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[RalphH]

Recently I found this video that BC Hydro has committed to continuing it's lake enrichment project at Alouette for 70 years. This is part of the Stave Lake Power house and dam project. This is good news as it will support efforts to establish sockeye runs into the lake and because it enhances the fishery in Alouette Lake. Lately I have seen some photos of nice catches of kokanee and cutthroat including some cutties in the 20+  inches range. It should also help the resident bull trout that can reach 15lbs - c&r only on these.

Youtube link from the Province and Alouette River Management Society below:


https://alouetteriver.org/alouette-reservoir-project

[ja]

Thank for the information RalphH!

[wildmanyeah]

Recently I found this video that BC Hydro has committed to continuing it's lake enrichment project at Alouette for 70 years. This is part of the Stave Lake Power house and dam project. This is good news as it will support efforts to establish sockeye runs into the lake and because it enhances the fishery in Alouette Lake. Lately I have seen some photos of nice catches of kokanee and cutthroat including some cutties in the 20+  inches range. It should also help the resident bull trout that can reach 15lbs - c&r only on these.

Youtube link from the Province and Alouette River Management Society below:


https://alouetteriver.org/alouette-reservoir-project

I may be missing remembering but I thought we had a decision about lake fertilization years ago and you said it was pointless on a coastal lake like allouette.

Due to it being flushed out so fast with glacial runoff.

May have been AA tho on the other forum, I can’t remember tho lol

[RalphH]

I don't recall saying that at least not precisely. However enrichment has been happening on Alouette for something like 20 years though there was doubt BC Hydro would continue to pay for it until the last few years but now it will continue.

Sockeye Lake enrichment on the Island started happening in the mid-70s and was largely regarded as successful though the results vary depending on the situation in specific lakes. Enrichment of small lakes on the Island to enhance sportfishing has also been done though I understand it's been discontinued. It doesn't always work or perhaps the results aren't worth the money. There a number of papers available online if you look & are inclined to read them.

https://hctf.ca/wp-content/uploads/2026/04/1-644-Vancouver-Isand-Small-Lakes-Enrichment-Program-BCCF.pdf#page=5.09

https://waves-vagues.dfo-mpo.gc.ca/Library/38344373.pdf

https://publications.gc.ca/collections/collection_2025/mpo-dfo/fs97-6/Fs97-6-1324-eng.pdf#page=11.53

https://onlinelibrary.wiley.com/doi/abs/10.1002/%28SICI%291099-1646%28199607%2912%3A4/5%3C547%3A%3AAID-RRR407%3E3.0.CO%3B2-M

The abstract for the last paper (the link immediately above) states in it's last sentence: "The benefit : cost ratio of lake fertilization is the best of currently available salmonid enhancement techniques."

[clarki]

I’d be curious if the lake fertilization has any impact on the trophic state of the Alouette River downstream.

Wonder if more nutrient rich lake water leads to more nutrient rich river water leads to more benthic invertebrates in the river leads to greater survivability of juvenile salmonids?

[Dave]

I’d be curious if the lake fertilization has any impact on the trophic state of the Alouette River downstream.

Wonder if more nutrient rich lake water leads to more nutrient rich river water leads to more benthic invertebrates in the river leads to greater survivability of juvenile salmonids?

Sounds logical to me and that is why myself and others have, for years, been pushing DFO to fertilize Chilliwack Lake.

[RalphH]

All the papers describe the method and objectives of the nutrient application. In general it provides a limited boost over the warm months to encourage growth and reproduction of various microorganisms that feed kokanee. While some nutrients probably does spill over the dam how much depends on where the water is drawn from. Most of the water from Alouette Lake actually goes to Stave Lake. The river itself gets a lot of nutrient benefit from the hatchery enhancement.

The objective of all  those projects was to enhance sockeye production not downstream areas. The Chilliwack sockeye seem pretty healthy and they and other salmon that spawn above the lake help provide nutrient contribution to the lake. What's to be gained with more? Does such a project meet the goals of nutrient projects in general? IS there a good cost /benefit to such a project? The Chilliwack run isn't significant commercially. Overall it seems kind of a leap of assumption that such a project on Chilliwack Lake would have major downstream benefits for the river. 

