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

A history of nearshore benthic surveys from 2005 to 2011 documents habitat composition and eelgrass distribution in Bras d'Or Lake. Surveys utilized drop cameras, sidescan sonar, and a towfish platform to ground truth echosounder data from depths of less than 1 meter to 10 meters. Data were integrated into a Geographic Information System to support habitat management and long-term change detection.

Use Cases

• Map eelgrass (Zostera marina L.) distribution and health status using georeferenced survey data to assess habitat quality.
• Analyze substrate type and macrophyte canopy proportions from sidescan and video data to distinguish different shoreline characteristics.
• Use the integrated GIS data to model the impact of water column turbidity and siltation on benthic habitats for management planning.
• Establish a baseline from the 2005-2011 time series to detect long-term changes in nearshore protected areas.

Strengths

• Surveys span a 7-year time series from 2005 to 2011, providing a historical baseline.
• Data collection employed multiple complementary technologies including drop cameras, sidescan sonar, and echosounders.
• Surveys cover a specific depth gradient from less than 1 meter to 10 meters in the northern half of the lake.
• Results are packaged within a Geographic Information System for spatial analysis and management applications.

Limitations

• Spatial coverage is limited primarily to the northern half of Bras d'Or Lake.
• The eelgrass beds documented were frequently noted as being in poor shape, indicating potential data quality concerns related to habitat degradation.
• The dataset's age means conditions may have changed significantly since the last survey in 2011.

Provenance

Source

Fisheries and Oceans Canada, Coastal Ecosystems Science Division.

Collection Method

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

Time Range

2005 to 2011

Freshness

Data collection concluded in 2011, though the record was published in 2022 and last updated on the platform in 2026.

Geography

Bras d'Or Lake, specifically the northern half and the St. Andrews area, Nova Scotia, Canada.