Projects at Goldstream Hatchery

Construction of the Goldstream River Fence

Summer or 1996

Project Initiation

In the winter of 1995/96, the Goldstream River was made an indicator stream for Coho salmon. This meant that accurate numbers of returning Coho must be counted each fall to provide the Department of Fisheries and Oceans with a census on the Coho population in the river. The one reliable method of accurately counting Coho is to place a fence or obstruction across the river below where the Coho typically spawn in order to capture and count the Coho. The fence provides a method of blocking the migration of Salmon and providing protection from predators such as Eagles and humans before hatchery staff can net and count the fish. Brood stock for the hatchery is taken at the fence and after the quota of adult Coho are taken, the remainder are let go over the fence to spawn naturally in the river. The fence also captures Chum and Chinook salmon. The Chinook are taken for the hatchery along with some Chum. The bulk of Chum salmon are let go over the fence.

DFO provided the funding and engineering resources to design and construct the fence. Members of the Goldstream hatchery volunteered during construction to aid in the construction of the wooden sill which rests on the bottom of the river. Volunteers also aided in the construction of the initial fence panels and their installation onto the wooden sill. During the fall, volunteers visit the fence on a daily basis to count and capture fish and clear debris off the fence which could cause water to pass overtop and enable fish to bypass the fence.

Fence Construction

To begin, a level area needed to be excavated across the river to support the wood sill which the fence rests onto. The wooden sill provides the foundation for anchoring the panels which comprise the fence. The panels float in the river and impede the passage of the salmon. The figure below provides an illustration as to the mechanism behind the fence panels. Fish swimming upstream, swim under the panels and cannot proceed upstream. The cover of the panels, keeps the fish protected from predators. An opening in the fence leads the fish into a trap for collection and counting purposes. Unfortunately, not all fish go to the trap and must be netted manually.