Eastern Arctic Sponge Grounds Identified from Alfredo Trawl Survey Data

Polygons identifying concentrations of sea pens, gorgonian corals, and sponges on the east coast of Canada were created through spatial analysis of research vessel survey by-catch data. Kernel density analysis and catch weight thresholds were used to define aggregations across five biogeographic zones. The dataset, provided by Fisheries and Oceans Canada, includes tow positions for dense aggregations and for non-aggregating black coral.

Use Cases

• Mapping vulnerable marine benthic habitats based on identified sponge and coral aggregations.
• Analyzing the spatial distribution of long-lived, fishing-vulnerable taxa like black coral based on provided tow positions.
• Comparing species concentrations across biogeographic zones (e.g., Laurentian Channel, Eastern Arctic) as described in the analysis.
• Identifying areas for marine protected area designation based on the 70 kg minimum threshold for sponge ground habitat.

Strengths

• Analysis covers five distinct biogeographic zones of eastern Canada.
• Aggregations are defined using a specific methodological approach (kernel density analysis and catch weight thresholds) used by NAFO.
• Includes data for both aggregating (sponges, corals, sea pens) and non-aggregating (black coral) taxa.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data may reflect geographic and methodological bias inherent to the Alfredo gear trawl sampling method.

Provenance

Source

Fisheries and Oceans Canada

Collection Method

Spatial analysis of research vessel survey by-catch data using kernel density and catch weight thresholds.

Freshness

Last updated 2026-05-08 08:01:07.911981; freshness should be verified.

Geography

East coast of Canada, including the Eastern Arctic biogeographic zone, Gulf of St. Lawrence, Labrador slope, Scotian Shelf, and Grand Banks.