CFP CFP Fish Population Dynamics & Stock Assessment 2 — Questions and Answers
Question 1: Which statistical method is commonly used to estimate population size using mark-recapture data?
- Linear regression
- Chapman modification of the Lincoln-Petersen estimator (Correct answer)
- Analysis of variance (ANOVA)
- Principal component analysis
Correct answer: Chapman modification of the Lincoln-Petersen estimator
The Chapman modification of the Lincoln-Petersen estimator is a standard mark-recapture formula used to estimate closed population size.
Question 2: In fisheries, what does the term 'F_MSY' represent?
- The fishing mortality rate that produces maximum sustainable yield (Correct answer)
- The fraction of the population that migrates seasonally
- The minimum stock size required for fishery opening
- The mean spawning frequency of the target species
Correct answer: The fishing mortality rate that produces maximum sustainable yield
F_MSY is the level of fishing mortality at which the stock produces its maximum sustainable yield.
Question 3: What is an age-structured population model primarily used for in fisheries management?
- Tracking individual fish movement with acoustic tags
- Projecting future population size and yield under different harvest scenarios (Correct answer)
- Mapping spawning habitat using GIS layers
- Calculating genetic diversity indices
Correct answer: Projecting future population size and yield under different harvest scenarios
Age-structured models project how fish populations will change over time under various fishing pressures by accounting for survival and growth by age class.
Question 4: What is the primary purpose of a spawning stock biomass (SSB) reference point?
- To determine legal harvest size limits
- To set a threshold below which the reproductive capacity of the stock may be compromised (Correct answer)
- To identify peak spawning months for closed seasons
- To calculate total allowable catch for commercial fleets
Correct answer: To set a threshold below which the reproductive capacity of the stock may be compromised
SSB reference points define a minimum reproductive biomass level needed to maintain adequate recruitment and long-term stock viability.
Question 5: Which tool is widely used by US federal fisheries scientists to conduct integrated stock assessments?
- FRAGSTATS
- Stock Synthesis (SS3) (Correct answer)
- ArcGIS Spatial Analyst
- SWAT hydrological model
Correct answer: Stock Synthesis (SS3)
Stock Synthesis (SS3) is an age- and length-structured statistical stock assessment model widely used by NOAA and other US fisheries agencies.
Question 6: What does a high natural mortality (M) estimate imply about managing a fish stock?
- The stock requires more restrictive harvest limits than a low-M species
- The stock can sustain higher exploitation rates because it has a fast population turnover (Correct answer)
- The stock is less vulnerable to habitat degradation
- The stock's abundance is not influenced by fishing pressure
Correct answer: The stock can sustain higher exploitation rates because it has a fast population turnover
Species with high natural mortality tend to have short life spans and fast reproduction, allowing them to sustain higher fishing pressure than slow-growing, long-lived species.
CFP CFP Fish Population Dynamics & Stock Assessment 2
Which statistical method is commonly used to estimate population size using mark-recapture data?