Maximum sustainable yield in fisheries
... Fishery isn’t considered depleted until we fish population down to 1/3 of its original estimate (and on
the other hand once it reaches 1/3 we consider its recovered
MSY is working reasonably well in the US, Iceland, New Zealand, and Australia, but not without issues or
continuous reform of managemen ...
Ecosystems - TeacherWeb
... You are an ecologist attempting to manage the catch of a salmon
population so that replacement of caught fish will happen at the fastest
rate. The salmon population size is estimated to be about 80,000 fish and
the carrying capacity of this environment is estimated to be about 100,000
fish. Given th ...
... area, or volume. Ex. Number of deer/km2.
• Dispersion: The distribution or
arrangement of individuals in space.
• Dispersion may be clumped, even or
... the deaths of these cows?
Was it density-dependent or Independent?
How Populations Grow - Brookwood High School
... F. Carrying capacity: maximum
population level that can be
supported with the resources
1. Not only during that
organism’s lifetime, but also
Ecology - the study of the relationships between organisms and their
... Ecology - the study of the relationships between organisms and their environment. The environment includes an
organism’s its surroundings and other organisms. Ecology studies the relationships and interactions among
individuals within a population and with individuals of different populations. Becau ...
Populations III: Harvest Models
... Hindsight always helps – the Allee effect
Low population density is prone to sudden extinction
Fewer mating opportunities; simply too few to be fit enough
... population size that yielded maximum
•Minimal Viable Population: The goal for a
threatened or endangered species
Ecology Unit Test review
... Know the following terms/processes
o Populations, communities, ecosystems
o Survivorship curves
o Population growth – factors that attribute to growth and decline
o Age structures
o Carrying capacity
o Density dependent/independent factors
o Competition, interspecific competition
o Mut ...
Characteristics of Populations
... • To grow
1. Has to have
abundant space and
2. Is well protected from
4.3-Aquatic Food Production Systems
... • Calculating MSY is difficult as it is hard to determine
the actual carrying capacity
• Must look at the annual growth in a population
• MSY is obtained if the population size remains the
Population Size Factors
... • Three stages
– 1) Slow growth
– 2) Exponential growth
– 3) Carrying Capacity:
greatest number of
individuals that a
population can sustain
Three Key Features of Populations Size
... • Doubled three times in the last three centuries
• About 6.1 billion and may reach 9.3 billion by
the year 2050
• Improved health and technology have lowered
UNIT 3 Chp 5.1 and 5.2
... birthrate, death rate, and the rate at which
individuals enter or leave the population.
6A Population Ecology 2015
... maximum number of individuals that
can be supported in an environment
Changes based on resource availability
... • Occurs when the individuals in a population
reproduce at a constant rate
• Under ideal conditions with unlimited
resources, a population will grow
Quiz 5 Key
... b. a predator keeps the population of its prey species well below its carrying
c. an early frost kills a large fraction of the insects in a population
d. food limitation reduces the birth rate as the population increases
e. none of the above
Growth Cycles and Stresses PPT
... Carrying capacity (K) – maximum population of a given species
that a habitat can sustain indefinitely without being degraded
... Geographic distribution, density, growth rate, and age structure
4. Which of those four characteristics describes the number of plants per square kilometer in a certain
5. Define exponential growth.
When individuals in a population reproduce at a constant rate
6. The various ...
Maximum sustainable yield
In population ecology and economics, maximum sustainable yield or MSY is theoretically, the largest yield (or catch) that can be taken from a species' stock over an indefinite period. 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 extensively used for fisheries management. Unlike the logistic (Schaefer) model, MSY has been refined in most modern fisheries models and occurs at around 30% of the unexploited population size. This fraction differs among populations depending on the life history of the species and the age-specific selectivity of the fishing method.However, the approach has been widely criticized as ignoring several key factors involved in fisheries management and has led to the devastating collapse of many fisheries. As a simple calculation, it ignores the size and age of the animal being taken, its reproductive status, and it focuses solely on the species in question, ignoring the damage to the ecosystem caused by the designated level of exploitation and the issue of bycatch. Among conservation biologists it is widely regarded as dangerous and misused.