A noted increase in the production of phytoplankton in Upper Adams Lake indicates a project to restore the Upper Adams sockeye run is proceeding as intended.
2021 was the second year of a four-year project being conducted by the Adams Lake band, with the goal of bringing back to sustainable levels the Upper Adams salmon run which, according to the band, collapsed over a century ago as a result of logging, splash dams and other factors.
“The salmon that returned to the Upper Adams River and Adams sustained our community for thousands of years and it is imperative that we see this run returned to its former glory,” commented former Adams Lake Kukpi7 (Chief) Cliff Arnouse in an announcement about the project in January 2020.
The first year of the project revolved around collecting data. This year involved adding nutrients, in the form of agricultural-grade liquid fertilizer, to the lake. Overseeing the project, registered professional biologist Don Holmes of Lakeside Environmental explained these nutrients, critical to fish growth, were once provided by the dead salmon flushed back into the lake after they spawned and died. With the collapse of the Upper Adams run, however, the lake wound up becoming ultra-oligotrophic – essentially devoid of the nutrients needed for sockeye fry and smolts to grow.
Holmes said nutrients were added to the lake from April until the end of August. This was accompanied by extensive monitoring, to assess the impact of the “nutrient-enrichment activities used to increase juvenile salmon food availability and support the restoration of degraded lake rearing habitat for Upper Adams Lake sockeye through the addition of lake limited nutrients (nitrogen/ phosphorous).”
As a result of this year’s activities, there was an increase in the production of phytoplankton, which Holmes said is the main food source for zooplankton in the lake.
“Zooplankton is the main food source for young sockeye and will allow for better growth in the smolts,” said Holmes. “The increased size of the sockeye smolts will result in better survival rates on their ocean migration.”
Results from Year 2 activities indicated that the addition of nutrients resulted in the increased production of phytoplankton which is the main food source for zooplankton in the lake. Zooplankton is the main food source for young sockeye and will allow for better growth in the smolts. The increased size of the sockeye smolts will result in better survival rates on their ocean migration.
Holmes said nutrients will continue to be added to the lake in 2022 and 2023. The project is expected to conclude in March 2024.
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