Milky seas effect
Milky seas called mareel, is a luminous phenomenon in the ocean in which large areas of seawater appear to glow brightly enough at night to be seen by satellites orbiting Earth. Modern science only tentatively attributes this effect to bioluminescent bacteria or dinoflagellates, causing the sea to uniformly display an eerie blue glow at night. However, no modern research proves that bioluminescent bacteria are capable of illuminating the ocean from horizon to horizon and for days at a time, as described in mariners' tales for centuries. In fact, the effect has not been rigorously documented nor explained in modern times. Between 1915 and 1993, 235 sightings of milky seas were documented, most of which are concentrated in the northwestern Indian Ocean and near Indonesia; the luminescent glow is concentrated on the surface of the ocean and does not mix evenly throughout the water column. In 1985, a research vessel in the Arabian Sea took water samples during milky seas, their conclusions were. Mareel is caused by Noctiluca scintillans, a dinoflagellate that glows when disturbed and is found in oceans throughout much of the world.
In July 2015, at Alleppey, India, the phenomenon occurred and the National Institute of Oceanography and Kerala Fisheries Department researched it, finding that the glittering waves were the result of the Noctiluca scintillans. In 2005, Steven Miller of the Naval Research Laboratory in Monterey, was able to match 1995 satellite images with a first-hand account of a merchant ship. U. S. Defense Meteorological Satellite Program showed the milky area to be 15,400 km2; the luminescent field was observed to glow over three consecutive nights. While monochromatic photos make this effect appear white, Monterey Bay Aquarium Research Institute scientist Steven Haddock has commented, "the light produced by the bacteria is blue, not white, it is white in the graphic because of the monochromatic sensor we used, it can appear white to the eye because the rods in our eye don't discriminate color." In Shetland, mareel has sometimes been described as being green, rather than the traditional blue or white milky seas effect seen by the rest of the world.
It is not known whether this difference depends on the area, or a perception of a cyanic colour as being green. The phenomenon is known as mareel in Shetland; this term is derived from the Norn word *mareld, itself derived from the Old Norse word mǫrueldr, a compound of marr and eldr. Detailed discussion and images of milky sea observation BBC News:'Milky seas' detected from space Miller, S. D. S. H. D. Haddock, C. D. Elvidge, T. F. Lee. Detection of a bioluminescent milky sea from space. Proceedings of the National Academy of Sciences. V102:14181-14184 Abstract Nealson, K. H. and J. W. Hastings Quorum sensing on a global scale: massive numbers of bioluminescent bacteria make milky seas Appl. Environ. Microbiol. 72:2295-2297. Manuscript
Plankton are the diverse collection of organisms that live in large bodies of water and are unable to swim against a current. The individual organisms constituting plankton are called plankters, they provide a crucial source of food to many large aquatic organisms, such as fish and whales. These organisms include bacteria, algae and drifting or floating animals that inhabit—for example—the pelagic zone of oceans, seas, or bodies of fresh water. Plankton are defined by their ecological niche rather than any phylogenetic or taxonomic classification. Though many planktonic species are microscopic in size, plankton includes organisms over a wide range of sizes, including large organisms such as jellyfish. Technically the term does not include organisms on the surface of the water, which are called pleuston—or those that swim in the water, which are called nekton; the name plankton is derived from the Greek adjective πλαγκτός, meaning errant, by extension, wanderer or drifter, was coined by Victor Hensen in 1887.
While some forms are capable of independent movement and can swim hundreds of meters vertically in a single day, their horizontal position is determined by the surrounding water movement, plankton flow with ocean currents. This is in contrast to nekton organisms, such as fish and marine mammals, which can swim against the ambient flow and control their position in the environment. Within the plankton, holoplankton spend their entire life cycle as plankton. By contrast, meroplankton are only planktic for part of their lives, graduate to either a nektic or benthic existence. Examples of meroplankton include the larvae of sea urchins, crustaceans, marine worms, most fish; the amount and distribution of plankton depends on available nutrients, the state of water and a large amount of other plankton. The study of plankton is termed planktology and a planktonic individual is referred to as a plankter; the adjective planktonic is used in both the scientific and popular literature, is a accepted term.
