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Mesophotic
A Mesophotic coral reef or mesophotic coral ecosystem (MCE), originally from the Latin word ''meso'' (meaning middle) and ''photic'' (meaning light), is characterised by the presence of both light-dependent coral and algae, and organisms that can be found in water with low light penetration. Mesophotic Coral Ecosystem (MCEs) is a new, widely-adopted term used to refer to mesophotic coral reefs, as opposed to other similar terms like "deep coral reef communities" and "twilight zone", since those terms sometimes are confused due to their unclear, interchangeable nature. They normally grow between 30 and and up to in tropical and subtropical water. The most common species at the mesophotic level are corals, sponges and algae. The corals ranges can overlap with Deep-water coral but are distinguished by the presence of zooxanthellae and their requirement for light. They can also be thought of as part of shallow water coral ecosystems, and a crossover of coral species between the two is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesophotic Coral Ecosystem
A Mesophotic coral reef or mesophotic coral ecosystem (MCE), originally from the Latin word ''meso'' (meaning middle) and ''photic'' (meaning light), is characterised by the presence of both light-dependent coral and algae, and organisms that can be found in water with low light penetration. Mesophotic Coral Ecosystem (MCEs) is a new, widely-adopted term used to refer to mesophotic coral reefs, as opposed to other similar terms like "deep coral reef communities" and "twilight zone", since those terms sometimes are confused due to their unclear, interchangeable nature. They normally grow between 30 and and up to in tropical and subtropical water. The most common species at the mesophotic level are corals, sponges and algae. The corals ranges can overlap with Deep-water coral but are distinguished by the presence of zooxanthellae and their requirement for light. They can also be thought of as part of shallow water coral ecosystems, and a crossover of coral species between the two is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep-water Coral
The habitat of deep-water corals, also known as cold-water corals, extends to deeper, darker parts of the oceans than tropical corals, ranging from near the surface to the abyss, beyond where water temperatures may be as cold as . Deep-water corals belong to the Phylum Cnidaria and are most often stony corals, but also include black and thorny corals and soft corals including the Gorgonians (sea fans). Like tropical corals, they provide habitat to other species, but deep-water corals do not require zooxanthellae to survive. While there are nearly as many species of deep-water corals as shallow-water species, only a few deep-water species develop traditional reefs. Instead, they form aggregations called patches, banks, bioherms, massifs, thickets or groves. These aggregations are often referred to as "reefs," but differ structurally and functionally. Deep sea reefs are sometimes referred to as "mounds," which more accurately describes the large calcium carbonate skeleton that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photic Zone
The photic zone, euphotic zone, epipelagic zone, or sunlight zone is the uppermost layer of a body of water that receives sunlight, allowing phytoplankton to perform photosynthesis. It undergoes a series of physical, chemical, and biological processes that supply nutrients into the upper water column. The photic zone is home to the majority of aquatic life due to the activity (primary production) of the phytoplankton. Photosynthesis in photic zone In the photic zone, the photosynthesis rate exceeds the respiration rate. This is due to the abundant solar energy which is used as an energy source for photosynthesis by primary producers such as phytoplankton. These phytoplankton grow extremely quickly because of sunlight's heavy influence, enabling it to be produced at a fast rate. In fact, ninety five percent of photosynthesis in the ocean occurs in the photic zone. Therefore, if we go deeper, beyond the photic zone, such as into the compensation point, there is little to no phyto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coral
Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton. A coral "group" is a colony of very many genetically identical polyps. Each polyp is a sac-like animal typically only a few millimeters in diameter and a few centimeters in height. A set of tentacles surround a central mouth opening. Each polyp excretes an exoskeleton near the base. Over many generations, the colony thus creates a skeleton characteristic of the species which can measure up to several meters in size. Individual colonies grow by asexual reproduction of polyps. Corals also breed sexually by spawning: polyps of the same species release gametes simultaneously overnight, often around a full moon. Fertilized eggs form planulae, a mobile early form of the coral polyp which, when m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as ''Chlorella,'' ''Prototheca'' and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to in length. Most are aquatic and autotrophic (they generate food internally) and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the ''Charophyta'', a division of green algae which includes, for example, ''Spirogyra'' and stoneworts. No definition of algae is generally accepted. One definition is that algae "have chlorophyll ''a'' as their primary photosynthetic pigment and lack a sterile covering of cells around thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sponge
