Chapter 8-9 Growth ppt.

Define absolute population size and list methods used to estimate it.

Absolute population size is the total number of individuals or total biomass. Methods include aerial surveys, acoustics, area-based counts, mark-recapture, niche models, and distance methods. “Absolute population size: total number of all animals or total biomass.”

What is a closed population in abundance studies?

A population with no significant migration, mortality, or recruitment during the study period. “Closed population - on that remains unchanged during the period of study.

Define relative abundance and give an example.

A measure correlated with true abundance, such track or scat counts. Often called an index of abundance… proportional to absolute abundance such the N=qU”.

Describe the basic idea behind distance sampling.

Observers record individuals at measure distances from a line or point; a detection function converts counts to absolute abundance.

Explain the logic behind mark-recpature.

The proportion of marked individuals in the second sample equal the proportion originally marked in the population.

List the assumption of the Petersen model.

Closed population, equal catchability, marks not lost, marking does not affect recapture, second sample in random.

Why must CPUE be standarized?

To remove variation caused by gear, environment, fisher behavior, and other non-abundance factors.

Define life history.

The major event in an organism’s growth, development, reproduction, and reproduction, and survival.

Why is life history important in population modeling?

It provides quantitative relationships for growth, maturity, fecundity, mortality and sex structure.

What biological processes drive growth?

Growth occurs when anabolism (surface-based) exceeds catabolism (volume-based).

Name structures used to age fish.

Otoliths, spines, vertebrae

Define precision vs. accuracy in age reading.

Precision = agreement among readers

Accuracy = closeness to true age.

Define fecundity.

Number of fertilized eggs produced by a mature female.

Define Compensatory vs. Depensatory density dependence.

Compensatory: recruiters per spawner decrease as stock increases.

Depensatory: recruits per spawner increase as stock increases

What is sequential hermaphroditism?

Ability to change sex:

Protogynous: female → male (groupers)

Protandrous: male → female (snook)

List major reproductive strategies in fish.

Pelagic vs. demersal eggs, broadcast spawning, live bearing, parental care, nest building, spawning aggregations.

What percentage of eggs typically survive to adulthood?

Less than 0.001%

What is spawning stock biomass (SSB)?

Biomass of mature individuals capable to reproducing.

Define the Beverton-Holt Recruitment model.

A density dependent model where recruitment increases with stock but levels off asymptotically.

Define the Ricker recruitment model.

Recruitment increases at low stock sizes but decline at high stock due to density-dependent mortality.

What is the Spawning Potential Ration (SPR)?

Ratio of lifetime egg production per recruit in fished vs. unfished conditions.

Which method estimates absolute abundance?

A. CPUE

B. Mark‑recapture

C. Scat counts

D. Fisher interviews

Mark-recapture

Relative abundance requires which condition?

A. Closed population

B. N = qU proportionality

C. No migration

D. No mortality

N = qU proportionality

In Petersen estimator, R represents

A. Total population

B. Number marked initially

C. Number recaptured that are marked

D. Total second sample

Number recapture that are marked

Increasing gear depth generally does what to catchability (q)?

A. Decreases it

B. Increases it

C. Has no effect

D. Makes CPUE unusable

Increases it

The von Bertalanffy model assumes

A. Infinite growth

B. Discontinuous growth

C. Growth slows as size approaches L∞

D. Growth accelerates with age

Growth slows as size approaches L

Which structure is not used for aging fish?

A. Otoliths'

B. Spines

C. Vertebrae

D. Scales

Scales

Which fish type change from female to male/

A. Snook

B. Grouper

C. Salmon

D. Flounder

Grouper

Which recruitment model decline at high stock sizes?

A. Beverton–Holt

B. Ricker

C. Logistic

D. von Bertalanffy

Ricker

Growth Overfishing occurs when

A. Fish are caught too small

B. Too many large fish remain

C. Recruitment is too high

D. CPUE is standardized

Fish are caught to small