Demersal Fish Biomass in the St. Lawrence Estuary and Gulf (2014-2023)

Fisheries and Oceans Canada provides mean total biomass estimates for demersal fish from 2014 to 2023 in the Estuary and Gulf of St. Lawrence. Data is aggregated from annual August and September multidisciplinary surveys, averaged within 10 km x 10 km grid cells. The dataset is presented as distinct layers for the northern and southern surveys due to differing fishing gear protocols.

Use Cases

• Analyze spatial distribution patterns of total biomass across the 10 km x 10 km grid cells to identify high-density fishing grounds.
• Compare temporal trends in mean total biomass between the northern (August) and southern (September) survey layers from 2014 to 2023.
• Model the relationship between biomass estimates from different survey protocols to assess the impact of fishing gear type on data comparability.
• Integrate biomass data with environmental layers to study ecosystem drivers of demersal fish populations in the St. Lawrence system.

Strengths

• Provides a decadal time series of biomass data from 2014 to 2023.
• Data is spatially explicit, aggregated to a standardized 10 km x 10 km grid.
• Based on long-term, standardized multidisciplinary surveys conducted annually since 1990 (north) and 1971 (south).
• Clear documentation of distinct survey protocols and gear types is provided, explaining data layer separation.

Limitations

• Total biomass values are not directly comparable between the northern and southern survey layers due to different fishing gears.
• The dataset is a derived, aggregated product (mean biomass per grid cell); raw tow-level data is not included.
• Spatial coverage is limited to the Estuary and Gulf of St. Lawrence, not representative of broader Atlantic ecosystems.

Provenance

Source

Fisheries and Oceans Canada.

Collection Method

Data derived from annual August (north) and September (south) multidisciplinary bottom trawl surveys. Biomass (kg) for all species per tow is summed and averaged across tows within each 10 km x 10 km grid cell.

Time Range

2014 to 2023.

Freshness

Data is updated annually following the completion of the multidisciplinary surveys; the record was last updated in March 2026.

Geography

Estuary and Gulf of St. Lawrence, Canada.