Witch Flounder Biomass Estimates for Gulf of St. Lawrence 2021

Yearly biomass estimates for Witch Flounder in the Gulf of St. Lawrence (NAFO 4RST) to 2021, derived from a Bayesian Schaefer Surplus Production model. The data provides median estimates and uncertainty percentiles (2.5th, 25th, 75th, 97.5th) in thousands of tons for 30+ cm biomass.

Use Cases

• Analyze trends in median biomass estimates over time to assess stock status.
• Model stock dynamics using the Bayesian Schaefer Surplus Production framework referenced in the data's methodology.
• Quantify uncertainty in biomass using the provided 2.5th, 25th, 75th, and 97.5th percentile values for risk assessment.
• Compare biomass estimates in thousands of tons for the 30+ cm size class across different assessment years.

Strengths

• Data is associated with a Canadian Science Advice Secretariat (CSAS) Regional Science Advisory Process, indicating a formal review.
• Provides uncertainty estimates via multiple percentiles (2.5th, 25th, 75th, 97.5th) for each biomass value.
• Model-based estimates are derived from Markov Chain Monte Carlo (MCMC) simulations, a standard statistical method.

Limitations

• Specific row count, column count, and temporal start year are not provided in the input.
• Biomass values are limited to the 30+ cm size class, excluding smaller fish.
• The most recent data point is for year 2021, which may not reflect current stock conditions.

Provenance

Source

Fisheries and Oceans Canada

Collection Method

Bayesian Schaefer Surplus Production model and Markov Chain Monte Carlo (MCMC) simulations as part of a stock assessment.

Time Range

Time series to 2021.

Freshness

Last metadata update was 2026-03-24, but the stock assessment data is current to 2021.

Geography

Gulf of St. Lawrence (NAFO Division 4RST).