Maximum Sustainable Yield Explained
The question describes the population size where net recruitment is highest, allowing for the maximum harvest without threatening the population's long-term survival. This specific concept is known as the maximum sustainable yield.
Understanding Key Ecological Terms
Let's look at the options:
- Maximum Sustainable Yield (MSY): This refers to the largest yield (or catch) that can be taken from a species' stock over an indefinite period. It occurs at the population size where the growth rate is maximized, balancing harvest with population renewal.
- Carrying Capacity: This is the maximum population size that an environment can sustain indefinitely, given the available resources. At carrying capacity, the population growth rate is typically zero, not maximal for harvesting.
- Maximum Survival Density: This term is not standard ecological terminology for harvest management. Survival is related to density, but this specific phrase doesn't define the point of maximum harvestable surplus.
- Optimal Recruitment: While high recruitment is necessary for MSY, 'optimal recruitment' itself doesn't specifically define the harvestable amount or the population size yielding the greatest harvest. MSY is the outcome of optimal conditions for harvest.
Therefore, the population size yielding the greatest harvest sustainably is the definition of maximum sustainable yield.
Important Questions from Population growth curves
The population of whirligig beetles in a lake grows or declines exponentially i.e.
$N(t) = N(0)e^{rt}$
where $N(t)$ is the population size at time $t$, $N(0)$ is the initial population size and $r$ is the per capita rate of population change, occurring only due to birth and death.
A researcher tracks population sizes for a year and finds the following:Time interval Number of beetles at start Number of beetles at end January - March 1000 150 April – June 150 3013 July – September 3013 100 October - December 100 2009 Assuming that the individual birth rates remain constant throughout the year and only death rates are affected, which one or more of the following statements is/are true?
(In your calculations, round off the birth and date rates to two decimal places)The graphs shown represent the relationship between population size ($N$) and population growth rate ($\frac{dN}{dt}$). Which one of the following growth curves represents a density-dependent population that experiences a strong Allee effect?
Overfishing reduced food availability for sea lions in California, causing a decline in their population size. In 1972, under the US Endangered Species Act, fishing was banned from sea lion foraging areas. Subsequently, the population of sea lions increased in a logistic form as shown in the figure.
The per capita growth rate is highest in the interval __________ and the population growth rate is highest in the interval __________
Consider the logistic population growth model, given by $$ \frac{dn}{dt} = rn \left(1 - \frac{n}{k}\right) $$ where $r$ is the intrinsic growth rate, $n$ is the population size and $k$ is the carrying capacity. Which one or more of the following is/are assumption(s) of the model?
A population of unicorns is growing over time, but its rate of growth is declining. Which of the following graphs best represents this pattern of growth?
