WA bioindicator is any species or group of species whose function, population, or status can reveal the qualitative status of the environment. For example, copepods and other small water crustaceans that are present in many water bodies can be monitored for changes that may indicate a problem within their ecosystem. Bioindicators can tell us about the cumulative effects of different pollutants in the ecosystem and about how long a problem may have been present, which physical and chemical testing cannot.
WAncyronyx, commonly known as spider water beetles or spider riffle beetles, is a genus of aquatic riffle beetles from North America, South Asia, China, and Southeast Asia. They are small beetles with extremely long legs ending in strong claws. Both the adults and the larvae are found underwater in the shallow riffles of streams and rivers, clinging to rocks or submerged wood. They feed on algae and decaying wood tissue. The genus contains twenty-one species, eleven of which are endemic to the Philippines.
WOceanic anoxic events or anoxic events (anoxia conditions) were intervals in the Earth's past where portions of oceans became depleted in oxygen (O2) over a large geographic areas. During some of these events, euxinia, waters that contain hydrogen sulfide, H2S, developed. Although anoxic events have not happened for millions of years, the geological record shows that they happened many times in the past. Anoxic events coincided with several mass extinctions and may have contributed to them. These mass extinctions include some that geobiologists use as time markers in biostratigraphic dating. Many geologists believe oceanic anoxic events are strongly linked to slowing of ocean circulation, climatic warming, and elevated levels of greenhouse gases. Researchers have proposed enhanced volcanism (the release of CO2) as the "central external trigger for euxinia".
WAnthocyanidins are common plant pigments, the sugar-free counterparts of anthocyanins. They are based on the flavylium cation, an oxonium ion, with various groups substituted for its hydrogen atoms. They generally change color from red through purple, blue, and bluish green as a function of pH.
WAnthoxanthins are a type of flavonoid pigments in plants. Anthoxanthins are water-soluble pigments which range in color from white or colorless to a creamy to yellow, often on petals of flowers. These pigments are generally whiter in an acid medium and yellowed in an alkaline medium. They are very susceptible to color changes with minerals and metal ions, similar to anthocyanins. As with all flavonoids, they exhibit antioxidant properties, and are important in nutrition, and are sometimes used as food additives. Darkening with iron is particularly prominent in food products. They are considered to have more variety than anthocyanins. Some examples are quercetin.
WAquatic biomonitoring is the science of inferring the ecological condition of rivers, lakes, streams, and wetlands by examining the organisms that live there. While aquatic biomonitoring is the most common form of biomonitoring, any ecosystem can be studied in this manner.
WA biosurvey, or biological survey, is a scientific study of organisms to assess the condition of an ecological resource, such as a water body.
WCarotenoids, also called tetraterpenoids, are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, corn, tomatoes, canaries, flamingos, salmon, lobster, shrimp, and daffodils. Carotenoids can be produced from fats and other basic organic metabolic building blocks by all these organisms. The only land dwelling arthropods known to produce carotenoids are aphids, and spider mites, which acquired the ability and genes from fungi., It is also produced by endosymbiotic bacteria in whiteflies. Carotenoids from the diet are stored in the fatty tissues of animals, and exclusively carnivorous animals obtain the compounds from animal fat. In the human diet, absorption of carotenoids is improved when consumed with fat in a meal. Cooking carotenoid-containing vegetables in oil increases carotenoid bioavailability.
WCarotenoid oxygenases are a family of enzymes involved in the cleavage of carotenoids to produce, for example, retinol, commonly known as vitamin A. This family includes an enzyme known as RPE65 which is abundantly expressed in the retinal pigment epithelium where it catalyzed the formation of 11-cis-retinol from all-trans-retinyl esters.
WCopepods are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic, some are benthic, and some continental species may live in limnoterrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, bogs, springs, ephemeral ponds, and puddles, damp moss, or water-filled recesses (phytotelmata) of plants such as bromeliads and pitcher plants. Many live underground in marine and freshwater caves, sinkholes, or stream beds. Copepods are sometimes used as biodiversity indicators.
