areas, but it took quite a considerable amount of time for that to happen. Coral is among the slowest-growing creatures on Earth, with an estimated 1-centimeter growth in height every year. This means that a coral reef spreading just a few square kilometers would have taken around 1 million years to grow.
The growth rate of coral depends on a couple of factors, such as nutrition and the quality of the water it is in. Although the average growth of coral is 2 centimeters per year, at some locations, a healthy coral that inhabits an area with a good amount of sunlight and no pollution in the water could easily grow over ten centimeters a year.
The Great Barrier Reef covers an area of roughly 350,000 square kilometers, and the first corals in this reef started growing about 25 million years ago at a pace of 7 centimeters per year.
Polyps are very decisive about the environment they will grow in. They need various things to survive, so they can only grow in specific regions of the ocean.
One factor for the location of coral reefs is the depth of water. Corals require lots of sunlight to provide for zooxanthellae, which grow in their system. Below certain depths, this Symbiodinium can't procure enough energy for the polyp through photosynthesis, which means the polyp dies.
Thus, corals grow in areas of the ocean where the water depth is low enough for the corals to still catch sunlight, and the seabed is only about a couple dozen meters below the surface. To prevent newer corals from being exposed to anything out of water, corals have adapted to grow higher rather than wider. This also lets each layer of polyps have the necessary nutrients for survival.
Corals are known for being colorful creatures, and marine tourism is mostly attributed to that. But where the color comes from is an interesting piece of information.
Corals can feed in two ways: by capturing zooplankton with polyp tentacles, or by their symbiotic relationship with zooxanthellae. Zooxanthellae is a type of algae that grows within corals and has a symbiotic relationship with polyps. Zooxanthellae are photosynthetic organisms that need sunlight to survive.
Zooxanthellae produce nutrients that they share with the polyp, while the polyp offers zooxanthellae safety - a classic symbiotic relationship. Zooxanthellae come in different colors based on their species and due to the presence of chlorophyll. Zooxanthellae usually come in colors such as brown and green, which are adopted by the environment. However, they can also come in colors like pink or yellow, which occurs when the environment changes. Zooxanthellae change their color when the temperature and amount of sunlight change to protect themselves against ultraviolet rays.
Reefs that grow closer to the surface are more colorful, given the algae can utilize the increased amount of sunlight effectively.
The Great Barrier Reef is the biggest coral reef system on Earth. Its size is about 350,000 square kilometers, and it has roughly 3,000 individual reef systems within it, which indeed makes it large enough to be seen from space.
With almost 1,000 islands, the Great Barrier Reef is the largest single structure made by living organisms on planet Earth. And to the best of our knowledge, anywhere else, too. The Great Barrier Reef is home to billions of corals and millions of sea creatures. This coral reef is one of the largest ecosystems on our planet.
In 2022, the Great Barrier Reef is only half of its size compared to the 1980s. This decrease was caused by pollution, but there are things Australia is doing to protect it and slowly restore it.
Most lifeforms on Earth live close to a source of food, from humans who live near streams to killer whales hanging around the Arctic Circle for prey. Creatures need nutrition as a source of energy, but corals aren't in lockstep with this kind of system.
In 1842, Charles Darwin took note of how corals seemed to flourish in areas with violent currents and strong waters. This makes the water void of anything considered a nutrient, but corals thrive in this condition nonetheless.
Corals grow in the tropics, which have a slow rate of nutrient replenishment. This is partly because of the slow breakdown of organisms and the creation of thermoclines that stop the vertical passage of nutrients. But coral reefs are filled with other creatures that need nutrients. The food chain is peculiar in reefs, to say the least. The bottom of the food chains in reefs is marine plants and dissolved nutrients.
How could a coral reef without nutrients support an ecosystem of organisms that need those nutrients?
Charles Darwin's paradoxical theory is that coral reefs are great at reusing nutrients in a closed biosphere, which lacks matter but has energy. Corals of the tropics live in sheltered areas and can provide a steady supply of nutrients within the reef. Phytoplankton and zooplankton create the base of the food chain. They are eaten by mostly polyps, fish, and crustaceans. Sponges that live in the reef can clean the water and provide nutrients that can be used by corals.
Other relatively small creatures living in the reef also play a hand in nutrient cycling. In conclusion, while coral reefs may live in parts of the ocean that do not provide many nutrients, the reefs themselves can still produce minerals and reuse them in the ecosystem that coral reefs provide.
Coral reefs are necessary arbiters for the damage caused by hurricanes. Scientists have mapped out the connection between protecting the coastline of a region and the healthiness of the coral in that region.
Throughout the multitude of hurricanes that landed on the East Coast of North America in the 2000s, areas with coral reefs were able to deal with the hurricanes better. Reefs can intervene with energy by about 97%, so the harmful effects of tropical storms can be controlled. The water inside the bay area is always tamer than the water outside of the coral reef.
Nations in hurricane-prone areas (which is most of the world) can reduce the effects of hurricanes and damage done to life and housing by around 30% by having maybe thirty meters of corals or more outside of the coastline.
That is right. The same place Jesus Christ Himself preached in is also very resistant to coral bleaching.
A bacterium referred to as "Thalassomonas loyona" is notorious for causing a deadly infection that has been dubbed the white plague. It bleaches the corals, effectively killing them. While the pace of coral bleaching is at extreme highs in almost every other reef around the world, the Red Sea has proven to be more resistant to the white plague and other bleaching forces. Corals have an extremely low bleaching rate of only about 9%.
The reason the Red Sea is such a unique case in coral bleaching, or more accurately, a lack thereof, is the presence of a disease we call BA3. BA3 can be lethal to Thalassomonas loyona, the white plague, and others. Research is being done in the present day to look into the possibility of utilizing BA3 to stop bleaching at other coral reefs. Talk about efficiency.
Okay, let me set the stage for you. By now, we have all heard of medical marijuana, right? I've heard plenty about its use for combating seizures. It turns out that marijuana isn't the only thing in nature that has that type of value. Coral is used for medical purposes in a similar manner and has been since ancient times.
We often struggle with sorting out what is truth and what is myth regarding how effective corals are as a medical source, but there is no denying that it has medical value. The most ancient origins for coral having medical purposes come from Indian medicine, in which the coral calx was referred to as Praval Bhasma. It was frequently utilized to take care of bone disorders, lack of calcium, or unbalanced metabolisms.
In other times and places, calcium carbonate from a coral shell was powdered and utilized to ease the intensity of ulcers and other health problems within the digestive system. Today, corals can do all that, as well as even help people with cancer or AIDS.
Polyps are very delicate when it comes to sudden changes in their habitats. A sudden new temperature, pH level, and a couple of other factors can kill the polyp.
Due to this, corals have an internal system that essentially works as a filter, which keeps the temperature, salinity, and pH level the same. Polyps use little sieves to adapt to small alterations of temperature and salinity. Given their natural ability to make the water quality better so they can survive, they also improve their ecosystems. Creatures that live in coral reefs benefit from the cleaner environment just as much as the coral does.
As the reef grows, the amount of corals increases, allowing them to filter larger amounts of water and provide better filtration. Even when a polyp dies, the coral skeleton continues to provide partial filtration. The downside is that creatures living in the reef become vulnerable to major changes in the environment and can't adapt to sudden, large changes.