[Dave]

 In a nutshell, the idea was to find a champion who would pull together DFO's lake study group based out of Cultus Lake, the Chilkwayuhk tribes and the LFFA, and the University College of the Fraser Valley, to test the theory fertilization could not only benefit Chilliwack Lake salmonids but also the invertebrate populations in the river downstream.
 DFO has a ton of limnology and fish stock population data for Chilliwack Lake, FN want a limited terminal fishery for these early returning sockeye, and the University could supply the manpower. along with valuable field experience. It seems like a reasonable proposal that doesn't appear to have a lot of downside but, potentially a lot of benefits.

[wildmanyeah]

I don't recall saying that at least not precisely. However enrichment has been happening on Alouette for something like 20 years though there was doubt BC Hydro would continue to pay for it until the last few years but now it will continue.

Sockeye Lake enrichment on the Island started happening in the mid-70s and was largely regarded as successful though the results vary depending on the situation in specific lakes. Enrichment of small lakes on the Island to enhance sportfishing has also been done though I understand it's been discontinued. It doesn't always work or perhaps the results aren't worth the money. There a number of papers available online if you look & are inclined to read them.

https://hctf.ca/wp-content/uploads/2026/04/1-644-Vancouver-Isand-Small-Lakes-Enrichment-Program-BCCF.pdf#page=5.09

https://waves-vagues.dfo-mpo.gc.ca/Library/38344373.pdf

https://publications.gc.ca/collections/collection_2025/mpo-dfo/fs97-6/Fs97-6-1324-eng.pdf#page=11.53

https://onlinelibrary.wiley.com/doi/abs/10.1002/%28SICI%291099-1646%28199607%2912%3A4/5%3C547%3A%3AAID-RRR407%3E3.0.CO%3B2-M

The abstract for the last paper (the link immediately above) states in it's last sentence: "The benefit : cost ratio of lake fertilization is the best of currently available salmonid enhancement techniques."

All good, I remember it being something along these lines

The Water Residence Problem: For lake fertilization to work, the liquid nitrogen and phosphorus need to sit in the upper layer of the water (the photic zone) long enough for phytoplankton to bloom, which then allows zooplankton populations to grow.

The Rapid "Flush": Many coastal and glacier-fed lakes have massive winter rain freshets or intense summer glacial meltwater pouring through them. some of these lakes have a water retention time of only a few months—meaning the entire volume of the lake replaces itself multiple times a year.

Wasted Money: If you drop expensive liquid fertilizer into a lake with high flushing rates, the nutrients are swept down the outlet river and out to the ocean before the food web can even utilize them.

[RalphH]

AFAIK among all these projects, they were not all equally successful. They were not all equally effective year to year. Last I heard the lake feralization the Province carried out to improve sport fishing on  some Island Lakes was not continued past the pilot phase of a few years.

If you look at the lake flushing patterns you wrote about. The period when the fertilizations take place particularly on Alouette corresponds to the lowest precipitation time of year and there is little to no late spring summer snow or glacial melt. I also believe they pond more water on Alouette than in the past meaning less flushing.

It always seemed to me that if you want to fertilize a coastal lake to improve fish production do it on a lake that is mainly sourced from groundwater not surface water in flow.

Lake feralization is not a magic bullet.

[Trout_Bum]

Lake fertilization has also been used successfully in interior lakes. Arrow Lakes annually has 250 metric tons of fertilizers added to boost lake levels impacted by the upstream dams (Revelstoke, Mica). Interestingly the fertilizer is distributed by the Galena Bay ferry every time it makes a run across the lake.

More info here: https://a100.gov.bc.ca/pub/acat/documents/r63035/COL_F24_F_3793_DCA_1716914401730_28CDF653E5.pdf

[RalphH]

Kootenay Lake also has had such a program since 1992. Funded by BC Hydro it's objective is to restore nutrient losses created by the Lardeau dam. The US Libby dam on the Kootenay River has also caused a massive nutrient loss that's devastated fish stocks, particularly Kokanee in the South Arm.

https://www.friendsofkootenaylake.ca/wp-content/uploads/2012/12/Fertilization-Program-Overview.pdf