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were first to branch off the evolutionary tree from the last common ancestor of all animals, making them the sister group of all other animals. Etymology The term ''sponge'' derives from the Ancient Greek word ( 'sponge'). Overview Sponges are similar to other animals in that they are multicellular, he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zooxanthellae
Zooxanthellae is a colloquial term for single-celled dinoflagellates that are able to live in symbiosis with diverse marine invertebrates including demosponges, corals, jellyfish, and nudibranchs. Most known zooxanthellae are in the genus ''Symbiodinium'', but some are known from the genus '' Amphidinium'', and other taxa, as yet unidentified, may have similar endosymbiont affinities. The true ''Zooxanthella'' K.brandt is a mutualist of the radiolarian ''Collozoum inerme'' (Joh.Müll., 1856) and systematically placed in Peridiniales. Another group of unicellular eukaryotes that partake in similar endosymbiotic relationships in both marine and freshwater habitats are green algae zoochlorellae. Zooxanthellae are photosynthetic organisms, which contain chlorophyll a and chlorophyll c, as well as the dinoflagellate pigments peridinin and diadinoxanthin. These provide the yellowish and brownish colours typical of many of the host species. During the day, they provide their host ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecosystem Services
Ecosystem services are the many and varied benefits to humans provided by the natural environment and healthy ecosystems. Such ecosystems include, for example, agroecosystems, forest ecosystem, grassland ecosystems, and aquatic ecosystems. These ecosystems, functioning in healthy relationships, offer such things as natural pollination of crops, clean air, extreme weather mitigation, and human mental and physical well-being. Collectively, these benefits are becoming known as ecosystem services, and are often integral to the provision of food, the provisioning of clean drinking water, the decomposition of wastes, and the resilience and productivity of food ecosystems. While scientists and environmentalists have discussed ecosystem services implicitly for decades, the Millennium Ecosystem Assessment (MA) in the early 2000s popularized this concept. There, ecosystem services are grouped into four broad categories: ''provisioning'', such as the production of food and water; ''regul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Acidification
Ocean acidification is the reduction in the pH value of the Earth’s ocean. Between 1751 and 2021, the average pH value of the ocean surface has decreased from approximately 8.25 to 8.14. The root cause of ocean acidification is carbon dioxide emissions from human activities which have led to atmospheric carbon dioxide (CO2) levels of more than 410 ppm (in 2020). The oceans absorb CO2 from the atmosphere. This leads to the formation of carbonic acid (H2CO3) which dissociates into a bicarbonate ion () and a hydrogen ion (H+). The free hydrogen ions (H+) decrease the pH of the ocean, therefore increasing acidity (this does not mean that seawater is acidic yet; it is still alkaline, with a pH higher than 8). A decrease in pH corresponds to a decrease in the concentration of carbonate ions, which are the main building block for calcium carbonate (CaCO3) shells and skeletons. Marine calcifying organisms, like mollusks, oysters and corals, are particularly affected by this as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Debris
Marine debris, also known as marine litter, is human-created waste that has deliberately or accidentally been released in a sea or ocean. Floating oceanic debris tends to accumulate at the center of gyres and on coastlines, frequently washing aground, when it is known as ''beach litter'' or tidewrack. Deliberate disposal of wastes at sea is called ''ocean dumping''. Naturally occurring debris, such as driftwood and drift seeds, are also present. With the increasing use of plastic, human influence has become an issue as many types of (petrochemical) plastics do not biodegrade quickly, as would natural or organic materials. The largest single type of plastic pollution (~10 %) and majority of large plastic in the oceans is discarded and lost nets from the fishing industry. Waterborne plastic poses a serious threat to fish, seabirds, marine reptiles, and marine mammals, as well as to boats and coasts. Dumping, container spillages, litter washed into storm drains and waterways and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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