W5β-Coprostanol (5β-cholestan-3β-ol) is a 27-carbon stanol formed from the biohydrogenation of cholesterol (cholest-5en-3β-ol) in the gut of most higher animals and birds. This compound has frequently been used as a biomarker for the presence of human faecal matter in the environment.
WIn geochemistry, paleoclimatology, and paleoceanography δ13C is an isotopic signature, a measure of the ratio of stable isotopes 13C : 12C, reported in parts per thousand. The measure is also widely used in archaeology for the reconstruction of past diets, particularly to see if marine foods or certain types of plants were consumed
WThe δ34S value is a standardized method for reporting measurements of the ratio of two stable isotopes of sulfur, 34S:32S, in a sample against the equivalent ratio in a known reference standard. Presently, the most commonly used standard is Vienna-Canyon Diablo Troilite (VCDT). Results are reported as variations from the standard ratio in parts per thousand, per mil or per mille, using the ‰ symbol. Heavy and light sulfur isotopes fractionate at different rates and the resulting δ34S values, recorded in marine sulfate or sedimentary sulfides, have been studied and interpreted as records of the changing sulfur cycle throughout the earth's history.
WA lichen is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship. Lichens have properties different from those of their component organisms. Lichens come in many colors, sizes, and forms and are sometimes plant-like, but lichens are not plants. Lichens may have tiny, leafless branches (fruticose), flat leaf-like structures (foliose), flakes that lie on the surface like peeling paint (crustose), a powder-like appearance (leprose), or other growth forms.
WIn the deep ocean, marine snow is a continuous shower of mostly organic detritus falling from the upper layers of the water column. It is a significant means of exporting energy from the light-rich photic zone to the aphotic zone below which is referred to as the biological pump. Export production is the amount of organic matter produced in the ocean by primary production that is not recycled (remineralised) before it sinks into the aphotic zone. Because of the role of export production in the ocean's biological pump, it is typically measured in units of carbon .The term was first coined by the explorer William Beebe as he observed it from his bathysphere. As the origin of marine snow lies in activities within the productive photic zone, the prevalence of marine snow changes with seasonal fluctuations in photosynthetic activity and ocean currents. Marine snow can be an important food source for organisms living in the aphotic zone, particularly for organisms which live very deep in the water column.
WPeriphyton is a complex mixture of algae, cyanobacteria, heterotrophic microbes, and detritus that is attached to submerged surfaces in most aquatic ecosystems. The related term Aufwuchs refers to the collection of small animals and plants that adhere to open surfaces in aquatic environments, such as parts of rooted plants. Periphyton serves as an important food source for invertebrates, tadpoles, and some fish. It can also absorb contaminants, removing them from the water column and limiting their movement through the environment. The periphyton is also an important indicator of water quality; responses of this community to pollutants can be measured at a variety of scales representing physiological to community-level changes. Periphyton has often been used as an experimental system in, e.g., pollution-induced community tolerance studies.
WSPEARpesticides is a trait based biological indicator system for streams which quantitatively links pesticide contamination to the composition of invertebrate communities. The approach uses species traits that characterize the ecological requirements posed by pesticide contamination in running waters. Therefore, it is highly specific and only slightly influenced by other environmental factors. SPEARpesticides is linked to the quality classes of the EU Water Framework Directive (WFD)
WA trace fossil, also ichnofossil, is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, which are the fossilized remains of parts of organisms' bodies, usually altered by later chemical activity or mineralization. Ichnology is the study of such trace fossils and is the work of ichnologists.
WThe meadow vole, sometimes called the field mouse or meadow mouse, is a North American vole found across Canada, Alaska and the northern United States. Its range extends farther south along the Atlantic coast. One subspecies, the Florida salt marsh vole, is found in Florida, and is classified as endangered. Previously it was also found in Chihuahua, Mexico, but has not been recorded since 1998.