Restigouche River

March 4, 2015

Some 15-thousand aerial photos of the Restigouche River system were taken in 2011. That may sound like a lot, but it’s just the beginning of a huge data collection project that will make the world-renowned salmon system one of the most documented on the continent.

“Until now, the photos being used to set up conservation levels and management targets have dated back to the 1970’s,” explains David LeBlanc, Executive Director of the Restigouche Watershed Management Council. “Today’s imaging technology is so advanced that the data and resulting analysis from this project will have a major influence on conservation and management of the watershed for years to come.”

The imaging is part of a study that is interprovincial in scope, Quebec and New Brunswick, covering the entire Restigouche River watershed and its tributaries. The main sub-basins are the Matapedia and Patapedia in Quebec and the Kedgwick, Little Main Restigouche and Upsalquitch Rivers in neighboring New Brunswick.

There were actually two separate, but complementary, imaging projects in 2011, with the Atlantic Salmon Conservation Foundation contributing $20,000. Both projects required aerial surveying. In the first, LIDAR (light detection and ranging) laser technology was used to map the Five Fingers sub-watershed, an area of 150 km2. The equipment takes one laser shot every square metre, and the data is used to prepare a precise 3-D mapping, GIS analysis of the ground with details on contour lines at 15 cm precision, dips, surface drainage and other characteristics. The objective was to evaluate surface runoff in the sub-watershed which was showing the greatest problem of soil erosion for the Restigouche River system. The results of the survey identified sources of sediment harmful to fish habitat and will lead to a plan to improve farm soil quality, road infrastructure maintenance and wood yard activity.

The second, larger project uses two camera technologies in an aerial helicopter survey. One camera captures thermal imaging and the other, a precise photogrammetric imaging of 2cm2pixels.In 2011, the photography was completed along more than 400 km of streams and rivers in the boundary waters and Quebec portions of the Restigouche River watershed. It is expected to take two more years to cover all of the 1,500 km of rivers identified as salmon habitat in the watershed.

“This imagery will improve the management of rivers at different levels,” says LeBlanc. “First, it will identify cold-water refuges needed for salmon in the event of rising temperatures to ensure their protection and reduce stress during confinement. Second, it will enable the updating of the characterization of salmon habitat—information that is needed to establish thresholds of conservation and in the annual evaluation of the success of spawning runs in each of the tributaries.”

The helicopter photography was completed in 2012; LeBlanc says there are more than 15,000 images in total that were analyzed. The whole process, from the helicopter photography to completed data, took up to three years in total. “This is a major project that will generate a huge amount of valuable information for evaluating the habitat in precise detail. The data will be useful for many years to come in guiding restoration, conservation and management.”

All of the materials—images, analysis and final data—will have a broad audience of interest beyond the Restigouche Watershed Management Council. LeBlanc says the group is looking at developing partnerships with universities.