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A fishery is an area with an associated fish or aquatic population which is harvested for its commercial or recreational value. Fisheries can be wild or farmed. Population dynamics describes the ways in which a given population grows and shrinks over time, as controlled by birth, death, and migration. It is the basis for understanding changing ...
In fisheries and conservation biology, the catch per unit effort (CPUE) is an indirect measure of the abundance of a target species. Changes in the catch per unit effort are inferred to signify changes to the target species' true abundance. A decreasing CPUE indicates overexploitation, while an unchanging CPUE indicates sustainable harvesting.
Most oceanic species (78 per cent, or 44 per cent of all fish species), live near the shoreline. These coastal fish live on or above the relatively shallow continental shelf. Only 13 per cent of all fish species live in the open ocean, off the shelf. Of these, 1 per cent are epipelagic, 5 per cent are pelagic, and 7 per cent are deep water. [16]
Sustainable yield in fisheries. The sustainable yield of natural capital is the ecological yield that can be extracted without reducing the base of capital itself, i.e. the surplus required to maintain ecosystem services at the same or increasing level over time. This yield usually varies over time with the needs of the ecosystem to maintain ...
3 cm of adult fish length per 4 litres of water (i.e., a 6 cm-long fish would need about 8 litres of water). [73] 1 cm of adult fish length per 30 square centimetres of surface area. [74] 1 inch of adult fish length per US gallon of water. [73] 1 inch of adult fish length per 12 square inches of surface area. [74]
Strouhal number (Sr) as a function of the Reynolds number (R) for the flow past a long circular cylinder. For large Strouhal numbers (order of 1), viscosity dominates fluid flow, resulting in a collective oscillating movement of the fluid "plug". For low Strouhal numbers (order of 10 −4 and below), the high-speed, quasi-steady-state portion ...
6,200,000 m 3 (8,100,000 cu yd) Surface elevation. 427 m (1,401 ft) Rožmberk is a fish pond in the South Bohemian Region of the Czech Republic. It was founded at the end of the 16th century and is part of the Třeboň fishpond system. With an area of 4.89 km 2 (1.89 sq mi), it is the largest fish pond in the world. [1]
Fish mortality is a parameter used in fisheries population dynamics to account for the loss of fish in a fish stock through death. The mortality can be divided into two types: Natural mortality: the removal of fish from the stock due to causes not associated with fishing. Such causes can include disease, competition, cannibalism, old age ...