However, from the standpoint of prescriptive grammar, the less-commonly used planktic is more the correct adjective. When deriving English words from their Greek or Latin roots, the gender-specific ending is dropped, using only the root of the word in the derivation. Plankton are divided into broad functional groups: Phytoplankton, autotrophic prokaryotic or eukaryotic algae that live near the water surface where there is sufficient light to support photosynthesis. Among the more important groups are the diatoms, cyanobacteria and coccolithophores. Zooplankton, small protozoans or metazoans that feed on other plankton; some of the eggs and larvae of larger nektonic animals, such as fish and annelids, are included here. Bacterioplankton and archaea, which play an important role in remineralising organic material down the water column. Mycoplankton and fungus-like organisms, like bacterioplankton, are significant in remineralisation and nutrient cycling; this scheme divides the plankton community into broad producer and recycler groups.
However, determining the trophic level of many plankton is not always straightforward. For example, although most dinoflagellates are either photosynthetic producers or heterotrophic consumers, many species perform both roles. In this mixed trophic strategy — known as mixotrophy — organisms act as both producers and consumers, either at the same time or switching between modes of nutrition in response to ambient conditions. For instance, relying on photosynthesis for growth when nutrients and light are abundant, but switching to predation when growing conditions are poor. Recognition of the importance of mixotrophy as an ecological strategy is increasing, as well as the wider role this may play in marine biogeochemistry. Plankton are often described in terms of size; the following divisions are used: However, some of these terms may be used with different boundaries on the larger end. The existence and importance of nano- and smaller plankton was only discovered during the 1980s, but they are thought to make up the largest proportion of all plankton in number and diversity.
The microplankton and smaller groups are microorganisms and operate at low Reynolds numbers, where the viscosity of water is much more important than its mass or inertia. Plankton inhabit oceans, lakes, ponds. Local abundance varies horizontally and seasonally; the primary cause of this variability is the availability of light. All plankton ecosystems are driven by the input of solar energy, confining primary production to surface waters, to geographical regions and seasons having abundant light. A secondary variable is nutrient availability. Although large areas of the tropical and sub-tropical oceans have abundant light, they experience low primary production because they offer limited nutrients such as nitrate and silicate; this results from large-scale ocean water column stratification. In such regions, primary production occurs at greater depth, although at a reduced level. Despite significant macronutrient concentrations, some ocean regions are unproductive; the micronutrient iron is deficient in these reg
Crustaceans form a large, diverse arthropod taxon which includes such familiar animals as crabs, crayfish, krill and barnacles. The crustacean group is treated as a subphylum, because of recent molecular studies it is now well accepted that the crustacean group is paraphyletic, comprises all animals in the Pancrustacea clade other than hexapods; some crustaceans are more related to insects and other hexapods than they are to certain other crustaceans. The 67,000 described species range in size from Stygotantulus stocki at 0.1 mm, to the Japanese spider crab with a leg span of up to 3.8 m and a mass of 20 kg. Like other arthropods, crustaceans have an exoskeleton, they are distinguished from other groups of arthropods, such as insects and chelicerates, by the possession of biramous limbs, by their larval forms, such as the nauplius stage of branchiopods and copepods. Most crustaceans are free-living aquatic animals, but some are terrestrial, some are parasitic and some are sessile; the group has an extensive fossil record, reaching back to the Cambrian, includes living fossils such as Triops cancriformis, which has existed unchanged since the Triassic period.
More than 10 million tons of crustaceans are produced by fishery or farming for human consumption, the majority of it being shrimp and prawns. Krill and copepods are not as fished, but may be the animals with the greatest biomass on the planet, form a vital part of the food chain; the scientific study of crustaceans is known as carcinology, a scientist who works in carcinology is a carcinologist. The body of a crustacean is composed of segments, which are grouped into three regions: the cephalon or head, the pereon or thorax, the pleon or abdomen; the head and thorax may be fused together to form a cephalothorax, which may be covered by a single large carapace. The crustacean body is protected by the hard exoskeleton, which must be moulted for the animal to grow; the shell around each somite can be divided into a dorsal tergum, ventral sternum and a lateral pleuron. Various parts of the exoskeleton may be fused together; each somite, or body segment can bear a pair of appendages: on the segments of the head, these include two pairs of antennae, the mandibles and maxillae.
