The elimination of sockeye and other salmon from the upper watershed has altered the flow of marine-derived nutrients in Alouette lake. These energy flows are naturally obtained from decaying salmon carcasses and are entwined with the food webs of local wildlife, plants and aquatic species. This disruption in nutrient influxes has had substantial negative impacts on the productivity of aquatic life in Alouette Lake.
In 1991, the Bell-Cor Netpen Project was established as a joint program between BC Corrections (Alouette River Corrections Center), the BC Ministry of Environment (Fraser Valley Trout Hatchery) and BC Hydro to improve the sport fishery. The initiation of this project saw the construction of a netpen facility on the east side of Alouette Lake, about 3.5 km north of the Alouette Dam, across from Gold Creek. It was here that juvenile rainbow and cutthroat trout, provided by the Fraser Valley Trout Hatchery, were raised for release into Alouette Lake.
The attached chart shows the release of various species into Alouette Lake in recent history.
Energy Project Certificate (EPC) that was issued to B.C. Hydro for the reconstruction of the Stave Falls Generation Station in 1995 included a number of legal mitigation and/or compensation conditions designed to address the impacts associated with this project. While the effects arising from this project occurred on the Stave Watershed, because of the hydraulic connectivity and the smaller size, it was recognized that the Alouette Reservoir would provide an efficient location to address some of the restorative activities. Regardless, it was clearly recognized that a need had been established to rebuild a failing fishery in the Alouette Reservoir. Modern lake scientific and chemical analyzes showed this water body to be depleted of a natural food source for fish due to the loss of marine-derived nutrients resulting from the blocking of pre-dam salmon migrations. Also, the normal system operation of this hydro reservoir is a contributing factor in depleting the natural food web over time. It became clear to the scientists, managers and ARMS that fish stocking alone would never succeed in rebuilding a sport fishery in the Alouette Reservoir. The net pens were removed in 2005 due to a lack of operation capacity and funding.
However, a Pilot Fertilization Plan for the Alouette Reservoir was put forward by provincial biologists as one method to replace lost habitat capacity arising from the Stave Falls reconstruction and to BC Hydro’s great credit; this project was approved for funding by this Crown agency. BC Hydro and the agencies agreed that the condition for the long term commitment for this project (70 years, or the life of the power plant) was, that rigorous scientific analysis must prove, beyond a reasonable doubt, that this project would be biologically and cost effective.
The first five years of the project were to be the scientific assessment phase to determine if fertilization could be employed to achieve these goals. This project was undertaken as a partnership with Ministry of Water, Land and Air Protection, Region #2, fish culture (Fraser Valley Trout Hatchery), and Biodiversity Branch staff; BC Hydro; BC Corrections; and ARMS. This included: liquid fertilizer inputs; inventory and assessment of water quality, fish and plankton, fish stocking of hatchery rainbow and cutthroat trout; creel surveys; and public relations.
The fertilization process in the reservoir was achieved through a semi-natural technique of adding small amounts of liquid nitrogen and phosphorus.
BC Hydro has agreed that the Alouette Reservoir Fertilization Program has well proved its worth. With the pilot test phase now completed, a less costly, but indexed, fertilization maintenance program will continue to address the nutrient requirements and legal commitments in the EPC.
ARMS are pleased to record this success and look forward to the public enjoying quality sport fishing closer to home. ARMS gives kudos to BC Hydro and the Provincial Government, UBC Biodiversity Branch staff and BC Corrections, for a job well done. B.C’s public is clearly well served when a new, more efficient, generating station can be built and at the same time, incorporate a method to bring back a lost sport fishery in Golden Ears Provincial Park.