Bottlenecks to Survival is part of the PSF 
Marine Science Program

Fishery & Predation Monitoring

Another mainstay of the Bottlenecks project is an innovative and novel fishery and predation monitoring programs.

To better understand the 'top-down' pressures on Salmon, we are using the PIT technology to track predation and recreational fishery catches.

Enhanced Fishery Monitoring

At key high-traffic recreational landing sites on the east coast of Vancouver Island, we have begun retrofitting and building new cleaning tables with integrated PIT and video technology to modernize and supplement DFO's ongoing Creel Survey Program. This work is being done in collaboration with DFO’s Stock Assessment Division and local marinas, and with support from the BC Sport Fishing Advisory Board.

In 2021, three tables were built: one in the Nanaimo's Brechin Marina and two at French Creek Marina. Another monitoring location was also established at Pacific Playgrounds Resort in 2023. The operational tables are already providing interesting information and are a great way to collect recreational catch data when DFO Survey staff are not present.

When fish are brought to the tables to be cleaned, overhead video cameras are triggered to collect imagery. Video imagery allows us to record the species caught and identify those that were adipose fin clipped. We can also determine how many heads of clipped fish are deposited for voluntary participation in the coded wire tag recovery program.

The person cleaning their fish remains anonymous due to the positioning of the camera, so only information about the fish is collected.If the fish being cleaned happens to be one that has a PIT tag, integrated receivers will log that information as well.

Operational enhanced fishery monitoring cleaning table at French Creek Marina and example of imagery captured from overhead cameras of fish.

Predation Monitoring

Scanning for expelled tags will help to better understand the proportional levels of mortality occurring from predation. The team periodically visits known pinniped (harbour seal) haulouts and scans for deposited tags. Also, areas below heron rookeries are explored and scanned.

Harbour seal haulout scanning to detect PIT tags from tagged fish that had been consumed by predators, photo credit: D. Swainson.
Copyright © The Pacific Salmon Foundation