NAFO 4T Herring Acoustic Survey: Annual Abundance Index for Stock Assessment

Fisheries and Oceans Canada conducts an annual fishery-independent acoustic survey of Herring in the southern Gulf of St. Lawrence. The survey, active since 1991, uses a random stratified design with parallel transects and trawl sampling to generate a standardized abundance index and catch-at-age data from 1994 onward. It provides age-disaggregated acoustic abundance indices for ages 2 to 10 for both spring and fall spawners.

Use Cases

• Modeling herring stock abundance based on the standardized acoustic index mentioned in the description.
• Analyzing age-specific population trends for ages 2 to 10 based on the age-disaggregated index.
• Assessing spatial distribution of herring spawning components in NAFO Division 4T based on the survey's stratified design.
• Calibrating acoustic target strength models using trawl sample data for species composition and size distribution.

Strengths

• Survey has been conducted annually since 1991, providing a long-term time series.
• Data includes catch-at-age information from 1994 onward.
• Uses a standardized random stratified design with parallel transects, following documented methodology.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.

Provenance

Source

Fisheries and Oceans Canada

Collection Method

Annual acoustic survey using a hull-mounted 120 KHz split-beam transducer and pelagic trawl sampling.

Time Range

Annual surveys from 1991 onward, with catch-at-age data from 1994.

Freshness

Last updated 2026-04-15 20:31:38.964333; freshness should be verified.

Geography

Southern Gulf of St. Lawrence, specifically NAFO Division 4T (areas 4Tmno).