The abdomen bears pleopods, ends in a telson, which bears the anus, is flanked by uropods to form a tail fan. The number and variety of appendages in different crustaceans may be responsible for the group's success. Crustacean appendages are biramous, meaning they are divided into two parts, it is unclear whether the biramous condition is a derived state which evolved in crustaceans, or whether the second branch of the limb has been lost in all other groups. Trilobites, for instance possessed biramous appendages; the main body cavity is an open circulatory system, where blood is pumped into the haemocoel by a heart located near the dorsum. Malacostraca have haemocyanin as the oxygen-carrying pigment, while copepods, ostracods and branchiopods have haemoglobins; the alimentary canal consists of a straight tube that has a gizzard-like "gastric mill" for grinding food and a pair of digestive glands that absorb food. Structures that function as kidneys are located near the antennae. A brain exists in the form of ganglia close to the antennae, a collection of major ganglia is found below the gut.
In many decapods, the first pair of pleopods are specialised in the male for sperm transfer. Many terrestrial crustaceans return to the sea to release the eggs. Others, such as woodlice, lay their eggs on land, albeit in damp conditions. In most decapods, the females retain the eggs; the majority of crustaceans are aquatic, living in either marine or freshwater environments, but a few groups have adapted to life on land, such as terrestrial crabs, terrestrial hermit crabs, woodlice. Marine crustaceans are as ubiquitous in the oceans; the majority of crustaceans are motile, moving about independently, although a few taxonomic units are parasitic and live attached to their hosts, adult barnacles live a sessile life – they are attached headfirst to the substrate and cannot move independently. Some branchiurans are able to withstand rapid changes of salinity and will switch hosts from marine to non-marine species. Krill are the bottom layer and the most important part of the food chain in Antarctic animal communities.
Some crustaceans are significant invasive species, such as the Chinese mitten crab, Eriocheir sinensis, the Asian shore crab, Hemigrapsus sanguineus. The majority of crustaceans have separate sexes, reproduce sexually. A small number are hermaphrodites, including barnacles and Cephalocarida; some may change sex during the course of their life. Parthenogenesis is widespread among crustaceans, where viable eggs are produced by a female without needing fertilisation by a male; this occurs in many branchiopods, some os
Copepods are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic, some are benthic, some continental species may live in limnoterrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, springs, ephemeral ponds, puddles, damp moss, or water-filled recesses of plants such as bromeliads and pitcher plants. Many live underground in marine and freshwater sinkholes, or stream beds. Copepods are sometimes used as biodiversity indicators; as with other crustaceans, copepods have a larval form. For copepods, the egg hatches into a nauplius form, with a head and a tail but no true thorax or abdomen; the larva molts several times until it resembles the adult and after more molts, achieves adult development. The nauplius form is so different from the adult form that it was once thought to be a separate species. Copepods form a subclass belonging to the subphylum Crustacea; some 13,000 species of copepods are known, 2,800 of them live in fresh water.
Copepods vary but can be 1 to 2 mm long, with a teardrop-shaped body and large antennae. Like other crustaceans, they have an armoured exoskeleton, but they are so small that in most species, this thin armour and the entire body is totally transparent; some polar copepods reach 1 cm. Most copepods have a single median compound eye bright red and in the centre of the transparent head. Like other crustaceans, copepods possess two pairs of antennae. Free-living copepods of the orders Calanoida and Harpacticoida have a short, cylindrical body, with a rounded or beaked head, although considerable variation exists in this pattern; the head is fused with the first one or two thoracic segments, while the remainder of the thorax has three to five segments, each with limbs. The first pair of thoracic appendages is modified to form maxillipeds; the abdomen is narrower than the thorax, contains five segments without any appendages, except for some tail-like "rami" at the tip. Parasitic copepods vary in morphology and no generalizations are possible.
Because of their small size, copepods have no need of any heart or circulatory system, most lack gills. Instead, they absorb oxygen directly into their bodies, their excretory system consists of maxillary glands. The second pair of cephalic appendages in free-living copepods is the main time-averaged source of propulsion, beating like oars to pull the animal through the water. However, different groups have different modes of feeding and locomotion, ranging from immotile for several minutes to intermittent motion and continuous displacements with some escape reactions Some copepods have fast escape responses when a predator is sensed, can jump with high speed over a few millimetres. Many species have neurons surrounded by myelin, rare among invertebrates. Rarer, the myelin is organized, resembling the well-organized wrapping found in vertebrates. Despite their fast escape response, copepods are hunted by slow-swimming seahorses, which approach their prey so it senses no turbulence suck the copepod into their snout too for the copepod to escape.
