Coral Reef Chaturbate

Coral reefs are a rock-like ecosystem that protects harbors, beaches and coasts against erosion. They also shelter and feed an abundance of marine life. Yet, they are also fragile and easily harmed by a multitude of factors including global climate change and unsustainable fishing practices.

Scientists are breeding corals to create more robust types. This project could have a similar impact as selective breeding of dogs, cats, or livestock.

1. What is a coral?

Coral reefs are underwater landscapes made up of calcareous alga, fish and other organisms. They are among the most complex and largest ecosystems on Earth. Their longevity and ecological diversity rival that of old-growth forest. They are made up of colonies of stony polyps that are held together by their hard skeletons. The structure of the reef is also influenced by other organisms like mollusks, shelly corals and echinoderms. Reef-building corals belong to the cnidarians family, which includes jellyfish and sea anemones.

Stony corals (Sclerosia) require bright light and warm water to thrive. They live in shallow sunlit waters with normal salinity up to a depth of about 11 meters (36 feet). Corals that build reefs require clear water to absorb sunlight and convert it into food via photosynthesis.

Coral polyps have a fixed base and a tube-like body with feeding tentacles. They also have a symbiotic relation with the microscopic algae zooxanthellae. The symbiotic relationship provides the coral with nutrients, including carbon dioxide and oxygen. The tentacles are able to capture small particles of food dissolved in the water. Each tentacle is covered with thousands of stinging cells, or nematocysts, which can stun or kill prey.

Reef-building symbiotic corals are colonial, forming large colonies from the initial polyp’s offspring. These colonies are held together by a rigid skeleton of calcium carbonate. They grow side-by-side, often on top each other, and eventually become limestone reefs.

2. What is a coral reef?

Coral reefs are underwater communities dominated by photosynthesizing corals. Corals are multicellular animals that are related to jellyfishes and anemones. They secrete hard, calcareous exoskeletons (aragonite), which give them structural rigidity. This makes them an important part of the coral reef structure. Most corals are symbiotic with algae (zooxanthellae), which provides them with additional food through photosynthesis. Together, the corals and zooxanthellae build reefs that are spectacular in their beauty and biodiversity.

The majority of coral reefs are coralline (stony) reef-building reefs that cluster together. They grow fast and, under the right conditions, can build large, thick masses of limestone that may cover many square kilometers of ocean floor. Many stony reef-building corals are colonial, with each individual polyp (coralline) growing on and over the limestone skeleton of the previous generation. Polyps can also grow side by side, covering the skeleton of limestone with a thin layer of living tissue known as coenosarc.

Almost all shelly and calcareous organisms (including mollusks, echinoderms, and soft marine invertebrates such as sponges and sea cucumbers) and algae contribute to reef building by providing fragments that wash into or fall into gaps between corals. The reef crest is primarily an encrusting zone of calcareous alga. It lies on the outer edge the coralline zone. Its presence marks the boundary between the tropical coastal currents’ warm waters and the colder inland waters, where most corals reside.

3. What is a fish?

With more than 27,900 living species, fish are one of the most diverse groups of animals on Earth. They range in size from the smallest cyprinids (8mm) to the whale shark Rhincodon typus (up to 12m), and their skeletons show great variation in shape and composition. Fish are divided into five groups that span multiple evolutionary lines. From the jawless hagfishes and primitive lampreys to the living sharks, rays and cartilaginous species, as well as extinct placoderms, and acanthodians. Most fish have cold blood, and their body temperature varies with the temperature of surrounding water.

While fish, coral polyps, and other reef-building critters can move away from threats, many sessile organisms like sponges, sea anemones, and mollusks cannot. These animals face daily risks from diseases, parasites, and direct threats of violence like being eaten by fish.

To help these animals, Academy biologists work with partners at SECORE Foundation to develop new technologies to aid coral reproduction in the wild. SECORE collects sperm and egg bundles from coral using special nets during spawning events, which occur in the wild at full moons. The sperm, eggs and larvae are fertilized in a lab and then planted on the reef using specialized tiles developed by SECORE. The technique has proven to be successful in regenerating coral that has been damaged by disease or destroyed due to natural or human-caused disturbances.

4. What is a macroalgae?

Macrolagic algae, often referred to as seaweeds, are multicellular photosynthetic marine plants that grow attached to the reef substrate. They are not related to the flowering plants (plants that produce flowers) and, unlike corals, they do not have vascular tissue that transports water, but rather depend on their long root-like rhizoids to anchor them to the sediment or reef surface. They typically form dense forests and are important primary producers in the reef ecosystem. They are also very important for nutrient cycling and are key indicators of water quality. In eutrophic water, they can form overgrown green cyanobacteria blooms and/or the eutrophic indicators macroalga Chaetomorpha Linum that can cause major disruptions to coral reefs because of their competition for space.

Corals are a diverse group of invertebrates that form the phylum Cnidaria and include scleractinians, algae and stony corals. The Great Barrier Reef is dominated by stony corals, which are responsible for building the reef structure and laying its foundations. They are primarily colonies and, like anthozoans in general, they are symbiotic to the microalgae that they feed on.

Reef-building corals require very specific environmental conditions to thrive, including a narrow band of temperature tolerance and the occurrence of high light penetration. These requirements are why most reef-building corals are restricted to the euphotic zone.