Eelgrass Sonar Transects in Southern Gulf of St. Lawrence 2018-2023

Between 2018 and 2023, acoustic surveys mapped eelgrass presence at 48 processed coastal sites in New Brunswick, Prince Edward Island, and Nova Scotia. Data includes geographic coordinates, timestamps, and submerged aquatic vegetation presence, collected via boat-based sonar transects. An additional 18 sites from the same period have been surveyed but await full processing.

Use Cases

• Map eelgrass distribution using geographic coordinates and submerged aquatic vegetation presence data.
• Analyze seasonal or annual trends in eelgrass presence using timestamp data from 2018-2023 surveys.
• Validate sonar-derived eelgrass presence classifications against ground-truthing notes and underwater photos mentioned in the quality control process.
• Assess spatial coverage of eelgrass beds across the 48 processed sites in the Southern Gulf of St. Lawrence.

Strengths

• Data spans a 5-year time range from 2018 to 2023.
• Covers 48 fully processed coastal sites across three Canadian provinces.
• Processing used a defined threshold (vegetation canopy height >= 0.1 m) to assign eelgrass presence values.

Limitations

• No independent ground-truthing points were surveyed to validate the sonar classifications, potentially affecting accuracy.
• The dataset is incomplete, with 18 additional surveyed sites not yet processed for depth and eelgrass classification.
• Positional accuracy varied, with GPS accuracy of 1-2 meters for data collected through 2020.

Provenance

Source

Fisheries and Oceans Canada, in partnership with the Southern Gulf of St. Lawrence Coalition on Sustainability.

Collection Method

Acoustic data collected using BioSonics MX Aquatic Habitat Echosounder units during summer/early fall boat transects, processed with BioSonics Visual Aquatic software.

Time Range

2018 to 2023

Freshness

Last updated in March 2026, with ongoing processing for additional sites.

Geography

48 coastal sites in New Brunswick, Prince Edward Island, and Nova Scotia, Canada (Southern Gulf of St. Lawrence).