Intervention planned to boost smolt stocks
The Pacific Salmon Commission has approved the Cowichan Estuary Restoration and Conservation Association's grant application for breaching the causeway of the Westcan Terminal in Cowichan Bay.
"The proposed intervention aims at breaching the man-made causeway currently acting as a barrier between the two parts of the Cowichan Estuary via a bridge,'' explained Dr. Goetz Schuerholz, chair of the CERCA, in a media release.
"The project rationale is to re-enable water circulation and ecosystem functioning between the two parts of the Cowichan/Koksilah estuary which are currently artificially divided by the man-made Westcan causeway which provides road access to the Westcan Terminal.
"The causeway effectively blocks Cowichan River smolt from accessing a large section of a highly-productive part of the Cowichan Estuary, blocking freshwater flow from the Cowichan south fork to the southern section of the estuary, thus preventing proper ecosystem functioning of the Cowichan Estuary which constitutes one ecological entity.''
The in-filling for the causeway was done in the 1970s.
Schuerholz added the chinook is the target species of the proposal. The focus will be on rebuilding the chinook stock from the low escapement of 2009 and also benefiting chum and coho stocks that use the estuary at critical stages of the life cycle.
"Quality habitat in the estuary and marshlands is key for smolt survival,'' noted Schuerholz.
Cowichan chinook declined from 10,000 spawners in the early 1990s to a low of only a few hundred natural spawners in 2009, he added.
"This habitat enhancement proposal addresses one of the key limiting factors to chinook smolts in the Cowichan Estuary — the lack of connectivity between the north and south side of the estuary as a result of the man-made Westcan causeway.
"This has been identified at the March 2013 workshop on the Cowichan estuarine and freshwater risk factors by a group of scientific, biological and local knowledge experts, with over 300 years combined experience on the Cowichan, as limiting the productive capacity of Cowichan River fall run chinook.''
The estimated potential economic benefit of the proposed intervention is high, according to Schuerholz.
The project is to be implemented under the auspices of CERCA in May.