Magdalen Islands Sea Scallop Biodiversity Survey 1992-2021

Fisheries and Oceans Canada conducted a scallop stock assessment and biodiversity survey in the Magdalen Islands (fishing area 20) using a dredge approximately every 1-2 years since 1992. The survey documents occurrences of sea scallops, Icelandic scallops, and associated epibenthic invertebrates and demersal fish by station, with taxonomic validation using the World Register of Marine Species. Sampling occurs at depths of 10 to 38 meters using a fixed random sampling plan.

Use Cases

• Analyze sea scallop (Placopecten magellanicus) stock trends over time using station-level occurrence data for fisheries management.
• Model biodiversity patterns of associated taxa, including molluscs, echinoderms, and crustaceans, across the study area's station grid.
• Investigate the presence and relative abundance of undersized or colonial organisms noted in the dredge basket samples.
• Assess habitat associations by examining station-level data for scallops and documented associated species.
• Monitor for invasive species, such as ascidians, using the taxonomic records retained for special cases.

Strengths

• Long-term temporal coverage with surveys conducted approximately every 1-2 years since 1992.
• Taxonomic validity checked using the authoritative World Register of Marine Species for naming all recorded taxa.
• Standardized sampling methodology using a lined Digby scallop dredge over 500m transects at randomly drawn stations from a fixed grid.
• Explicit documentation of sampling depth range (10-38 m) and geographic scope (south of the Magdalen Islands, fishing area 20).

Limitations

• Unknown total row count and specific column structure, limiting immediate analytical utility.
• Data availability is split, with current data from 2021 onward hosted separately, potentially complicating a complete time-series analysis.
• Sampling focuses on scallop beds, which may introduce a habitat bias for the documented associated biodiversity.

Provenance

Source

Fisheries and Oceans Canada

Collection Method

Research survey using a lined Digby scallop dredge over 500m seabed transects at randomly selected stations from a fixed grid. One basket was sorted for associated species, with most specimens counted by taxon.

Time Range

1992 to present (with a noted separate link for data starting in 2021)

Freshness

Data collection is ongoing; the dataset record was last updated in March 2026, and surveys occur every 1-2 years.

Geography

Magdalen Islands, specifically south of the islands in fishing area 20, at depths of 10 to 38 meters.