Finding a mate in the three-dimensional space of open water is challenging. Some copepod females solve the problem by emitting pheromones, which leave a trail in the water that the male can follow. Copepods experience a low Reynolds number and therefore a high relative viscosity. One foraging strategy involves chemical detection of sinking marine snow aggregates and taking advantage of nearby low-pressure gradients to swim towards food sources. Most free-living copepods feed directly on phytoplankton. A single copepod can consume up to 373,000 phytoplanktons per day, they have to clear the equivalent to about a million times their own body volume of water every day to cover their nutritional needs. Some of the larger species are predators of their smaller relatives. Many benthic copepods eat organic detritus or the bacteria that grow in it, their mouth parts are adapted for scraping and biting. Herbivorous copepods those in rich, cold seas, store up energy from their food as oil droplets while they feed in the spring and summer on plankton blooms.
These droplets may take up over half of the volume of their bodies in polar species. Many copepods are parasites, feed on their host organisms. In fact, three of the 10 known orders of copepods are wholly or parasitic, with another three comprising most of the free-living species. Most nonparasitic copepods are holoplanktonic, meaning they stay planktonic for all of their lifecycles, although harpacticoids, although free-living, tend to be benthic rather than planktonic. During mating, the male copepod grips the female with his first pair of antennae, sometimes modified for this purpose; the male produces an adhesive package of sperm and transfers it to the female's genital opening with his thoracic limbs. Eggs are sometimes laid directly into the water, but many species enclose t
Animals are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 millionths of a metre to 33.6 metres and have complex interactions with each other and their environments, forming intricate food webs. The category includes humans, but in colloquial use the term animal refers only to non-human animals; the study of non-human animals is known as zoology. Most living animal species are in the Bilateria, a clade whose members have a bilaterally symmetric body plan; the Bilateria include the protostomes—in which many groups of invertebrates are found, such as nematodes and molluscs—and the deuterostomes, containing the echinoderms and chordates.
Life forms interpreted. Many modern animal phyla became established in the fossil record as marine species during the Cambrian explosion which began around 542 million years ago. 6,331 groups of genes common to all living animals have been identified. Aristotle divided animals into those with those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between animal taxa. Humans make use of many other animal species for food, including meat and eggs. Dogs have been used in hunting, while many aquatic animals are hunted for sport.
Non-human animals have appeared in art from the earliest times and are featured in mythology and religion. The word "animal" comes from the Latin animalis, having soul or living being; the biological definition includes all members of the kingdom Animalia. In colloquial usage, as a consequence of anthropocentrism, the term animal is sometimes used nonscientifically to refer only to non-human animals. Animals have several characteristics. Animals are eukaryotic and multicellular, unlike bacteria, which are prokaryotic, unlike protists, which are eukaryotic but unicellular. Unlike plants and algae, which produce their own nutrients animals are heterotrophic, feeding on organic material and digesting it internally. With few exceptions, animals breathe oxygen and respire aerobically. All animals are motile during at least part of their life cycle, but some animals, such as sponges, corals and barnacles become sessile; the blastula is a stage in embryonic development, unique to most animals, allowing cells to be differentiated into specialised tissues and organs.
All animals are composed of cells, surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. During development, the animal extracellular matrix forms a flexible framework upon which cells can move about and be reorganised, making the formation of complex structures possible; this may be calcified, forming structures such as shells and spicules. In contrast, the cells of other multicellular organisms are held in place by cell walls, so develop by progressive growth. Animal cells uniquely possess the cell junctions called tight junctions, gap junctions, desmosomes. With few exceptions—in particular, the sponges and placozoans—animal bodies are differentiated into tissues; these include muscles, which enable locomotion, nerve tissues, which transmit signals and coordinate the body. There is an internal digestive chamber with either one opening or two openings. Nearly all animals make use of some form of sexual reproduction, they produce haploid gametes by meiosis.
