Eelgrass Health Assessment in New Brunswick Estuaries Using Towfish

A 2008 bay-scale assessment of eelgrass (Zostera marina) beds in three northern New Brunswick estuaries: Cocagne, Bouctouche, and Tabusintac. The dataset includes maps of eelgrass cover, health scores based on epiphyte load, and ancillary bottom features like algal growth and bacterial mats. Data was collected using a novel towfish package combining underwater video, scaling lasers, and sidescan sonar to achieve sub-meter precision in turbid waters.

Use Cases

• Compare eelgrass health scores and epiphyte load across the Cocagne, Bouctouche, and Tabusintac estuaries to identify environmental stressors.
• Analyze the spatial correlation between eelgrass cover maps and ancillary bottom features like benthic algal growth or bacterial mats (Beggiatoa).
• Validate remote sensing methods by using the towfish-derived eelgrass cover data as ground truth for turbid, shallow estuaries.
• Assess the cost-effectiveness of the towfish method for real-time, bay-scale habitat mapping by examining the precision of the collected geospatial data.

Strengths

• Data was collected with a novel towfish system designed for sub-meter precision in turbid waters where aerial or satellite methods fail.
• Provides comparative analysis of eelgrass health across three distinct estuaries in northern New Brunswick.
• Includes multiple data products such as maps of eelgrass cover, health scores, and ancillary bottom features.

Limitations

• Data is from a single year (2008), limiting analysis of temporal trends or changes in eelgrass beds.
• The dataset's spatial coverage is limited to three specific estuaries in New Brunswick, Canada.
• The presence of material reminiscent of the oomycete Leptomitus was noted but not positively identified, introducing uncertainty for related analyses.

Provenance

Source

Coastal Ecosystems Science Division, Fisheries and Oceans Canada.

Collection Method

Data gathered using a towfish package deployed along transects, containing an underwater video camera with scaling lasers, sidescan sonar, and a transponder-based positioning system.

Time Range

2008

Freshness

Data was collected in 2008 and published in November 2019; the record was last updated in March 2026.

Geography

Three northern New Brunswick estuaries: Cocagne, Bouctouche, and Tabusintac.