Deaths in a fish stock caused by predation, pollution, senility, etc., but not fishing.
A technical term which refers to the proportion of the fish population dying by any causes other than fishing. As with fishing mortality, can be translated into a yearly natural mortality rate expressed as a percentage, using a mathematical formula. See also Fishing mortality.
deaths of fish from all causes except fishing. It is often expressed as a rate that indicates the percentage of fish dying in a year; for example, a natural mortality rate of 0.2 implies that e-0.2 of the population—about 22%—will die in a year from causes other than fishing.
Deaths of fish from all causes except fishing. It is often expressed as a rate that indicates the percentage of fish dying in a year; e.g. a natural mortality rate of 0.2 implies that approximately 20 per cent of the population will die in a year from causes other than fishing.
A measurement of the rate of removal of fish from a population from natural causes. Natural mortality can be reported as either annual or instantaneous. Annual mortality is the percentage of fish dying in one year. Instantaneous is the percentage of fish dying at any one time. The rates of natural mortality may vary from species to species.
Mortality due to natural causes. Mathematical symbol: M.
The death of animal life through natural causes; e.g. predation, disease, natural environmental stress, etc.