Population Dynamics
The number of new individuals after successful reproduction.
What is natality?
Also called the logarithmic phase, it constantly increases at a faster rate
What is the exponential growth curve
The availability of resources, build up of waste, predation, and disease are affecting the population.
What are limiting factors that define the carrying capacity?
Tasks on-board scientists from ICES do
What are:
Recording the number and kinds of fish that are thrown back
Tagging and releasing some fish
Developing questionnaires for fishermen about their perception of the catch
Reviewing the ship logbooks, which provide data on catch per unit effort (increased effort for the same catch indicates that fish are getting scarcer).
Mathematical models are used to turn all of the data into a form that can be used by the fishing industry and governments to plan the future of fish in our oceans and lakes.
What are mathematical models?
The number of deaths
What is mortality?
The population number slows down, but still increases at a slower rate
What is the transitional phase?
Abiotic Factors, biotic factors, density independent factors, and density dependent factors
What are four factors that influence change in the sigmoid growth curve?
The total population
What can be estimated as the fish are recaptured?
A method that predicts where should tracking equipment should be located
What is sound-tracking equipment placement?
The number of individuals arriving from other places.
What is immigration?
The phase where the number of individuals has stabilized and there is no more growth.
What is the plateau phase?
Change in population density = (natality + immigration) minus (mortality + immigration)
What is the equation to indicate change?
Sampling with nets
What is trawling?
The highest number of fish that can be remove without affecting the future outcome
What is the maximum sustainable yield (MSY)?
The number of individuals leaving the population.
What is emigration?
This phase are plentiful resources, little or no competition, little or no disease, and there is no competition
What is exponential growth?
A sampling technique that allows you to estimate the number of animals in an ecosystem
What is the capture-mark-release method?
One method of calculating age is to measure the rings in the ear bones of a fish
What is one method of calculating age of the fish?
Used to turn all of data into a form that can be used by scientists for the future.
What are mathematical models?
Trees were knocked down by the amount Saint Helens blast in 1980 affecting the population and environment. The case showed even from a nonexistent or very small population of individuals, there can soon be a dramatic increase in numbers.
What happen in the case of Mount Saint Helens and what did it show?
The growth curve tends to level off and the number of births balances out with the number of fatalities
What is the plateau phase?
This carrying capacity is unknown by many scientists; they are something that you see everyday.
What is the carrying capacity of the human population?
Ear bones of fish
What is otoliths?
Gathering data from fishermen, Computers, Observers, Sound-tracking
What are some ways we evaluate these methods?