Atlantic Surfclam Concentration Areas in the Gulf of St. Lawrence

20 years of data from Fisheries and Oceans Canada inventories, commercial fisheries logs, and interviews delineate known concentration areas of the Atlantic surfclam around the Magdalen Islands. This dataset was created for the National Environmental Emergencies Centre to support oil spill preparation and response. It integrates information from sources including DFO inventories (2000-2020), commercial fisheries data (2002-2020), and at-sea observations (2005-2017).

Use Cases

• Map known concentration areas from DFO inventories and commercial fisheries data for environmental emergency planning.
• Analyze changes in shellfish bed extent over time using data spanning up to 20 years.
• Cross-reference interview-based polygon delimitations with sampling-based data to assess spatial precision for resource management.
• Model potential oil spill impacts on Atlantic surfclam habitats using the delineated concentration areas.

Strengths

• Integrates multiple data sources over a 20-year period, from 2000 to 2020.
• Created for a specific, high-stakes application: National Environmental Emergencies Centre oil spill response.
• Data precision is noted as sufficient for resource protection and management needs in environmental incidents.

Limitations

• Represents only known areas, not the general species distribution, and likely underestimates the full extent.
• Some concentration areas were delimited based on interviews, resulting in approximate boundaries.
• Polygons based on sampling data may underestimate concentration areas as sampling targeted known abundant locations.

Provenance

Source

Fisheries and Oceans Canada (DFO) inventories, commercial fisheries data (logbooks, purchase receipts), exploratory fisheries data, and interviews.

Collection Method

Concentration areas were delineated by integrating DFO inventories, commercial data, exploratory fisheries data, and local interviews.

Time Range

Primary data spans 2000 to 2020, with specific commercial data from 2002-2020 and at-sea observations from 2005-2017.

Freshness

Last updated 2026-03-24, though underlying data collection ended by 2020.

Geography

Gulf of St. Lawrence, specifically around the Magdalen Islands.