Matrix population models describe populations as discrete life-, size-, or age-stages. Scientists apply these models to understand population ecology and guide conservation. However, some species have continuous life histories. For example, thistles grow continuously as presented within this paper.
Fish also grow continuously. We sought to understand how different management approaches could be used to control grass carp. This species impacts native ecosystems by out-competing native fish. Mangers were interesting in evaluating the use of YY-males to control populations. YY-males work because they spawn and only produce male offspring. Thus, it is possible in theory to cause a population to crash by biasing the sex-ratio.
We constructed an integral projection model for grass carp and compared different yy-male release methods. We found the life history of grass carp does not work well with the YY-male strategy because the species lives long and females produce many offspring.