These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In sponges, blastula larvae swim to a new location, attach to the seabed, develop into a new sponge. In most other groups, the blastula undergoes more complicated rearrangement, it first invaginates to form a gastrula with a digestive chamber and two separate germ layers, an external ectoderm and an internal endoderm. In most cases, a third germ layer, the mesoderm develops between them; these germ layers differentiate to form tissues and organs. Repeated instances of mating with a close relative during sexual reproduction leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. Animals have evolved numerous mechanisms for avoiding close inbreeding. In some species, such as the splendid fairywren, females benefit by mating with multiple males, thus producing more offspring of higher genetic quality; some animals are capable of asexual reproduction, which results
An arthropod is an invertebrate animal having an exoskeleton, a segmented body, paired jointed appendages. Arthropods form the phylum Euarthropoda, which includes insects, arachnids and crustaceans; the term Arthropoda as proposed refers to a proposed grouping of Euarthropods and the phylum Onychophora. Arthropods are characterized by their jointed limbs and cuticle made of chitin mineralised with calcium carbonate; the arthropod body plan consists of each with a pair of appendages. The rigid cuticle inhibits growth, so arthropods replace it periodically by moulting. Arthopods are bilaterally symmetrical and their body possesses an external skeleton; some species have wings. Their versatility has enabled them to become the most species-rich members of all ecological guilds in most environments, they have over a million described species, making up more than 80 per cent of all described living animal species, some of which, unlike most other animals, are successful in dry environments. Arthropods range in size from the microscopic crustacean Stygotantulus up to the Japanese spider crab.
Arthropods' primary internal cavity is a haemocoel, which accommodates their internal organs, through which their haemolymph – analogue of blood – circulates. Like their exteriors, the internal organs of arthropods are built of repeated segments, their nervous system is "ladder-like", with paired ventral nerve cords running through all segments and forming paired ganglia in each segment. Their heads are formed by fusion of varying numbers of segments, their brains are formed by fusion of the ganglia of these segments and encircle the esophagus; the respiratory and excretory systems of arthropods vary, depending as much on their environment as on the subphylum to which they belong. Their vision relies on various combinations of compound eyes and pigment-pit ocelli: in most species the ocelli can only detect the direction from which light is coming, the compound eyes are the main source of information, but the main eyes of spiders are ocelli that can form images and, in a few cases, can swivel to track prey.
Arthropods have a wide range of chemical and mechanical sensors based on modifications of the many setae that project through their cuticles. Arthropods' methods of reproduction and development are diverse; the evolutionary ancestry of arthropods dates back to the Cambrian period. The group is regarded as monophyletic, many analyses support the placement of arthropods with cycloneuralians in a superphylum Ecdysozoa. Overall, the basal relationships of Metazoa are not yet well resolved; the relationships between various arthropod groups are still debated. Aquatic species use either external fertilization. All arthropods lay eggs, but scorpions give birth to live young after the eggs have hatched inside the mother. Arthropod hatchlings vary from miniature adults to grubs and caterpillars that lack jointed limbs and undergo a total metamorphosis to produce the adult form; the level of maternal care for hatchlings varies from nonexistent to the prolonged care provided by scorpions. Arthropods contribute to the human food supply both directly as food, more indirectly as pollinators of crops.
Some species are known to spread severe disease to humans and crops. The word arthropod comes from the Greek ἄρθρον árthron, "joint", πούς pous, i.e. "foot" or "leg", which together mean "jointed leg". Arthropods are invertebrates with jointed limbs; the exoskeleton or cuticles consists of a polymer of glucosamine. The cuticle of many crustaceans, beetle mites, millipedes is biomineralized with calcium carbonate. Calcification of the endosternite, an internal structure used for muscle attachments occur in some opiliones. Estimates of the number of arthropod species vary between 1,170,000 and 5 to 10 million and account for over 80 per cent of all known living animal species; the number of species remains difficult to determine. This is due to the census modeling assumptions projected onto other regions in order to scale up from counts at specific locations applied to the whole world. A study in 1992 estimated that there were 500,000 species of animals and plants in Costa Rica alone, of which 365,000 were arthropods.
