Seston can simply be defined as the particles suspended in bodies of water such as lakes, oceans, ponds and rivers. The term "seston" applies to

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

, organic

detritus In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts commun ...

, and

minerals In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

. Detritus is dead organic material and a mineral is a solid chemical compound. Small particles of seston may be formed by the breaking down of larger particles. This can happen by the crashing of waves, mixing of water currents, or by slow disintegration. Most seston in the water is made up of a combination of both organic and

inorganic compounds In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistr ...

. The inorganic compounds are from mineral origin and are essentially particles of mud suspended in the water column. The

organic compounds In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The s ...

are from biological origin and can be either living or dead. Seston is used by many species in their day-to-day activities. Some examples are

barnacle A barnacle is a type of arthropod constituting the subclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in eros ...

mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other ...

scallop Scallop () is a common name that encompasses various species of marine bivalve mollusks in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is also sometimes applied to species in other closely related families ...

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 sec ...

sea anemone Sea anemones are a group of predation, predatory marine invertebrates of the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classifi ...

sea squirt Ascidiacea, commonly known as the ascidians, tunicates (in part), and sea squirts (in part), is a polyphyletic class (biology), class in the subphylum Tunicate, Tunicata of sac-like marine (ocean), marine invertebrate filter feeders. Ascidians ar ...

s, and

sea cucumber Sea cucumbers are echinoderms from the class Holothuroidea (). They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothuria ...

s. Suspension feeders and filter feeders like

whale Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and ...

s also rely on seston as a food source. Nutrient-rich seston particles can support the local ecosystem by providing nutrition to organisms. The higher the amount of organic matter in the seston, the more nutritious it is for the suspension feeders who count on seston as a food source. Many of these animals have adapted to be able to eat both organic and inorganic seston. Animals that eat seston also have to adapt because the seston is not always present or may have periods of time when it is less nutritious. They adapt by eating more when it is there or by storing it to eat later when it would otherwise be unavailable. Studies of rivers have shown that downstream seston is more nutritious that it is upstream. While seston is necessary for many animals and in many ecosystems, it can also be harmful in large quantities. Sometimes human activities like fishing and farming that generate nutrient-rich

surface runoff Surface runoff (also known as overland flow) is the flow of water occurring on the ground surface when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate in the soil. This can occur when th ...

can make the presence of organic seston increase dramatically. This sudden increase can destabilize the

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

if there are not enough organisms that eat that seston to make up for the increase. As the amount of seston grows, the other organisms in the ecosystem may not be able to live there anymore, the end stage of

cultural eutrophication Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytoplank ...

. Florida often sees one example of this issue with the algae bloom on

Lake Okeechobee Lake Okeechobee (), also known as Florida's Inland Sea, is the largest freshwater lake in the U.S. state of Florida. It is the tenth largest natural freshwater lake among the 50 states of the United States and the second-largest natural freshwat ...

. Runoff from nearby farming increases the nutrients in the lake and causes the amount of algae to grow. Especially in the more shallow parts of Lake Okeechobee, the algae grows very well because it requires sunlight to carry out the process of photosynthesis to make food for itself. Because parts of Lake Okeechobee are so shallow, there is a high degree of light penetration through the water, which allows more of the algae to receive the sunlight it needs. Because the algae needs a warm and sunny environment, this is especially a problem in warmer climates like Florida’s. Some of the algae bloom is blue-green algae, which is also known as

cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...

. It grows very quickly when it has nutrition from

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

and

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

. The algae bloom decreases water quality and can make people and animals sick. Some symptoms in people include nausea and vomiting, but the worst side effect could be liver failure. Since Lake Okeechobee waters are released to the ocean through canals to the east and west, coastal areas in Florida are affected too. The algae bloom has caused businesses near the ocean to close and hurt tourism revenues in recent years. Florida has even declared a state of emergency in the past because of the algae bloom.

References

Biological oceanography Limnology Aquatic ecology {{Ocean-stub

See also

References