Coral reefs are bustling ecosystems. Though covering less than 1% of the ocean surface area, they provide home for millions of fish and other marine life species.
Stony corals form hard calcium carbonate structures known as skeletons which may take the shape of towers, domes or fan shapes. Many species live in harmony with microalgae that utilize sunlight for food production by the coral.
1. They’re related to jellyfish and anemones
Corals, jellyfish and sea anemones all belong to one branch of animal evolution; they belong to a subclass known as cnidarians (animals with tentacles) that share some key traits. Jellyfish and anemones start off anchored to the bottom of the ocean but gradually move through water currents towards new habitats while corals remain relatively stationary if their surroundings become unfavorable; researchers at Okinawa Institute of Science and Technology Graduate University (OIST) have observed how these marine organisms do this.
Coral reefs are made up of living organisms known as coral polyps, which form large colonies to support themselves and each other. Although soft-bodied, these soft-bodied polyps produce a calcium carbonate skeleton to support themselves; iconic reef formations we see today in the ocean are actually clusters of these soft-bodied polyps that have grown together over time into three-dimensional habitats that support an incredible array of life, rivaling rainforests in biodiversity while creating beaches full of sand for recreational use and providing natural protection from waves.
Most corals feed by stinging small marine life with their tentacles, but they also rely on zooxanthellae algae for energy through photosynthesis. These organisms live inside coral polyps’ gastrodermal cells and use sunlight to produce carbon dioxide, oxygen, carbohydrates, lipids amino acids and other vital substances that sustain life on Earth. In turn, corals provide their home as well as carbon and nitrogen needed for continued growth of these zooxanthellae communities.
Coral skeletons provide not only support, but they also shape and color the reef. Different species of coral form formations resembling branching trees, bushes, ridges, domes, antlers or antler-like shapes in various locations throughout a reef ecosystem. Pink coral can even be found with vibrant hues like red yellow purple blue hues. Interestingly enough, some species produce both eggs and sperm, yet only reproduce when faced with mass spawning events once per year!
2. They’re clean
Coral reefs provide habitats for a wide range of marine animals. Additionally, these natural breakwaters act to shield nearby beaches from erosion during storms. Furthermore, these reefs help reduce carbon emissions by trapping carbon dioxide from the air and turning it into limestone deposits – essential building blocks of our planet!
Coral gets its colors from an incredible symbiotic relationship between itself and zooxanthellae algae that live inside its tissues, which photosynthesize and provide energy for photosynthesis in coral cells. Their cells contain chlorophyll that produces pigments of various concentrations which give coral its colors; type and intensity of lighting also has an influence on this process2.
Mutualism in reef ecosystems, where different species live together and benefit from one another, is abundant and diverse. For instance, corals use nematocysts (stinging tentacles) as protection from predators while parrotfishes eat seaweed and expel it as sand as excreta.
Reef-building stony corals can be found throughout the oceans of the world, though reef-building corals tend to only thrive in shallow tropical and subtropical waters due to zooxanthellae needing sunlight in order to photosynthesize and grow, thus prohibiting their presence in deeper-sea environments.
Coral and algae may not be the only symbiotic relationships found within marine ecosystems; for example, fishes that consume the debris that falls off reefs play an essential part in keeping its health balanced and sustainable. Furthermore, these fish also feed upon seagrasses, corals, and other marine life, helping keep everything regulated and in balance.
Reefs can be protected through keeping the water clean, planting trees to reduce runoff, and using organic fertilizers in our gardens to avoid chemicals seeping into the ocean. We can also encourage people to visit local reefs and to spread awareness of their importance; once we understand their beauty and wonderment we’ll work harder at protecting it.
3. They’re strong
Coral reefs are among the world’s largest and most diverse marine ecosystems, composed of living polyp-shaped creatures known as coral animals that build structures out of calcium carbonate mineral. These skeletons provide shelter and protection for an incredible diversity of sealife such as fish, shellfish, invertebrates and even larger plants and birds; in turn helping stabilize beaches and islands across their surroundings.
Corals are animals that live together as colonies, meaning that individual corals tend to be smaller than a dime while one coral mound can reach up to the size of an entire car. Corals don’t move very often and their protective skeletons protect them from waves or any form of erosion.
Coral animals, or polyps, feature simple bodies with central mouths and tentacles on each edge. Their primary source of nutrition comes from microcyllarian algae called zooxanthellae that reside within their tissues; these organisms photosynthesize sugars into energy that’s then transferred back into the coral animal, giving it 90 percent of its energy requirements and providing vibrant hues as a bonus!
As adults, corals can reproduce either asexually (by themselves) or sexually (with male and female corals). Asexual reproduction results in the creation of new colonies with identical genetic makeup; sexual reproduction increases genetic diversity within their colonies. Corals may also reproduce via fragmentation when part of their polyp breaks off to form new corals.
Coral reefs face one of their greatest threats from an increase in carbon dioxide levels, leading to ocean water becoming more acidic and decreasing availability of aragonite, which corals use to construct their skeletons. As a result, their growth becomes slower, weaker, more susceptible to storm damage and other stressors, and ultimately more at risk from potential threats such as hurricanes or earthquakes.
Overfishing; sediment, nutrient, and marine pollution; global warming/ocean acidification; too much heat exposure which results in coral cells losing zooxanthellae cells leading to their bleaching out and dying off globally – are all significant threats for coral reefs.
4. They’re millions of years old
Coral reefs are some of the oldest living things on Earth and one of its largest living structures, providing shelter to an astonishing array of marine life. A true natural marvel!
Coral reefs are impressive sights; their formation takes millions of years. The Great Barrier Reef, considered one of the oldest and most diverse reefs, took over 240 million years to form; other reefs may even be older!
Scientists have recently unearthed fossilized coral skeletons dating back over 480 million years in the ocean – longer than dinosaurs existed! This staggering discovery shows how incredible life forms once existed within it!
Coral reefs thrive in warm, clear water that receives ample sunlight. Corals depend on photosynthetic algae for food, while in turn providing coral with vibrant hues we know and love. Their relationship is mutualistic – coral provides shelter to the algae while in return providing essential nutrients.
There are various species of coral, each one featuring its own distinctive shape. From soft and squishy to hard and stony. Scleractinians hard coral is by far the most prevalent variety – protecting reefs as it builds. Other common forms are mound corals (which form large round mounds on the seafloor); brain corals that look similar to human brains; finger corals which have rings of fingers reaching out for tiny fish or planktonic life forms – but mound corals form large round mounds on seafloor; mound corals (which form large round mounds); finger corals (which reach out with fingers for fish or planktonic life forms).
Coral reefs that we know today are created by generations of coral polyps depositing their calcium carbonate skeletons upon one another, leading to enormous reefs with striking colors and vibrant hues.
Coral reefs are very particular about where they thrive, preferring certain ocean regions over others. Corals also develop slowly over time – taking decades for some reefs to reach full maturity. But their benefits make up for it; reefs protect shorelines against erosion while their structure helps ward off erosion. If you ever get the opportunity to visit one, be sure to snap some photos!