0000000001071460
AUTHOR
Silva Uusi‐heikkilä
Age is not just a number : Mathematical model suggests senescence affects how fish populations respond to different fishing regimes
Senescence is often described as an age-dependent increase in natural mortality (known as actuarial senescence) and an age-dependent decrease in fecundity (known as reproductive senescence), and its role in nature is still poorly understood. Based on empirical estimates of reproductive and actuarial senescence, we used mathematical simulations to explore how senescence affects the population dynamics of Coregonus albula, a small, schooling salmonid fish. Using an empirically based eco-evolutionary model, we investigated how the presence or absence of senescence affects the eco-evolutionary dynamics of a fish population during pristine, intensive harvest, and recovery phases. Our simulation …
Atlantic cod recovery from the Allee effect zone : contrasting ecological and evolutionary rescue
The ability of a population to recover from disturbances is fundamental for its persistence. Impaired population recovery might be associated with a demographic Allee effect. Immigration from adjacent populations could accelerate the recovery not only by promoting population growth beyond the Allee effect threshold but also by bringing in advantageous genotypes. We explore the nature and role of ecological and evolutionary rescue in an Atlantic cod (Gadus morhua Gadidae) population fished below its Allee effect threshold. We utilize an eco-evolutionary model and simulate scenarios, where the target population evolves in response to selective fishing and sample immigrants from (a) a source p…
Generalist invasion in a complex lake food web
Invasive species constitute a threat not only to native populations but also to the structure and functioning of entire food webs. Despite being considered as a global problem, only a small number of studies have quantitatively predicted the food web-level consequences of invasions. Here, we use an allometric trophic network model parameterized using empirical data on species body masses and feeding interactions to predict the effects of a possible invasion of Amur sleeper (Perccottus glenii), on a well-studied lake ecosystem. We show that the modeled establishment of Amur sleeper decreased the biomasses o ftop predator fishes by about 10%–19%. These reductions were largely explained by inc…