A reef is a ridge of material at or near the surface of the ocean. Reefs can occur naturally. Natural reefs are made of rocks or the skeletons of small animals called corals.
Why are coral reefs important?
Coral reefs provide habitat for a large variety of marine life, including various sponges, oysters, clams, crabs, sea stars, sea urchins, and many species of fish. Coral reefs are also linked ecologically to nearby seagrass, mangrove, and mudflat communities. One of the reasons that coral reefs are so highly valued is because they serve as ...
Where are Coral Reefs Found?
Corals can be found throughout the world’s oceans, in both shallow and deep water. However, the reef-building corals that rely on a symbiotic relationship with algae need shallow, clear water allowing light penetration for photosynthesis. Stony corals also require tropical or sub-tropical temperatures, which exist in a band 30 degrees north to 30 degrees south of the equator.
What are coral polyps?
Polyps of reef-building corals contain microscopic algae called zooxanthellae, which exist with the animal in a symbiotic relationship. The coral polyps (animals) provide the algae (plants) a home, and in exchange the algae provide the polyps with food they generate through photosynthesis. Because photosynthesis requires sunlight, most ...
Why do corals have transparent polyps?
Because photosynthesis requires sunlight, most reef-building corals live in clear, shallow waters that are penetrated by sunlight. The algae also give a coral its color; coral polyps are actually transparent, so the color of the algae inside the polyps show through.
What are the benefits of coral reefs?
Healthy coral reefs provide: 1 Habitat, feeding, spawning, and nursery grounds for over 1 million aquatic species, including commercially harvested fish species. 2 Food for people living near coral reefs, especially on small islands. 3 Recreation and tourism opportunities, such as fishing, scuba diving, and snorkeling, which contribute billions of dollars to local economies. 4 Protection of coastal infrastructure and prevention of loss of life from storms, tsunamis, floods, and erosion. 5 Sources of new medicines that can be used to treat diseases and other health problems.
How many species of fish are in coral reefs?
Coral reefs are among the most biologically diverse and valuable ecosystems on Earth. An estimated 25 percent of all marine life, including over 4,000 species of fish, are dependent on coral reefs at some point in their life cycle. Approximately half a billion people globally depend on coral reef ecosystems for food, coastal protection, ...
What is the difference between a coral and a stony coral?
Coral is a class of colonial animal that is related to hydroids, jellyfish, and sea anemones. Stony corals, a type of coral characterized by their hard skeleton, are the bedrock of the reef. Stony coral colonies are composed of hundreds of thousands of individual living polyps.
What are coral polyps made of?
Anatomy of a Coral Polyp. 1. One coral is made of many polyps. Polyps are the basic building block for all coral colonies. They are small, colorful, and essential for corals to grow, eat, reproduce, and recover if ever injured. 2.
What is the food web system of coral reefs?
With small animals seeking shelter in the coral—and herbivorous fish keeping corals clean of nuisance algae—corals lie at the heart of a complex food web system that allows marine life to thrive in a coral reef. More Information.
What is coral reef?
Coral reefs are living, ocean-dwelling animals. Each individual coral exists as a colony consisting of multiple small, identical coral polyps. Wherever corals make up the foundation of an underwater habitat, a coral reef occurs. Coral reefs are complex marine ecosystems that include diverse collections of colorful fish and other sea creatures.
Why are corals important?
They are small, colorful, and essential for corals to grow, eat, reproduce, and recover if ever injured. 2. Corals build coral reefs. Corals build their skeleton from calcium and carbonate in seawater. This skeleton not only gives corals their structure, but also provides the architecture for the coral reef overall. 3.
What does "reef friendly" mean?
What does “Reef-safe” or “Reef-friendly” Sunscreen Mean? Terms like “reef-safe” or “reef-friendly” are typically used to identify sunscreens that do not contain oxybenzone and octinoxate, two common UV-blocking chemicals, that studies have shown can cause coral bleaching.
What chemicals are used in sunscreen?
Oxybenzone and octinoxate are two of the more widely studied chemicals in sunscreens, but other ingredients, such as preservatives, fragrances and other UV-blocking chemical agents, like as octocrylene, are also being scrutinized for their impact on coral.
How much sunscreen is in coral reefs?
The National Park Service estimates that up to 6,000 tons of sunscreen enters areas in and around reefs every year and studies show that chemicals in these sunscreens may be contributing to the declining health of coral.
What chemicals are bad for reefs?
Avoid oxybenzone or octinoxate: Evidence suggests that oxybenzone and octinoxate are two of the more harmful chemicals for reefs found in sunscreens.
How to get sunscreen off skin?
Use a rub-on lotion: Use a lotion that you rub onto your skin rather than a spray that can easily land on the sand and wash into the ocean . Look for good water resistance: A sunscreen that stays on longer when you’re in the water is less likely to wash off.
Can you use butylparaben in sunscreen?
Butylparaben has been shown to cause coral reef bleaching, and some health questions surround parabens in general, so many brands don’t use them and promote their sunscreens as “paraben-free.”
Is sunscreen safe for coral reefs?
Now the truth of it is, no sunscreen has been proven to be completely safe for marine life. And terms like “reef-safe” or “reef-friendly” do not have agreed-upon definitions, nor is their use regulated by the FDA or managed by a standard-setting organization. Oxybenzone and octinoxate are two of the more widely studied chemicals in sunscreens, but other ingredients, such as preservatives, fragrances and other UV-blocking chemical agents, like as octocrylene, are also being scrutinized for their impact on coral. In 2018, the Journal of the American Academy of Dermatology published a paper stating that more research is required to fully comprehend the impact of sunscreens on coral and that people should continue to take all necessary steps to protect themselves from the sun’s harmful ultraviolet rays.
