Nearshore Benthic Habitat Surveys in Bras d'Or Lake 2005-2011

2005-2011 surveys document nearshore benthic habitats in Bras d'Or Lake using drop cameras, sidescan sonar, and echosounders. Data from the northern half of the lake, from depths less than 1 meter to 10 meters, was integrated into a Geographic Information System. The report highlights widespread but poor-condition eelgrass beds and potential impacts from turbidity and siltation.

Use Cases

• Analyze substrate type and macrophyte canopy proportions to distinguish shoreline characteristics for habitat classification.
• Use echosounder and sidescan sonar data to ground-truth and map eelgrass (Zostera marina L.) distribution within the first 3 meters of depth.
• Leverage the Geographic Information System package to model habitat compensation project placement or select nearshore protected areas.
• Assess long-term changes in benthic habitat by using the 2005-2011 survey data as a baseline for comparison with future studies.

Strengths

• Surveys span 7 years (2005-2011) providing a multi-year perspective on nearshore conditions.
• Data collection employed multiple technologies including drop cameras, sidescan sonar, and echosounders for cross-validation.
• Surveys cover a specific depth gradient from shallow waters (<1 m) to 10 meters, capturing critical nearshore zones.
• All data is consolidated into a Geographic Information System package for spatial analysis and management applications.

Limitations

• Surveys were primarily conducted in the northern half of Bras d'Or Lake, limiting geographic coverage of the entire lake.
• Eelgrass beds are noted as frequently in poor shape, suggesting potential data quality issues or environmental stressors affecting baseline conditions.
• The dataset's integration into a GIS package may require specialized software (e.g., ESRI) for full access and analysis.

Provenance

Source

Fisheries and Oceans Canada, Coastal Ecosystems Science Division.

Collection Method

Nearshore benthic surveys using drop cameras, fixed mount sidescan, a developed towfish platform, and echosounders.

Time Range

2005 to 2011.

Freshness

null

Geography

Bras d'Or Lake, primarily the northern half, from depths less than 1 meter to 10 meters.