They are important members of marine, freshwater and air ecosystems, are one of only two major animal groups that have adapted to life in dry environments. One arthropod sub-group, insects, is the most species-rich member of all ecological guilds in land and freshwater environments; the lightest insects weigh less than 25 micrograms. Some living crustaceans are much larger; the embryos of all arthropods are segmented, built from a series of repeated modules. The last common ancestor of living arthropods consisted of a series of undifferentiated segments, each with a pair of appendages that functioned as limbs. However, all known living and fossil arthropods have grouped segments into tagmata in which segments and their limbs are specialized in various ways; the three-
Cyanobacteria known as Cyanophyta, are a phylum of bacteria that obtain their energy through photosynthesis and are the only photosynthetic prokaryotes able to produce oxygen. The name cyanobacteria comes from the color of the bacteria. Cyanobacteria, which are prokaryotes, are called "blue-green algae", though the term algae in modern usage is restricted to eukaryotes. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes; these are flattened. Phototrophic eukaryotes perform photosynthesis by plastids that may have their ancestry in cyanobacteria, acquired long ago via a process called endosymbiosis; these endosymbiotic cyanobacteria in eukaryotes may have evolved or differentiated into specialized organelles such as chloroplasts and leucoplasts. By producing and releasing oxygen, cyanobacteria are thought to have converted the early oxygen-poor, reducing atmosphere into an oxidizing one, causing the Great Oxygenation Event and the "rusting of the Earth", which changed the composition of the Earth's life forms and led to the near-extinction of anaerobic organisms.
Cyanobacteria are a group of photosynthetic bacteria, some of which are nitrogen-fixing, that live in a wide variety of moist soils and water either or in a symbiotic relationship with plants or lichen-forming fungi. They include colonial species. Colonies may form filaments, sheets, or hollow spheres; some filamentous species can differentiate into several different cell types: vegetative cells – the normal, photosynthetic cells that are formed under favorable growing conditions. Some cyanobacteria can fix atmospheric nitrogen in anaerobic conditions by means of specialized cells called heterocysts. Heterocysts may form under the appropriate environmental conditions when fixed nitrogen is scarce. Heterocyst-forming species are specialized for nitrogen fixation and are able to fix nitrogen gas into ammonia, nitrites or nitrates, which can be absorbed by plants and converted to protein and nucleic acids. Free-living cyanobacteria are present in the water of rice paddies, cyanobacteria can be found growing as epiphytes on the surfaces of the green alga, where they may fix nitrogen.
Cyanobacteria such as Anabaena can provide rice plantations with biofertilizer. Many cyanobacteria form motile filaments of cells, called hormogonia, that travel away from the main biomass to bud and form new colonies elsewhere; the cells in a hormogonium are thinner than in the vegetative state, the cells on either end of the motile chain may be tapered. To break away from the parent colony, a hormogonium must tear apart a weaker cell in a filament, called a necridium; each individual cell has a thick, gelatinous cell wall. They lack flagella. Many of the multicellular filamentous. In water columns, some cyanobacteria float by forming gas vesicles, as in archaea; these vesicles are not organelles as such. They are not bounded by a protein sheath. Cyanobacteria can be found in every terrestrial and aquatic habitat—oceans, fresh water, damp soil, temporarily moistened rocks in deserts, bare rock and soil, Antarctic rocks, they can form phototrophic biofilms. They are found in endolithic ecosystem. A few are endosymbionts in lichens, various protists, or sponges and provide energy for the host.
Some live in the fur of sloths. Aquatic cyanobacteria are known for their extensive and visible blooms that can form in both freshwater and marine environments; the blooms can have the appearance of blue-green scum. These blooms can be toxic, lead to the closure of recreational waters when spotted. Marine bacteriophages are significant parasites of unicellular marine cyanobacteria. Cyanobacteria growth is favored in ponds and lakes where waters are calm and have less turbulent mixing, their life cycles are disrupted when the water or artificially mixes from churning currents caused by the flowing water of streams or the churning water of fountains. For this reason blooms of cyanobacteria occur in rivers unless the water is flowing slowly. Growth is favored at higher temperatures, making increasing water temperature as a result of global warming more problematic. At higher temperatures Microcystis species are able to outcompete green algae; this is a concern because of the production of toxins produced by Microcystis.
Based on environmental trends and observations suggest cyanobacteria will increase their dominance in aquatic environments. This can lead to serious consequences the contamination of sources of drinking water. Cyanobacteria can interfere with water treatment in various ways by plugging filters and by producing cyanotoxins, which have the potential to cause serious illness if consumed. Consequences may lie within