Antarctic krill is a species of krill found in the Antarctic waters of the Southern Ocean. It is a small, swimming crustacean that lives in large schools, called swarms, sometimes reaching densities of 10,000–30,000 individual animals per cubic metre. It feeds directly on minute phytoplankton, thereby using the primary production energy that the phytoplankton originally derived from the sun in order to sustain their pelagic life cycle. It grows to a length of 6 centimetres (2.4 in), weighs up to 2 grams (0.071 oz), and can live for up to six years. It is a key species in the Antarctic ecosystem and in terms of biomass, is one of the most abundant animal species on the planet.
The biomass is the mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms, plants or animals. The mass can be expressed as the average mass per unit area, or as the total mass in the community.
Herring are forage fish, mostly belonging to the family Clupeidae.
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word zooplankton is derived from the Greek zoon (ζῴον), meaning "animal", and planktos (πλαγκτός), meaning "wanderer" or "drifter". Individual zooplankton are usually microscopic, but some are larger and visible to the naked eye.
Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than that at which the substance is lost by catabolism and excretion. Thus, the longer the biological half-life of a toxic substance, the greater the risk of chronic poisoning, even if environmental levels of the toxin are not very high. Bioaccumulation, for example in fish, can be predicted by models. Hypotheses for molecular size cutoff criteria for use as bioaccumulation potential indicators are not supported by data. Biotransformation can strongly modify bioaccumulation of chemicals in an organism.
Copepods 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.
Atlantic herring is a herring in the family Clupeidae. It is one of the most abundant fish species in the world. Atlantic herrings can be found on both sides of the Atlantic Ocean, congregating in large schools. They can grow up to 45 centimetres (18 in) in length and weigh up to 1.1 kilograms (2.4 lb). They feed on copepods, krill and small fish, while their natural predators are seals, whales, cod and other larger fish.
The ecoSCOPE is an optical sensor system, deployed from a small remotely operated vehicle (ROV) or fibre optic cable, to investigate behavior and microdistribution of small organisms in the ocean.
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish. Some birds, such as flamingos and certain species of duck, are also filter feeders. Filter feeders can play an important role in clarifying water, and are therefore considered ecosystem engineers. They are also important in bioaccumulation and, as a result, as indicator organisms.
Mysida is an order of small, shrimp-like crustaceans in the malacostracan superorder Peracarida. Their common name opossum shrimps stems from the presence of a brood pouch or "marsupium" in females. The fact that the larvae are reared in this pouch and are not free-swimming characterises the order. The mysid's head bears a pair of stalked eyes and two pairs of antennae. The thorax consists of eight segments each bearing branching limbs, the whole concealed beneath a protective carapace and the abdomen has six segments and usually further small limbs.
Biomagnification, also known as bioamplification or biological magnification, is any concentration of a toxin, such as pesticides, in the tissues of tolerant organisms at successively higher levels in a food chain. This increase can occur as a result of:
The Antarctic Technology Offshore Lagoon Laboratory (ATOLL) was a floating oceanographic laboratory for in situ observation experiments. This facility also tested instruments and equipment for polar expeditions. The ATOLL hull was the largest fiberglass structure ever built at that time. It was in operation from 1982 to 1995.
Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, as a branch of agriculture.
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 communities of microorganisms that colonize and decompose, i. e., remineralize, it. In terrestrial ecosystems it is present as leaf litter and other organic matter that is intermixed with soil, which is denominated "soil organic matter". The detritus of aquatic ecosystems is organic material that is suspended in the water and accumulates in depositions on the floor of the body of water; when this floor is a seabed, such a deposition is denominated "marine snow".
Aquarium filters are critical components of both freshwater and marine aquaria. Aquarium filters remove physical and soluble chemical waste products from aquaria, simplifying maintenance. Furthermore, aquarium filters are necessary to support life as aquaria are relatively small, closed volumes of water compared to the natural environment of most fish.
Neomysis integer is a species of opossum shrimp found in shallow marine bays and estuaries of Europe, with a transparent greenish or brownish body and a large cephalothorax. It is found in very shallow water in both high and low-salinity habitats. It is a filter feeder and the female broods her eggs in a brood pouch beneath her cephalothorax.
The San Francisco Estuary together with the Sacramento–San Joaquin River Delta represents a highly altered ecosystem. The region has been heavily re-engineered to accommodate the needs of water delivery, shipping, agriculture, and most recently, suburban development. These needs have wrought direct changes in the movement of water and the nature of the landscape, and indirect changes from the introduction of non-native species. New species have altered the architecture of the food web as surely as levees have altered the landscape of islands and channels that form the complex system known as the Delta.
A fishery is an area with an associated fish or aquatic population which is harvested for its commercial value. Fisheries can be marine (saltwater) or freshwater. They can also be wild or farmed.
Forage fish, also called prey fish or bait fish, are small pelagic fish which are preyed on by larger predators for food. Predators include other larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the food chain on plankton, often by filter feeding. They include particularly fishes of the family Clupeidae, but also other small fish, including halfbeaks, silversides, smelt such as capelin and goldband fusiliers.
Sex is influenced by water pollutants that are encountered in everyday life. These sources of water can range from the simplicity of a water fountain to the entirety of the oceans. The pollutants within the water range from endocrine disruptor Chemicals (EDCs) in birth control to Bisphenol-A (BPA). Foreign substances such as chemical pollutants that cause an alteration of sex have been found in growing prevalence in the circulating waters of the world. These pollutants have affected not only humans, but also animals in contact with the pollutants.
