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Fish stocks are subpopulations of a particular species of fish, for which intrinsic parameters (growth, recruitment, mortality and fishing mortality) are traditionally regarded as the significant factors determining the stock's population dynamics, while extrinsic factors (immigration and emigration) are traditionally ignored. Stocks fished ...
An example of a multispecies stock is river herring. Alewives and blueback herring are labeled as river herring for management purposes due to their similar physical appearances and being harvested together. Individuals within a stock are subdivided into cohorts. A cohort is a group of fish born in the same year within a population or stock.
The concept of maximum sustainable yield (MSY) has been used in fisheries science and fisheries management for more than a century. Originally developed and popularized by Fedor Baranov early in the 1900s as the "theory of fishing," it is often credited with laying the foundation for the modern understanding of the population dynamics of fisheries. [1]
Schaefer published a fishery equilibrium model based on the Verhulst model with an assumption of a bi-linear catch equation, often referred to as the Schaefer short-term catch equation: (,) = where the variables are; H, referring to catch (harvest) over a given period of time (e.g. a year); E, the fishing effort over the given period; X, the ...
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.
Fish stock or stock fish may also refer to: Fish stocks are subpopulations of a particular species of fish. Fish stock (food), liquid made by boiling fish bones with vegetables, used as a base for fish soups and sauces; Fish stocking, the practice of raising fish in a hatchery and releasing them into a river, lake, or ocean
The new technologies adversely affected the northern cod population by both increasing the area and depth that was fished. The cod were being depleted until the surviving fish could not replenish the stock lost each year. [4] The trawlers caught enormous amounts of non-commercial fish, which were very important ecologically.
A mixed stock fishery is a fishery whose stock consists of fish that are of a variety of ages, sizes, species, geographic or genetic origins or any combination of these variables. Mixed stock fisheries offer a challenge to fisheries managers due to the difficulty in targeting fish of a specific type using many commercial fishing methods.