Maximum sustainable yield ,maximum economic yield
optimum sustainable yield
Compiled by Archana A Nair
Maximum Sustainable Yield
Maximum Sustainable Yield (MSY) or surplus production is the maximum catch
that can be extracted from a fish or other population in the long term.It is the
highest theoretical equilibrium yield that can be continuously taken (on average)
from a stock under existing environmental conditions without affecting
significantly the reproduction process. The MSY is also called as Potential yield.
Maximum Economic Yield (MEY) is the Economic Optimal Catch.
Concept of MSY
Fundamental to the notion of sustainable harvest, the concept of MSY aims to
maintain the population size at the point of maximum growth rate by harvesting the
individuals that would normally be added to the population, allowing the population
to continue to be productive indefinitely. Under the assumption of logistic growth,
resource limitation does not constrain individuals’ reproductive rates when
populations are small, but because there are few individuals, the overall yield is
small. At intermediate population densities, also represented by half the carrying
capacity, individuals are able to breed to their maximum rate. At this point, called the
maximum sustainable yield, there is a surplus of individuals that can be harvested
because growth of the population is at its maximum point due to the large number of
reproducing individuals. Above this point, density dependent factors increasingly
limit breeding until the population reaches carrying capacity. At this point, there are
, no surplus individuals to be harvested and yield drops to zero. The maximum
sustainable yield is usually higher than the optimum sustainable yield and maximum
economic yield.
MSY is based on a simple and easily understood concept of how a stock reacts to
fishing. It is calculated on a simple physical measure. i.e., weight of fish caught. In a
steady state fishery, biomass declines as effort increases. The effort level
corresponding to MSY being referred as FMSY. FMSY is used as biological
reference point. MSY and FMSY could be estimated by surplus production models
and by prediction models (Refer chapter on surplus production and prediction
models)
Merits and demerits of MSY
Merits
MSY has been especially influential in the management of renewable biological
resources such as commercially important fish. Maximum sustainable yield (MSY) is
the largest average catch that can be captured from a stock under existing
environmental conditions. MSY aims at a balance between too much and too little
optimum sustainable yield
Compiled by Archana A Nair
Maximum Sustainable Yield
Maximum Sustainable Yield (MSY) or surplus production is the maximum catch
that can be extracted from a fish or other population in the long term.It is the
highest theoretical equilibrium yield that can be continuously taken (on average)
from a stock under existing environmental conditions without affecting
significantly the reproduction process. The MSY is also called as Potential yield.
Maximum Economic Yield (MEY) is the Economic Optimal Catch.
Concept of MSY
Fundamental to the notion of sustainable harvest, the concept of MSY aims to
maintain the population size at the point of maximum growth rate by harvesting the
individuals that would normally be added to the population, allowing the population
to continue to be productive indefinitely. Under the assumption of logistic growth,
resource limitation does not constrain individuals’ reproductive rates when
populations are small, but because there are few individuals, the overall yield is
small. At intermediate population densities, also represented by half the carrying
capacity, individuals are able to breed to their maximum rate. At this point, called the
maximum sustainable yield, there is a surplus of individuals that can be harvested
because growth of the population is at its maximum point due to the large number of
reproducing individuals. Above this point, density dependent factors increasingly
limit breeding until the population reaches carrying capacity. At this point, there are
, no surplus individuals to be harvested and yield drops to zero. The maximum
sustainable yield is usually higher than the optimum sustainable yield and maximum
economic yield.
MSY is based on a simple and easily understood concept of how a stock reacts to
fishing. It is calculated on a simple physical measure. i.e., weight of fish caught. In a
steady state fishery, biomass declines as effort increases. The effort level
corresponding to MSY being referred as FMSY. FMSY is used as biological
reference point. MSY and FMSY could be estimated by surplus production models
and by prediction models (Refer chapter on surplus production and prediction
models)
Merits and demerits of MSY
Merits
MSY has been especially influential in the management of renewable biological
resources such as commercially important fish. Maximum sustainable yield (MSY) is
the largest average catch that can be captured from a stock under existing
environmental conditions. MSY aims at a balance between too much and too little
