Selectivity and demographic change in the anchovy fishery
Published:
Scientific question
Has the selectivity of the industrial anchovy fishery changed through time, and how are those changes associated with fleet characteristics, management regimes, seasonality, and the demographic structure of the stock?
Data
The project combines paired acoustic-survey and fishing-season information, length-frequency distributions, vessel characteristics, fishing-season classification, regulatory periods, and biological reference information.
Methods
- Logistic selectivity models.
- Estimation of length at 50% selection and selection range.
- Mann–Kendall tests and Sen slopes for temporal trends.
- Structural-break and change-point analysis.
- Seasonal and regulatory-period comparisons.
- Length–age key evaluation and synthetic age-structure reconstruction.
Current status
Active manuscript and methodological development. The current analysis evaluates long-term trends, seasonal contrasts, fleet-related differences, and potential changes in the capture of juvenile fish.
Expected outputs
- Long-term selectivity time series.
- Comparative length–age key framework.
- Scientific manuscript on selectivity and demographic consequences.
- Reproducible code and diagnostic visualizations.
Relevance
The project links fishing technology and operational behaviour with population structure, juvenile exposure, and management performance.