Marine Population Dynamics

Flashcards on marine population dynamics, covering key concepts, factors influencing population size, and case studies.

Population dynamics

How populations of a species change over time.

Population

Group of individuals of the same species occupying a specific area and sharing a gene pool over a certain period of time.

Per capita population growth rate

Rate at which the population size changes.

Factors determining per capita growth rate

Births, deaths, emigration, and immigration rates in the population.

Minimum Viable Population (MVP)

A lower bound on the population of a species, such that it can survive in the wild.

Carrying Capacity

Maximum sustainable population size of a species in a given area.

Intra-specific competition

Competition between individuals for limited resources within the same species.

Inter-specific competition

Competition between individuals for limited resources between different species.

Relationship between organism size and population density

General decline of population density with increasing organism size due to larger animals needing more resources.

Recruitment

Appearance of new, young organisms in a population following a previous reproductive event, or the maturing of individuals into the adult age classes.

Mortality (M)

Process of mortality (death) of fish due to natural causes such as predation, disease, etc., expressed as a rate.

Dispersal/Migration

Increase or decrease in local population size/density due to immigration/emigration, potentially leading to range shifts.

Metapopulations

A larger ‘metapopulation’ or ‘population of populations’ created by periodically connecting semi-isolated sub-populations.

Extinction

Eventual disappearance of a population due to mortality exceeding recruitment, potentially influenced by resource decline, competition, predation, disease, or environmental changes.

Steller’s Sea Cow

A population decline and extinction example, was largest of sirenians (~7.5 m long, 4500-5900 Kg).

Trophic Cascades

Powerful indirect interactions that can control entire ecosystems, occurring when a trophic level in a food web is suppressed.