Lower River and Estuary Pinniped Monitoring Program
A-Tlegay Fisheries Society, Wei Wai Kai Marine Guardians, Wei Wai Kum Marine Guardians, Cowichan Tribes, Snuneymuxw First Nation, BC Conservation Foundation, Pacific Salmon Foundation
2025-08-29
The following is a preliminary summary of the pinniped data collected through the Lower River and Estuary Pinniped Monitoring Project. The data herein are from visual shore-based surveys conducted by crews up until August of 2025. This project is a collaboration between the Bottlenecks to Survival Project (run by the Pacific Salmon Foundation and BC Conservation Foundation) and A-Tlegay Fisheries Society (including the Wei Wai Kai and Wei Wai Kum Guardians), Snuneymuxw First Nation, and Cowichan Tribes.
If you have any questions about these data, please contact sjames@psf.ca
Seal Counts
The following figures display the raw seal counts at each site on each river system over time. The dashed line shows the separation between 2024 and 2025. Note, not all river systems have 5 sites. The following are the sites and their distance up river:
Campbell River:
- 1: 0 km
- 2: 0 km
- 3: 0.6 km
- 4: 1.3 km
- 5: marine site off the end of Spit Rd
Cowichan River:
- 1: 0 km (North Arm)
- 2: 0 km (South Arm)
- 3: 2.9 km (North Arm)
- 4: 2.7 km (South Arm)
- 5: 3.7 km
Nanaimo River:
- 1: 0 km (West Arm)
- 2: 1.3 km
- 3: 3.7 km
- Note: a fourth site was explored and dropped early on
Sea Lion Counts
The same counts of individual sea lions per site in each river system is shown below.
Pinnipeds and Salmon
The figures below combine salmon and pinniped data. The salmon data are from the PIT detections from the Bottlenecks to Survival Project, separated into outmigrant/juvenile detections and adult/return detections at our PIT arrays in each river system. The pinniped data are from the visual surveys conducted by field crews on each system.
The red dashed line indicates the date that pinniped visual surveys began on each system, while the black dashed line shows the separation between 2024 and 2025.
Note the difference in scale on the y-axis in each plot.
Surveys and Pinnipeds by Time of Day
Campbell River Pinnipeds and Surveys Across Tides
Figures below show the distribution of surveys, seal, and sea lion observations across tidal heights at each site in each river system. Note, tide heights have been binned into 0.5 m intervals. Sites/tides with no surveys conducted or pinnipeds observed are white/blank in the heat maps.
Cowichan River Pinnipeds and Surveys Across Tides
Nanaimo River Pinnipeds and Surveys Across Tides
